OVERHAUL MANUALFOR AIRCRAFT ENGINE

MODELSC75, C85, C90 & O-200

FAA APPROVEDFORM X-30010 JANUARY 1984

Courtesy of Bomar Flying Service www.bomar.biz

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FOREWORD

This manual is published for the guidance of all facilities engaged in operation, maintenance andoverhaul of four cylinder engines of the Teledyne Continental C and 0-200 Series.

A description is included in this manual of the various models and special equipments of the series andphotographs selected to illustrate the major differences between models. The Table of Specificationsprovides more detailed information in regard to features and performance of the models. It should benoticed that such descriptive material is neither intended nor adequate to enable conversion of anymodel to another in instances in which such conversion is permissible. For detailed informationregarding application of parts and their interchangeability, refer to the Spare Parts Catalog. For modeland series number conversion instructions, refer to the Teledyne Continental Service Bulletin on thatsubject.

Service maintenance instructions relative to accessories installed on Teledyne Continental aircraftengines in our factory are reprinted herein by permission of the accessory manufacturers. Instructionsfor overhaul of these accessories may be obtained direct from the manufacturers or through theirauthorized service facilities.

All descriptive and dimensional information and all instructions contained in this edition have beenrevised and extended to cover all four cylinder models of the Teledyne Continental C Series in currentproduction. The parts catalog section is not included in this edition, since it is subject to frequentchange in details.

A manual of this scope cannot be revised often enough to be kept up to date at all times, since it is ourpolicy to improve details of engine design in the interest of maximum safety and utility of our productswhenever the results of our continuous experimental and development program indicate the desirabilityof replacing the old with something even better. For this reason we issue Service Bulletins to ourApproved Distributors to advise of important changes in parts, desirable inspections and precautionsfound necessary in operation and maintenance. These bulletins are available for reading at all TeledyneContinental Approved Service Stations. Those who need permanent copies of Service Bulletins mayobtain them by direct mail, as issued, from the factory Publications Department on an annualsubscription basis. A nominal charge is made to cover the cost of mailing.

It is suggested that a careful study of the text of this manual will provide the reader with knowledge ofengine construction and of techniques for both operation and repair work which, if applied in practice,will promote safety in flight and long engine life.

If, in spite of the high quality of materials and the careful inspection and testing of these engines, anydefect is suspected, the question should be brought immediately to the attention of the nearestTeledyne Continental Approved Service Station so that a diagnosis and any necessary correction maybe made.

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TABLE OF CONTENTSSection& Para. Title Page

I Introduction. ...............................................91-1 Model Designation. ...................................91-2 Definitions and Abbreviations. .................91-3 Measurement ...........................................101-4 Cleanliness ..............................................10

II Table of Specifications. ...........................11

III General Description. ...............................163-1 Difference Between Model Groups. .......163-2 Significance of C Series Dash

Numbers and Letters. ..............................163-3 Model Conversions. ................................163-4 Optional Equipment. ...............................173-5 Superseding Parts. ...................................173-6 Crankcase Construction. .........................173-7 Crankshafts ..............................................183-8 Nitrided Crankshafts. ..............................183-9 Crankshaft Gears. ....................................193-10 Connecting Rods. ....................................193-11 Camshafts ................................................193-12 Camshaft Gears .......................................193-13 Hydraulic Valve Lifters ...........................203-17 Pushrods and Housings. ..........................213-18 Piston Assemblies ...................................213-19 Cylinder Assemblies. ..............................213-25 Crankcase Cover Assembly for

-12, -14, -16 & 0-200 Models. ................223-26 Crankcase Cover Assembly for

-8 Models. 23 3-27 Gear Train ................233-28 Carburetor Induction System. .................243-29 Oil Sumps. ...............................................243-30 3-30 Ignition System ...............................243-36 Delco-Remy Starter. ................................253-37 Prestolite Starter ......................................263-38 Generator and Drive. ...............................263-39 Side Mounted Fuel Pump. .......................263-40 Duel Fuel Pump Equipment. ...................263-41 Lubrication System. ................................27

IV Unpacking the Engine. ............................294-1 Shipping Crates .......................................294-2 Method of Packing and Preservation. ...294-3 Removal of Engine from Crate. ..............304-4 Preparation for Installation. .....................30

V Storage of Engines ..................................315-1 General ....................................................315-2 Flyable Storage .......................................315-3 Temporary Storage ..................................31

Section& Para. Title Page

5-4 Indefinite Storage ....................................325-5 Procedure For Return of A/C to Service..335-6 Indefinite Storage Inspection. .................33

VI Installation in Airplane & Removal. .......346-1 Mounting the Engine. .............................346-2 Fuel Systems. ..........................................386-3 Oil System ...............................................386-4 Propeller Installation. ..............................386-5 Engine Removal ......................................39

VII Operating Instruction. .............................407-1 Procedure Preliminary to Starting. ..........407-2 Starting Procedure. ..................................407-3 Warm-Up ................................................407-4 Ground Test ............................................407-5 Take-Off ..................................................417-6 Climbing .................................................417-7 Level Flight ..............................................4l7-8 Let-Down and Landing. ..........................427-9 Stopping the Engine. ...............................427-10 Lubricating Oil ........................................427-11 Viscosity. ................................................427-12 Oil Change Periods .................................427-13 Oil Change Procedure. ............................437-14 Engine Fuel .............................................43

VIII Engine Troubles and Service Repairs .....44

IX Periodic Inspection and Maintenance. ....489-1 Daily Inspection ......................................489-2 First Fifty Hour Inspection. .....................489-3 100-Hour Periodic Inspection. ................49

X Adjustment and Minor Repair. ...............5110-1 Carburetors. .............................................5110-7 Magnetos .................................................5310-18 Replacement of Ignition Cables. .............5710-24 Delco-Remy Starter. ...............................5910-30 Prestolite Starter. .....................................6010-38 Generator and Drive. ...............................6210-47 Hydraulic Valve Lifters. .........................64

XI Disassembly ............................................6711-1 Preliminary Operations. ..........................6711-10 Disassembly ............................................68

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TABLE OF CONTENTS (Con’t)

Section& Para. Title Page

XII Cleaning ..................................................7212-1 Materials and Processes. .........................7212-6 Specific Parts ...........................................72

XIII Inspection ................................................7413-1 Definitions ...............................................7413-2 Inspection Tools ......................................7413-5 Inspection Methods .................................7513-14 Inspection of Critical Parts. .....................77

XIV Repair and Replacement. ........................8114-1 General Repair ........................................8114-7 Repair and Replacement of

Specific Parts ...........................................8214-13A Crankcase Modification. .........................8714-21 Protective Coatings. ................................90

XV Assembly of Subassemblies. ...................9315-1 General Procedure. ..................................9315-4 Detailed Procedure ..................................93

Section& Para. Title ..................................... Page

XVI Final Assembly .......................................9716-1 General Procedure. ..................................9716-4 Detailed Procedure. .................................97

XVII Testing after Overhaul. .........................10617-1 Testing Equipment ................................10617-2 Test Stand .............................................10617-3 Instruments ............................................10617-4 Test Club ...............................................10617-5 Test After Overhaul ..............................10617-6 Preservation. .........................................11117-7 Fuel and Lubricating Oil. ......................11117-8 Testing Engines Installed in Aircraft. ....11117-9 Inspection ..............................................111

XVIII Table of Limits ......................................114

LIST OF TABLES

Section& Para. Title Page

I Features Common to all Models. ............11II Type Certificate Numbers .......................11III Features Peculiar to Each

Model Group ...........................................11IV Dimensions Peculiar to Each Model

or Model Dash Number. ..........................11V Speed and Power Ratings. .......................12VI Operating Temperature Limits. ...............12VII Operating Pressure Limits .......................12VIII Model or Model Dash Number

Equipment ...............................................12IX General Ignition System

Specifications ..........................................13X Ignition Timing .......................................13XI Valve Mechanism Specifications. ...........13XII Lubrication System Specifications. .........13XIII Fuel Metering System Specifications ......14

Section& Para. Title Page

XIV Accessory Drive Speed Ratiosand Rotation ............................................14

XV Line and Instrument Connections. ..........14XVI Weights of Standard Engine

Equipment. ..............................................15XVII Additional Weights of Optional

Equipment ...............................................15XVIII Recommended Oil Viscosity Grades .......43XIX Magnflux Inspection Data. ......................77XX Stud Identification Chart. ........................81XXI Test Operating Limits. ..........................109XXII Test Schedule ........................................110XXIII Oil Sump Capacity ................................111XXIV General Use -Tightening Torques. ........118XXV Pipe Plugs .............................................118

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LIST OF ILLUSTRATIONSFigure No. Page

1. Left Side View, Model C85-12F ...............................................................................................................62. Three-Quarter Right Rear View, Model C85-12 ......................................................................................63. Three-Quarter Left Front View, Model C90-16F .....................................................................................74. Three-Quarter Right Rear View, Model C90-16F ....................................................................................75. Right Front View, Model C-90 .................................................................................................................86. Left Front View, Model O-200 .................................................................................................................87. Cylinder Arrangement Diagram (Top View) ..........................................................................................108. Section Through Hydraulic Valve Lifter ................................................................................................209. Crankcase Cover and Accessories of -12, -14, -16 and O-200 Models. .................................................2210. Gear Train of -12,-14,-16 and O-200 Models .........................................................................................2411. Hoisting Engine by Crankshaft Lifting Eye ............................................................................................2912. Typical Installation Diagram for -12,-14 & -16 Models, Side View ......................................................3513. Installation Drawing for -12, -14 & -16 Models, Front View. ................................................................3514. Installation Drawing for -12, -14 & -16 Models, Rear View. .................................................................3615. Installation Drawing for -12, -14 & -16 Models, Side and Top Views. ..................................................3716. Engine Mounting Equipment of Models C90-14 & 16 and 0-200 ..........................................................3817. Ignition Wiring Diagram. ........................................................................................................................5718. Removal of Hydraulic Unit from Valve Lifter Body. .............................................................................6919. Compressing Valve Spring to Remove Locks ........................................................................................7120. Removing Plunger from Hydraulic Unit with Taped Pliers. ...................................................................7121. Installing Helical Coil Inserts ..................................................................................................................8222. Dimensions of Rocker Shaft Boss Bushings ...........................................................................................8423. Drill Fixture .............................................................................................................................................8724. Drilling Hole in Bearing. .........................................................................................................................8825. Drilling Adapter Assembly. ....................................................................................................................8826. Plug Detail. ..............................................................................................................................................8927. Drill Fixture .............................................................................................................................................8928. Drill Fixture Installed ..............................................................................................................................8929. Name Plate Change .................................................................................................................................8930. Tightening No.1 Connecting Rod Bolts ..................................................................................................9531. Installing Crankshaft Bearing and Old Type Thrust Washer. .................................................................9732. Installing Crankshaft and Connecting Rods ............................................................................................9833. Installing Dowel Type Thrust Washers and Split Oil Seal. ....................................................................9834. Installing Starter Pinion Pivot .................................................................................................................9935. Installing Crankcase 1, 3 Side on 2, 4 Side .............................................................................................9936. Installing Crankcase Cover on -12, -14, -16 and O-200 Models. .........................................................10237. Installing No.3 Cylinder ........................................................................................................................10338. Installing "O" Rings on Intake Manifold Studs ....................................................................................10339. Placing Crankshaft in Firing Position of No.1 Piston. ..........................................................................10440. Placing Flange Crankshaft in Firing Position of No.1 Piston. ..............................................................10441. Fuel Flow Limits vs. R.P.M. at Propeller Load, Model C90 ................................................................11242. Fuel Flow Limits vs. R.P.M. at Propeller Load, Models C75 and C85. ...............................................11243. Fuel Flow Limits vs. R.P.M. at Propeller Load, Model 0-200. .............................................................11344. Limits and Lubrication Chart (Sheet 1 of 4) -Cross Section View. ......................................................12045. Limits and Lubrication Chart (Sheet 2 of 4) -Longitudinal Section View. ...........................................12139. Limits and Lubrication Chart (Sheet 3 of 4) -Rear View & Horizontal Section -8 Models. ................12240. Limits and Lubrication Chart (Sheet 4 of 4) -Rear View & Sections, -12,-14and O-200 Models ........123

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Figure 1. Left Side View, Model C85-12F.

Figure 2. Three-Quarter Right Rear View, Model C85-12.

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Figure 3. Three-Quarter Left Front View, Model C90-16F.

Figure 4. Three-Quarter Right Rear View, Model C90-16F.

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Figure 5. Right Front View, Model C90.

Figure 6. Left Rear View, Model O-200.

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SECTION IINTRODUCTION

1.1 MODEL DESIGNATIONS.

This publication covers the maintenance andoverhaul instructions applicable to the fourcylinder C Series and the O-200 AircraftEngines. C Series Engines covered by thispublication fall into three model groups, namely,C75, C85 and C90, according to normal ratedhorsepower. Within each C model group,variations in equipment of the basic engine aredenoted by suffix dash numbers, as explained inthe Table of Specifications. Further explanationof the meaning of model dash numbersapplicable to C models will be found in SectionIII. Each engine bears an identification plate, onwhich is stamped the information peculiar to thatparticular model, including the exact model anddash number designation and the engine serialnumber.

NOTE

If a new nameplate is required, refer toService Bulletin M75-5.

All correspondence with Teledyne ContinentalDistributors and with the factory ServiceDepartment in regard to specific engines shouldrefer to the exact model designation and serialnumber.

1-2. DEFINITIONS & ABBREVIATIONS

A. B. C. After Bottom CenterApprox. Approximately

A. T. C. After Top CenterBar. BarometricB. B. C. Before Bottom CenterB. H. P. Brake HorsepowerB. T. C. Before Top CenterF. A. A. Federal Aviation Administration

C. F. M. Cubic Feet Per MinuteC. G. Center of GravityDia. Diameter° . Degree of Angle° F. Degrees FahrenheitFig. Figure (Illustration)Front Propeller EndFt. Foot or FeetG. P. M. Gallons Per MinuteH2O WaterHg. MercuryI.D. Inside DiameterIn. (") InchesHex. HexagonHr. HourLeft Side Side on Which No's 2 & 4 Cylinders

LocatedLbs. PoundsLockwire Soft Steel Wire Used to Safety

Connections, Etc.Man. Manifold or ManometerMax. MaximumMin. Minimum30' Thirty Minutes of Angle

(60' Equals One°)N. P. T. National Pipe Thread (Tapered)N. C. National Coarse (Thread)N. F. National Fine (Thread)O. D. Outside DiameterPress. PressureP. S. I. Pounds Per Square InchRear Accessory End of EngineRight Side Side on Which No's 1 & 3 Cylinders

LocatedR. P. M. Revolution Per MinuteStd. StandardT. D. C. Top Dead CenterTemp. TemperatureTorque Force X Lever Arm (125 ft. lbs.

torque = 1251bs. Force Applied OneFt. From Bolt Center or 62-1/2 lbs.Applied 2 Ft. From Center)

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1

3

2

4

LEFT RIGHT

Figure 7. Cylinder Arrangement Diagram (Top View

1-3. MEASUREMENT

Throughout this manual are instructionsregarding measurement of parts dimensions andproper tightening of nuts and screws. Theimportance of accuracy in these operationscannot be over-emphasized. All necessary datawill be found in the Table of Limits. A chartprovides a visual reference to locations of thepoints where measurements are to be made.

1-4. CLEANLINESS

Every effort should be made to keep engines freefrom external accumulations of foreign matterand to prevent the entrance of abrasive particles.

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SECTION IITABLE OF SPECIFICATIONS

TABLE I. FEATURES COMMON TO ALL MODELS

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TABLE V. SPEED AND POWER RATINGS

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TABLE IX. GENERAL IGNITION SYSTEM SPECIFICATIONS

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TABLE XIII. FUEL METERING SYSTEM SPECIFICATIONS

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TABLE XVI WEIGHTS OF STANDARD ENGINE EQUIPMENT

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SECTION IIIGENERAL DESCRIPTION

3-1. DIFFERENCE BETWEEN MODEL GROUPS.Models within the C series are grouped according torated power, the groups being 75, 85 and 90. Thesethree model numbers are prefixed by the seriesdesignation "C". Models in the C75 group differ fromthe corresponding dash numbered models in the C85group only in calibration of the carburetor installed.C90 models differ from C75 and C85 models in thedesign of several major parts and accessories,including the crankshaft, camshaft, crankshaft gear (in-8 models only), carburetor, oil sump, connectingrods, pistons and valve springs. The 0-200, in turn,differs from C Series in the design of its crankcase,camshaft, crankcase cover, carburetor and oil sump. Itdiffers further in that shielded ignition is standardequipment. As indicated in Table III, C90 and O-200models have a longer piston stroke, resulting in ahigher compression ratio and larger pistondisplacement. A higher fuel octane rating is requiredby these features.

3-2. SIGNIFICANCE OF C SERIES DASHNUMBERS AND LETTERSFollowing the series letter and power designation, andseparated from them by a dash, a figure and, in someinstances, a suffix letter or two in the complete modelnumber denote the installation of certain parts orequipment designed to adapt the basic engine tovarious classes of aircraft. Those dash numbers andsuffix letters which have been used to identifyproduction models built to date are as follows:

-8: No provisions for starter or generator.

-12: Starter, generator and associated partsinstalled.

-14: Lord Engine Mount Bushings installed.Otherwise like -12 models.

-16: Vacuum Pump Adapter. Otherwise like -12 models.

F: Flange type crankshaft installed (replaces taperedshaft).

H: Crankcase and crankshaft adapted to feed oil tohydraulic controllable pitch propeller.

Various combinations of the foregoing dash numbersand suffix letters are used to describe equipment of thedifferent models. In the following discussions andinstructions the term "-12 models" will indicate allmodels equipped with starter and generator, whetheror not they have flange crankshafts (1.2F). Theabsence of a suffix letter in the model number, asC75-12, indicates that a tapered crankshaft is installed.The Lord mount bushing equipment of C90-14 and O-200 models is illustrated in Figure 16.

3-3. MODEL CONVERSIONS.Conversion of C75 and C85 models to correspondingdash numbered C90 models is not approved, due tothe nature and extent of parts differences and to thepossibility of unsatisfactory results. It is not possibleto convert any -8 model to a -12 model, because the -8crankcase is not adaptable to the -12 crankcase coverin several respects. Conversion of -12 models to -8models is not approved for similar reasons. Neither -8nor -12 models can be converted to -14 models in thefield because of the special machining required forLord mount bushings. Conversion of C75 models tocorresponding dash numbered C85 models may beaccomplished in accordance with instructionscontained in our Service Bulletin on this subject.Installation of a flange crankshaft in place of taperedshaft is considered merely a crankshaft replacementand does not require factory approval or specialinstructions, however, engine identification platesbearing model or dash numbers, other than thoseoriginally assigned, cannot be issued unless anapplication for conversion approval has beensubmitted and approved by the factory ServiceDepartment.

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3-4. OPTIONAL EQUIPMENT.While the assignment of model numbers, as describedabove, represents an attempt to establish categories ofengines of the same basic design and to denote theequipment installed, any extension of the list of modelnumbers, intended to specify in detail the optionalparts installed to adapt engines to all aircraftinstallations, would be of little or no value, since theserequirements change frequently, and since optionalequipment may be replaced by other parts in the field.Accordingly, engines are equipped with certainoptional types of part, such as oil sumps, accessories,and equipments (or systems), such as radio shieldedignition, as specified by the purchaser, and no attemptis made to denote such installations in the enginemodel designation. Unshielded ignition systems arestandard equipment on all C series engines. Shieldedignition systems are standard on the O-200. Strombergtype NA-S3Al carburetors are standard on all C75,CBS and earlier C90 engines and are designed forgravity feed. Type NA-S3Al carburetors designed foruse with pump feed systems are available. Marvel-Schebler type MA-3SPA carburetors are standard forO-200 and current production C90 engines. Oil sumpsare shaped to suit various aircraft in regard to location,capacity and length of the filler neck. The oil gage rodassemblies are located in the oil filler neck and aremarked per customer's specification for capacity.

3-5. SUPERSEDING PARTS.Whenever possible, parts of improved design aremade to fit into existing engines so that modernizationof older assemblies requires replacement of only theredesigned part. This is not always possible, becausesome parts are so related that a change in onenecessitates a corresponding change in the other.Service Bulletins list serial numbers of engines whichrequire new type parts for modernization. When asuperseding part is not interchangeable with theoriginal type of part, the old style part is kept in stockfor maintenance of the older engines.

3-6. CRANKCASE CONSTRUCTION.Aluminum alloy castings which form the left and righthalves of the crankcase are machined flat and smoothalong their parting surfaces. Upper and lower flangesare attached by fourteen hex head screws, washers,and plain nuts, two of which also attach the enginelifting eye to the upper flanges. Each casting has twocylinder mount pads machined in its vertical side.Cylinder openings in pads on the two sides of the caseare not quite opposite. Each casting has a heavy lateralweb at the rear, another near the center and a third

near the front. These webs are cut out for ventilationand oil drainage and have enlarged bosses at the caseparting surface for crankshaft and camshaft bearings.Seats for steel backed, precision inserts of thecrankshaft main bearings are line bored through theweb bosses, and camshaft bearings are bored directlyin the case metal. These bearings are all dividedequally by the parting surface, camshaft bearingsbeing directly below the main bearings. Earlier casehalves of the C series engines are prevented fromspreading by eight through studs installed in thebosses above and below the main bearings and onestud below the rear camshaft bearing. Currentproduction C series and all O-200 case halves areretained by six through studs installed in the bossesabove and below the front and rear main bearings, twothrough bolts installed in lieu of the two through studsat the center bearing bosses and one through studbelow the rear camshaft bearing. In addition to thethrough studs or through bolts, cylinder mount padshave short studs to make a total of six in each.Cylinder pads and case webs are stiffened by ribs castinside the case. A counterbore around the crankshaftopening in the front of the case receives the crankshaftoil seal. In current production crankcases, the shoulderbehind the oil seal recess is deeper than in older casesto make a better oil baffle. The long boss for the frontmain bearing in early C series production cases hadtwo dowels, driven through longitudinal holes on thehorizontal centerline, to engage holes at the mid-points of semi-circular thrust washers which wereinstalled at front and rear ends of the bearing. In laterC series crankcases, the two halves of each washerwere different. One half had a short rivet at its mid-point to fit into a notch in the bearing boss. The otherhalf was plain. These washers were installed with thesplit perpendicular to the case parting surface,whereas the original type washer split was in line withthe parting surface.

A groove has been added to each end of the front mainbearing boss to accommodate thrust washers on the O-200. Old style cases not having this groove must beserviced with flanged front main bearings.

A notch is provided to accept the tang of thesebearings. Below each cylinder pad, and on thehorizontal plane of the camshaft, two lateral bossesinside the case are bored to form valve lifter guides.These bores emerge at the case side surface, and apushrod housing adapter, installed over their openends, is retained by three case studs and nuts. Betweenthe line of lifter guides and the line of cylinder

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openings at each side of the case are the main oilgalleries extending from front to rear. The oil galleriesare plugged at the front. Current C series crankcasesuse a 5/8-18 hex head plug and annular gasket. EarlierC series and current O-200 crankcases use (2) 3/8NPT countersunk hex pipe plugs. An enlargement ofeach casting's lower parting flange at the front endforms half of a boss which is machined and studded tomake a mount pad for a vacuum pump on the -16 andO-200. A semicircular flange at the rear of thecrankcase bottom surface is machined flat and studdedto form the front half of the oil sump mount pad. Twostuds driven into bosses at the lower parting flangesare used for attachment of the intake manifold. Thecrankcase breather elbow is screwed into a tappedboss ahead of No.3 cylinder. An upper and a lowerarm at the rear of each case casting affords an enginemounting point. For -8, -12 and -16 models the endbosses of mounting arms have front and rear conicalrecesses for rubber mount bushings. The arm bossesof-14 and O-200 model crankcases are bored throughand counterbored for Lord mount bushing assemblies.Parts of the Lord mount assembly are illustrated inFigure 16. The flange surrounding the rear end of thecrankcase is machined flat and studded for attachmentof the crankcase cover. Locations and lengths of thestuds are different in -8 and -12 crankcases. Thecrankcase of -12, -14, -16 and O-200 models has ahole bored through the rear web above the rear mainbearing to hold the starter pinion pivot. A doweldriven into the left side of the hole fits into the pivotto hold it in position. Some models have a studdedmount pad for a fuel pump on the 1-3 side ofcrankcase.

3-7. CRANKSHAFTSEach type of crankshaft is machined from a singleforging. The four crankpins are spaced 1800 apart.Starting at the rear and proceeding forward, thecrankpin numbers are 1, 2, 3 and 4, according to thecylinders which they serve. Each crankshaft has threemain journals, the front one being immediately aheadof No.4 front crankcheek. The cheek is ground flataround the journal and contacts the rear crankcasethrust washer to transfer propeller thrust. A small anti-thrust flange at the front end of the front journal actsas an oil slinger.

CAUTION

This design should not be used in pusherinstallations.

Older types of shaft had a taper on the front side of theslinger flange. These cannot be installed in presenttype crankcases because of interference between thetaper and the case oil baffle. The slinger flange ofpresent type crankshafts has parallel sides. Allcrankshafts are center bored for lightness. The frontbore runs out at the front crankcheek and the rear endbore at the rear crankcheek. Steel oil tubes arepermanently installed in holes drilled from the frontand rear journals through crankcheeks to Nos. 1 and 4crankpins. Oil holes are drilled through solid cheeksfrom the center journal to Nos. 2 and 3 crankpins. Thetapered type shaft has a slot along the propeller hubtaper for a square key to drive the steel hub used withit. The hub fits tightly on the taper and is retained by atube nut, which is locked by a flat head pin. A snapring in a hub groove ahead of the nut flange acts as ahub puller. The propeller is clamped between the steelhub flange and a loose steel flange in front by six boltsand nuts. The flange type shaft has a propeller mountflange forged on its front end with six tapped bushingspressed into holes spaced equally around the flange.Six bolts, screwed into the shaft flange bushings,clamp the propeller between a loose front flange andthe shaft flange. The loose front flange and the sixbolts are not supplied as part of the O-200 engine. Asteel cased oil seal is installed over the front end oftapered shafts and is retained in the crankcase recessaround the shaft opening. With flange typecrankshafts a split, composition seal is used. It is madein one piece, and the seal lip is held against the shaftrace by a spring. The gear pilot flange at the rear endof the crankshaft has four unequally spaced tappedholes for gear retaining screws. Current productionshafts have a dowel between two of the screw holes.

3-8. NITRIDED CRANKSHAFTSLatest types of flanged and tapered crankshafts havenitrided main journals and crankpins. Flange shafts forC90 and O-200 models have always been nitrided.These are identified by a 1/4 inch hole drilled throughthe propeller mount flange. Nitrided flange type shaftsfor C75 and C85

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models are identified by the letter "N" stamped on theedge of the propeller flange. Tapered shafts for C75and C85 models, if not nitrided, have four hub nutlock pin holes at the front end. One additional hole isdrilled to identify nitrided shafts.

3-9. CRANKSHAFT GEARSThe gear is piloted on the small rear flange of thecrankshaft and aligned by the crankshaft dowel. It isretained by four screws. Screw holes are unequallyspaced to assure correct installation. The spacebetween two adjacent punch marked gear teeth pointsto the camshaft when No.1 crankpin is at T. D. C.Gears for -8 models are plain spur gears. In -12, -16and O-200 models a cluster gear is installed. Its largewheel has beveled teeth and is driven by the starterpinion.

3-10.CONNECTING RODSConnecting rod assemblies of C90 and O-200 modelsdiffer in dimensions from those of C75 and C85models, but the two types are of similar design. Therod and bearing cap assembly are made from a singlesteel alloy forging, which is sawed through the centerof the big end before the bearing seat is bored. Eachhalf of the split big end bore is notched to accept thetang of the semicircular bearing insert which fits in it.The replaceable crankpin bearing inserts are thin steel-back shell type, lined with special alloy metal. Thebearing cap is attached to the rod by two special boltsand hex nuts. The cylinder number is stamped on theupper bolt boss of both rod and cap. A tapered "I"beam connects the big end and the piston pin boss.The piston pin bushing is a plain bronze sleeve,pressed into the rod boss and bored parallel to the bigend bearing. The original type solid piston pinbushing has been replaced by a single piece, split typebushing in both C75, C85, C90 and O-200 type rods.

3-11. CAMSHAFTSAll camshafts installed in C75 and C85 models areflame hardened iron castings. The same material wasemployed in early production C90 camshafts. Presenttype C90 and the original O-200 camshafts are alloysteel forgings. These are identified, when new, by anover-all black Parko-Lubrite coating and anunderlying copper plate on unfinished surfaces. AllC90 and O-200 camshafts are reduced in diameterbetween cam lobes to provide connecting rodclearance. Standard camshafts for C series carburetor

engines have an eccentric machined at the front fuelpump lever. A special camshaft with two eccentrics isavailable for installations which require a second fuelpump. Camshafts installed with vacuum pumpequipment in -16 and O-200 engines have no pumpdrive eccentric. The front end of this type has sixtapped holes for screws which attach the vacuumpump drive bevel gear. A special combination gearand eccentric is also available for the vacuum pumpand side mounted fuel pump. The C90-16 and O-200also have a camshaft for a side mounted fuel pumpwith no provision for a vacuum drive gear. The gear isspaced from the shaft end, for correct backlash withthe vacuum pump gear, by one or more shims, whichare available in two thicknesses. A few of the earlyproduction O-200 engines have these shims installed.Current production engines do not require these shimsto provide proper backlash. All camshafts have threejournals. The center journal is plain, while the frontjournal has a deep groove to register with oil holesdrilled from its bearing into the main oil galleries. Therear journal has flanges at its front and rear ends torestrict camshaft end movement in the rear bearing.The rear flange has four unequally spaced tappedholes for the camshaft drive gear retaining screws.Three cam lobes between each two journals operatevalve lifters for two cylinders. In each group, the outerlobes each operate one exhaust valve lifter, and thecenter lobe operates two opposite intake valve lifters.Lobes of O-200 camshafts have a greater lift thanothers.

3-12. CAMSHAFT GEARSCamshaft drive gears installed in -8 models are singlespur gears with the web at the rear, while those in -12,-14, -16 and O-200 models have both external andinternal teeth, and the web is at the front. The internalteeth drive the generator gear. Both types of gearshave a square hole in the center to receive the oilpump driving impeller shaft. A ground recess in thefront side of each gear web fits closely over thecamshaft pilot flange. The gear is retained by four hexhead screws in holes spaced unequally around theweb. Thus, the gear can be installed in only oneposition in relation to the cam lobes. A punch markedtooth is meshed, at assembly, between two similarlymarked teeth on the crankshaft gear, and this simpleoperation assures correct valve timing withoutmeasurement.

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3-13. HYDRAULIC VALVE LIFTERS3-14. CONSTRUCTIONEach lifter assembly is composed of an outer body, ahydraulic unit and a pushrod socket. These parts areillustrated in Figure 8. The cam follower is part of thelifter body. The shank of the body is encircled by twooil grooves, which are connected by a flat area. Twoholes are drilled through the shank wall in the flat.The hydraulic unit rests against a shoulder in thebody. It is composed of a cylinder and a plunger andexpanding spring assembly. An inlet tube at the innerend of the cylinder is closed by a ball check valveinside the cylinder. The pushrod socket rests on thehead of the hydraulic unit plunger. Its flat base has anoil groove across the center. A hole is drilled from thegroove to the socket surface.

3-15. TYPESValve lifters installed with cast iron camshafts havesteel cam follower faces. Those installed with forgedsteel camshafts have cast iron cam followers. It isnecessary that the dissimilarity of contacting metals bemaintained when replacements are made. Valve liftersinstalled in C90 and O-200 models have 1-1/4 inchdiameter cam followers, as required by the cam lobedesign. Cam followers of other lifters are 1 inch indiameter.

3-16. OPERATIONRotation of the lifter is assured by a small taper on thetoe line of the cam lobe. This prevents wearing of agroove in the cam follower face. At the outer end ofthe lifter stroke the outer encircling groove in theshank registers with the crankcase oil supply hole, andengine lubricating oil is forced into the groove, to theflat area and through the two holes in the shank wall.Oil entering the outer hole fills the space surroundingthe plunger head, and the intermittent supply flowsthrough the pushrod socket passage and into thehollow pushrod. Oil which enters the inner hole in theshank wall replenishes the reservoir supply. This inletis indicated in Figure 8 by the letter "H". whenever thevalve in the engine cylinder is closed, the camfollower (a) is in contact with the heel of the camlobe, as shown in Figure 8. Since there is no inwardforce on the pushrod, the plunger spring (K) holds theplunger (C) and the socket outward against thepushrod end and the hydraulic unit cylinder and lifterbody inward, keeping the cam follower against thecam lobe. This expanding action takes up any increasein effective length of the valve linkage due toexpansion of the engine cylinder. It also compensatesfor any wear in linkage parts. Such expansion in the

hydraulic unit increases the volume of the lashadjusting chamber (L) and causes a negative pressurewithin it. With no inward pressure exerted on it, thecheck valve ball (D) leaves its seat, allowing oil toflow from reservoir (J) to keep chamber (L) filled.Since engine oil is not supplied to reservoir (J) duringthis period, the reservoir pressure is reduced by thesmall loss of oil, thus preventing any "pumping up" ofthe hydraulic unit. As the cam rotates and lifts thefollower, the hydraulic unit is forced outward with thelifter body. The force required to open the enginecylinder valve is transmitted to the pushrod, throughthe free sliding socket, by plunger (C), creating a highpressure chamber (L) and forcing the check ball (D)on its seat. The plunger (C) is carried outward on thecolumn of oil confined in chamber (L). The pressurecauses a "leak-down" of oil around the plunger at arate controlled by selection of hydraulic unit cylindersand plungers to maintain their diametrical clearancewithin very close limits. The leak-down permitscontraction of the valve linkage when the enginecylinder shrinks with a reduction in temperature. Eachtime the engine valve closes the small loss of oil fromchamber (L) is replaced and any linkage expansioncompensated by a flow from the reservoir (J). Thus,zero lash is maintained under all standing andoperating conditions, thereby eliminating the necessityof valve clearance and manual adjustments. Hydrauliclifters are designed to operate correctly when thevalve linkage clearance, as measured with thehydraulic unit completely deflated, is .030-.110 inch.

Figure 8. Section Through Hydraulic ValveLifter.

3-17. PUSHRODS AND HOUSINGS.Each pushrod is made by pressing a hardened steelball end into each end of a steel tube. Ball ends aredrilled through on the tube axis for oil passage.Each pushrod is surrounded by a thin, tubular steelhousing, two of which are permanently installed in

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the downward extension of each cylinder rockerbox. A cast aluminum adapter, attached to thecrankcase by three studs and nuts, is located beloweach cylinder. Two pushrod housings are sealed toeach adapter by rubber connections and hoseclamps.

3-18. PISTON ASSEMBLIESThe solid trunk, flat head pistons are machinedaluminum alloy castings. Those in C7S and C8Smodels have four ring grooves above the pin, whileC90 and O-200 pistons have three rings above thepin and one below. The upper three compressionrings are similar in both types of piston. The topring is faced with hard chrome to withstand heat.The second and third are plain cast iron rings. Thefaces of all these are tapered inward toward the topso that wear and seating begin at the bottom,providing good scraping action and quick seal.Center slotted oil control rings in the bottomgrooves are slightly different in the two types ofpiston assembly. Piston pins are seamless steeltubes, ground on the outside and fitted withaluminum end plugs to space them from thecylinder walls. Original type pin assemblies hadremovable end plugs. End plugs of currentproduction pins are pressed in before final grindingand are not replaceable. This type of pin assemblymust be used for all replacements. Pins are a pushfit in piston bores.

3-19. CYLINDER ASSEMBLIES3-20. CYLINDER AND HEADExternally finned aluminum alloy head castings arescrewed and shrunk permanently on externallyfinned steel barrels. The rocker box cast in the outerend of the head has a surrounding flange which ismachined flat. The pressed steel rocker cover issealed to the flange by a soft gasket and retained bysix fillister head screws. Three bosses cast in therocker box are bored in a horizontal line at rightangles to the cylinder axis to form rocker shaftsupports. Valve ports in the head open downwardinto two flanges, each provided with two studs.Bronze guides for intake and exhaust valves arepressed into holes bored from the bottom of therocker box into the valve chambers in line with thevalve seats. Alloy steel exhaust valve seat insertsand aluminum bronze intake valve seat inserts areshrunk into counterbores in the combustionchamber surface. Early production cylinders had

threaded spark plug inserts screwed and pinned intapped holes above and below the valve seats.

CAUTION

Use original piston with original cylinder orreplace spark plug bushing with helicoilwhen using current piston in originalcylinder.

Current production cylinders incorporate helicalcoil type inserts. A 1/8 inch pipe tapped holethrough the upper wall of the intake valve chamberof earlier production cylinders is intended for aprimer jet, which may be installed by the owner.The hole is normally sealed by a countersunk hexhead pipe plug. An external base flange below thecylinder barrel fins is ground flat and drilled for thesix crankcase studs, to which the assembly isattached by flanged hex nuts. From the base flange,the cylinder skirt extends inward through thecrankcase wall opening, as a pilot. A rubber packingring, placed around the cylinder skirt and againstthe flange, is compressed in a chamfer around thepad opening and prevents oil leakage. Two tubularsteel pushrod housings are swelled into holes in thedownward extension of the rocker box and liebelow the cylinder.

3-21. VALVESBoth intake and exhaust valves are a modified tulipdesign. The head of the intake valve is marked"IN", and the exhaust valve head is marked "EX".The tip of each valve stem is hardened and groundflat and square with the stem surface. Near the tip, agroove is cut in the stem to engage the split lock.The face of the exhaust" valve has a 3/64 inchminimum thickness of No.6 Stellite welded on towithstand heat.

3-22. VALVE SPRINGSAn inner valve spring retainer of pressed steel isinstalled over each valve guide and seated on therocker box bottom to center the valve springs andprevent wear on the aluminum head surface. Oneinner and one outer spring fit in each retainer,surrounding the valve stem. They are retained by outerspring seat of steel, whose conical center hole fits overthe valve stem and is engaged to it by the split locks.Each valve in C90 and O-200 cylinders has threesprings.

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3-23. ROCKER ARMS AND SHAFTTwo rocker arm assemblies are pivoted on a tubularsteel shaft, which is ground on its outer surface to apush fit in the cylinder head support bores. The rockeris a steel forging with a bronze bushing. A pushrodsocket is machined in the lower end. The valvecontact surface, at the upper end, is hardened andground to an arc. A small oil hole, drilled from thecenter of the pushrod socket, intersects a hole drilledupward and through the bushing wall. A groovearound the bushing's inner surface carries the oilchannel to a second vertical hole, which ends in asquirt nozzle facing the valve stem. An orifice in thevalve stem end of the exhaust valve rocker armprovides lubrication to the exhaust valve stem duringengine operation.

3-24. TYPESCylinder heads installed in early production C90

models were hand polished to eliminate roughness inthe intake passage and to assure full air flow to thecombustion chambers. Later improvement insmoothness of the head castings made the handpolishing operation unnecessary, and currentproduction cylinder and head assemblies are identicalin all models. Any cylinder and head assembly with asmooth air intake passage may be installed on C90models. Older assemblies with any roughness in thepassage must be used only on C75 and C85 models.Outer and inner valve springs are installed in cylinderassemblies of models C75 and C85. Outer,intermediate and inner valve springs are installed incylinder assemblies of model C90 and O-200. Thelatter type cylinders have the additional spring on eachvalve because of the greater valve lift obtained withthe C90 and O-200 camshafts. For details of valvesprings in each model engine, refer to the SpringPressures Chart in the Table of Limits, Section XVIII.

Figure 9. Crankcase Cover and Accessories of –12, -14, -16 and O-200 Models

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3-25. CRANKCASE COVER ASSEMBLY FOR -12,-14, -16 AND O-200 MODELSThe magnesium cover casting is 2-3/8 inches deep.Accessory mount pads on the rear surface are allmachined in one plane parallel to the machinedparting flange which surrounds the front side of thecasting. Locations of the pads and methods ofaccessory attachment are illustrated in Figure 9.Two holes, drilled through the casting at the top, arefor the bolts which attach the starter adapter to thecrankcase rear flange. Central openings in magnetomount pads admit the magneto drive gears andlocate the magneto pilot shoulders. The tachometerdrive housing is attached by three studs and nutsover a gasket which also covers the generator mountpad. The tachometer drive shaft is the slotted rearend of the oil pump driven impeller shaft. Thetachometer drive housing has an external thread forthe drive conduit nut. A steel cased oil seal ispressed into the front end of the housing. Its seal lipcontacts the tachometer drive shaft ahead of theslot. Below the tachometer drive shaft hole, asecond bearing is bored through the cover rear wallfor the oil pump driving impeller shaft. The oilpump impeller chambers are machined in the frontside of the cover rear wall in line with the shaftholes. An aluminum cover is attached over the openfront end of the pump chambers by four screws. Thesquared front end of the driving impeller shaftprojects forward through the pump cover to engagethe square hole in the center of the camshaft gear.The generator mount pad has two short studs and ahole for one of the crankcase studs. The generator isattached to these three studs by elastic stop nuts.The gear opening is counterbored to fit thegenerator pilot shoulder. The oil screen housing isattached, over a triangular gasket, by nuts installedon a short stud, driven into the pad, and two longcrankcase studs, which project through holes in thecover. The bottom of the cover casting is asemicircle, open at the front, with a surroundingflange, which is machined and studded to finish therear half of the oil sump mount pad. The oil pumpsuction tube is screwed into the bottom cover wallwithin the semicircle and is sealed by a copper-asbestos gasket. A screen is permanently attachedover the lower tube end, which lies below the sumpoil level. A cored passage in the cover castingextends from the upper end of the suction tube tothe oil pump inlet. From the delivery port of the

pump, a second cored passage extends to the rightand surrounds the oil screen opening. The screencap is screwed into the screen housing over acopper-asbestos gasket. The oil screen ispermanently attached to the cap and is reinforced bya ferrule at its open front end. The ferrule fitsclosely in a hole bored in the front wall of the oilpassage. From the screen outlet, another passage inthe cover leads to a hole drilled in the cover partingflange in register with the crankcase oil inlet. In linewith the crankcase right oil gallery, a hole is drilledfrom the cover casting parting flange rearward. Anintersecting hole to the right ends in an open cavitywithin the hollow boss for the oil pressure reliefvalve. The valve plunger seats on the end of thedrilled hole. It is guided in a bronze cap, which isscrewed into the boss, and is held on its seat by aspring. A drilled and tapped hole on the left side ofthe O-200 crankcase cover ends in the coredpassage on the suction side of the oil pump andprovides an oil return from the vacuum pump.

3-26. CRANKCASE COVER ASSEMBLY FOR -8MODELSThe magnesium cover casting is 1-5/32 inches deepat the magneto mount pads, while the integral oilscreen housing, at the left side, extends 3-11/16inches from the parting flange, and the central bossfor the tachometer drive housing extends 3-3/8inches. The bottom of the casting is similar to thatof the cover to -12 models, and the oil pump suctiontube is attached in the same manner. Cored passagesconnect the suction tube to the oil pump inlet andthe pump outlet to the oil screen cavity. The squaredfront end of the oil pump driving impeller extendsthrough the pump cover and into the square hole inthe camshaft gear. The rear end of the drivingimpeller is the tachometer drive shaft. Thetachometer drive housing is screwed into a left handthread in the cover boss. An oil seal pressed into thefront of the housing rides on the tachometer driveshaft. The oil screen and pressure relief valveassemblies are the same as installed in -12, -14, -16and O-200 models. The cover passage from thescreen leads to the left oil gallery. The pressurerelief valve closes the rear end of a hole drilled fromthe cover flange, in line with the right oil gallery, tothe gear cavity.

3-27. GEAR TRAIN (See Figure 10)Courtesy of Bomar Flying Service www.bomar.biz

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The crankshaft gear (1) is rotated in a clockwisedirection by the crankshaft. The small gear sectionof the crankshaft gear mates with and drives, at 1/2crankshaft speed, the camshaft gear (2). For -8models the crankshaft gear also drives the magnetogears direct in a counterclockwise direction. Themagneto gears (3), oil pump driver gear (4) andgenerator drive gear (6), of -12, -14, -16 and O-200are driven by the camshaft gear. The tachometershaft, in the -8 model, is driven by the oil pumpdrive impeller shaft, while in the -12, -14, -16 andO-200 models it is driven by the pump drivenimpeller shaft. Starting power is transmitted to thecrankshaft by the starting motor pinion (7) engagingthe large gear section of the crankshaft gear on -12,-14, -16 and O-200 models.

3-28. CARBURETOR INDUCTION SYSTEMThe intake manifold is attached to two long studs inthe crankcase lower flange. The carburetor isattached to a studded square flange on the bottom ofthe manifold. The air passage through the manifolddivides into four horizontal outlets, to which thecylinder intake tubes are sealed by rubber hoseconnectors and clamps. The intake tubes areconnected by the same means to cast aluminumelbows, attached to the studded cylinder intake portflanges. The air intake housing is attached to thestudded carburetor bottom flange. The flat sheetmetal housing flares upward at its front end tomatch the square air filter. The filter is fastened tothe housing front flange by four slotted head studs,which may be released by a quarter turn. A sheetmetal bracket ties the front end of the intakehousing to the manifold. A lever-operated platevalve in the intake housing opens and closes a hotair inlet to the manifold. A collar at the right rearcorner of the housing attaches the hot air supplytube. A fuel drain tube is welded to the bottom ofthe intake housing.

3-29. OIL SUMPSThe sump body is a welded assembly composed offront and rear halves of pressed sheet steel. A thickmounting flange ring, four brackets, an oil fill neckand a drain plug boss are welded to the body tocomplete the assembly. The location and length ofthe oil fill neck vary to suit the aircraft installation.A bracket is welded to the neck for support byattachment to a stud in the lower crankcasemounting arm. The tubular steel neck has a bayonet

locking device at the outer end for quick attachmentof the gauge cap. The sump drain boss is tapped fora 5/8-18 plug, which is sealed by a copper-asbestosgasket. The mount flange ring is drilled for the sixattaching studs in the crankcase and cover pad. Theoil gauge rod is graduated in quarts to the "FULL"mark. At present, sumps are attached with elasticstop nuts to undrilled case studs.

1. Crankshaft gear2. Camshaft gear3. Magneto drive gears4. Oil pump driving impeller5. Oil pump driven impeller6. Generator drive gear7. Starter Pinion

Figure 10. Gear Train of –12, -14, -16 and O-200Models

3-30. IGNITION SYSTEM3-31. UNSHIELDEDUnshielded ignition cables and unshielded sparkplugs are standard equipment of all C7S, C8S andC90 models. Individual cables connect all upperplugs to the high tension terminals of the rightmagneto, and all lower plugs are connected toterminals of the left magneto. Unshielded ignitioncables are of conventional construction, with hightension insulation over 19 strand copper conductors.Each cable assembly is attached to a spark plug by a

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safety lock terminal and has a magneto end terminalof the type required by the magneto installed. Fourplate brackets, attached to crankcase studs, supporteach pair of upper cables and each pair of lowercables near the cylinder bases. Two similarbrackets, attached by magneto retaining nuts of -8models and by crankcase cover retaining nuts of -12models, support four ignition cables on each side ofthe engine. A rubber grommet in each bracketprevents chafing of the cable insulation. C90-8models are equipped with Bendix S4RN-21magnetos, and all C90-12, -14 and O-200 modelshave Bendix S4LN-21 or slick Series 4000magnetos. C75, C85 models may also have Bendixmagnetos. F or this type of magneto, all four cablesare attached by cable piercing screws to aremovable terminal plate and grommet assembly,making a single cable assembly for each magneto.

3-32. RADIO SHIELDED IGNITION SYSTEMSEither Eisemann LA-4, Bendix S4LN-20 or slickSeries 4000 magnetos may be used with shieldedsystem where approved. (See Table IX). Radioshielded ignition cables are assembled in pairs forthe upper right, upper left, lower right and lower leftspark plugs. The brackets which hold together thetwo cables in each assembly are attached tocrankcase studs. A wrapping of friction tapeprevents the old style bracket from cutting orchafing cable insulation. New brackets are neoprenecoated to prevent cutting or chafing. Cableassemblies for-8 and -12 models with LA-4 magnetos have onlyone bracket each. An additional bracket is installedon the bottom starter retaining stud to hold upperleft and lower right spark plug cables away from thestarter clutch shaft. Shielded cable assemblies forBendix magnetos of -8 models have one bracket oneach pair of cables, and for -12 models they have asecond bracket on each pair. The two pairs of cablesserved by each magneto are attached to the terminalplate grommet by cable piercing screws. Allshielded cables are equipped with spark plugelbows and contact sleeves. To make contact withother shielding members, the outer plastic wrap ofthe cable is stripped for a short distance at each end,and the sheath of braided copper wires is foldedback to make a cuff. At the spark plug end a splitlead cone is placed over the cuff and held in theelbow by a union nut. At the magneto end a flanged

ferrule is swaged on over the cuff and is held to themagneto terminal plate by a coupling nut.

3-33. SWITCH WIRE TERMINALSThe AM-4 magneto has a stud terminal, to whichthe switch wire is attached by a hex nut. Shieldedmagnetos have spring terminals within the breakerhousing, and switch wires must be equipped withterminal assemblies consisting of contact,insulators, ferrules and union nut. Wire terminalassemblies are furnished with LA-4 magnetos,Bendix terminal kits are sold separately and areslightly different.

3-34. MAGNETO DRIVE GEARSEisemann AM-4 magnetos installed on the left sideof C85-8 models have impulse couplings, but thoseon the right side are driven by a gear mounteddirectly on the rotor shaft. All Eisemann LA-4Bendix S4N, and Slick magnetos have impulsecouplings. Drive gears for these magnetos arecentered on a sleeve on the rotor shaft, and they areretained by a nut screwed on the shaft, but they arefree to a nut screwed on the shaft, but they are freeto rotate on the sleeve. They drive the impulsecoupling barrel lugs, which fit in slots in the gearweb. The type of gear installed with impulsecouplings on -12, -14, -16 and O-200 modelsextends further forward than the type installed on -8models, due to the difference in crankcase coverdepth.

3-35. IMPULSE COUPLING OPERATIONThe impulse coupling performs two importantoperations to facilitate starting, i.e., it holds back themagneto rotor, just before the breaker openingposition, while the drive gear continues its rotation,thereby retarding the spark, and it releases the rotorapproximately at T. D. C. of the engine piston,allowing the coupling spring to spin the rotorrapidly through its neutral position, opening thebreaker and producing a hot spark at crankingspeed. Two counterweighted latches in the couplingflange assembly provide the automatic spark retard.The upper latch engages a stud in the housing andstops rotation of the flange and rotor shaft. Furtherrotation of the barrel (or drive cup) winds up thecoupling spring until the barrel contacts the latchand forces it inward and clear of the stud. Then, thespring spins the flange and rotor through neutral toproduce the spark. After the engine starts, the latch

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counterweights hold the latch pawls away from thestud, and the coupling spring drives the rotor in thefull advance position.

3-36. DELCO-REMY STARTER

The motor and clutch of the direct cranking starterare mounted on an adapter plate, by which the unitis attached to crankcase cover studs and throughbolts. The clutch and pinion assembly bears in aOilite bushing, pressed in a hole bored through theadapter below the motor. Another Oilite bushing inthe hollow clutch shaft bears on the pivot held in thecrankcase. A large gear on the clutch shaft is drivenby the armature shaft gear. The pinion is driven bythe clutch shaft through an over-riding clutch. Aspring in the front end of the clutch shaft is slightlycompressed by the pivot, tending to disengage thestarter pinion. A lever, pivoted on the motor coilhousing and operated by a cable from the cockpit,shifts the clutch shaft forward, for starting, and thepinion meshes with the teeth of the large wheel onthe crankshaft cluster gear. The starter switch buttonis depressed, to close the electrical circuit, by theshift lever. The shift lever operates the clutchthrough a spring cap and spring in the rear end ofthe clutch shaft, so that the clutch can be closed,even though the pinion and cluster gear teeth areabutted. Immediately the motor turns, the pinionmeshes.

3-37. PRESTO LITE STARTERThe Prestolite Starter is solenoid actuated andemploys a Formsprag Torque Limiting Drive whichis used with, but is not part of, the starter. Theclutch assembly bears in a needle bearing pressed ina hole bored through the adapter below the motor.The other end rides in a needle bearing pressed intothe starter jackshaft adapter located in thecrankcase. As the solenoid is actuated, by the key orswitch, the starter gear turns engaging a gearshaftwhich activates a sprag pack in the clutch assembly.The sprag pack expands and drives the hub, whichdrives the idler gear and thereby the crankshaftgear. When the engine fires and the crank is runningat a greater speed than the starter, the sprag pack isno longer driving the hub.

3-38. GENERATOR/ALTERNATOR ANDDRIVEThe Delco-Remy generators have specific amperesoutput at 12 volts. It is attached to the three case

studs by elastic stop nuts; A vent tube connection isbuilt on the brush cover, which may be rotated. Anoil seal is pressed into a counter bore around theshaft hole at the front of the drive end frame,contacts the rear shoulder of the coupling hub. Thehub has a slot for the woodruff key installed in theshaft. The rubber drive disc and its pressed steelretainer fit into a slot in the front side of the hub.Two lugs on the drive gear fit into a front slot in therubber disc. Gear torque is transmitted through thelugs to the disc. The flat sides of the disc and steelretainer transmit the torque to the slotted hub, whichdrives the generator shaft through the woodruff key.A steel sleeve passes through the gear, rubber discand retainer and presses the hub against the shaftshoulder. A nut is tightened on the shaft threadagainst the sleeve, but the gear is free. In the latesttype of drive the rubber disc is replaced by tworubber bushings, which fit between the flat sides ofthe retainer and the gear lugs. The drive lugs of thegear used in this drive extend through the entirethickness of the bushings, but clear the retainer.

3-39. SIDE MOUNTED FUEL PUMP

This optional equipment consists of an ACdiaphragm pump, which may be obtained with theinlet port at either front or rear, inlet and outletelbow fittings, a delivery tube assembly and acarburetor inlet elbow. The pump is installed, withthe fuel dome upward, on a, pad at the front of thecrankcase right side. The pump lever extendsthrough the pad opening into the crankcase and restson top of the camshaft eccentric. Rotation of theeccentric operates the lever to produce the pumpingaction. The inlet elbow is connected to the" aircraftfuel supply line. The pump delivery tube isconnected to the pump outlet elbow and to thecarburetor inlet elbow by union nuts. Check valvesin the pump allow fuel to flow only toward thecarburetor.

3-40. DUAL FUEL PUMP EQUIPMENT

When the aircraft installation requires two fuelpumps, a second diaphragm pump is installed on therear side of a special adapter, which is attached tothe mount pad of early models. This adapter can beinstalled only on crankcases of which the vacuumpump pad is machined and studded. A verticalpushrod, guided in the adapter, is depressed by therear eccentric of the special camshaft which must be

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installed with the dual pump equipment. The frontof this camshaft operates the side pump lever. Thepushrod transfers the eccentric motion to the lowerpump operating lever. Both pump inlets areconnected to the aircraft supply line. A nipple isscrewed into the lower pump outlet, and a crossfitting is screwed onto the nipple. The delivery tubefrom the side pump is connected to the cross. Thus,the cross receives the output of both pumps. A tubedelivers the combined output from the cross thecarburetor inlet. The fourth branch of the cross isplugged. A sediment bowl is incorporated in thelower pump. A special bracket, attached to thelower pump adapter by one of the pump retainingnuts, supports the carburetor air intake housingwhen this equipment is installed. Oil, fed to thelower pump adapter to lubricate the pushrod guide,is drained through a tube from the adapter to atapped boss on the special oil sump.

3-41. LUBRICATION SYSTEM3-42. OIL CIRCULATION IN -8 MODELSOil rises, under atmospheric pressure, from thesump supply through the suction tube to fill thevolume displaced by the pump. The oil is carriedaround the chambers between impeller teeth and isforced from the pump outlet port through thecrankshaft cover passage to the cavity surroundingthe oil screen. As the oil flows through the screenmesh, any foreign particles are deposited on theexterior. The strained oil flows from the open frontend of the screen, through a short cored passage,and into the rear end of the left oil gallery. The oilstream flows forward through the left gallery, acrossthe crankcase, through the passages connected bythe camshaft front journal groove, and into the rightgallery. The oil pressure relief valve closes the rearend of the right gallery until delivery of the pumpcreates a pressure above the normal range of 30 to35 psi. Excessive pressure opens the valve, allowingoil to drain into the crankcase rear cover, until thepressure again drops to normal. Three oil ducts,drilled from crankshaft main bearings to the left oilgallery, conduct a portion of the oil stream to thesebearings. Other drilled holes conduct a portion ofthe oil to the camshaft bearings. Part of the mainbearing supply flows through crankcheek passagesto the crankpins. The oil film formed in all of thesebearings is continually replenished, and oil is forcedto spray from their ends, filling the case with a mist.

Oil sprayed into the cylinders is scraped back intothe case by piston rings. Piston pins and cylinderwalls are lubricated and cooled by the spray. Gearsin the crankcase cover cavity are lubricated by sprayfrom rear main and rear camshaft bearings. Valvelifters are supplied with oil, as described inparagraph 3-16 and shown in figure 8. From thelifter sockets, oil flows through the hollow pushrodsto the rocker arm passages described in paragraph3-23, to lubricate the rocker bushings and the valvestems. Oil sprayed into the rocker boxes drains backto the crankcase through the pushrod housings. Allthe oil returned to the crankcase and the portionwhich is sprayed into the rear cover drains back tothe sump through the open center of the sumpmount flange.

3-43. OIL CIRCULATION IN -12, -14, -16 ANDO- 200 MODELSThe oil flow path in -12, -14, -16 and O-200 modelsis the same as in -8 models, except in the followingdetails. The pump delivers oil to the screen on theright side of the crankcase cover. The screen outletis registered with a drilled hole in the crankcasebelow the right oil gallery. An intersecting hole isdrilled across to the left of the crankcase, emergingat the oil cooler mount pad above the left oilgallery. If no cooler is installed a pad cover passageconducts the oil stream down to a second hole in theside of the case and into the left oil gallery. Inaddition to the details mentioned above, the -16 andO-200 crankcase has an oil passage drilled from thevacuum pump adapter mount pad into the leftcrankcase cross passage. The vacuum pump adapterinlet registers with the drilled hole in the leftcrankcase and directs the oil stream through theadapter to the vacuum pump mounting pad. Anintersecting hole is drilled from the adapter oiloutlet to provide pressure lubrication to the adapterbushing. Oil drainage from the bushing is returnedto the crankcase cavity through two oil passages justabove the oil seal seat. Whenever a vacuum pump isinstalled, it will be necessary to provide an externaloil return line to direct the oil from the pump to thetapped hole in the crankcase cover.

3-44. OIL COOLER EQUIPMENTThe cooler adapter, an aluminum casting, isattached by two case studs over the pad behind No.2cylinder, described in paragraph 3-42. The oilstream from the pump enters the adapter inlet port,

28

passes through the adapter into the cooler, which isattached to the adapter by three studs and nuts,flows through the cooler core and returns to theadapter outlet passage. The adapter outlet portdelivers the oil stream to the crankcase inlet holeleading to the left oil gallery. A spring loaded ballvalve closes a by-pass in the adapter between theinlet and outlet passages. In the event of radiatorcore stoppage, the increased pump delivery pressurecaused by the restriction, opens the by-pass valve,allowing the oil to by-pass the cooler and return tothe crankcase inlet.

The by-pass valve also permits cold, viscous oil toby-pass until its pressure is reduced by increasedtemperature. This equipment can be installed onlyon -12, -14, -16 and O-200 models.

29

SECTION IVUNPACKING THE ENGINE

4-1. SHIPPING CRATESThe side and top panel assembly of the domesticshipping crate is attached to the wood base andengine cradle assembly by nails. The plywoodcradle is bolted to the base. Skids under the baseplatform permit a rope or cable to be passed underthe crate to make a lifting sling. The exportshipping crate is composed of a heavy wood baseassembly and a wood side and top panel assembly,which is lined with waterproof paper. The sidepanels are nailed to the base. A wood clamp blocksecures the crankshaft to a base bolster, and twosteel angle members, bolted to a parallel bolster,support the crankcase upper mounting arms.

CAUTION

Do not lift domestic shipping crates byattachment of the lifting sling to sidesor top. All lifting force must be applieddirectly to the base.

4-2. METHOD OF PACKING ANDPRESERVATIONBefore the engine is stopped, after completion ofthe factory test, a corrosion-preventive mixture isfed into the lubrication system and sprayed intothe air intake. During the packing operation, thesame mixture is sprayed into spark plug holes. Allopenings are closed to exclude moisture. Enginesare supported in shipping crates in the invertedposition. Carburetor air intake assemblies, airfilters and other installation equipment parts arefastened securely to the engine. Propeller hubs, ifused, are fastened to the crate base. A moistureproof shroud is placed over the engine to protect itfrom dripping water.

CAUTION

The factory preservation treatmentapplied to new and re-manufacturedengines will be effective for a perioddependent on atmospheric conditions atthe point of storage. During prolonged

storage, it is advisable to inspect cratedengines at regular intervals of not morethan 30 days to determine that internalsurfaces are covered with the corrosion-preventive oil. Cylinder walls may beinspected through spark plug holes.Rocker covers may be removed forinspection of rocker box parts. Thecrankshaft must not be turned duringinspection. In very warm or dampclimates or in localities where dailytemperature variation is large,inspection of stored engines at morefrequent intervals is recommended.After inspection, replace all closures.

Figure 11. Hoisting Engine by Crankshaft LiftingEye.

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4-3. REMOVAL OF ENGINE FROM CRATE

Remove the crate side and top panel assembly bypulling out the nails which attach the sides of thebase. Remove nuts and bolts which secure theupper crankcase mount arms to the domestic cratecradle or to the export crate angle members.Loosen the crankshaft clamp bolts if it is an exportcrate. If the engine has a flange crankshaft,remove the bolts attaching the propeller flange tothe cradle or base bolster. Lift the engine from thecradle, taking care not to pinch or pull ignitioncables. Turn the engine to the vertical position;attach a lifting eye to the crankshaft, and take upthe engine weight on the hoist, as illustrated inFigure 11. If the engine has a flange typecrankshaft a different type of lifting eye will berequired. Such an eye can be made locally bybending a length of steel bar stock, at least 3/16 X1 inch to a horseshoe shape (in the flat), bendingthe ends in opposite directions to right angles, anddrilling holes in the bent ends for 3/8-24 bolts,with which to attach the eye to opposite propellerbolt bushings.

4-4. PREPARATION FOR INSTALLATION

Fasten the engine mounting arms securely to asuitable assembly stand or support which will holdthe engine in the vertical position. Detach andremove all loose parts fastened to the engine, andremove closures from the breather elbow, cylinderexhaust ports, carburetor bottom flange and anyother sealed openings. If it is a carburetor engine,install the gasket and intake housing on thecarburetor bottom flange and attach to the fourstuds with slotted nuts and lockwire. Bend theintake housing bracket to correct position, andattach to the housing with two drilled fillister headscrews, washers and lockwire. Prepare the airfiller of any type engine by placing the four slottedhead studs through holes in the filter frame fromthe front side and through the filter gasket, thendriving the cross pins through the stud holes. Placethe filter and gasket on the intake housing frontflange, with the studs entering the cam plates, andturn each stud to the right to lock it, holding filterand stud firmly in place. Install the fuel pump, oilcooler, cylinder baffles and any other engineaccessories and attachments required by theaircraft installation.

31

SECTION VSTORAGE OF ENGINES

5-1. GENERAL

Engines in aircraft that are flown onlyoccasionally tend to exhibit cylinder wallcorrosion more than engines in aircraft that areflown frequently.

Of particular concern are new engines orengines with new or freshly honed cylindersafter a top or major overhaul. In areas of highhumidity, there have been instances wherecorrosion has been found in such cylindersafter an inactive period of only a few days.When cylinders have been operated forapproximately 50 hours, the varnish depositedon the cylinder walls offers some protectionagainst corrosion.

Obviously even then proper steps must betaken on engines used infrequently to lessenthe possibility of corrosion. This is especiallytrue if the aircraft is based near the sea coast orin areas of high humidity and flown less thanonce a week.

In all geographical areas the best method ofpreventing corrosion of the cylinders and otherinternal parts of the engine is to fly the aircraftat least once a week long enough to reachnormal operating temperatures which willvaporize moisture and other by-products ofcombustion.

Aircraft engine storage recommendations arebroken down into the following categories:

Flyable Storage (7 to 30 days) TemporaryStorage (up to 90 days) Indefinite Storage

5-2. FLYABLE STORAGE (7 to 30 days)

a. Service aircraft per normal airframemanufacturer's instructions.

b. Each seven days during flyable storage, thepropeller should be rotated by hand withoutrunning the engine. Rotate the engine sixrevolutions, stop the propeller 450 to 900 fromthe original position.

For maximum safety, accomplish enginerotation as follows:

(1) Verify magneto switches are "OFF"

(2) Throttle position "CLOSED"

(3) Mixture control "IDLE CUT-OFF"

(4) Set brakes and block aircraft wheels (5)Leave aircraft tie-downs installed andverify that the cabin door latch is open (6)Do not stand within the arc of the propellerblades while turning the propeller

c. If at the end of thirty (30) days the aircraft isnot removed from storage, the aircraft shouldbe flown for thirty (30) minutes, reaching, butnot exceeding, normal oil and cylindertemperatures. If the aircraft cannot be flown itshould be represerved in accordance with "B"(Temporary Storage) or "c" (IndefiniteStorage).

5-3. TEMPORARY STORAGE (Up to 90 Days)

a. Preparation for Storage

1. Remove the top spark plug and sprayatomized preservative oil, (Lubrication Oil-Contact and Volatile Corrosion-Inhibited,MIL-L-46002, Grade 1) at roomtemperature, through upper spark plug holeof each cylinder with the piston inapproximately the bottom dead centerposition. Rotate crankshaft as each pair ofopposite cylinders is sprayed. Stopcrankshaft with no piston at top dead center.

NOTE

Shown below are some approvedpreservative oils recommended for use inTeledyne Continental engines for temporaryand indefinite storage:

MIL-L-46002, Grade 1 Oils:

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NOX RUST VCI-I05Daubert Chemical Company4700 S. Central AvenueChicago, Illinois

TECTYL 859AAshland Oil, Inc.1401 Winchester AvenueAshland, Kentucky

2. Re-spray each cylinder without rotatingcrank. to thoroughly cover all surfaces of thecylinder interior, move the nozzle or spraygun from the top to the bottom of thecylinder.

3. Re-install spark plugs.

4. Apply preservative to engine interior byspraying the above specified oil(approximately two ounces) through the oilfiller tube.

5. Seal all engine openings exposed to theatmosphere using suitable plugs, or moistureresistant tape, and attach red streamers ateach point.

6. Engines, with propellers installed, that arepreserved for storage in accordance with thissection should have a tag affixed to thepropeller in a conspicuous place with thefollowing notation on the tag: "DO NOTTURN PROPELLER ENGINEPRESERVED."

b. Preparation for Storage

1. Remove seals, tape, paper and streamersfrom all openings.

2. With bottom spark plugs removed from thecylinders, hand turn propeller severalrevolutions to clear excess preservative oil,then re-install spark plugs.

3. Conduct normal start-up procedure.

4. Give the aircraft a thorough cleaning andvisual inspection. A test flight isrecommended.

5-4. INDEFINITE STORAGE

a. Preparation for Storage

1. Drain the engine oil and refill with MIL-C-6529 Type II. Start engine and run untilnormal oil and cylinder head temperaturesare reached. The preferred method would beto fly the aircraft for thirty (30) minutes.Allow engine to cool to ambienttemperature. Accomplish steps "5-2.a." and"5-3.a." of temporary storage.

NOTE

MIL-C-6529 Type II may be formulated bythoroughly mixing one part compound MIL-C-6529 Type I (Esso Rust-Ban 628,Cosmoline No. 1223 or equivalent) withthree parts new lubricating oil of the graderecommended for service (all at roomtemperature).

2. Apply preservative to engine interior byspraying MIL-L-46002, Grade 1 oil(approximately two ounces) through the oilfiller tube.

b. Install dehydrator plugs MS27215-2, in each ofthe top spark plug holes, making sure that eachplug is blue in color when installed. Protect andsupport the spark plug leads with AN -4060protectors.

c. If the carburetor is removed from the engine,place a bag of desiccant in the throat of thecarburetor air adapter. Seal the adapter withmoisture resistant paper and tape or a coverplate.

d. Place a bag of desiccant in the exhaust pipes andseal the openings with moisture resistant tape.

e. Seal the cold air inlet to the heater muff withmoisture resistant tape to exclude moisture andforeign objects.

f. Seal the engine breather by inserting adehydrator MS27215-2 plug in the breather hoseand clamping in place.

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g. Attach a red streamer to each place on theengine where bags of desiccant are placed.Either attach red streamers outside of the sealedarea with tape or to the inside of the sealed areawith safety wire to prevent wicking of moistureinto the sealed area.

h. Engines, with propellers installed, that arepreserved for storage in accordance with thissection should have each propeller tagged in aconspicuous place with the following notationon the tag: "DO NOT TURN PROPELLER-ENGINE PRESERVED."

As an alternate method of indefinite storage, theaircraft may be serviced in accordance with theprocedures under Temporary Storage providingthe airplane is run-up at maximum intervals of90 days and then re-serviced per the temporarystorage requirements.

5-5. PROCEDURES NECESSARY FORRETURNING AN AIRCRAFT TO SERVICEARE AS FOLLOWS:

a. Remove the cylinder dehydrator plugs and allpaper, tape, desiccant bags, and streamers usedto preserve the engine.

b. Drain the corrosion preventive mixture and re-service with recommended lubricating oil.

WARNING

When returning the aircraft to service do notuse the corrosion preventive oil referenced inparagraph 5-4.a.l. for more than 25 hours.

c. With bottom plugs removed rotate propeller toclear excess preservative oil from cylinders.

d. Re-install the spark plugs and rotate thepropeller by hand through the compressionstrokes of all the cylinders to check for possibleliquid lock. Start the engine in the normalmanner.

e. Give the aircraft a thorough cleaning, visualinspection and test flight per airframemanufacturer's instructions.

5-6. AIRCRAFT STORED IN ACCORDANCEWITH THE INDEFINITE STORAGE PRO-CEDURES SHOULD BE INSPECTED PERTHE FOLLOWING INSTRUCTIONS:

a. Aircraft prepared for indefinite storage shouldhave the cylinder dehydrator plugs visuallyinspected every 30 days. The plugs should bechanged as soon as their color indicates unsafeconditions of storage. If the dehydrator plugshave changed color in one-half or more of thecylinders, all desiccant material on the engineshould be replaced.

b. The cylinder bores of all engines prepared forindefinite storage should be resprayed withcorrosion preventive mixture every six months,or more frequently if bore inspection indicatescorrosion has started earlier than six months.Replace all desiccant and dehydrator plugs.Before spraying, the engine should be inspectedfor corrosion as follows: Inspect the interior ofat least one cylinder on each engine through thespark plug hole. If cylinder shows start of rust,spray cylinder corrosion preventive oil and turnprop six times, then respray all cylinders.Remove at least one rocker box cover from eachengine and inspect the valve mechanism.

34

SECTION VIINSTALLATION IN THE AIRCRAFT AND REMOVAL

6-1. MOUNTING THE ENGINE

It will be assumed that all parts shipped loose withthe engine except propeller attaching parts, havebeen installed and that any aircraft equipment, suchas cylinder baffles, has been attached to theassembly. It will be necessary to have an adapterhook which will pass through the engine lifting eye,with a loop of sufficient diameter to admit the hoisthook. Proceed as follows:

a. If the engine is mounted on a rotating assemblystand, turn the engine to the flight position, andtake up the engine weight on the hoist. If theengine rests on a fixed stand with crankshaftvertical, attach the hoist to the lifting eye, andlift the engine manually, or by means of thecrankshaft lifting eye and another hoist, andswing the engine to the flight position as thelifting eye is raised.

b. Raise the engine to the level required to alignthe crankcase mounting arm holes with boltholes in the aircraft mounting.

c. If the engine is a -8 or -12 model, install therubber cone bushings in front and rear seats ofthe mounting arm holes. place a steel washer oneach mounting bolt, and push the bolts throughthe engine mount bosses from the rear.

d. Place the number of steel washers required (forcorrect C. G. location) between the aircraftmount and the rear engine rubber bushings.

e. Move the engine rearward carefully so that themount bolts will enter the rubber bushing holeswithout tearing them.

f. Place a steel washer (supplied with engine) oneach bolt end.

g. Install a slotted nut on each mount bolt, andtighten all nuts to 60-80 inch pounds torque.This is very important, since insufficient

tightness will allow excessive vibration,whereas too much tightening will deform therubber bushings.

h. Install cotter pins.

i. If the engine is a C90-14, -16 or 0-200 model,place a Lord mount bushing in the rearcounterbore of each engine mount arm, andplace a cupped steel washer on the rear side ofeach bushing. Push the engine carefully onto themount bolts. Center one of the rubber hosesnubbers on each of the four steel tubes suppliedwith the equipment, and push the tube over theend of each bolt. Install the front Lord bushingsin the front mount arm counterbores and the lastfour cupped washers over them. Install slottednuts on the mount bolts, and tighten each nut to180-190 inch pounds torque. Install cotter pins.

j. Remove protective covering from the crankshafttaper, and remove tape which secures the shaftkey, if a tapered shaft is installed.

k. Remove exhaust port covers and spacers,carburetor fuel inlet plug, oil pressure gauge lineplug (in front of lower right mount arm), primerjet plug (left side of intake manifold),tachometer housing cover nut, and crankcasebreather elbow cover, unless these wereremoved earlier, and install fittings forconnection of aircraft parts where necessary.

1. Connect the following aircraft parts:

(1) Magneto switch wires.

(2) Throttle control cable.

(3) Carburetor mixture control cable.

(4) Carburetor air heat control.

(5) Oil temperature gauge.

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Figure 12. Typical Installation Diagram for –12, -14 & -16 Models, Side View.

Figure 13. Installation Drawing for –12, -14 & -16 Models, Front View.

36

A. Name plate K. Tachometer drive S.A.E. standard ½ engineB. Oil Filler (optional location) Speed C.W. rotation.C. S.A.E. No. 1 flanged crankshaft (optional) L. Oil drain 5/8-18 N.F. tap and plugD. Fuel pump – special equipment M. Oil temp. capillary 5/8-18 N.F. tapE. Breather connection 5/8 I. D. hose N. Oil screenF. Exhaust mounting P. Oil pressure relief valveG. Throttle control lever R. Air intake housingH. Oil pressure gauge connection S. Delco-Remy generatorJ. Oil quantity gauge T. Delco-Remy starter

U. Oil cooler optional special equipment

Figure 14. Installation Drawing –12, -14 & -16 Models, Rear View.

37

Figure 15. Installation Drawing for –12, -14 & -16 Models, Side and Top Views.

38

(6) Fuel supply line to carburetor.

(7) Tachometer drive cable and conduit.

(8) Oil pressure gauge.

(9) Primer discharge line and nozzle to manifold.

(10) Electric power cable to starter (-12, -14, -16and 0-200 models).

(11) Wires from switch to generator "F" terminaland from regulator "GEN" terminal togenerator "A" terminal.

(12) Starter shift lever control cable (-12, -14, -16and 0-200 models).

(13) Crankcase breather hose or tube.

(14) Exhaust manifold.

(15) Air scoop tube to generator vent (-12, -14, -16and O-200 models).

(16) Air heat tube to carburetor intake housing.

6-2. FUEL SYSTEMSWhen a carburetor engine is installed in an aircraftwith elevated fuel tank, the carburetor must be theproper parts list number and have the correct floatneedle seat for the gravity flow system. A differentcarburetor with a smaller float needle seat isrequired when a fuel pump is installed. In all cases,be sure that the carburetor is the correct parts listnumber for the make and model of aircraft, sincemetering differs for various installations. If a fuelpump is installed on the engine, connections to theaircraft supply line and carburetor must be made asdescribed in paragraph 3-38 and paragraph 3-39.The normal priming nozzle is installed in a 1/8 inchN. P. T. hole in the left side of the intake manifold.

6-3. OIL SYSTEMThe lubrication system is contained with the engine,except that an oil cooler and adapter may beinstalled on the engine, if required. When thevacuum pump is installed on the -1-6 and 0-200engines, an oil return line between the pump andcrankcase cover must be installed. Connect the oil

Figure 16. Engine Mounting Equipment of ModelsC90-14, -16 and O-200

return line to the 5/8 in. tapped hole in the left sideof the crankcase cover. The oil temperature bulb isscrewed into a hole in the center of the oil screencap.

6-4. PROPELLER INSTALLATIONMake sure that the propeller is the correct type forthe engine and aircraft models. If the engine isequipped with a tapered crankshaft proceed in thefollowing manner:

a. Install the steel hub in the propeller from therear.

b. place the loose flange on the front side of thepropeller.

c. Tap the hub bolts through from the rear.

d. place a steel washer and a castle nut on eachbolt end.

e. Tighten all nuts evenly to 200-220 inch poundstorque.

f. Check fit of hub on crankshaft taper and key.

g. place a tapered arbor in the hub and check staticbalance and track of the propeller and hubassembly. Correct as necessary.

h. Place the snap ring on the shaft nut, against theshoulder, and compress it. Tap the snap

39

ring into the front hub bore, pushing the nutwith it, until the ring snaps into the groove.

i. Install the propeller, hub and nut assembly onthe crankshaft, and screw the nut in. Torque to200-225 foot pounds.

j. Install the nut locking pin with its head insidethe crankshaft bore, and install a cotter pin tosecure it. If the engine has a flange crankshaftthe bolt holes in the rear side of the propellermust be reamed to fit over the shaft bushings.Install the propeller firmly on the shaft flange.place the moisture impervious plate on the frontside of the propeller, then the loose steel flange.Insert the six hub bolts and screw them into thebushings. Tighten the bolts evenly, and installlockwire through their head holes so as toprevent loosening.

6-5. ENGINE REMOVALThe following suggested order of disconnection andremoval must be varied to suit the aircraftinstallation.

a. Remove propeller.

b. Remove engine cowling and any baffles whichwill interfere with removal of the engine.

c. Drain the oil sump.

d. Disconnect throttle control cable fromcarburetor.

e. Disconnect mixture control from carburetor.

f. Disconnect fuel supply line from carburetor orpump.

g. Disconnect carburetor hot air tube.

h. Disconnect carburetor air heat control cablefrom intake housing.

i. Disconnect oil pressure gauge line.

j. Unscrew and remove oil temperature capillaryfrom oil screen.

k. Disconnect tachometer drive conduit nut andcable.

l. Remove primer discharge line from manifoldjet.

m. Disconnect starter shaft lever control (-12, -14, -16 and 0-200 models).

n. Disconnect generator wires (-12, -14, -16 and 0-200 models).

o. Disconnect ignition switch wires &ommagnetos.

p. Attach a hoist to the engine lifting eye and takeup the engine weight on the hoist.

q. Remove engine mounting bolts, starting withthose at the bottom.

r. Move the hoist or the aircraft to clear theengine, making sure that engine parts do notstrike the mount.

s. Install the engine on a support stand, assemblystand, or a shipping crate cradle, and attach itsecurely.

t. Unless the engine is to be overhauled at once,cover all engine openings, after removingfittings belonging to the aircraft.

40

SECTION VIIOPERATING INSTRUCTIONS

7-1. PROCEDURE PRELIMINARY TOSTARTINGPlace engine controls in following positions:

a. Ignition Switch: "OFF".

b. Parking Brakes: Set.

c. Throttle: Wide open.

d. Mixture Control: "FULL RICH".

e. Carburetor Heat: "COLD".

Turn the propeller through four or five revolutions.

7-2. STARTING PROCEDUREPerform the following operations in the ordernamed:

a. Close throttle, if open.

b. Turn fuel supply valve "ON" a full tank.

c. Unless engine is still hot, prime one to fourstrokes with hand primer, depending on airtemperature.

d. Open throttle slightly.

e. Turn ignition switch to "ON".

f. Close master switch (-12, -14, -16 and 0-200models).

g. Start -8 models by pulling propeller through acompression stroke. Start -12, -14, -16 and 0-200 models by engaging electric starter.

CAUTION

Never engage the electric starter while thepropeller is turning. Gear teeth will be chippedif this rule is violated.

In cold weather prime the engine as it starts, andcontinue to prime only enough to keep the enginerunning until it will run smoothly on the normalmixture. If the engine cannot be started after severalattempts, refer to Section VIII for possible causes.

7-3. WARM-UPAs soon as the engine starts, adjust throttle to obtainapproximately 800 R.P.M., and observe thefollowing precautions:

a. Watch oil pressure gauge closely. If no pressureis indicated within 30 seconds, stop the engine,and determine the cause.

b. Do not allow engine speed to exceed 800R.P.M. during the first minute. Cold oil will notcirculate rapidly enough for adequatelubrication at higher speeds.

c. Leave carburetor mixture control in "RICH"position for all ground running.

d. Open throttle gradually until the engine isrunning at approximately 1200 R.P .M. Do notexceed this speed until oil temperature hasreached 750 F.

e. Avoid prolonged running on the ground. Enginecylinders do not receive enough cooling air flowunless the aircraft is moving forward at highspeed.

7-4. GROUND TESTWhen ready to take-off, set parking brakes andcheck the following:

a. Mixture control: "FULL RICH"

b. Oil pressure at fun throttle: 30-60 p.s.i.

c. Oil temperature (minimum): 750 f.

41

d. Decrease in speed when ignition switch isturned from "BOTH" to "L" or from "BOTH" to"R". Maximum 75 R.P.M.

e. Carburetor air heat: Move control to full "HOT"position, and observe decrease in engine speedif air heater and control are operating properly.Return control to full "COLD" position.

NOTE

Under some conditions, ice may form in thecarburetor during ground test. It must beeliminated before take-off.

f. Fuel supply valve: "ON", full tank.

g. Propeller pitch control (if installed): HighR.P.M.

7-5. TAKE-OFFUsually the throttle will be opened wide for take-off, however, it is possible to exceed the rated take-off speed of. the engine if an automatic orcontrollable pitch propeller is improperly adjustedor if a fixed pitch propeller of sub-standarddimensions is installed. Rated take-off speed mustnot be exceeded at any time. With approvedpropeller in proper adjustment, the take-off speedwill not be realized until the aircraft is nearlyairborne. If a special take-off speed is specified forthe engine model, it must not be maintained longerthan one minute, in order to prevent overheating. Itis advisable to reduce speed to the normal rating forthe engine model as quickly after take-off asimmediate obstacles are cleared.

7-6. CLIMBINGExcept in unusual situations, it is advisable toreduce engine speed below maximum and to restrictthe angle of climb so as to maintain adequate airspeed to assure proper cylinder cooling. This isparticularly important in warm weather.

7-7. LEVEL FLIGHTWhen the desired cruising altitude has beenreached, adjust the throttle (and propeller pitchcontrol, if installed) to obtain the specified cruisingR.P .M. With hydraulic controllable propellers,

reduce manifold pressure first with the pitchcontrol: then reduce R. P. M. with the throttle.During flight, observe the following procedures andprecautions:

a. If a Stromberg carburetor is installed leavemixture control in the "FULL RICH" position ataltitudes less than 5000 ft. above sea level. If aMarvel-Schebler carburetor is installed themixture control may be adjusted to obtain bestrich power at any cruising altitude.

b. To obtain best rich power, move the mixturecontrol toward the "LEAN" position, and watchthe tachometer closely to detect any change inengine speed. If speed decreases or remainsunchanged return the control to the "FULLRICH" position. However, as the control ismoved to lean mixture an increase in speed willordinarily result if an automatic enrichment hasoccurred, due to decreased air pressure. Furthercontrol movement will cause a decrease inspeed. when the position of maximum speed hasbeen found, return the control toward "RICH"position until engine R.P .M. decreases justperceptibly. This setting produces the bestpower obtainable under existing atmosphericconditions with a slightly rich mixture toprevent overheating.

c. If the mixture control is in any but "FULLRICH" position change the setting, as describedin paragraph 7-7b., for each change in altitudeor power setting. If a Stromberg carburetor isinstalled return the mixture control to the"FULL RICH" position before letting downbelow an altitude of 5000 feet.

d. The carburetor air heat control should be in the"COLD" position unless icing conditions areencountered. Formation of ice in the carburetoris indicated by a loss in R.P .M. (usuallyprogressive). To overcome ice formation, flfstapply full heat to melt the ice which has formed;then close the hot air valve in small steps untilonly enough heat is applied to prevent furtherice formation.

e. Observe engine oil temperature and pressurefrequently. Unless other temperature andpressure gauges are installed, these indications

42

will give the first warning of trouble. If a rapidor continuous rise in oil temperature or drop inoil pressure is noticed the aircraft should belanded without delay and the cause determined.

7-8. LET-DOWN AND LANDINGBefore the throttle is retarded, place the mixturecontrol in the "FULL RICH" position. During let-down and final approach:

a. Retard throttle to obtain approximately 1200R.P.M.

b. The mixture control must be in "FULL RICH"position prior to landing. If a long glide is made,it is good practice to "gun" the engineperiodically to clear the cylinders and retainengine temperatures so that the engine willremain ready for instant use.

c. Carburetor heat is available only when engineoutput is well above that for idle; therefore, thecarburetor heat control should be applied beforeclosing the throttle and "off" after closing thethrottle so that full power will be available ifrequired in an emergency.

CAUTION

Do not open a carburetor throttle abruptly afteridling in flight. To do so may cause the engineto stop. If the engine tends to stop while glidingwith closed throttle, the idling mixture should bereadjusted. If the engine stops when throttle isopened suddenly, return the throttle to theclosed position and open slowly or operate theprimer for one or two strokes.

7-9. STOPPING THE ENGINE

a. Normally the engine will have cooledsufficiently during the glide and taxiing periodto permit placing the ignition switch in the offposition without additional idling. If taxi timehas been excessive, operate the engine at 800-1000 RPM for two or three minutes beforestopping.

b. If the engine is equipped with a Stromberg N A-S3Al carburetor, stop the engine from idlingspeed by turning the ignition switch to "OFF".As the engine stops open the throttle rapidly andleave it open to prevent after firing. If thecarburetor is a Marvel-Schebler MA-25SP A,stop the engine by moving the mixture controlto the "full lean" position, where it acts as anidle cut-off. Do not open the throttle, because itactuates the accelerator pump and rapid openingwill flood the engine.

7-10. LUBRICATING OILTeledyne Continental Aircraft Engines arecertificated on straight mineral oil. Detergent oilsare not a requirement. It is recognized that forengine operation in extreme ambient temperatureranges of high or low temperatures, detergent oilsshow advantages of coping with sludge, varnish andcarbon formation in the engine, and improvedperformance can be obtained for aircraft operatingunder these adverse conditions. For obviousreasons, we do not propose to indulge in testing ofany oils to ascertain whether or not they meet ourspecifications MHS-24B. The proof of compliancerests with the oil manufacturer. Recommendationsrelative to transition from a straight mineral oil to adetergent oil, as outlined in Federal AviationAdministration "Power plant Branch Report No. 1"titled "Evaluation of Aircraft Engine Fuels andLubricating Oils", apply to the use of SpecificationMHS-24B detergent oil. It is safest and simplest tobegin use of this oil when the engine is new or justmajor overhauled. However, if an engine has beenusing straight mineral oil for a considerable periodof time, and it is desired to change MHS-24B oil, itis generally agreed that the oil should be drainedafter five or ten hours of operation and the conditionof the oil screen checked. If an abnormal amount ofsludge is found, the oil should be changed and thescreen should be checked at approximately fivehour intervals, until the condition of the screenappears normal. Teledyne Continental Motorsapproves the use of only those detergent oilsmeeting oil specifications MHS-24B.

7-11. VISCOSITYViscosity grades of oil, as listed in Table XVIII,should be used in season, according to theprevailing air temperature. In extremely cold

43

weather it is advisable to drain the oil sumpimmediately after stopping for a long period and towarm the oil to 100° F. before refilling the sump.To prevent excessive cooling of the oil sump andexcessively high oil viscosity in cold weather, thesump may be covered with an oil-proof lagging.

7 -12. OIL CHANGE PERIODSUnder normal operating conditions, engine sumpsshould be drained and refeuled with fresh oil aftereach 30 hours of operation. Condition of oil and oilscreen after this period will determine whether theoperating time between oil changes should bealtered to suit local conditions. Under adverseconditions of dust and humidity, the operatingperiod may need to be reduced to 20 hours.

7-13. OIL CHANGE PROCEDUREAlways drain engine oil immediately after warmingup the engine to obtain an oil temperature of 100° F.place a clean container under the sump. Remove thedrain plug, and allow the old oil to drain

completely. When it is reinstalled, use a newcopper-asbestos gasket and safety with lockwire.Remove and inspect the oil screen. If the screencontains heavy sludge deposits or if the drained oilis highly diluted, more frequent oil changes will beadvisable. If many or large metallic particles arefound on the screen or in the drained oil (exceptmachinings in new engines) the engine is in need ofoverhaul. clean the screen in unleaded gasoline.Replace it with a serviceable gasket; tighten the capsecurely, and install lockwire. Replace the oiltemperature capillary. Refill the sump with fresh oilto the gauge "FULL" mark.

7-14. ENGINE FUELThese engines are designed to operate efficiently ongasoline of aviation quality with octane ratings atleast equal to those specified in Table XIII.Tetraethyllead content should not exceed 1/2 cc. pergallon. The fuel should be free from water and asfree as possible from solid particles.

TABLE XVIII RECOMMENDED OIL VISCOSITY GRADES

AMBIENT AIR TEMPERATURE Below 40°F Above 40°F

OIL VISCOSITY GRADE S.A.E. No. 20 S.A.E. No. 40

When average ambient air temperature is approximately at the dividing line of the above temperature ranges,use the lighter oil.

44

SECTION VIIIENGINE TROUBLES AND SERVICE REPAIR

TROUBLE PROBABLE CAUSE REMEDYEngine does not start. Insufficient fuel.

Fuel does not reach carburetor.

Carburetor float valve stuck shut.

Carburetor screen or jets plugged.

Insufficient priming (weakexplosions).

Excess priming (puffs of blacksmoke).

Engine hot (Vapor lock in fuelsystem).

Low battery charge

Cold oil

Incorrect starter adjustment.

Spark plugs fouled

Spark plug cables defective.

Magneto breaker points burned orfouled.

Magnetos incorrectly timedinternally or to engine.

Fill tank.

Clean tank vents, blowout supplyline, replace shut-off valve, repairpump, clean filter.

Remove carburetor and repair.

Remove and clean.

Repeat starting procedure withmore priming.

Clear cylinders by turningpropeller several revolutions,with ignition switch "OFF",throttle wide open.

Disconnect fuel line at carburetorand purge system.

Recharge battery.

Turn propeller by hand severalrevolutions to break loosecongealed oil. Also refer toparagraph 7-11.

Readjust shift lever screw. Referto paragraph 10-27.

Remove and clean. Check gaps.

Replace defective parts.

Remove oil from breaker.Replace defective condenser.

Check and correct timing toOverhaul if internal engine.

45

TROUBLE PROBABLE CAUSE REMEDYIrregular idling.

Rough running.

Incorrect idle mixture adjustment.

Carburetor idle air bleed plugged.

Spark plugs fouled.

Leak in air induction system.

Propeller out of balance.

Engine mount bolts loose.

Fouled spark plugs.

Defective spark plug cables.

Cracked magneto distributor block.

Worn cam lobe.

Defective valve lifter.

Scored valve stems.

Warped valves.

Detonation.

Correct carburetor adjustment.

Disassemble, as required, andclean.

Remove and clean.

Tighten loose joints. Replacedamaged parts.

Remove and inspect.

Tighten (Refer to Section XVIII).

Remove and clean. Inspect gaps.Replace worn valve guides orpiston rings.

Test for break-down at highvoltage.

Overhaul magneto. Check forvery fine cracks in block.

Overhaul engine.

Remove and test hydraulic unit.Replace if worn.

Replace valves and guides.

Replace. Grind seats.

Use specified fuel. Keep cylinderhead temperature below specifiedmaximum.

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TROUBLE PROBABLE CAUSE REMEDYPoor acceleration.

Low power.

Engine not warm enough.

Defective throttle control.

Plugged air filter.

Idling mixture too lean.

Idling jet plugged.

Water in fuel.

Leak in air induction system.

Defective ignition cable.

Scored valve stems.

Warped valves.

Defective magneto.

Throttle not fully open.

Carburetor air heat valve notclosing fully.

Incorrect propeller installed.

Propeller blades warped.

Ice forming on carburetor throttlevalve.

Air filter plugged.

Fuel flow restricted.

Worn cylinders, pistons and/orpiston rings.

Continue warm-up.

Check for binding, kinks,slipping, worn parts.

Remove and clean filter.

Readjust.

Clean carburetor.

Drain sediment trap.

Check all joints and throttle shaftbearings.

Test for high voltage leaks.Replace parts.

Replace valves and guides.

Replace valves. Grind seats.

Overhaul magneto.

Readjust linkage.

Remove filter, inspect valve.Straighten plate.

Check specification and propellermodel. Replace.

Inspect pitch. Replace.

Apply full carburetor air heat.

Remove and clean.

Inspect tank vents. Inspect shut-off valve. Clean strainer. Cleancarburetor screen. Blow out fuelsupply line.

Overhaul engine.

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TROUBLE PROBABLE CAUSE REMEDYLow oil pressure.

High oil temperature.

Low oil supply

Low oil viscosity.

Plugged oil screen.

Dirt on oil pressure relief valveseat.

Oil pressure relief valve seat worn.

Oil pressure relief valve plungersticking.

Oil pump suction tube screenplugged.

Engine bearings worn.

Oil pressure gauge defective.

Internal oil leak.

Cracked crankcase cover casting,defective oil pump, leaking suctiontube.

Low oil supply.

Dirty or diluted oil.

Winter baffles installed.

Prolonged ground operation at highspeed.

Excessive rate of climb.

Lean fuel-air mixture.

Replenish.

Drain sump. Refill with correctgrade.

Remove and clean.

Clean plunger and seat. Replacedirty oil.

Overhaul engine. Refinish valveseat.

Remove cap and plunger. Cleanparts.

Remove sump. Clean screen.

Overhaul engine.

Test gauge, and replace or repair.

Overhaul engine.

Overhaul engine. Replacedamaged parts.

Replenish.

Drain sump, and fill with freshoil of proper grade.

Remove in warm weather.

Avoid prolonged running on theground.

Avoid low air speed.

Refer to Section X.

48

SECTION IXPERIODIC INSPECTION AND MAINTENANCE

9-1. DAILY INSPECI'ION.Engines should be inspected prior to first flightand after the last flight each day. The purpose ofthis inspection is to detect serious maladjustment,leaks, looseness and other developments of adangerous character. Inspect the following pointsand make necessary corrections:

a. Inspect propeller for nicks, cracks and otherdamage. Ascertain that all attaching parts aretight and secure.

b. Check operation of throttle control for freeoperation and full travel.

c. Check fuel meter bowl for water and sediment.Clean, if necessary, and safety.

d. Inspect oil gauge to estimate rate ofconsumption and determine need ofreplenishment.

e. Refill fuel tanks, and inspect vent openings incaps.

f. Trace any oil leaks or fuel leaks to their sourceand correct.

g. Wipe any oil from surfaces of engine andcowling.

h. Inspect spark plug cable terminals andbrackets for tight installation and for anydamage.

i. Inspect accessory attachments, controlattachments and cylinder baffle attachmentsand fits. Baffles must fit snugly on cylinders.

j. Inspect starter and generator electricalconnections and magneto switch wire terminalconnections.

k. Visually inspect entire engine for loose ormissing nuts, palnuts, screws and lockwire.Properly safety plugs.

1. Inspect air intake filter for excessivedirtiness.

NOTE

The air 61ter should be cleaned as itbecomes dirty, every day under severeconditions. Whenever the intake f1lter isfound to be restricted by dust it must beremoved and cleaned. To remove the f1lter,turn each of the four locking studs to theleft, and draw the filter forward. Remove thegasket if it adheres to the f1lter. Clean thefilter element with mineral spirits solventused for cleaning parts. Use fresh solvent forfinal cleaning and dry thoroughly. Ifavoidable, use a jet of dry compressed air toblow off all liquid on the surfaces. If, aftercleaning, the surface of the air filter showsmetallic wires through the remainingflocking material, the f1lter is no longereffective and should be replaced with a newpart. Dip the f1lter in clean enginelubricating oil, and allow to drain overnightbefore installing. Replace the f1lter with agasket in serviceable condition, making sureto push each stud home before turning tolock. A damaged f1lter will allow dust andforeign matter to enter the combustionchambers, which results in a high rate ofcylinder, piston and ring wear.

9-2. FIRST FIFTY HOUR INSPECTIONInspect each engine after the first fifty hours ofoperation when new, remanufactured oroverhauled, giving particular attention to thefollowing checks and adjustments.

a. Inspect propeller for tightness and security ofattaching parts and check track of blades. !

b. Remove palnuts, and check tightness ofcylinder retaining nuts with a torque wrench.Refer to Section XVIII for correct torque.

c. Check fit of all cylinder baffles on cylinder fins.

49

d. d. Remove lockwire, if installed, and checktightness of oil sump retaining nuts. Tighten totake up gasket set, and safety.

e. Remove palnuts from stud, if installed, andcheck tightness of retaining nuts onaccessories and crankcase cover. Checktightness of upper starter retaining bolts.Tighten all nuts and bolts, as necessary, to takeup gasket set. Do not tighten excessively.

f. Remove palnuts, if installed, from pushrodhousing adapter studs, and check tightness ofadapter retaining nuts. Tighten, as necessary.

g. Check tightness of hose clamps on intakepipes, and pushrod housing rubber connectors.Do not tighten excessively.

h. Check tightness of retaining nuts of carburetor,and air intake. Tighten, if necessary to take upgasket set, and replace lockwire or other safetydevices which were removed.

i. Check tightness of rocker cover retainingscrews, and tighten, if necessary, to take upgasket set. Tighten screws evenly around eachcover. Do not tighten excessively.

NOTE

The first fifty hours of operation is a"shakedown" period, during which softgaskets take a permanent compression or"set", and certain other parts may becomeslightly less tight than when initiallyinstalled. A general inspection and necessaryretightening after this period will help toprevent oil leaks and other annoyingtroubles which result from the nature ofmaterials subjected to high temperatures andstresses.

9-3. 100-HOUR PERIODIC INSPECTIONThis inspection should be made to coincide with aregular oil change. The following inspections andservicing should be considered preventivemaintenance, and whatever maladjustments,looseness, wear or damage are discovered willindicate and demand appropriate readjustment,repair or replacement of parts, accessories and/orinstruments.

a. Start and warm up the engine to obtain an oiltemperature of 1000 F. During this period,check all engine instruments to detectfluctuations or other abnormal indications.Test operation of all engine controls, andobserve engine response. Restrict running tothe minimum time necessary for warm-up andinstrument checks. In warm weather prolongedrunning for tests should be performed in flight.

b. Immediately after stopping the engine, drainthe oil sump, and carry out the complete oilchange and inspection procedure described inparagraph 7-14. Refer to Table XVIII forcorrect oil viscosity grade.

c. Check the propeller for visible defects, trackwithin 1/8 inch, tightness of attaching parts.Remove the engine cowling.

d. With ignition switch "OFF" and throttle fullyopen, turn the propeller, and test compressionin all cylinders. Uniformly low compressionwill usually indicate the need of overhaul. Lowcompression in one or two cylinders only maybe caused by defective valve lifters.

e. Remove rocker covers, and inspect all partswithin each rocker box for breakage, wear andfull lubrication. Remove all spark plugs, andobserve valve lift while the propeller is turnedslowly. Replace rocker covers with newgaskets, and tighten retaining screws evenly.

f. Remove magneto breaker covers. Wipe any oilfrom breaker housings. Inspect magneto pointsfor pitting or burning (indicating a defectivecondenser). If magneto points are suspected ofincorrect gap or opening position, or if thebreaker assembly must be replaced, refer toSection X for procedures. When finished,replace the breaker covers.

g. Clean spark plugs. Check and adjust electrodegaps. (Refer to current Spark Plug ApplicationBulletin.) Test plugs in dry compressed air at100 psi pressure. Reinstall plugs withserviceable gaskets, and tighten to specifiedtorque.

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h. Examine cylinder head fins for breakage orserious cracks, and make sure that cylinderbaffles fit closely and firmly on the fins.

i. Inspect all spark plug cables for condition ofterminals, cracked or chafed insulation,attachment and fit of brackets and installationof rubber grommets (in unshielded systems).Reconnect cables to spark plugs.

j. Inspect all electrical connections and magnetoswitch wires for firm attachment, propersupport and insulation condition.

k. Inspect all connections and attachments in theinduction system, including air intake housingand air filter, carburetor and cylinder elbows.

l. Remove and service the air filter as describedin the note following paragraph 9-1-1.

m. Test operation of all engine controls, andinspect control connections for wear andlooseness and conduits for firm support.

n. Remove fuel filter bowl. Empty and cleanbowl and screen, and reassemble parts.Remove carburetor screen; clean, and replace.Turn on fuel supply, and check for leaks.

o. Remove cotter pins from engine mount bolts,and test torque on nuts. Tighten all nuts 60-80inch pounds torque, and replace cotter pins.(Lord mount bushing bolts of model C90-14, -16 and 0-200 require 180-190 inch poundstorque.)

p. Test adjustment of starter lever. (Refer toparagraph 10-27.)

q. Remove all dirt and oil from the exterior of theengine and accessories and dry thoroughly.

r. Start the engine and warm up as described inparagraphs 7-2 and 7-3. Perform the groundtest described in paragraph 7-4. Stop theengine and inspect for fuel and oil leakage.Replace cowling.

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SECTION XADJUSTMENT AND MINOR REPAIR

10-1. CARBURETORS

10-2. REMOVAL

Disconnect and remove parts in the following order:

a. Shut off fuel supply; then disconnect supply linefrom the carburetor fuel inlet.

b. Loosen clamp screw in carburetor throttle leverswivel on right side, and pull control cable fromswivel.

c. Disconnect control cable or rod from mixturecontrol lever. This lever is located on top of thefloat chamber at the left side on the Strombergcarburetors, and at the rear of the Marvel-Schebler carburetors.

d. Remove carburetor heat valve control cableclamp from its support at left rear corner ofintake housing, and remove control cable endfrom valve lever.

e. Remove air filter from intake housing.

f. Remove lockwire from heads of two bracketscrews inside the intake housing and fromslotted retaining nuts at carburetor top andbottom flanges. Current production engines nolonger use drilled studs for attaching the airintake housing and carburetor and use plain hexnuts and lock washers in these locations.

g. Remove the two bracket screws and the fournuts or nuts and lockwashers attaching theintake housing to carburetor. Remove the intakehousing.

h. Remove the four carburetor attaching nuts ornuts and lockwashers and remove the carburetorand gasket from the manifold.

CAUTION

Do not use sharp or pointed tools toremove gasket material. Damage toparting surfaces will result in prematurereplacement of an otherwise serviceablepart.

10-3. INSTALLATIONCoat the carburetor upper flange gasket with a filmof non-hardening gasket paste, and place the gasketon the manifold studs. Install the carburetor on themanifold with the throttle lever on the right side.Install four slotted hex nuts and plain washers if themanifold studs are drilled or plain washers,lockwashers and plain hex nuts if manifold studs areundrilled. Secure slotted hex nuts with lockwire.Similarly, install the intake housing on thecarburetor bottom flange. Attach the supportbracket to the intake housing with the two fillisterhead screws and plain washers. Install lockwire toconnect and secure the screw heads. Replace the airfilter, and push each locking stud fully home beforeturning it to lock. Apply a thin film of gasoline andoil resistant lubricant to the first three pipe threadsand install a 1/4 inch pipe and tube connector of thetube required by the aircraft, in the carburetor fuelinlet. Reconnect throttle, mixture and air heat valvecontrols, and test for full range operation. If thethrottle lever motion is short, loosen the lever clampscrew, and readjust the lever position on the throttleshaft until the control cable will move it through thefull range between stops.

10-4. STROMBERG CARBURETORADJUSTMENTThe main metering jet is a fixed orifice type. Its sizeis determined by factory test, and no adjustment isprovided. The rear adjusting screw on the throttleshaft stop assembly controls the open throttleposition. It is set at the factory to contact the bodystop when the throttle valve is parallel to the barrel,and no further adjustment is required. This screw

52

stops forward motion of the throttle lever. The frontscrew on the throttle stop assembly adjusts theidling position of the throttle valve by stoppingrearward motion of the lever. The slotted andknurled brass screw head projecting from theoblique boss behind the throttle body is part of theidle mixture adjusting needle valve. To adjust idlespeed and mixture, proceed as follows:

a. Start the engine and warm up in the normalmanner.

b. Slightly loosen the idle adjusting stop clampscrew.

c. Close the throttle, and observe engine speed. Donot lock the throttle.

d. Turn the idle speed adjusting screw in (righthand) to increase idling speed or out (left hand)to reduce. Set idling speed at approximately 600R.P.M. with throttle closed against the stop.

e. Turn the idle mixture adjusting needle valve tothe right to lean mixture or left to enrich. Adjustuntil engine runs smoothest; then turn to the leftvery slightly. Again observe engine speed andcorrect with the speed adjusting screw. Againadjust idling mixture for smoothest operationand enrich by turning valve to the left slightly.When smooth idling at 600 R.P .M. is obtainedthe mixture will be slightly on the rich side forsafety.

f. Tighten the idle speed stop clamp screw, andsecure the idle mixture needle valve withlockwire.

NOTE

The Stromberg Parts List number of eachcarburetor is stamped on the lower flangeunder the throttle lever. The Continental partnumber is stamped on an adjacent side of theflange. Make sure that the proper carburetorfor the engine model and aircraft is installed.Otherwise, no adjustment can be made,except by disassembling the carburetor andchanging jets, to provide correct fuelmetering at high speed.

10-5. MARVEL-SCHEBLER CARBURETORADJUSTMENTIf after checking all other possibilities, it is foundnecessary to readjust this type of carburetor,proceed as follows:

a. Start and warm up the engine in the normalmanner.

b. Set throttle stop screw to obtain an idle speed of500 R.P .M.

c. Turn idle adjusting needle out slowly untilengine "rolls" from richness, then turn in slowlyuntil engine lags, or runs irregularly fromleanness. This step will determine theadjustment range and how the engine operatesunder extreme idle mixtures.

d. From the lean setting, turn needle out slowly tothe richest mixture that will not cause the engineto "roll" or run unevenly. This adjustment willin most cases give a slower idle speed than aslightly leaner adjustment with the same throttlestop screw setting, but will give smoothest idleoperation. A change in idle mixture will changethe idle speed and it may be necessary toreadjust the idle speed with the throttle stopscrew to the desired point. The idle adjustingneedle should be from 3/4 to 1 turn from its seatto give satisfactory idle mixture.

CAUTION

Care should be taken not to damage the idleneedle seat by turning the idle adjustingneedle too tightly against seat, as damage tothe seat will make a satisfactory idleadjustment very difficult.

10-6. MAINTENANCEOnce the carburetor is installed and the controls andidling properly adjusted, very little attention isrequired. At each Periodic Inspection alladjustments and attachments should be inspectedfor security. The large hex plug in the left side ofthe float chamber at the rear covers the fuel screen.A drain plug is screwed into the bottom of the floatchamber. These should be removed to clean thescreen and to flush accumulations of dirt and waterfrom the chamber as frequently as necessary.

53

10-7. MAGNETOS

10-8. REMOVAL

Spark plug cables may be removed from EisemannAM-4 magnetos merely by pulling the terminalsfrom the distributor blocks. To remove the cablesfrom Eisemann LA-4 magnetos, first remove thebreaker cover; then back out the distributor blockscrews to free the cable terminal eyes. Unscrew theunion nuts from the cable plate spigots, and pull thecables carefully from the distributor housing. Toremove the spark plug cables from Bendix S4RN-21, S4LN-21 or Slick magnetos, the high tensionoutlet plate must be freed by removing the retainingscrews. Carefully pull the plate, grommet and cableassembly from the magneto housing. Remove AM-4 magneto switch wires by loosening the hex nutswhich attach them to the rear side studs. To removeEisemann LA-4 or Bendix switch wires, unscrewthe union nut which attaches each wire terminal tothe magneto housing. LA-4 switch wire terminalspigots are on the left side near the bottom of thebreaker housing. Bendix spigots may be either atthe bottom or at the rear of the housing. To free themagneto (any type), remove the two palnuts, thenthe two plain hex nuts from studs through themagneto mount flange slotted holes. Currentproduction engines no longer use palnuts at themagneto mount flange, but use plain washers andlockwashers, together with the plain hex nut. Exceptfor gasket adhesion, the magneto will be free andmay be pulled straight to the rear. The drive gearwill come with the magneto.

10-9. INSTALLATION AND TIMINGUnless the original magneto drive gear isunserviceable, install it on the replacement magnetoin the same manner as it was positioned on theoriginal magneto. This requires only loosening thegear retaining nut, removal and installation of thegear and tightening and pinning the nut.

10-10.Before installing a replacement magneto, it isadvisable to test the opening position of the breakerpoints. This should occur at the same time thattiming marks are aligned when the drive gear isturned in the direction of its normal rotation.Magneto timing marks are located and may beinspected as follows:

a. Eisemann AM-4: There are no timing marks forinstallation. Locate No.1 firing position roughlyby inserting a cable in the marked outlet socketholding the bare cable end near the bare mountflange, and spinning the shaft through the firingpositions. When spark occurs, the rotor has justpassed No.1 position.

b. Eisemann LA-4: There are no exact timingmarks for installation purposes. When breakerpoints are installed at assembly their openingposition is adjusted to occur when the rotormagnet has passed its neutral position and isseparated from the pole shoe .059-.138 inch(edge gap). With this adjustment made, thebreaker cam opens the points a maximum "gapof .018-.022 inch. The distributor terminal forNo.1 spark plug cable is located radially in linewith the timing window in the distributor block.When the rotor arm is centered in the timingwindow, the magneto is in position to fire No.1spark plug, and the breaker points should beopening. Remove the distributor cover at therear to observe the timing window and toconnect spark plug cables. Depress the impulsecoupling pawls so that they will pass under thestop pins to permit forward rotation of themagneto shaft.

c. Bendix S4RN-21 and S4LN-21: The fixedtiming mark is located inside the breakerhousing at the top and is covered by analuminum hex head screw plug. The timingmark or pointer in the housing will be seen inthe center of the opening when the plug isremoved. A white tooth on the distributor gearaligns with the fixed mark at the No.1 firingposition. The breaker points will open at thesame time if internal timing is correct. Alsoinspect the position of the impulse couplingpawl stop pin. It should be installed in the No.2hole at the lower right side of the magneto pilotshoulder, as viewed from the drive end, inmodel S4RN-21, and in the No. 3 hole at thelower left side in model S4LN-21. The firstnamed model is used on -8 model engines andrequires an impulse coupling with pawls solocated that they will stop against the pin whenthe shaft is turned clockwise, as viewed fromthe drive end, whereas the S4LN-21 couplingpawls must be

54

stopped by the pin when the coupling is turnedcounterclockwise, as in operation of -12, -14, -16 and O-200 models.

d. The Slick Model 4000 has fixed timing markswhich appear as red marks through the ventwindow on the side of the magneto whichcarries the Slick Trademark and as black marksthrough the vent hole on the opposite side.

NOTE

The special breaker grounding spring used onthese magnetos short-circuits the primarywhen the switch wire terminal is notinstalled. A strip of thin cord may be insertedbetween the spring and the breaker housingfor insulation before the timing light isconnected. This requires removal of thebreaker cover plate. Alternatively, the platemay be left in place and the timing light leadconnected to a short lead wire assembled intoa Bendix switch wire terminal assembly,which can be installed in the terminal spigotof the breaker housing or cover plate todepress the grounding spring, breaking itscontact with the housing and making contactwith the insulated breaker point. Connect theother timing light lead to a bare spot on themagneto housing.

10-11Refer to Table X for correct crankshaft angles to beused for timing magnetos to each engine model.Crankshaft angles of 240, 260, 300, and 320 B.T.C.and a top dead center mark between the letters "TC"are stamped on the edge of flange type crankshaftpropeller flanges. These marks indicate positions ofNo.1 crankpin when they are aligned with thecrankcase split line below the crankshaft. Figure 33illustrates one method of aligning a crankshaftflange timing mark with the split, with the propellerremoved. Another method, which does not requireremoval of the propeller, involves the use of atriangular piece of sheet metal, on which an indexmark is scribed perpendicular to the base andpassing through the apex. When the base of thisindicator is placed on the machined front surface ofthe crankcase, with the index mark at the split line,the apex will indicate No.1 crankpin angles. Figure32 illustrates the use of a special tool to locate No.1

crankpin positions when a tapered crankshaft isinstalled. A timing disc and a piston positionindicator or a Time-Rite indicator (for Time-Riteinformation and prices, address Gabb Mfg. Co., 16Orchard St., East Hartford 8, Conn.) may also beused to position the crankshaft for timing magnetos.The Time-Rite indicator does not require removalof the propeller. It is installed in No.1 upper sparkplug hole with the adjustable scale to the rear.Operating instructions are furnished with eachTime-Rite instrument. Scales and arms are availablefor adaptation to most aircraft engines.

10-12.Using any of the methods of crankshaft positioningmentioned in paragraphs 10-15 & 10-16, install andtime the magneto thus:

a. Remove all upper spark plugs.

b. Position the No.1 crankpin on its compressionstroke and at the proper-advance firing angle.(Refer to Table X.)

c. Position the magneto distributor at its No.1firing point, as described in paragraph 10-15 &10-16.

d. Work a small quantity of a non-hardeninggasket paste into both surfaces of the magnetogasket, and place it on the mount pad.

e. Install the magneto on its pad, meshing the drivegear with teeth of the crankshaft gear (in -8models) or camshaft gear (in -12, -14, -16 andO-200 models), and place plain washers,lockwashers, and plain hex nuts on the retainingstuds. Tighten the nuts with fingers only,leaving the magneto free to rotate within thelimits allowed by the slotted flange holes.

f. If an AM-4 magneto is being installed, connectthe timing light magneto lead to the switch wirestud and the ground lead to one of the mountstuds.

g. If an Eisemann LA-4, Bendix or slick magnetois being installed, place a switch wire terminalassembly and short lead in the magneto terminalopening; screw in the union nut, and attach thetiming light magneto lead to the bored end ofthe short lead wire. Connect the ground lead to amagneto mount stud.

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h. Turn the magneto case in the direction which itsdrive gear will rotate to the limit of the slots.The breaker points should be closed. Tap themagneto case in the opposite direction until thetiming light indicates that the points are justopening.

i. Check alignment of Bendix or Slick timingmarks or Eisemann distributor rotor arm.Tighten the mounting stud nuts to hold themagneto in place.

j. Back up the crankshaft 8 or 10 degrees. Thiswill not allow the impulse coupling pawl toleave its position under the stop pin. Tap thecrankshaft carefully forward until the timinglight indicates that the breaker points have justopened. Check the crankshaft or piston position.If it is not correct, loosen the magneto mountingstud nuts and repeat steps hand i.

k. When the breaker points open at the correctfiring angle, tighten the magneto retaining nuts.

10-13. CONNECTIONSConnect the bared end of the switch wire to AM-4magnetos by wrapping around the terminal stud atthe rear of the distributor housing and tightening thehex nut. The switch wire terminal assembly forEisemann LA-4 and Bendix magnetos must beassembled on the wire end piece by piece, thecoupling nut going on first, and secured by themethod provided. Install the terminal assembly andwire before replacing the breaker cover, if theterminal spigot is in the housing, and ascertain thatthe end of the terminal makes contact with thebreaker contact spring.

WARNING

If an insulating strip was inserted under aBendix magneto switch terminal groundingspring it must be removed before the switchwire terminal is installed. Failure to removethe insulator makes it impossible to groundthe primary circuit and creates a hazard topersons working about the aircraft.

Connect spark plug cables to AM-4 magnetos bypushing the terminal clips into the magnetodistributor housing sockets. Start by inserting No. 1plug cable in the marked socket, and continue in theclockwise direction around the cap, inserting Nos.3, 2 and 4 cables in that order. To connect sparkplug cables to an LA-4 magneto, start by insertingNo.1 plug wire through the left end spigot of thedistributor cable plate (on top), leading it around theleft side of the distributor block, and attaching itwith a screw to the terminal in line with the timingwindow. Then, insert No.3 plug cable through theright end cable plate spigot, lead it around the blockto the right, and connect it to the next terminal inthe counterclockwise direction (at the bottom).Insert the No.2 plug cable through the second spigotfrom the right, and connect it to the nextcounterclockwise terminal (upper right). Connectthe No.4 cable to the last terminal. If tubular cableterminals are installed on the ignition cables theirends must be pushed up inside the insulation andmust not be pulled out when the terminal screws aretightened. Seat the rubber cone bushings in the platespigots. Make sure that a plain washer is locatedbetween each cone and the cable coupling nut.Then, screw the knurled coupling nuts on the platespigots, and tighten with the fingers. Replace thedistributor cover and tighten its two retainingscrews. The terminal plates of Bendix cableassemblies need only to be inserted into thedistributor housings and retained by installation ofthe four lockwashers and screws which attach each.

WARNING

Eisemann magnetos are not equipped withgrounding springs at the switch wireterminals. No work should be performed onengines equipped with these magnetos whilethe spark plug cables are connected toinstalled spark plugs from either magnetountil the following points have beenchecked.

1. The connection from magneto to switch must becompleted.

2. The connection from the switch to the enginemust be completed.

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3. The magneto switch must be in the "OFF"position.

10-14. MAINTENANCE OF EISEMANN AM-4MAGNETOSThese magnetos have oil-impregnated breaker camsand grease packing bearings. The breaker followeris lubricated by oil held in the cam. Gears are alsoimpregnated with oil. No lubrication betweenoverhauls is required. At periodic inspections thedistributor housing may be removed by removal offour screws which attach it to the coil housing.Inspect the interior of the case, and remove any dirt,oil or moisture with a clean lintless cloth. Inspectthe condition of breaker points. If they are pitted orburned remove and test the condenser. If thecondenser is found to be defective replace it with anew part, and replace defective breaker assemblies.Do not dress breaker points, except in anemergency. For right hand rotation, the "V" markon the large distributor gear is aligned, at assembly,with the punch marked tooth on the rotor shaft gear.The breaker points are adjusted to open when therotor has passed its neutral position by the correctedge gap. The breaker cam then provides a fullpoint opening of .019-.021 inch. If a new breaker isinstalled, or if it becomes necessary to readjustbreaker point opening, the breaker follower shouldbe placed on the highest side of the cam, by turningthe propeller; then adjust the point gap within thelimits mentioned above. Check the adjustment bycarrying out the timing procedure check describedin paragraph 10-12j, without loosening the magnetoretaining nuts. If the magneto was correctly timedoriginally, the readjusted breaker will open at thespecified advance firing angle.

NOTE

The propeller must be turned backward tothe firing position to prevent engagement ofthe impulse coupling pawl.

10-15. MAINTENANCE OF EISEMANN LA-4MAGNETOSThe ball bearings are packed with grease, and thedistributor bearing and breaker cam are' both oilimpregnated, therefore no lubrication betweenoverhauls is required. Do not wash the breaker camor wipe it with any petroleum solvent. Duringperiodic inspections the magneto breaker should be

inspected. To gain access to the breaker, remove thetwo screws which attach the cable plate (on top) tothe end plate. These are the two front screws in thegroup of four. Remove the three screws whichattach the adapter to the end plate; then carefullyremove the adapter and cable plate assembly,bending the spark plug cables, arid allow it to hangto one side. Clean the inside of the distributor blockwith a clean lint-free cloth, and inspect the carbonbrush and spring. Check to see that they movefreely in the socket and that the brush extendsbeyond the socket. The high tension springassembly on the distributor block should be free onthe high tension pick-up post. Inspect visually fordirt on the contacts. To check the breakeradjustment, turn the crankshaft until the breakerfollower rests on the highest point of the cam. Inserta thickness gauge between the points. The gapshould be .018-.022 inch. If the gap is not withinthese limits, slightly loosen the two breakerfastening screws, and adjust by means of theeccentric stud. Retighten the fastening screws, andcheck the gap. When this operation has beenfinished, it will be necessary to recheck timing ofthe breaker point opening to No.1 piston. Inspectthe contact of the switch wire terminal with thebreaker contact spring.

CAUTION

Do not lift the movable breaker point toproduce an opening of over 1/16 inch wheninspecting points.

10-16. MAINTENANCE OF BENDIX S4RN-21AND S4-LN-21 MAGNETOS.Ball bearing of these magnetos are packed, atassembly, with grease, and the distributor bushingand breaker cam are impregnated with oil. Nolubrication need be applied between overhauls. Ifengine operating troubles appear to be caused by theignition system, it is advisable to check the sparkplugs and cables for defects before opening themagnetos. If ignition trouble is traced definitely to amagneto, the safest procedure is to replace thedefective unit with a new or rebuilt assembly and tosend the original magneto to the overhaul shop forcomplete rebuilding and test. If this should beimpossible, a visual inspection may disclose aminor trouble which can be corrected in place.

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Remove the high tension cable outlet plate. Inspect thecontact sockets in the distributor block for moisture.Remove any condensation with a lintless cloth.Remove the four cable contact screws at the front sideof the rubber outlet plate grommet. Remove thewashers, and slide the grommet from the cable ends.Inspect the interior of the grommet sockets formoisture and dry thoroughly. Remove any moisturefrom the cables. Replace the grommet, and secure itwith the cable contact screws. If no moisture wasfound, remove the hex head plug from the top of thecase, and turn the crankshaft backward until the whitegear tooth aligns with the timing mark or pointer. Thebreaker points should be just opening. If they do not,loosen the screw in the breaker slotted hole, and shiftthe breaker until the points just separate, as indicatedby a timing light connected across them. Rechecktiming, as in paragraph 10-12j, without loosening themagneto retaining nuts. Remove any oil from thebreaker points with a small cloth dampened in cleargasoline. Avoid wetting the breaker cam. If breakerpoints are burned, replace the condenser and thecomplete breaker.

10-17. SLICK MAGNETOSLike the Bendix this magneto has no set breaker pointclearance. A timing gauge key is used to lock the rotorin the position at which the contact points just open.

10-18. REPLACEMENT OF IGNITION CABLES10-19. UNSHIELDED CABLESIf only a single cable has been damaged a replacementmay be made up of component parts. The number andtype of terminal parts will depend on the type ofmagneto installed. This information will be found inthe parts catalog. Since cables for Eisemann magnetosare individual complete assemblies, they are suppliedseparately, by part number, for the various locations,with proper terminals and ready for installation. Sinceunshielded cables for Bendix magnetos are assembledinto the cable and plate assemblies, they are notsupplied separately. Replacements for Bendix -equipped engines may be made of bulk cable bycutting it to the same length as the original andinstalling a spark plug safety lock terminal. Themagneto end may be threaded through the bracketgrommets from which the old cable was removed. Theold cable may be detached from the high tensionoutlet plate grommet by removing the plate attachingscrews, pulling the plate and grommet assembly

Figure 17. Ignition Wiring Diagram.

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carefully from the magneto, and removing the cablepiercing screw installed in the cable end. Themagneto end of the replacement cable must be cutoff square. Insert it into the grommet through theoutlet plate hole; place a washer on the front end ofthe grommet boss, and insert the cable piercingscrew so that it will enter the copper conductor anddivide the strands. To install a replacement cable inan AM-4 magneto system, it is necessary only topull the old cable from the magneto terminal socket,disconnect the spark plug terminal, and pull theassembly from the brackets. A new cable assemblymay be replaced in the reverse order.

10-20. SHIELDED IGNITION CABLESWhile it is possible to fabricate a replacement radioshielded cable assembly for either Eisemann LA-4,Bendix or Slick magnetos, the length of timerequired for the work and the possibility ofunsatisfactory results make the undertakinginadvisable, except in emergencies. As a rule, if onecable in a shielded ignition system breaks downunder a high voltage test, the others should also beconsidered hazardous, and the entire assemblyshould be replaced.

10-21.Radio shielded ignition cable assemblies for upperright, upper left, lower right and lower left sparkplugs and Eisemann LA-4 magnetos are suppliedwith brackets and terminals installed, so that any ofthe assemblies may be installed on -12 and -16models by removing the contact elbows of the oldassembly from the spark plugs, detaching the cablebrackets from the crankcase studs, removing themagneto cable terminals, as described in paragraph10-19, attaching the new assembly brackets andspark plug elbows and installing the magneto cableterminals, as outlined in paragraph 10-19. Ifreplacement is due to mechanical damage of one ortwo cables, only the assembly affected need bereplaced, but if the old cables leaked under a highvoltage test, the complete system, consisting of fourcable assemblies, should be installed. (Refer todiagram, Figure 17.)

10-22.For model O-200 engines and either of the -8, -12, -14, or -16 models equipped with Bendix magnetos,the radio shielded ignition system consists of the

two magnetos and a cable and plate assembly foreach plus two ground terminal kits, with which tomake up the switch wire terminal assemblies. If thedielectric qualities of any cable have been reducedso that a break-down under high voltage occurs,both cable and plate assemblies should be replaced.They are obtainable under a single part number, oreach cable and plate assembly may be purchasedseparately. Bulk cable and other component partsmay be purchased for repair of mechanical damage.To replace a cable and plate assembly on a Bendix-equipped engine, remove the old cable elbows fromspark plugs, and detach the old cable brackets fromcrankcase and crankcase cover studs; then removethe four retaining screws from the high tensioncable outlet plate, and carefully pull the plate andgrommet from the magneto case. Attach brackets ofthe replacement cable and plate assembly to theengine studs, and install the new cable contactsleeves and elbows on spark plugs. Carefully insertthe new plate and grommet in the magneto in theonly position in which screw holes will align. Installthe plate retaining screws and lockwashers.

NOTE

Make sure that the correct cable and plateassembly is used. The sequence of cablenumbers around the high tension cable outletplate differs in assemblies for -8 modelsfrom that of assemblies for -12, -14, -16 andO-200 models. (The latter four areidentical.) Assemblies for -8 models haveonly one straight bracket on each pair ofupper and lower cables, while those for -12,-14, -16 and O-200 models have anadditional (twisted) bracket on each pair.(Refer to the wiring diagram, Figure 17.)

10-23.In an emergency, a single radio shielded cable maybe made up of bulk shielded cable and terminalparts. Remove terminal parts from the original;cable, and observe how the outer covering andshielding braid are stripped back and the braidturned into a cuff under the spark plug elbow leadcone and under the magneto and flanged ferrule.Duplicate lengths of cable and stripping. The ferrulemust be swaged onto the cable over the braid cuff,in order to hold the cable firmly to the magneto.The job should not be attempted unless a swaging

59

tool is available. Other operations require only theusual hand tools. Lengths of the stripped cable endsand of the bared copper strands must be accurate.Swage the ferrule on the magneto end so that thebraid cuff (3/16 inch long) is centered under it. Cutthe magneto end to final length after the ferrule isswaged in place. Then, cut the cable to correctoveral1length. For LA-4 magnetos, bare themagneto end, and install a tubular Eisemannterminal, pushing it 1/8 inch into the insulation andbending it to a hook, or wrap the bare strandsaround an eyelet, and form the straight eyelet tubeend into a second flange like the preformed end.Then, push a rubber cone bushing over the eye andup to the ferrule flange. For Bendix magnetos, cutoff the stripped magneto end cable insulation andcopper strands to final length and square afterswaging the ferrule in place. Cut the cable to overalllength. For either type of magneto, run theappropriate coupling nut on over the spark plug end.Spark plug ends of all cables are the same. Slide theelbow coupling nut on; then place the lead coneover the braid cuff, and push the stripped cable endthrough the elbow. Screw the coupling nut on theelbow. Strip the high tension insulation hack fromthe cable end about 1/8 inch; twist the strands ofwire, and install a contact sleeve. Make sure that thesleeve seats on the elbow; then spread the wirestrands and bend them over the sleeve eyelet. Thiscompletes the cable. To install it, the bracket rivetsmust be sheared and the tape removed. Rewrap thereplacement cable with the mate, using 3/4 inchfriction tape, and re-rivet the brackets to hold thepair of cables securely.

10-24. DELCO-REMY STARTER10-25. REMOVALDisconnect the cockpit control from the starterclutch shift lever, which is pivoted on the right sideof the motor housing. Unscrew the hex nut on thestarter switch terminal post, and remove the electricpower cable. Insulate the cable end. The starter isattached to its aluminum adapter plate, which alsosupports the pinion and clutch assembly. Thisassembly must be removed, as a unit, by removingthe lockwashers, plain washers, then the three plainhex nuts, which attach the round part of the adapterto crankcase cover studs, and the two through boltsinstalled from the front side of the upper extensionsof the crankcase rear flange. When these five

attachments have been removed the starter will befree, except for possible adhesion of the gasket. Tapthe motor housing with a non-marring hammer orbump the motor housing with a non-marringhammer or bump it with the hand, if necessary, tobreak loose the gasket. The starter clutch is pilotedon the pivot head in the crankcase. Slide theassembly straight to the rear until the clutch andpinion clear the pivot.

10-26. INSTALLATIONCoat the starter pinion pivot and the starter pinionand gear teeth with the engine oil. Apply a thin filmof non-hardening gasket paste to both surfaces of anew starter gasket, and install the gasket on thecrankcase cover pad, making sure that all old gasketmaterial has been removed. Examine the mountingsurface of the starter adapter for cleanliness, andwipe it dry. Keeping the clutch assembly backagainst the adapter, start the pinion over the end ofthe pivot. Hold the starter and clutch assembly inline with the pivot as it is moved forward. Thepinion will not mesh, and the adapter should seatfirmly on its gasket without interference. Installthree plain washers and three lockwashers oncrankcase cover studs and a plain washer andlockwasher on each through bolt. Run on the threeplain hex nuts, and install the two bolts through thecrankcase flange and cover. Tighten the bolts andnuts evenly to prevent warping the adapter plate.

10-27. ADJUSTMENTIt is very important that the control cable returnspring have sufficient tension to hold the startershift lever in the fully released position. There mustbe at least 1/16 inch clearance between the clutchshaft end and the shift lever end when the control isreleased. The shift lever switch contact screw mustbe adjusted to allow 9/16 inch clutch travel from thereleased position to the fully engaged position. Thelast 1/8 inch of clutch movement is made while theshift lever screw is compressing the switch button.When the screw has been adjusted to fulfill theserequirements, tighten its lock nut. To check theadjustment, turn the propeller so that the minimumclutch travel is now obtained. The pinion andcrankshaft gear teeth are now abutted. The clutchmust move from its released position to touch thecrankshaft gear, so that there will be a clearancewhen the control is released. Actuate the control,

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and determine, by inserting a screwdriver into theclutch shaft end and pushing forward, that thespring cap can be moved at least another 1/16 inchto assure that the switch is making contact.

WARNING

Before starting any work on the electricstarter or generator, make sure that boththe ignition switch and the master switchare in the "OFF" position.

10-28. MAINTENANCEThe starter commutator and brushes, visible whenthe brush cover band is removed, should beinspected periodically for cleanliness. Adjustmentof the shift lever should be checked at periodicinspections, however this will need no alteration,unless the adjustment was incorrectly madepreviously. No lubrication is required betweenoverhauls. An oilite bushing in the clutch bore forthe pinion pivot and another in the clutch shaft holein the adapter provide lubrication for the exteriorbearings, and the gears are lubricated by engine oil.If any repair or disassembly is necessary, the starterassembly must be removed from the engine.

10-29. PERFORMANCE DATAThe starter armature rotates counterclockwise, asseen from the drive end. Correct brush tension is24-28 ounces. With no load, the armature turns7000 R.P .M. when the drop across its terminals is11.25 volts. The current draw is then 75 amperes.On blocktest load it should develop 18 ft. lbs.torque at 6.1 volts, with a current draw of 590amperes.

10-30. PRESTO LITE STARTER10-31. REMOVALUnscrew the hex nut on the starter switch terminalpost, and remove the electric power cable. Insulatethe cable end. The starter is attached to itsaluminum adapter plate, which also supports theclutch assembly. Remove five sets of nuts andwashers and two bolts which are installed from theupper front side of the crankcase. It may benecessary to tap the adapter with a plastic hammer,or bump it with the hand to break loose the gasketadhesion. Be careful when removing the starter thatthe clutch assembly does not drop.

10-32. INSTALLATIONLubricate the starter pinion and intermediate gearand install on starter adapter. Hold the starterassembly in position to align the clutch bore withthe crankcase pivot and push the clutch over thepivot, holding the assembly in line as it approachesand seats in the pad. Install the nuts and washers onthe studs. Insert the two bolts and secure withwashers and nuts. Torque to value specified inTable of Limits.

10-33. ADJUSTMENTSee appropriate airframe manual.

10-34. MAINTENANCEThe starter commutator and brushes, visible whenthe brush cover band is removed, should beinspected periodically for cleanliness. Brushes mustbe replaced when they have worn down to a lengthof 1/4" or less.

10-35. PERFORMANCE DATAThe correct brush tension with new brushes is 32-40ounces. Measure with a spring scale hooked underthe spring at the brush. Pull on a line opposite theline of force exerted by the spring and take thereading just as the spring leaves the brush. With noload the armature turns at 8000 RPM when the dropacross its terminal is 10.0 volts. The current draw is50 amps max. On a stall torque test it shoulddevelop 11.1 min. ft. lbs. at 4.0 volts with a currentdraw of 560 amps.

10-36. PRESTOLITE STARTER CLUTCHOVERHAULComplete overhaul of the Prestolite starter clutchassembly can be accomplished with repair kit PIN639297, using tools supplied in tool kit PIN639298. The following instructions and dimensionalinformation is to be used in conjunction with theprocedures included with the repair kit.

1. Inspect the inner race sprag and needle bearingdiameters of the shaft portion of the large gear.If either of these areas are scored or pitted,replace the part. Needle bearings should bereplaced if they have more than 500 hoursservice. Measure for wear to the followinglimits:

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a. The dimension at the needle bearing area fora new part is 0.4997-0.5000. Service limit is0.4995.

b. The dimension at the inner race sprag areafor a new part is 0.5772-0.5777. Servicelimit is 0.5769.

2. Inspect the outer race of the sprag housing. Any"washboard" pattern is cause for replacement ofthe sprag housing and gear assembly. Measurethe outer race diameter for wear.

a. The dimension of the outer race for a newpart is 1.0734-1.0739. Service limit is1.0743.

3. Inspect sprags for pitting or worn flats.

10-37.When assembling the sprags, coating the inner raceof the sprag housing with a bearing grease will helphold the sprags in. place them around the insidediameter in the proper direction (see figure 17-1)and install one spring at the housing end. Theninsert the mandrel from the gear end and proceed asfollows:

NOTE

When assembling the PIN 634461 starterclutch adapter in the crankcase, be sure touse the new hardened dowel, PIN 637832.Also, check for proper tolerance between theadapter and crankcase bore, which should be0.001 T to 0.001L. This tolerance is critical.

1. Remove outer snap ring (1, figure 17-2) andwasher (2) from end of inner race (3). Discardsnap ring.

2. Remove inner race (3) from outer race assembly(4) by a slight rotation of inner race in the over-running direction (clockwise). Remove needlebearing.

a. Remove inner snap ring (5) and washer (6).Discard snap ring.

b. Examine inner race sprag and bearingdiameters.

3. Insert mandrel (7, figure 17-3) from needlebearing end.

a. Push sprags out of outer race assembly(4, figure 17-2) approximately 3/8-inch.

b. Wrap sprags with rubber band ontomandrel.

c. Remove spring (8) and discard.

d. Remove sprags from outer race. Spragsshould remain on mandrel.

e. Inspect bearings and outer race spragdiameters. If bearings or outer race spragdiameters show a "washboard" wearpattern, replace the sprag housing andgear assembly.

4. Insert inner race (3, figure 17-4) into spragsreplacing mandrel (7).

a. Remove spring (9) and discard.

b. Install new spring.

5. Insert mandrel (7, figure 17-5) into spragsreplacing inner race (3).

a. Install sprags in outer race. Removerubber bands.

b. Install new spacer (10) between sprags.

c. Install new springs (11).

d. Install washer (6) and remove mandreland install new inner snap ring (5).

6. Install inner race (3, figure 17-6) into sprags bygently pushing and turning in over-runningdirection (clockwise).

a. Locate bearings on inner race end andpush in with mandrel (12) until flushwith end of outer race (4).

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b. Install end washer (2) and new snap ring (1).

c. Check for smoothness and correct rotations.

Figure 17-1

Figure 17-2

Figure 17-3.

Figure 17-4

Figure 17-5.

Figure 17-6

10-38. GENERATOR/ALTERNATOR ANDDRIVE10-39. REMOVALBefore removing the generator and drive assembly,disconnect the tachometer drive conduit and pull thecable end from the engine drive shaft. Inspect for oilleakage into the tachometer drive conduit. Ifleakage is observed, a new oil seal should be

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installed in the tachometer drive housing when it isoff the engine. Remove the three elastic stop nutsand plain washers, and pull the tachometer drivehousing from the shaft. Disconnect both electricalwires from the generator terminals. Remove thethree elastic stop nuts which retain the generatorand the three plain washers, and pull the unitstraight to the rear. Remove all gasket material fromthe mount pad and generator flange.

10-40. DISASSEMBLY OF DRIVERemove the cotter pin from the end of the generatorshaft, and unscrew the drive retaining nut. The gear,sleeve (if installed), bushings (or old type rubberdrive disc) and retainer will slide off the shafteasily. Use a gear puller to remove the couplinghub. The woodruff key may be lifted by tapping onits outer end with a hammer and screwdriver verycarefully. The oil seal may be removed from thecounterbore in the generator drive end frame withsome type of bearing race puller, or it may be priedfrom the recess by cutting two holes in the rollededge of the seal case with a small, sharp chisel andprying on opposite sides against wood blocks set onthe flange. Present generator shafts are equippedwith an "D" ring seal installed between the bearingand coupling hub. Remove and discard the "D" ringseal.

10-41. TYPES OF DRIVEThree types of drive assembly have been producedat various times. The earliest type included a singlepiece rubber drive disc without a retainer and thegear fit directly on the generator shaft. The secondtype of drive in production had a steel retainer toprevent spreading of the rubber drive disc, and thegear, disc and retainer were centered on a steelsleeve which was held against the coupling hub bythe shaft nut, leaving the gear a free fit to avoidcompression of the rubber drive disc. The latesttype of drive assembly is similar to the second type,however the rubber cushioning member is nowcomposed of two bushings, instead of the slotteddisc, and the drive gear lugs extend to the rear sideof the bushings, not quite touching the surface ofthe bushing retainer, but contacting the full bushingface. This arrangement prevents any possibility ofshearing the rubber member. If the drive gear isserviceable and single piece discs still available, thesecond type of drive may be continued in service,

though the latest type is preferable. The originaldrive without disc retainers, should not bereinstalled.

10-42. REASSEMBLY OF DRIVEIf groove is machined in the generator shaftadjacent to the bearing, lightly coat an "O" ring sealwith engine lubricating oil and install it in thegroove. New generators are not sold without oilseals. Coat the lip of the oil seal with Gredag No.44. Center the seal in the generator recess with theseal lip outward. Tap the seal case squarely into therecess. Tap a woodruff key into the shaft slot. Slidethe coupling hub on the shaft, and align its key slotwith the woodruff key. Drive the hub over the shaftshoulder and key until its rear end seats against theshaft bearing shoulder and over the "O" ring seal.Slide the steel sleeve over the shaft end, then thepressed steel retainer. Place either two new typerubber bushings or a rubber drive disc, dependingon the gear type, in the retainer. Place the drive gearon the sleeve, and engage its lugs in the bushing ordrive disc slot. When pressed back firmly by hand,the front end of the gear hub should lie slightly tothe rear of the sleeve end, and the end of the steelsleeve should be slightly ahead of the shaft frontshoulder, so that the nut flange will bear on thesleeve, but not on the gear. Tighten the shaft nut,and install a cotter pin to retain it. If the cotter pinhole and nut slot cannot be aligned withoutexcessive tightness or looseness of the nut, selectand try another nut. (Refer to Section XVIII.) Testfor flexibility between the coupling hub and thegear.

WARNING

Do not install a gear with short lugs, forthe single piece rubber disc, incombination with two new type rubberbushings. Disintegration of the rubber,caused by insufficient contact area, mayallow bits to plug the suction oil screen oran oil passage hole, with consequentfailure of all or part of the lubricationsystem.

10-43. INSTALLATIONCoat the generator and tachometer gasket with athin film of non-hardening gasket paste and position

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it in place on the crankcase cover. Replace thetachometer housing oil seal if the leakage isindicated. To prevent cutting the seal lip place astrip of fiber or wood in the drive shaft slot. Theprotective strip must fit exactly and have acurvature corresponding to that of the shaft surface.Apply Neates Foot Oil to the lip of the seal andinstall the tachometer drive housing on thecrankcase cover. Secure the housing with three newelastic stop nuts and washers. Remove theprotective strip from the shaft slot.

NOTE

Older engines have drilled studs for slottednuts to retain the tachometer drive housing.Do not use elastic stop nuts with these.

10-44.Install the generator and drive assembly on itsmount pad, meshing the drive gear with thecamshaft gear internal teeth as it moves intoposition. Install three plain washers and elastic stopnuts on the cover studs to retain the generatorassembly. Tighten the nuts evenly. Check gearbacklash by inserting two fingers through openingsnear the drive end and attempting to rotate thearmature. There must be a slight backlash to preventshaft breakage. Attach the wire from regulatorterminal marked "GEN" to the generator armatureterminal, marked "A". Connect the wire from thegenerator field switch or master switch to thegenerator field coil terminal, marked "F".

10-45. MAINTENANCEThe generator armature bearings are grease packedand shielded. They require no lubrication betweenoverhauls. The drive gear is lubricated by engineoil. At periodic inspections the brush cover and venttube assembly may be removed by loosening theclamp screw, and the commutator and brushes maybe inspected for cleanliness. The performance of thegenerator will indicate its electrical condition, andits mechanical condition may be consideredsatisfactory unless overheating or noise or suddenstoppage point to damage of one of the few movingparts. Any disassembly or repair work must beperformed after removal from the engine.

10-46. PERFORMANCE DATAThe generator armature rotates in the clockwisedirection, as seen from the drive end. The unit isdesigned for operation in a battery charging circuitin which the battery negative terminal is grounded.For proper performance, the air blast directedthrough the vent tube must provide a minimum airpressure differential across the generator of 1-1/2inches of water column, by manometer test. Brushspring tension should be 24 ounces. For early 12volts -12 amperes generators the field current drawat 12 volts is 1.62-1.69 amperes. Output at 3650 R.P.M. at operating temperature is 13 amperes at 15volts. For the current 12 volts -20 amperesgenerator the field current draw at 12 volts is 1.58-1.67 amperes. Output at 4100 R.P.M. at operatingtemperature is 20 amperes at 14 volts. Cruisingspeed range for either generator is 4000-4900R.P.M. Maximum output is regulated by a currentand voltage regulator.

10-47. HYDRAULIC VALVE LIFTERS10-48. TYPES OF FAILUREIn general, there are four types of trouble whichaffect valve lifter operation, only two of which arecaused by the lifter assemblies. The indications andcauses of these troubles may be described as:

a. Slight single or multiple noise, if caused by thevalve lifters, is due to either a leaky check valveor excessive clearance between the hydraulicplunger and cylinder. Either fault will preventthe unit from maintaining zero lash in the valvetrain, though the resulting clearance and shocknoise are small. The same symptom mayindicate faults in parts of the train other than thelifters, since any binding or imperfect seating ofthe valve or wear in the moving parts whichwould increase the "deflated" lash beyond thelimit specified in The Table of Limits wouldmake it impossible for the lifter to compensatefor the shrinkage in total train length.

b. A single, loud "tappet noise" is usually causedby sticking of the plunger in the bore of thehydraulic unit cylinder. This may be due to agummy deposit or to formation of a ring ofcarbon above the shoulder of the plunger. Eithertrouble will cause the plunger to be held downin the cylinder and will prevent it fromcompensating for cylinder expansion, thus

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allowing a large lash in the train. Since the fulllash occurs only when the engine is at operatingtemperature, it is difficult to locate thetroublesome lifter by any visual means, thoughit may be possible to feel the lash immediatelyafter the engine is stopped. With the enginerunning, a listening rod may be used to comparethe noise level of all cylinders and to locate thefaulty one. Then, it is a matter of eliminatingone of the two lifters of that cylinder. If one unitis stuck because of oil varnish or carbon, it isprobable that the others are approaching thesame state and all require attention.

c. General "tappet noise" is nearly always anindication that insufficient oil is reaching thehydraulic units. This starvation may be causedby anyone, or a combination, of the following:

1. Hydraulic Units installed without oil. Inorder to check "deflated" lash in thevalve train, it is necessary to install thelifters in a completely dry condition. Ifhydraulic units are removed from aninstalled engine, oil will inevitably drainfrom the reservoirs. (See Figure 8.)Unless other trouble is present, the lifterswill fill within 45 seconds of running atwarm-up speed.

2. Oil supply running low. If the oil supplylevel is lowered until the oil pump cansuck in air, it will not pick up oil, andcontinued running will result incomplete engine failure. Usually, thevalve lifters will give a warning byintermittent noise as air is fed in with theoil a short time before complete failureoccurs.

3. Air leak on suction side of pump. Theeffect is the same as that due to low oilsupply, and the result may, or may not,be as rapid and as serious. A defectivecopper-asbestos gasket between the oilsuction tube hex and the crankcase coverwill allow a small leakage of air withoutincrease. Failure to tighten or safety thesuction tube at assembly may allow it to

loosen progressively. A crack, caused bydropping or other shock, can develop inthe crankcase cover oil suction passagewall, allowing a constant air leakage.Warp in the oil pump cover can have thesame effect.

4. Solid particles in the oil, after long use,may be fine enough to pass the oil screenand plug or restrict passages to thelifters. Under some conditions, rapidformation of large flakes of carbon cancoat the oil screen and cause it to becollapsed by pump pressure, admittingthe solid matter on its surface to the oilsystem. Partial starvation or abrasionmay cause the hydraulic unit plungers tostick down in the cylinders, causing aload noise.

d. Overheating and low power, if not the result oflow oil supply or a lean fuel-air mixture, may becaused by subnormal valve lift. Failure of thelifter to rotate leads to grooving of its camfollower, causing excessive friction and possiblecam wear. In early stages, this may not affectlifter compensation of noise, however, areduction in travel will eventually prevent intakeof oil to the lifter reservoirs, causing starvation.

10-49. INSPECTION BEFORE REMOVALIf valve lifter faults are suspected because of noise,the quantity and quality of engine oil should bechecked. If a loud single noise was heard, removethe rocker cover of the cylinder affected, and test bypushing on the socket end of each rocker arm. Iflash is found in the train, the lifter is definitelyinoperative. Inspect valve stems for battering;inspect rocker contact surfaces, and look for brokenvalve springs. If the tappet noise was not loud, andif it was continuous, the cylinder or cylindersaffected should be removed, and the pushrods androckers should be inspected for wear, as well as thelifters. If the noise was intermittent the sump shouldbe removed and the suction tube and gasketchecked, provided that oil condition is good.

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10-50. REMOVALRemove spark plug cable terminals and plugs of thecylinder affected, and turn the crankshaft to T.D.C.of that cylinder on its compression stroke. Removehose clamps, and push the pushrod housing rubberconnectors back on the housings. Remove palnutsand cylinder base nuts. Withdraw the cylinder andpushrods, catching the piston as it comes free.Inspect pushrods and rocker sockets for wear, andreplace serviceable pushrods in their originalpositions. With a bent wire, hook lifter socket andremove it. (See Figure 18.) Similarly, remove thehydraulic unit. If it tends to stick and the plungercomes out alone, turn the crankshaft until oilpressure forces the cylinder out far enough to begrasped. Test the lifter body for free movement inits guide, and inspect the cam lobe and the followerfor wear and scoring.

10-51. CLEANING AND TESTING HYDRAULICUNITSWash the unit in clean petroleum solvent. Twist theplunger to wind up the spring while pulling outwardto remove it. If the plunger appears to be stuck,insert a hard wood stick into the inlet tube to releasethe check valve, and push the plunger inward. If itwas held only by a ring of carbon it will slide infreely as the oil drains. The ring can be broken bytwisting the plunger and pulling outward with tapedpliers (See Figure 20) or, in stubborn cases, by useof a carbon solvent. Wash the separate partsthoroughly in clean solvent, and dry them with drycompressed air. Start the plunger into the uprightcylinder; push it down, and immediately release it.If the valve is seating and the plunger fits thecylinder correctly, the plunger will kick back. If itdoes not the valve may be leaking or the plungermay be excessively worn. Check the plunger fit bysealing the inlet tube with a finger and pushing theplunger inward momentarily. If it does not kickback the clearance is too great. If it does, either thevalve seat is dirty or it is worn out of round. Washthe cylinder again to remove possible dirt, andrepeat the first test. If the plunger still does not kickback discard the unit. In handling hydraulic lifters,

remember that cleanliness is essential. Also, nogrinding, lapping or interchanging of parts ispermissible. No shellac, paste or gum may beallowed to reach the units. The plunger must be freein the cylinder, and the check valve must not leakappreciably. For more exact testing, when suitableequipment is available, reassemble the unit byreleasing the check valve and installing the plunger,twisting it to wind up the spring until it snaps intothe cylinder recess. Hold the inlet tube in cleankerosene, and pump the plunger to fill the adjustingchamber. Place the unit in the fixture, and load theplunger with a force of 50 lbs. The check valveshould not leak more than one drop of kerosene persecond, nor should the plunger move more than1/16 inch per second. Some fixtures are designed totest units against a master unit for leak-down rate.These will provide an accurate test of serviceability.

10-52. INSTALLATION AND TESTInstall serviceable hydraulic units in the two liftersof the cylinder, and place the pushrod sockets on theplunger ends. The units should be completely dry totest for mechanical clearance in the valve train withdeflated lifters. With the piston at T.D.C. of itscompression stroke, stagger the piston ring gaps;compress the rings, and reinstall the cylinder. Pushthe pushrod housing connectors onto the adapterspigots, and tighten the hose clamps. Push eachrocker socket end inward, in turn, to compress thehydraulic unit spring, and measure the clearancebetween rocker and valve stem with a thicknessgauge. (Refer to the Table of Limits for clearancelimits.) If the clearances are within limits reinstallrocker covers, sparkplugs and cable terminals. Turnthe propeller by hand a number of revolutions to fillthe lifters as much as possible before starting theengine. If the trouble has been eliminated, the lifternoise should stop after a short period of running atwarm-up speed. Do not increase speed until the lashhas been adjusted to zero by displacement of air inall lifters.

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SECTION XIDISASSEMBLY

11-1. PRELIMINARY OPERATIONS11-2. FIXTURESThe engine should be mounted on a work standwhich can be moved over the floor and which hasa rotating bed to permit the engine to be held withcrankshaft either vertical or horizontal. In thelatter position, the crankcase 2, 4 side should bedownward. A wood fixture should be available tosupport a cylinder in such a way as to prevent thevalves dropping during disassembly of thesubassembly. Another fixture will be needed tohold the crankshaft by its propeller taper or flangeduring removal of connecting rods. A parts rack,on which to store all disassembled parts of oneengine, will prevent mixing. Suitable racks forparts of which more than one are installed, andwhich must not be interchanged, should be at handand should provide for separation andidentification of the multiple parts.

11-3. STARTER AND GENERATORRemove these accessories before washing theengine. The starter may be removed after the twothrough bolts and three plain nuts, lockwashersand plain washers which attach its adapter aretaken off. Pull the assembly straight to the rear.The generator may be freed by removing its threeretaining nuts. If gasket adhesion makes removalof either accessory difficult, do not pry. Bumpingwith the hand will loosen them.

11-4. PRELIMINARY CLEANINGThe engine assembly should be sprayed andbrushed with a petroleum solvent to remove allcaked dirt and oil, particular attention being givento attaching parts. To reduce oil drainage duringdisassembly, it is advisable to remove rockercovers, oil sump and oil suction tube during thisoperation.

11-5. IGNITION SYSTEMRemove spark plug cable terminals from theplugs. Detach cable brackets of shielded systemsfrom case studs. If Eisemann AM-4 magnetos areinstalled the unshielded cables may be pulled from

the magneto sockets and threaded through thebrackets to remove them individually. If EisemannLA-4 magnetos are installed, the cables should beremoved with the magnetos and disassembledlater. Bendix or Slick cable outlet plates may bedetached by unscrewing the screws which attacheach plate to the magneto. Pull the plate andgrommet carefully from its position. Remove allspark plugs. Remove two nuts retaining eachmagneto, and withdraw it to the rear.

11-6. LOCKING PARTSIt may be found expedient to remove all cotterpins, lockwire and palnuts before proceeding withdisassembly. If not, then the locking parts shouldbe removed completely and discarded beforeattempting to loosen nuts and screws. Make surethat no lockwire or cotter pin fragment remains ina stud hole to bind the nut.

CAUTION

Always remove the palnut beforeapplying the wrench to the plain nutunder it. If this procedure is notfollowed, an attempt to remove both nutsat once may back out the stud.

11-7. FUEL PUMPSDetach the delivery tube between dual pumps, ifboth are installed. The side pump is detached byremoving the two flange retaining nuts. Springforce on the lever will tend to cock the pump andmust be resisted to prevent binding on studs.Detach the lower pump from its adapter studs inthe same manner. The adapter will be free whenthe four nuts are removed from mount pad studs.Keep the pushrod with the adapter.

11-8. CARBURETOR AND AIR INTAKEHOUSINGDetach the air 61ter by turning the four lockingstuds to the left, and remove the gasket with it.Detach the intake housing by removing fourslotted nuts or plain nuts and lockwashers from

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carburetor lower flange studs. Similarly, detachthe carburetor from the manifold.

11-9. AIR SCOOPRemove the air filter and gasket by turning thefour locking studs to the left and withdrawing.Detach the scoop by removing two slotted nutsand cotter pins inside the scoop. Remove cotterpins from throttle link rod ends, and remove therod assembly from the throttle levers.

11-10. DISASSEMBLY

11-11. NON-REUSABLE PARTSAll lockwire, cotter pins, palnuts, lockwashers,elastic stop nuts, gaskets, oil seals and syntheticrubber parts must be discarded in such a way as toavoid the possibility of reuse. The nature andfunctions of these parts make it unwise to trusttheir reliability, once they have been removed.

11-12. OIL SUMP AND SUCTION TUBELoosen and run off the six castle nuts or elasticstop nuts which attach the sump flange to the case.Remove the slotted or elastic stop nut whichattaches the oil filler neck to the case lower mountarm. Withdraw the sump, being careful not tostrike the suction tube within. Remove lockwirefrom the suction tube hex, and unscrew the tube. Ifan oil cooler is installed remove the cooler fromits adapter and the adapter from the crankcase.

11-13. AIR INDUCTION SYSTEMLoosen all hose clamps, and push hose connectorsback to the intake tubes. This frees the tubes.Remove the two manifold retaining nuts, and drawthe casting from the crankcase studs squarely.Detach all intake elbows from cylinder flanges byremoving retaining nuts and tapping carefully toloosen the gaskets.

11-14. ROCKER COVERSThese are detached by removal of six fillister headscrews, lockwashers and plain washers from each,and they may be removed by carefully pullingoutward at points around the rims. Carefulhandling is necessary to avoid distortion andsubsequent oil leakage. Prying is not advisable

because of the possibility of scratching the rockerbox flange.

11-15. CYLINDERS

It is not necessary to remove rockers and pushrodsbefore the cylinders are removed, however thismay be done after pushing out the rocker shaft.Usually, the valve lifters make it difficult toremove the rocker shaft, because the units take upall lash. For this reason, the following procedure issuggested.

a. Remove pushrod housing hose clamps, andpush the rubber connectors outward onto thehousings. Do this on all cylinders.

b. Turn the crankshaft until the piston of the firstcylinder to be removed is at T.D.C. on itscompression stroke. The order of removal isnot important, except to avoid overbalancingthe work stand. To minimize crankshaftturning, the order of 4, 1, 3, 2 is suggested. For greatest accessibility, the crankshaft shouldbe vertical and its front end upward.

c. Loosen and remove the six base nuts; then pullthe cylinder outward, and make sure that theconnecting rod does not strike the crankcase.

CAUTION

Do not grasp or lift cylinder by pushrodhousings. They must not be loosened inthe cylinder head.

11-16. PISTON ASSEMBLIES

Remove each piston immediately after its cylinderhas been removed and stored in a safe place. If thepiston pins have loose fitting end plugs it isadvisable to remove the lower one as the cylindercomes off to prevent falling. The loose plugs maybe removed to permit insertion of a screw type pinpuller. Current production pins with pressed inplugs should not require force to remove unless aheavy varnish deposit has formed. If driving isnecessary support the piston against the impact,and use a non-marring drift. Remove and discardthe piston rings, spreading each ring as it isremoved to avoid scratching the piston lands. Pushthe pin back into the piston for storage.

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Figure 18. Removal of Hydraulic Unit fromValve Lifter Body.

11-17. PROTECTORSIt is advisable to install on each connecting rod,after removal of the piston, some type of protectorto prevent impact on the crankcase chamfer anddamage to it. Split pieces of rubber hose, usedcylinder base packings and other means may bekept on hand for this purpose.

11-18. CRANKCASE AND COVERSeparate the remaining subassemblies thus:

a. Remove nuts which attach all pushrod housingadapters to the crankcase, and remove theadapters, tapping carefully to loosen.

b. In the event that an old style lifter, without aretaining ring, is used, the following procedureshould be used. While the crankshaft remainsin the vertical position, hook each valve liftersocket, and remove it with a bent wire; thenremove the hydraulic units with the wire. Keepunit parts in original pairs. The parts are notinterchangeable. Store units to indicatecylinder number and position. (See Figure 18.)

c. Make a double loop of a cylinder base packingor obtain a rubber band of suitable length tohold each pair of lifter bodies on the 1, 3 side,and pass the loop around their outer ends. Thiswill prevent falling when the case casting islifted off later. Pushrod housing rubber

connectors may be placed on individual valvelifters for the same purpose.

d. Turn the work stand bed to place the crankcasecover upward. Loosen and remove the oilscreen from its housing in the cover.

e. Loosen the bronze acorn cap of the oilpressure relief valve at the right rear side ofthe -8 rear cover or at the right side of the -12,-14, -16 or 0-200 crankcase cover. Holdagainst spring force as the cap is unscrewedand comes free. Lift out the spring and theplunger.

f. If the engine is a -8 model loosen thetachometer drive housing by turning the hexshoulder to the right. Do not remove it.

CAUTION

The tachometer drive housing in the -8cover assembly is screwed into the coverboss with a left hand thread. Attempts toloosen by turning to the left will tightenthread and do serious damage.

g. At this stage, the -8 model crankcase coverwill be attached to the ten crankcase studs.Remove the retaining nuts, and lift off thecover and attached parts.

h. At the same stage of disassembly, thecrankcase cover of a -12, -14, ~16 or an 0-200model will be attached by two crankcase studsthrough the oil screen housing flange and fiveshorter studs. Re- move the oil screen housingretaining nuts and the housing; then removethe other five cover retaining nuts, and lift thepartial assembly from the crankcase.

i. Insert a screwdriver through one of thecamshaft gear holes to prevent turning, andloosen the four camshaft gear retaining screws.Run the screws out, and lift the gear from thecamshaft pilot.

j. Loosen and remove the four crankshaft gearretaining screws, and lift off the gear.

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k. Unscrew and remove the breather elbow aheadof No.3 cylinder.

l. Turn the work stand bed to place thecrankshaft in a horizontal position and thecrankcase, 1, 3, side upward.

m. If the engine is an O-200 model, remove three1/4 in. nuts, lockwashers and plain washersand one 5/16 in. nut, lockwasher and plainwasher; then withdraw the vacuum pumpadapter assembly.

n. Loosen the 14 nuts on the crankcase partingflange screws, and remove the eleven 1/4 inchscrews and three dowel screws. The enginelifting eye will be removed with two of thenuts. If necessary, tap the close-fitting dowelscrews from their flange holes.

o. Remove two nuts from 7/16 inch crankcasethrough studs ahead of No.4 cylinder and thenut from the 3/8 inch through stud above thelower right engine mount arm. Detach the 1, 3side mounting arms. If engine is equipped withthrough bolts at the center bearing bosslocations, drive them out with a non-marringhammer. Catch the bolts as they come free ofthe 2, 4 side crankcase half.

p. Lift the 1, 3 side case casting straight upwardclear of the through studs, and lay it on a woodsurface with parting flange up.

q. Lift out the crankshaft and connecting rodassembly, collecting the bronze thrust washersat the front main journal as they come out.(Old type thrust washers are retained by casedowels and must be removed after the casecastings and shaft are separated.)

r. Remove the camshaft from its bearings, andremove all valve lifter bodies from theirguides. Store bodies with mating units.

s. Lift each main bearing insert from its seat, anddiscard.

t. If the engine is a -12, -14, -16 or 0-200 model,remove the starter pinion pivot from the 2, 4side casting; then remove the casting from thework stand, and store it on a wood surface.

NOTE . . . Current production crankcases have agallery drilled to lubricate the starter clutchadapter. Old style cases can be adapted perinstructions in para. 14-13A.

11-19. CONNECTING RODSFor greatest ease of disassembly, it is suggestedthat the crankshaft be held in a fixture similar tothat illustrated in Figure 23, if it is a tapered shaft,or in a suitable flange holding fixture if it is aflange type shaft. Remove all cotter pins fromconnecting rod bolts, and loosen all slotted nuts.Unscrew the nuts from bolts of each rod, in turn,and take rod and cap from the crankpin. Discardbearing inserts, and reassemble rods and capsloosely to avoid mixing.

11-20. CRANKCASEIf no fuel pump or oil cooler was installed removethe mount pad covers and gaskets. Unscrew andremove the oil gallery front plug from eachcasting. Do not remove dowel pins from the caserear flanges. Remove mount bushings.

11-21. CRANKCASE COVERIf the engine is a -12, -14, -16 or 0-200 modelloosen and remove the three elastic stop nuts orslotted nuts which attach the tachometer drivehousing, and pull the housing straight to the rearand free of the shaft. If the cover is for a -8 modelunscrew and remove the tachometer drive housingand oil seal assembly. Discard gaskets. Removelockwire from the oil pump cover attaching parts,the attaching parts and the oil pump cover at thefront of the crankcase cover. Lift out the oil pumpimpellers.

11-22. CYLINDERSWith the following procedure a suitable lever typevalve spring compressor must be used to bear onthe rocker shaft as a fulcrum. If a press typefixture is used the process will be slightlydifferent.

a. Slide out the rocker shaft, and remove the tworocker arms. Mark the arms for position orstore them in a marked container.

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b. If pushrods were not previously removed, takethem from their housings, and store them inmarked containers to identify their cylindernumbers and positions and their crankcaseends.

c. Replace the rocker shaft, and set the cylinderon a suitable fixture which will hold down thebase flange, with the cylinder upright, andwhich will prevent the valves droppinginward.

d. With the lever compressor, depress eithervalve spring retainer enough to free the splitstem lock, and lift out the two locks with longnose pliers, being careful to avoid binding inthe stem groove and nicking the valve stem.(See Figure 19.)

e. Release the spring seat, and lift off the valvesprings, spring seat and inner retainer.

f. Repeat steps d and e to remove the parts fromthe other valve.

g. Lift the cylinder by the two valve stems;remove it from the fixture, and lay it on itsside on a bench.

h. Grasp one valve head at a time, and withdrawthe valve through its guide. Valves need not bemarked for position, since they will be refaced.Remove the cylinder base packing ring fromthe barrel skirt.

11-23. HYDRAULIC VALVE LIFTERSA Rack should be constructed to hold thedisassembled lifter parts, i.e., lifter bodies,hydraulic units and sockets so that their originalassembly relation will be obvious. The groups ofrack holes or compartments should be labeled"No. 1 IN.", "No.1 EX.", etc. The parts named willalready be separated and should be in the properrack holes at this stage. The only disassemblyremaining is that of removing the plungers fromhydraulic units. This operation should beperformed only at the time of cleaning ofindividual parts and testing of same. The plungersshould be replaced in cylinders immediately aftercleaning. Ordinarily, the plunger may be removedfrom the cylinder by turning to wind up the springand pulling it out. If the plunger appears to be

stuck, refer to paragraph 10-43 for removalprocedure. (Also see Figure 20.) If thesemeasures are not effective discard the unit.

Figure 19. Compressing Valve Spring to RemoveLocks

Figure 20. Removing Plunger From HydraulicUnit With Taped Pliers

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SECTION XIICLEANING PARTS

12-1. MATERIALS AND PROCESSES

12-2.Equipment, materials and processes in general usein aircraft engine overhaul shops are satisfactory forcleaning engine parts.

12-3.Aluminum alloy parts can be degreased by sprayingwith any fortified mineral spirit solvent or by brushapplication of the same liquid. Fortified mineralspirits are more effective when the parts areimmersed in them and allowed to remain for a shorttime to permit solvent action to loosen cakeddeposits. Carbon deposits and gum (oil varnish)may be removed most easily by immersing theseparts in a hot bath of an inhibited, mild alkalinecleaning compound. Immersion time should be onlyas long as necessary to remove the deposits. Carbonsolvent should be employed only when carbondeposits are too hard and thick for removal by othersolvents. Give special attention to cleaning studs,tapped holes and drilled holes. Caution must beexercised in cleaning of all aluminum alloy engineparts. Do not use any strong alkaline solutions toclean aluminum alloy castings or wroughtaluminum alloy parts, because strong solutions willattack and destruct a bare machined surface.Immediately after removing soaking parts from acaustic or inhibited, mild alkaline bath, remove alltraces of the alkali by spraying the parts with a jetof wet steam or by brushing vigorously with amineral spirit solvent. Cleaned parts may be driedby use of a jet of dry compressed air to remove allsolvent liquids.

CAUTION

All alkaline residues must be removedfrom crevices, recesses and holes, as wellas from other surfaces, to prevent theformation of a foaming emulsion in theengine lubricating oil after reassembly.

12-4.No polishing compound or abrasive paste or powdershould be needed or employed for cleaning engineparts. Scraping, abrasion with wire brushes, sandpaper or abrasive cloth and buffing wheels aredangerous methods to use on soft metals such asaluminum. Scratches resulting from such methodsallow a concentration of stress at the scratch andmay cause fatigue failure.

12-5.

Various blasting techniques can be employed toremove hard carbon deposits if suitable equipmentis available. The most suitable types of grit for dryblasting are plastic pellets and processed naturalmaterials, such as wheat grains and crushed fruitpits or shells. Air pressure should be the lowest thatwill produce the desired cleaning action. Smallholes and finished surfaces which do not requirecleaning should be protected from the blast by sealsand covers, particularly if .the grit is sharp. Sand,shot and metal grit are too abrasive and too heavyfor use on soft metals such as aluminum. After anyblasting process, blow off all dust with drycompressed air and make sure that no grit haslodged in crevices, recesses and holes.

12-6. SPECIFIC PARTS

12-7. CYLINDERSPrecautions applicable to both aluminum and steelmust be exercised in cleaning and storing theseassemblies. Remove oil and loose material with amild alkaline cleaner by spraying or brushing. Ifstubborn deposits of carbon remain on cylinderheads, the areas affected may be vapor blasted. Allmachined surfaces must be protected from abrasiveaction during the blasting operation.

12-8. PISTONSDo not use wire brushes or scrapers of any kind.Soft and moderately hard carbon deposits may yieldto solvent action. If deposits remain, blast the headswith soft grit or by the vapor grit method, firsthaving installed tight fitting skirt protectors. Ring

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grooves may be cleaned by pulling through themlengths of binder twine or very narrow strips ofcrocus cloth. Do not use automotive ring groovescrapers, since the corner radii at the bottoms of thegroove must not be altered, nor any metal removedfrom the sides. Discoloration and light scoring neednot be removed from piston skirts. The use ofabrasive cloth on the skirts is not recommended,because the diameters and cam-ground contourmust not be altered. Heavily scored or burnedpistons should be discarded.

12-9. VALVESAfter degreasing valves, inspect them and discardany whose head is warped excessively, or which hasinsufficient stock to permit refacing within specifiedlimits, or whose stem is burned, scored, eroded ornicked. Carbon deposits may be loosened by solventaction or they may be scraped off while the valve isrotated in a polishing head or lathe collet. Applycrocus cloth moistened in mineral spirit, and polishthe stems with dry crocus cloth.

12-10. ROCKER SHAFTSDegrease these parts by brushing on any mineralspirit solvent. Prior to magnetic inspection, polishthe steel bearing surfaces with crocus clothmoistened with kerosene, then with dry crocuscloth.

12-11. PUSHRODS, VALVE ROCKERS ANDOTHER SMALL STEEL PARTSDegrease these parts with mineral spirit solvent,paying special attention to removal of sludge fromall oil passages.

12-12. CAMSHAFT AND CRANKSHAFTAll parts may be degreased by brushing or sprayingwith mineral spirit solvent. Pay particular attentionto threads, oil holes and recesses. Before magneticinspection, the crank pins, main journals, oil sealrace of the crankshaft and all journals, cam lobesand gear mount flange of. the camshaft must besmoothed with crocus cloth, moistened in a mineralspirit. If possible, this should be accomplishedwhile shaft is rotated in a high speed lathe (about100 rpm). All gum (varnish) deposits must beremoved to permit reliable magnetic indications.

12-13. CONNECTING RODSIf a mineral spirit solvent does not clean these partsthoroughly, they may be immersed in a chemicalcarbon solvent. They should be immersed only longenough to loosen and soften the deposits withoutadversely affecting the metal. The parts should bepre-soaked in mineral spirit fortified with organicsolvents to soften the hardest deposits. Afterremoval from the carbon solvent the parts should berinsed or sprayed with mineral spirit. Do not use awire brush or other coarse abrasives. Vapor blastingmay be employed if bushings and bearing slots areprotected from the abrasive. Discoloration need notbe removed from piston pin bushings, and noabrasive cloth or paste should be used. All vaporblast grit or chemical must be removed.

12-14. CRANKCASEThe oil passages should be pressure-flushed withmineral spirit solvent and inspected with the aid of aflashlight. If the castings are immersed in analkaline bath, it is strongly recommended that suchtreatment be followed by spraying with a jet of wetsteam and this followed by flushing of the oilpassages with solvent. After the castings dry,inspect them thoroughly for alkaline residues, andremove any traces of scum.

12-15. GEARSGears without bushings may be freed of harddeposits by immersion in a caustic stripping bath,when cold solvents are not effective. Bushings arediscolored by such treatment, hence bushed gearsshould be cleaned by other methods such asspraying and/or brushing with a mineral spiritsolvent and brushing with a brass wire brush.

12-16. SHEET METAL PARTSClean these parts with a mineral spirit spray or bybrushing with the same liquid, or use a coldemulsion type cleaner and flush with water to rinse.

12-17.Immediately after cleaning bare steel parts spraythem with or dip them in clean engine oil or, forlonger storage, in a corosion-preventive oil mixture.Wrap ball bearings in waxed paper. Wrap or coverother clean parts to protect them from abrasive dustin the air.

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SECTION XIIIINSPECTION

13-1. DEFINITIONS

Terms used in this section to describe variousdefects are defined as:

a. Abrasion: Light scoring or scratching caused bydirect contact and friction between two parts orby cleaning with abrasive materials.

b. Burrs: Sharp, rough, upstanding edges.

c. Corrosion: Rust (oxidation) or deterioration ofmetal, leaving a rough, uneven surface.

d. Deformation: Any departure from originalsurface shape or finish, such as bends, twists,elongation, crushing, flattening, peening,indentation or gouging.

e. Fretting: Rusty appearance (of steel) caused byvibration of or against a mating part.

f. Elongation: Stretching, or increase in length.

g. Galling: Pick-up of soft metal on a hardersurface, due to excessive friction and heat.

h. Pitting (or spalling): Small, deep cavities in asurface.

i. Oxidation: Chemical combination of a metalwith oxygen.

j. Run-out: Eccentricity or wobble (full indicatordeflection).

k. Scoring: Deep scratches caused by friction orabrasive particles.

13-2. INSPECTION TOOLS

13-3. GAUGESMicrometer calipers, both inside and outside types,are the only measuring instruments which can beused to determine wear by measurement of a varietyof sizes with sufficient accuracy for reliablecomparison with specified limits. Since insidemicrometers are rather difficult to use with smallparts, telescoping gauges are often fit to the boresand locked so that they can be measured, as

substitutes, with outside micrometers. Allmicrometer calipers must be handled carefully andkept clean and free from corrosion to maintainaccuracy and free operation. They should bechecked for "zero error" and readjusted whennecessary, due to wear, in order that readings willbe of value. Nearly all micrometer calipers havemeans of taking up wear in the thread to overcomelooseness after long service. Such adjustments mustbe made carefully when necessary. Various types ofdial gauges are sold for measurement of largerbores. These provide a rapid method ofmeasurement when many pieces are handled.Cylinder bore gauges of this type are particularly tobe recommended, since they offer an easy and time-saving means of reaching the remote end of thebarrel. Dial gauges of this type must be set to anaccurate ring to give direct measurements within anarrow range. Other dial indicators of variouspatterns are available for measurement of "run-out",or eccentricity, between normally concentric boresand journals or between journals which arenominally in line. Such gauges may also be used tomeasure other type of "run-out", or wobble,between shafts, or bores, and nominallyperpendicular flanges or to indicate variations inheight, when used with height gauge holders, orfixed supports, and surface plates. Several types ofdial indicators should be available in every shop forinspection work. Fixed, adjustable, gauges, such assnap gauges and plug gauges materially speedinspection, however, they are useful for singledimensions only, so that a large number would berequired to make all necessary measurements in theengine. The expense of making these special toolsusually makes their cost prohibitive, unless a largevolume of work is handled. Thickness gauges arerequired for measurement of backlashes and endclearances. These are available in several ranges ofthickness and blade pattern. Spark plug wire gaugesare necessary for measurement of electrode gaps insome types of spark plugs. These are supplied byspark plug manufacturers and tool dealers.

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13-4. FIXTURESA surface plate is practically a necessity, unlessspecial fixtures are available for checking crankshaftalignment and connecting rod bearing alignment. Witha true surface plate, a set of accurate, matched Veeblocks, a surface gauge (or a fixed holder for a dialindicator) and two accurately ground parallel blocksof the same height, it is possible to measure alignmentof crankshafts, camshafts and connecting rod bearingsand bushings. In order to measure "run-out", orwobble, of gears, they may be assembled to the shaftson which they operate and checked in Vee blocks.This is unnecessary, except when the wear patternindicates an irregularity in running. Piston pins maybe mounted between bench centers of lathe centers orin Vee blocks to measure out-of-roundness andbending.

13-5. INSPECTION METHODS

13-6. VISUAL INSPECTIONA preliminary visual inspection of all parts willindicate whether any are deformed, corroded, scored,galled, pitted or otherwise damaged beyond repair. Amore careful visual inspection should be performed oneach part to determine the need for minor repair, suchas stoning to remove nicks, chasing or stoning ofslightly deformed threads or lapping of partingflanges. Visual inspection to detect cracks is oftendifficult, and a magnifying glass is a very useful toolfor this work, however, if cracks are suspected in anyaluminum casting and if they cannot be verified byvisual inspection, that part of the area should beetched. Visual inspection should also include adetailed observation of all areas, holes, pockets andthreads to ascertain that all foreign material, cleaningcompound and abrasives have been removed.

13-7. ETCHINGBefore etching any area to be inspected for cracks, allenamel, carbon and oil must be removed. The surfaceshould be clean and dry. The following procedure andprecautions apply.

a. Paint the area with a solution made by dissolvingcaustic soda in water (at room temperature) in theproportions of 2 lbs. of caustic soda per gallon ofwater. Expose the aluminum surface to thecleaning action of the solution for no more than 60seconds.

b. Immediately rinse the part in running water; thenneutralize the action with a solution of I part nitric

acid in 4 parts water. Allow the diluted acid to actonly long enough to remove the black deposit leftby the alkali.

c. Rinse the part thoroughly and dry withcompressed air. The etching process will leave thesurface perfectly clean, but the black deposit willremain in cracks and deep scratches. These maybe seen more clearly with a magnifying glass and,thus, distinguished.

13-8. DIMENSIONAL INSPECTIONDiametrical and end clearances, interference (tight)fits, out-of-roundness and "run-out" of all importantpart dimensions are listed in Section XVIII. In mostinstances, each of two mating parts must be measuredand their dimensions compared to determine whetherthe fit is correct. This applies to tight fits, as well as torunning fits. When a tight fit requires that the femalepart be heated before insertion of the male part, bothparts must be measured at the same room temperaturebefore heating 'of the former. Since new bearinginserts will be installed in the crankcase and allconnecting rods, it is unnecessary to measure the newbearing diameter. For this reason and others, certainparts should be inspected for individual dimensionsagainst individual limits or the serviceable limit of fit.Some dimensions for this purpose are listed in SectionXVIII. Other necessary dimensions are:

Feature New Dimensions(Inches)

Intake valve guide bore .....................Exhaust valve guide bore ..................Cylinder barrel bore ..........................C75, C85 Piston (Std.) diameter *At top of skirt .............................. *At bottom of skirt ........................C90, O-200 Piston (Std.) diameter *At top of skirt .............................. *At bottom of skirt (above 4th

groove) ........................................Piston pin bore diameter....................Piston pin diameter............................Rocker Arm bushing bore .................Rocker shaft diameter........................Rocker shaft boss bore ......................*Measured at right angles to pin bore.

0.3432-0.34420.437-0.4384.062-4.064

4.051-4.0534.054-4.055

4.049-4.050

4.052-4.0530.9217-0.92210.9214-0.92160.6097-0.61070.6082-0.60870.6089-0.6099

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NOTE

Reground barrels (.015 inch oversize mustbe within limits No. 44, Section XVIII,and taper may not exceed .002 inch, withlargest diameter, if any, at bottom. Boremust be less than .001 inch out-of-roundand less than .001 inch out-of-square withflange, full indicator reading, in length ofbarrel.

13-9. MAGNAFLUX INSPECTIONParts listed in Table XIX should be inspected ateach overhaul by the Magnaflux process or anequivalent method of crack detection. Table XIXprovides data for proper inspection by theMagnaflux method. When this process is used, thefollowing precautions must be observed to assurereliable results and safe condition of inspected parts.

a. Parts must be free of carbon and oil.

b. Crankshafts and piston pins must be polishedbefore inspection.

c. All parts should be inspected for forging laps,seams and grinding cracks which may haveopened in service.

d. The suspension liquid should be maintained at astrength of 1-1/2 oz. of red Magnaflux pasteNo.9 per gallon of kerosene.

e. The suspension liquid must be vigorously andcontinuously agitated to keep magnetic particlescirculating.

CAUTION

Before magnetization, all small openingsand oil holes leading to obscure cavitiesmust be plugged with either a hard greaseor similar non-abrasive material, which isreadily soluble in lubricating oil, or woodor fibre plugs to prevent accumulation ofmagnetic particles where they cannot beremoved completely by washing and airblasting.

f. All parts must be completely demagnetized afterinspection and between successivemagnetizations. Demagnetization is performedby inserting the part in an alternating currentdemagnetizer, from which it is withdrawnslowly. Irregular shaped parts must not bewithdrawn at a rate of more than 12 feet perminute.

g. The magnetic substance must be removedcompletely from all parts after inspection. Allplugs must be removed.

13-10.Both the wet continuous method and the wetresidual method are used. In the former process, themagnetic solution is poured over the part while it ismounted between poles of the magnetizer, andapplication of the fluid is stopped as themagnetizing current is started. In the wet residualprocess, the part is immersed in the magneticsuspension fluid after it has been magnetized.TABLE XIX shows the method recommended forinspection of each kind of part.

NOTE

If the crankshaft is suspected of any defectnot firmly established by inspection aftercircular magnetization, it should bedemagnetized and magnetizedlongitudinally for further inspection.

13-11.Two methods are used to support parts betweenpoles of the magnetizer for circular magnetization.They are:

a. Pads of copper braid or soft lead plate areinstalled on the pole pieces, and the part isclamped between them to assure good contactand to prevent burning.

b. The parts are strung on a copper rod, which isheld between poles of the magnetizer.

13-12.Following demagnetization the parts must bethoroughly cleaned by spray and air blast. Plugsshould be removed before cleaning to admit fluidand air to all holes and cavities. When dry, the partsshould be flushed in a corrosion-preventive oil.

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TABLE XIX

MAGNETIC PARTICLE INSPECTION

FLOURESCENT METHOD PREFERRED,WET CONTINUOUS PROCEDURE REQUIRED

Part *Method ofMagnetization

AC or DCAmperes

Critical Areas Possible Defects

Crankshaft

Connecting Rod

Camshaft

Piston Pin

Rocker Arms

Gears to 6 InchDiameter

Gears over 6 InchDiameter

Shafts

Thru BoltsRod Bolts

Circular andLongitudinal

Circular andLongitudinal

Circular andLongitudinal

Circular andLongitudinal

On Conductor BarAnd SingleBetween Heads

Circular orOn CenterConductor

Shaft CircularTeeth BetweenHeads Two Times90°

Circular andLongitudinal

Circular andLongitudinal

2000

1500

1500

1000

1000

1000 to1500

1000 to1500

1000 to1500

500

Journals, fillets, oilHoles, thrust flanges,Prop flange

All areas.

Lobes, journalsDrilled hole edges

Shear planes, ends,Center.

Pad, socket under sideSide arms and boss.

Teeth, splines,Keyways.

Teeth, splines

Splines, keways,Change of section.

Threads under head

Fatigue cracks,Heat cracks,Flange cracks,From prop strike

Fatigue cracks.

Heat cracks,Fatigue cracks

Fatigue cracks.

Fatigue cracks

Fatigue cracks

Fatigue cracks

Fatigue cracks,Heat cracks.

Fatigue cracks

13-13. FLUORESCENT PARTICLEINSPECTION

This process, commonly known under the tradename of "Zyglo", is recommended for inspectingaluminum alloy and magnesium alloy parts forinvisible cracks. The standard operating techniquefor the process is applicable.

13-14. INSPECTION OF CRITICAL PARTS

13-15. CRANKCASE

Inspect the following features by applicablemethods.

a. Examine carefully for fatigue cracks, especiallyaround cylinder pads.

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c. Examine bearing seats for cracks, scratches andnicks.

d. Inspect parting flange surfaces for nicks andwarp.

e. Examine camshaft bearings for scores, cracksand excessive wear.

f. Inspect valve lifter guides for wear and scoring.

g. Examine oil galleries and feed holes forcleanliness.

h. Check all studs for damaged threads, tight fit,height and bends.

i. Inspect all surfaces for removal of cleaningcompounds.

13-16. CRANKSHAFTInspect for the following kinds of damage and wear.

a. Cracks (use Magnaflux equipment or theequivalent.

b. Galling, scoring, burning and wear on mainjournals and crank pins and their fillets.

NOTE

Crankshafts which have been reground to.010 inch undersize should be inspectedfor fillet radii. Radii of main journal filletsmust be 5/32-11/64 inch, and radii ofcrank pin fillets must be 11/64-3/16 inch.Crankshafts which were originally nitridedmust be re-nitrided after grinding. (Referto paragraph 3-8.)

c. Make sure that oil tubes are tight and free ofobstructions.

d. The Hubbard plug at the front end of flangetype shafts must be removed before Magnafluxinspection.

e. The screw plug in the front end of a taperedcrankshaft must be removed before Magnafluxinspection. Observe thread condition of plugand tapped hole.

f. Nicked, pulled, peened or stripped threads inrear flange tapped holes or at front end(exterior) of a tapered shaft.

g. Fretting of the puller hub taper.

h. Run-out at center journals and front end (andpropeller flange).

13-17. CONNECTING RODSInspect alignment in plane (convergence) and twistof the crank pin bearing seat (without inserts) andthe piston pin bushing. If the bushing was replacedits bore should be compared with limits in TheTable of Limits, Section XVIII; if not, the boreshould be compared with the piston pin diameter.Look for peening on all surfaces and bends in thebeam. Check cap bolts for elongation. (Noteposition of cotter pin hole in nuts slots.) Observecondition of threads.

13-18. PISTON PINSThe pins should be inspected visually beforepolishing and dimensionally before and afterpolishing. Pressed in end plugs should be inspectedvisually for damage after Magnaflux inspection.Loose fitting end plugs should be checked for snugfit in pins and wear on ends. Measure pin diameter,out-of-round, bending.

13-19. PISTONSInspect for removal of carbon and oil varnish. Seethat fillets of roots of ring grooves were notdeformed or reduced. Look for scores extending thelength of the skirt, burning, and cracks. Discard anypiston which is cracked, heavily scored, deformed,burned, corroded by salt water or worn beyonddimensional limits (Refer to paragraph 13-8.)

13-20. PUSHRODSRoll all rods on a surface plate, and check forbending. Very slight bending may be corrected bytapping with a non-marring hammer or lead mallet.Inspect ball ends for excessive wear. See that the oilpassages are clear.

13-21. ROCKER ARMSExcessively worn bushings should be / removedbefore Magnaflux inspection and replacedafterward. Inspect used and replaced bushing bores.See that oil holes are clear. Look for worn sockets

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and badly worn, rough or chipped stem rockers. Seethat oil hole plugs are tightly installed.

13-22. VALVESInspect for cleanliness, warp of heads, limit of faceregrind, limit of stem tip regrind, scored stems, stemdiameter and burning. Discard all excessivelyground, worn, scored or warped valves. Afterregrinding, lapping and installation all valvesshould be checked for full seating.

13-23. VALVE SPRINGSLook for cracked or broken ends, corrosion andcorrect color coding. Use a spring test machine todetermine whether any valve spring is weak.

13-24. CAMSHAFTSInspect journals for scoring, deformation andexcessive wear. Inspect cam lobes for profile wear,scoring, and pitting, particularly along the toe line.If any valve lifter body in the group did not turnduring the previous operating period, its cam lobeshould be measured for a taper on the toe. A slighttaper is ground on the toe line of all lobes to turn thelifters. Its value is expressed as an angle and itslinear dimension amounts to a very few thousandthsof an inch, but it is important that some taper bepresent. Inspect fuel pump eccentrics for wear andscoring. Check thread condition of tapped holes atthe rear flange of all camshafts and at the front endof -16 and O-200 camshafts. Inspect shims of bevelgears for the latter type to make sure that they areperfectly flat.

13-25. CYLINDERSExamine steel barrel fins for bending and aluminumhead fins for cracks. All steel fins should be straightand even to permit air flow. Not over 10% of headfin area may be removed by cracking or by cuttingout to stop cracks, without reducing coolingefficiency dangerously. Small cracks starting at theedges of head fins should be marked for repair bydrilling reliefs. If cracks extend to the fin roots thehead wall is probably cracked and should bediscarded. Inspect all finished surfaces for nicks,peening, cracks, residual gasket material and deepscratches. These defects may permit oil leakage.Inspect valve port studs for burrs, stripping,bending, elongation and backing out. Examinespark plug inserts for thread condition and tight

installation. Inspect cylinder base flanges for cracks,bending, nicks, corrosion and smoothness of nutseats. Inspect rocker shaft support bosses for cracks,worn bores and side wear. If bores are wornexcessively the bosses may be repaired byinstallation of repair bushings, and they should bemarked for such attention. See paragraph 14-8g.Inspect valve guides for proper clearance with valvestems, and measure replaced guides for diameterand for concentricity within .002 inch with valveseat insert throats. Make sure that pushrod housingsare tightly installed in the rocker box holes. Markcylinders which will require replacement of valveseat inserts which have been ground to a diameterequal to the O.D. of the valve head. Measure thecylinder bore, and classify the cylinder, accordingto the reconditioning required, as:

a. Grind to remove ring step and hone bore.

b. Grind to .015 inch oversize and hone.

c. Rebarrel.

After regrinding and honing, the bore should berechecked for diameter, taper, squareness withflange, roundness at all sections and surfaceroughness, (Refer to limits, No. 43-44, SectionXVIII.)

13-26. HYDRAULIC VALVE LIFTERSInspection of lifter parts should be conducted at thetime of cleaning. A rough test of hydraulic unitoperation is described in paragraph 10-43. Accuratedetermination of leakdown rate is also discussed inthe same paragraph, and such methods arerecommended, however, they require specialinspection fixtures. Visual inspection should includeexamination of follower faces for scoring, grooving,spalling and corrosion. The shank of each lifterbody should be measured to determine clearance inits crankcase guide. The bearing surface should alsobe examined for scoring, galling, cracks and clearoil holes. Inspect each socket for clear oil passagesand for excessive wear in the cup. All parts must bethoroughly clean. Following inspection they shouldbe coated with a corrosion-preventive oil.

13-27. GEARSThe crankshaft and camshaft gears should beinspected by Magnaflux methods for cracks. Inaddition, all gears should be inspected visually for

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deformation and burring of the teeth, excessivetooth profile wear or scoring. The starter drivengear wheel of the crankshaft gear in -12, -14, -16

and O-200 models must be discarded if any chippingor serious gouging of the entering edges is found.

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SECTION XIVREPAIR AND REPLACEMENT

14-1. GENERAL REPAIR

14-2. CASTINGSRemove the raised edges of nicks and burrs onmachined surfaces with a hard Arkansas stone.Unobstructed flat surfaces, such as cover plates etc.may be returned to true flatness if a lapping plate isavailable. Use a fine grade lapping compound andmove the part in a figure 8 motion evenly.

14-3. STUD REPLACEMENTRemove damaged whole studs with a standard studremover or a small pipe wrench. Turn slowly toavoid overheating. Remove broken studs whichcannot be gripped by drilling on center to thecorrect diameter for and unscrewing them with asplined stud extractor. (Splined extractors and drillsare usually sold in sets.) Examine the coarse threadend of the damaged stud to determine its size.Standard studs have no marking. For oversize studidentification refer to Table XX. Clean the tapped

hole with solvent and blow dry with compressed air;then examine the thread. If it is not damaged installthe next larger oversize stud. If the old stud wasmaximum oversize, or if the thread is damaged, thehole may be tapped and a helical coil insert installedfor a standard size stud. Coat the new studs coarsethread with Alcoa Thread Lube if the hole is blindor with National oil Seal Compound if it is athrough hole that is subject to oil spray. It isadvisable to drive the new stud with a tee handlestud driver. Turn it slowly, and compare theestimated torque with values listed in SectionXVIII. Drive the stud in until it projects a distanceequal to others in the same group.

14-4. HELICAL COIL INSERT INSTALLATIONHelical coil thread inserts are factory installed atvarious locations. These inserts may be replaced, ifdamaged, with the aid of a helical coil remover andreplacer. (See Figure 21.)

TABLE XX STUD IDENTIFICATION CHART

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14-5.Helical coil inserts are manufactured from wire witha "diamond" shaped cross section forming both amale and female thread. Drilling and tapping depthsfor inserts, being installed in blind holes, should beequal to twice the nominal diameter of the insert.The helical coil drills and taps must be absolutelyperpendicular to the machined surface of thecasting. Drilling should be accomplished in a drillpress after the casting is firmly supported, clampedand alignment checked. For drilling and tappingaluminum alloy castings, use a lubricant made ofone part lard oil and two parts kerosene thoroughlymixed to prevent overheating the metal and damageto the threads.

14-6.To remove a damaged helical coil use the propersize extracting tool specified for the nominal threadsize. Tap the tool into the insert so the sharp edgesget a good "bite". Turn the tool to the left and backthe insert out. To install a new insert, blowout allchips and liquid, slide the insert over the slotted endof the mandrel, and engage the driving tang in themandrel slot. Wind the insert into the tapped holeslowly (See Figure 21). The outer end of the insertshould lie within the first full thread of the hole.Break off the driving tang with long nose pliers.

14-7. REPAIR AND REPLACEMENT OFSPECIFIC PARTS

Figure 21. Installing Helical Coil Inserts

14-8. CYLINDER AND HEAD ASSEMBLYBefore application of enamel, any of the followingrepairs found necessary by inspection should becompleted and reinspected.

a. If the cylinder bore is not more than .005 inchoversize the ring step at the head end of thebarrel may be removed by grinding and the boreglaze may be roughened by honing to restore theoriginal finish. The proper surface roughness ofrefinished cylinder walls is specified in limitNo. 44, Section XVIII. A close approximationof the correct bore surface may be maintainedby visual inspection of refinished cylinder wallswith a magnifying glass and by comparison withthe appearance of new cylinder bores. The honemarks in factory finished cylinders have adefinite cross pattern, with an appreciable flatbetween grooves. This finish allows enoughdepression to hold oil during the break-in periodwithout sacrificing flat bearing area for the ringfaces. The crossed pattern of the grooves allowseach ring to slide over them with no tendency todig in. Honing scratches which have a circularpattern invite the sharp lower edge of eachtapered ring face to attempt to follow theircontour, causing rapid removal of metal fromthe high points and ridges of both cylinder walland ring face. The crossed pattern is achievedby honing in a figure 8 motion with rapidreciprocation of the honing head in proportionto its rotation speed. If a spring-loaded hone isemployed it will not be possible to reduce theout-of-roundness of the bore appreciably norwill the taper be reduced by the amount ofhoning required to roughen the surface. If thevalues of these irregularities exceed thosespecified in limit No. 43, Section XVIII, thecylinder should be reground to oversize orrebarreled, if already oversize.

b. If cylinder bores are tapered or out-of-roundbeyond limits they may be reground and honedto .015 inch oversize and installed with .015inch oversize pistons and rings. The refinishedbores must be:

1. Not over .001 inch eccentric to ground skirtpilot.

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2. Not over .001 inch out-of-round at anypoint.

3. Not over .001 inch out-of-square withground surface of flange, as measured at topof bore.

4. Not over .001 inch tapered in full length ofbore, with large diameter, if any, at bottom.

5. Within limits of diameter (Refer to limit No.43, Section XVIII.)

c. If valve guides are loose, worn beyond limits orscored they must be replaced with the nextoversize. The cylinder should be supported inthe inverted position and the old guides pressedout with an arbor press and a driver piloted inthe guide bore. Bore or broach the cylinder headbore for the specified tight fit with thereplacement guide. (Refer to the Parts Catalogfor available oversizes.) The cylinder head boremust be square with the cylinder axis andconcentric with the valve seat throat.Concentricity must be maintained within .002inch, so that the same limit can be held in thereplacement guide. With the cylinder supportedupright on a suitable fixture and seated on itsmount flange, dip the insert end of the oversizeguide in engine oil, and insert the other end in aclose fitting socket driver which will bear on theguide flange. Start the guide into the head boresquare, and press it to fully seated position inthe cylinder head with the driver and an arborpress. Driving with a heavy mallet may be usedas a substitute when an arbor press is notavailable, however, it entails some risk ofpeeling metal from the cylinder head, with aresulting loose fit and an out-of-square hole. Itis not necessary to heat the cylinder for thisreplacement. Ream or broach the new guide tosize.

d. If the flanged and pinned type spark plug insertsare loose, stripped or rough on the gasketsurface they should be removed, after drillingout the locking pin, with a tool which will diginto the 18mm thread in somewhat the samemanner as a screw type stud extractor. Whendrilling out the locking pin, exercise care toavoid drilling into the combustion chamber. Usea No. 31 drill. Center punch the pin to locate the

drill point. Make sure that the lips of the drillare of equal length and angle to avoid enlargingthe hole. Drill to a depth of only 7/16 inch fromthe bushing surface. Mark the cylinder head tolocate the old pin hole. Inspect the cylinder headhole for thread condition, and clean it withsolvent. Obtain the next oversize insert, andclean it thoroughly. The cylinder assembly mustbe heated to not more than 575° F. beforeinstallation of the new insert. If valve seats areto be replaced they should be removed and thecylinder head prepared for replacements so thatone heat will serve both purposes. Drive thenew spark plug insert into the heated head witha tool which will fit the spark plug hole threadand shoulder on the insert face. Be careful tostart the insert thread square and to seat itfirmly. Remove the driver after the head hasshrunk enough to hold the insert tight. When thecylinder has cooled, drill a new pin hole with itscenter 3/16 inch from the center of the old holeand at a radius of 1/2 inch from the bushingcenter. Drill to a depth of 7/16 inch with a No.31 drill. Drive in a new locking pin. Face thenew insert square with the 18mm thread. Retapthe 18mm hole to eliminate any out-of-roundness. Use a standard 18mm tap with15mm pitch. If the cylinder incorporates ahelical coil spark plug insert refer to paragraph14-5 and 14-6 for removal and installinginstructions.

e. If either or both valve seats have been regrounduntil the slight overhang of the valve head hasbeen eliminated and can no longer be restoredby cutting back with a 25° stone, or if theexhaust valve seat is burned or pitted, or ifeither insert is loose, the defective inserts mustbe replaced. In practically all instances it will benecessary to heat the cylinder and headassembly in an oven to 575° F. or to heat thecylinder head to that temperature by othermeans in order to remove the inserts. A tap orsuitable alternate type of insert extractor mustbe used. Two extractors will be required, sincethe diameters of intake and exhaust valve seatsdiffer. This operation always involves somechance of failure, especially in removing thesteel exhaust valve seat, which is difficult togrip. Better results can be obtained if the tools

84

have a provision for feeding cold water to theinsert throat surfaces. A squirt of cold water willshrink the insert and make its removal mucheasier. provided that the water does not come incontact with the aluminum head and shrink ittoo. For this reason, the cylinder can best behandled in an upright holder with the open enddownward. If the tool has a pilot to enter thevalve guide, the water passage can be drilledthrough the pilot stem and side holes drilledfrom the central inlet to the tap surface, so as todeliver the water squirt close to the insert.Unless the water can drain downward withouttouching the cylinder head, very little should beused. The hand which holds the extractor in anupright cylinder should be protected by anasbestos glove. After removal of seat inserts,examine the cylinder head counterbores andclean them with a cloth saturated in solvent.Dimensional inspection of counterbores whichare not roughened will determine whether astandard or oversize insert must be installed. Ifthe counterbore has any roughness or scoringwhatever it should be bored to the correct tightfit with the smallest oversize insert for which itcan be cleaned up. The oversize recess must beconcentric with the valve guide within .002inch. Heat the cylinder to 575° F. throughout,and install the new insert with a tool which willgrip it lightly and will be piloted in the valveguide. A ball or lever detent on the insertholding shoulder is sufficient. When the tool ispiloted in the valve guide, a quick thrust must be

used to seat the insert before it has time to heat.It is best to have the cylinder inverted duringthis operation. After a few seconds a firm blowwith the installing tool will seat the insert.

f. Worn valve seats must be reground at eachoverhaul to make a true seating ring for thereground valves. Current production engineshave a 30° intake valve and seat. All cylindersbeing repaired should be converted to the newconfiguration. Replacement seat inserts must beground to correct size. Necessary dimensionsfor valve face and seat grinding are:

Valve seat angle (to guide axis)exhaust: 45°Valve seat angle (to guide axis)intake: 59° 30' - 60° 00'Valve face angle (to valve axis)exhaust: 45° 45'-46° 15'Valve face angle (to valve axis)intake: 60° 45'-61° 15'Intake valve seat outsidediameter: (inches) 1.662-1.682Exhaust valve seat outsidediameter: (inches) 1.537-1.557Valve seat inserts to (machined)mount flange surface(distance in inches): 6.060-6.064Intake valve minimum overalllength: (inches) 4.041Exhaust valve minimum overalllength: (inches) 4.056

Figure 22. Dimensions of Rocker Shaft Boss Bushings

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The difference in angle between valve and facepermits lapping the valves to a single ringcontact. The ring must be very narrow, butcomplete. Use fine grade lapping compound,and remove all traces of the abrasive beforetesting.

g. If the rocker shaft is excessively loose in thecylinder head support bosses they may bebrought back to standard size by boring orreaming in line and installing repair bushings.The center line of the enlarged boss bores mustbe 9.901-9.911 inches above the cylinder baseflange mounting surface, in order that thereamed bushing bores will maintain the samedistance. This dimension is important, becausevariations in spacing of the rocker axis from thecamshaft will change the mechanical clearancein deflated valve lifter units and may make theminoperative. The minimum boss wall thicknessmeasured at the edge of the center boss prior toany reaming and bushing must be 0.240 inch.The bore surface must be 60 RMS afterreaming. (See Figure 22.)

14-9. CRANKSHAFTIn addition to the normal stoning and polishingoperations, the following operations may beperformed if appropriate equipment is available.

a. Replace damaged propeller bolt bushings offlanged crankshafts by driving out the oldbushing with a drift piloted in the bushing holeand pressing in a replacement bushing with ascrew type puller. When driving a bushing out,support the propeller flange near the bushinglocation. An arbor press may be used toadvantage in this operation. The puller screwshould fit the bushing thread (3/8-24). Asatisfactory puller may be made with a hardenedscrew, squared at the front end for a wrench, apuller nut, a thrust bearing and a sleeve to bearon the crankshaft propeller flange. The screw isinserted, from the front, through the bushinghole. Dip the bushing in engine oil and screw iton the puller screw behind the flange. Pull thebushing into the hole with its rounded flangecorner toward the crankshaft.

b. If main journals and crankpins are worn beyondlimits of serviceability for standard sizecrankshafts they may be reground to .010 inchundersize and the crankcase and connecting rodsequipped with undersize bearing inserts.Reground crankshafts must meet the followingspecifications:

1. Main journals and crankpins must not tapermore than .001 inch, and any taper must beuniform from end to end.

2. No main journal or crankpin may be out-of-round more than .0005 inch or have flatspots or tool marks.

3. Radii of main journal fillets must be 5/32-11/64 inch.

4. Radii of crankpin fillets must be 11/64-3/16inch.

5. All crankpin and main journal fillets must betangent to the journals and each must be ofuniform curvature, without tool marks or flatspots, all around. The shoulder betweenfillets and crankcheeks must not beremoved.

6. All journals and crank pins must "clean up"within the undersize limits specified inSection XVIII.

7. All crankshafts which were originallynitrided must be renitrided after grinding.After nitriding, the run-out limits of newcrankshafts must be maintained.

8. Surface finish on reground cranks shall be 6RMS on all bearing journals and crankpins.Exercise care in polishing to maintainconcentricity.

14-10. CONNECTING RODSPiston pin bushings which are worn to give aclearance with the mating pins in excess of theserviceable limit specified in Section XVIII, orwhich are scored or burned, must be replaced withnew, standard bushings. The original types ofbushing used in C75, C85 and C90 connecting rodswere solid rings. The bushings used in current

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production are single piece, split rings. Either typeof bushing may be used for replacement. Bushingsfor C90 and O-200 models are of different lengthfrom those supplied for C75, C85 connecting rods.Press out the unserviceable bushing with ashouldered driver whose pilot will fit closely, butnot tightly, in the unfinished bore of a new bushing.The same tool will serve to press in thereplacement. The pilot and shoulder of the drivermust be machined square with each other, and theO.D. must clear the rod end bore. The rod end mustbe supported on a ring whose bore will clear the oldbushing. For pressing in the new bushing the rodmay be supported on the same ring or on a flatplate. Dip the new bushing in engine oil beforeinstalling. If the bushing is split, the split line mustbe located at an angle of 45° from the rod axistoward the big end and on the side opposite thenumbered bolt bosses. Press the new bushing insquarely to avoid peeling off its surface. The newbushing must be reamed or bored to a finisheddiameter within the limits stated in Section XVIII,No. 21. The finished bore must not be more than.0005 inch out-of-round or tapered more than .0005inch in its length. The centerline of the finishedbushing must be 6.373-6.377 inches from thecenterline of the crankpin bearing seat bore. Inorder to maintain this degree of accuracy, it isnecessary that reaming be performed in a suitablefixture which will pilot both the big end bore andthe reamer. When the volume of work permits, andwhen equipment is available, a more satisfactorybushing finish can be obtained by diamond pointboring. The big end should be clamped on an arborin the boring machine and the arbor indicatedparallel in all planes with the boring bar. The centerto center distance of bearings, mentioned above,must be established at the same time. Both ends ofthe bushing must be finished square and flush withthe connecting rod boss. After reaming or boring,the rebushed rod must be inspected for bushingdiameter, taper, out-of-round, bearing centerdistance, twist and convergence. Twist (out-of-plane) and convergence of bearing seat and bushingbore must not exceed .001 inch per inch of length.

NOTE

Connecting rod assemblies are balanced insets with a maximum difference in weightin any engine of 1/2 oz. per pair in

opposite bays. If new or reconditionedrods are purchased the weight limit mustbe maintained. In ordering singlereplacement connecting rods, specifymaximum and minimum permissibleweights.

14-11. PISTONS, RINGS AND PINSRepair small nicks in piston heads by dressing witha hard Arkansas stone. Dress light scores in skirts inthe same manner and polish lightly with dry crocuscloth.

CAUTION

Stone and polish piston surfaces onlyenough to remove upstanding metal.Scratches cannot be removed withoutreducing excessively the dimensions. Iflarge nicks or scores are found replace thepiston. Do not use wire brushes or buffingwheels.

Replace removable piston pin end plugs with newparts if they are excessively worn on the heads orloose in the pins. If the heads of pressed in plugs areexcessively worn or scored the pin and plugassembly must be replaced with a new part. Pistonpins must be polished with crocus cloth dampenedin kerosene while revolving at high speed. Finishwith dry crocus cloth. Pins equipped withremovable end plugs may swell slightly in service.Polish these to obtain the correct fit in piston bores.After Magnaflux inspection, the polished pins mustbe re-inspected for cleanliness, diameter and nicks.

14-12.Replace all piston rings with new parts at eachoverhaul. Piston rings are sold only in completesets, each set containing the correct number andtypes of ring for one engine. Ring sets are availablein standard size, .005 inch-oversize and .015 inchoversize. If cylinder bores are less than .005 inchoversize use standard size pistons and rings. If thebores are .005 inch oversize, or very slightly more,use standard pistons and .005 inch oversize rings. Ifcylinders are ground to .015 inch oversize, use thesame oversize of pistons and rings.

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NOTE

The set of pistons for each new engine isselected so that the maximum difference inweight does not exceed 1/2 oz. per pair inopposite bays. This limit must not beexceeded when replacements are made.When ordering single pistons, specifymaximum and minimum permissibleweights.

14-13. CRANKCASE AND COVER ASSEMBLYDress any nicks in machined surfaces by stoning.Replace any loose, bent, stripped, nicked or brokenstuds. Carefully chase any damaged threads in holesfor oil screen, oil pressure relief valve cap, oil plugsor tachometer drive housing (-8 models). Removeby stoning any burrs on threads of oil pressure reliefvalve cap, oil screen cap, oil pump suction tube ortachometer drive housing. Examine oil pumpimpellers, cover and chambers in the casting. If thechambers or cover are badly scored or if wear hasincreased impeller clearances beyond serviceablelimits the damaged part must be replaced. Ifimpeller tooth profiles are badly worn, scored,nicked or burned, or if the impeller driving square isnoticeably worn, both impellers must be replaced.Replace the tachometer drive housing oil seal ateach overhaul. Check seating of the oil pressurerelief valve. If it does not seat perfectly the covercasting seat must be lapped with the plunger, thelatter being guided in an old valve cap which hasbeen bored through for the purpose. Remove alllapping compound. If a -12, -14, -16 or O-200model oil screen housing flange is warped, lap itflat. Also lap the oil pump cover to a flat rearsurface. If camshaft bearings are worn beyondserviceable limits they may be line bored or reamedto .020 inch oversize and an oversize camshaftinstalled. It is most important that reboring ofcamshaft bearings be done without shifting thecamshaft centerline in any direction. The crankcasemust be firmly clamped together during thisoperation, and the finished bores must be 1.3945-1.3955 inches in diameter. Lap the parting flangesof pushrod housing adapters, fuel pump pad coverand oil cooler pad covers (if used) to flat surfaces.

14-13A. STARTER CLUTCH AND CRANK-SHAFT MODIFICATION

A change has been incorporated in the O-200crankcase and starter jack to extend service life byproviding positive lubrication to the starter clutch.

New parts are available through normal channels toaccomplish the revisions. Parts affected are thecrankcase, starter jack shaft and bearing. See partscatalog X30011A for appropriate part numbers.

Special tooling has been designed so thismodification can be accomplished in the field. Thistooling is available from the Burroughs Tool andEquipment Corporation, 2429 North Burdick Street,Kalamazoo, Michigan 49007. Instructions for theuse of this tooling are as follows:

Bearing-Bushing Drill Fixture, Burroughs P/N8094B. (See Figure 23)

Figure 23. Drill Fixture

a. Drilling rear main bearing.

1. Back off allen set screw and remove flatretaining bar from center of tool.

2. Insert bearing shell with index tab towardinside of tool and set shell into fixture soside of bearing is bottomed out in fixturebore.

3. Insert retaining bar between bearing shelland Allen set screw. Turn in Allen set screwso bearing shell is held firm.

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4. Put fixture in vise to hold securely. Drillhole in bearing with 1/4 inch drill thebushing in fixture. (See Figure 24.)

Figure 24. Drilling Hole in Bearing

5. Remove retaining bar and punch outbearing with a drift thru the hole in the45 degree bevel.

b. Drilling adapter assembly starter jack shaft PIN634461 (See Figure 25

Figure 25. Drilling Adapter Assembly

1. Insert adapter into fixture with flat end firstand index hole lined up with lock pin hole.

2. Lock adapter in place with lock pin.

3. Drill 1/8 inch hole until stop on drill bottomson drill bushing. Drill speed to be 2500 -4500 RPM. Drill length from tip to stop tobe 0.625 inch.

4. Use drill press for following operation. Drillremaining distance with a No. 60 drill(0.040 dia.). This operation forms the orificeto restrict oil flow. Minimum length of0.040 inch diameter hole is 0.125 inch. Drillspeed to be 6000 to 10,000 RPM. Back offdrill often to clear flutes.

CAUTION: Wear eye protection during alloperations. Use cutting oil to prolong drill andfixture life.

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5. Plug 0.500 inch dia. hole in back of adapterwith 0.500 dia. x 0.375 inch long aluminumbar stock. Stake securely in place. (SeeFigure 26)

WARNING: Use care in staking plug inadapter hole to preclude plug being forcedout into the engine, since oil to the adapterwill now be under pressure.

Figure 26. Plug Detail

c. Drill fixture, Borroughs P/N 8094A. (See Figure27)

Figure 27. Drill Fixture.

1. Remove two thru studs on either side of therear camshaft boss.

2. Install drill fixture over remaining stud atrear crankshaft boss. Align guide points offixture so they straddle the index pin. (SeeFigure 28)

Figure 28. Drill Fixture Installed

3. Place spacer tube on stud and lock downwith cylinder base nut.

4. Check drill to sleeve stop distance. Ex-posed drill should measure 2.625 inches totip.

5. Drill hole into crankcase web until drill stopbottoms on fixture bushing. Pull drill backfrequently to clear flutes. Use 2500 -4000RPM drill speed. Repeat drill process inother bushing, Use cutting oil to prolongdrill and fixture life.

6. Remove drill fixture and check with com-pressed air not to exceed 30 psi to make surethe holes meet inside the crankcase.

7. Reinstall studs removed in step 1.

When modification has been performed oncrankcase, the letters "SO" must be stamped afterthe serial number (See Figure 29) Recordmodification in Engine Log Book.

Figure 29. Name Plate Change.

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14-14. CAMSHAFTLight scoring on journals may be polished with ahard Arkansas stone and finished with dry crocuscloth. If cam lobes are pitted or worn or if eitherlobes or journals are severely scored the shaft mustbe replaced. Replace any camshaft which has notaper on the toe line of any cam lobe. This taper isnecessary to rotate the valve lifters. Make sure thatreplacement is made with a shaft of standard size oroversize, as required to fit the crankcase bearings.

14-15. HYDRAULIC VALVE LIFTERSLifter parts are not repairable, and any part which isdamaged or unserviceable, due to wear, must bereplaced. New lifter bodies may be installed withused hydraulic units if nicked, pitted, scored,grooved or broken bodies must be replaced.Hydraulic units must be replaced if either thecylinder or plunger of the old unit is damaged orworn. These parts are not interchangeable. Pushrodsockets may be replaced independently of otherlifter parts if the cups of old parts are excessivelyworn.

14-16. OIL SUMPSmall leaks in oil sump seams may be repaired bybrazing, after thoroughly cleaning and drying thesump. Lap the mounting flange to a flat surface, andremove all lapping compound. If necessary, retapthe 5/8-18 drain plug holes, and replace the plug ifits hex or thread is damaged. If the plug lockwireclip is broken off a new clip should be brazed to thesump.

14-17. INTAKE TUBESStraighten small dents in tubes by tapping with anon-marring hammer, while the tube is supportedon a mandrel. Make sure that tube ends are perfectlyround.

14-18. GEARSDress any small nicks with a hard Arkansas stone orwith a fine India stone. Do not attempt to correctscoring or roughness on gear tooth faces. If toothprofiles are noticeably worn or if the teeth arechipped, burned, scored, burred or deformed in anyway the gear must be replaced. Gear retainingscrews must be replaced if they are stretched orotherwise deformed.

14-19. AIR SCOOPS AND INTAKE HOUSINGSThese sheet metal parts may be repaired in minorways by brazing and straightening, however anyserious damage makes replacement with a new partnecessary. Lap mounting flanges flat, if necessary,and adjust plate valves to assure free operation andfull closing.

14-20. VACUUM PUMP ADAPTERReplace any loose, bent, stripped or broken stud.Clamp the adapter (pump mounting pad up)between soft shielded vise jaws. Engage jaws of anoil seal puller behind oil seal case and pull the seal.Smooth the adapter counterbore with crocus cloth,if necessary. Examine adapter bushingdimensionally. If worn beyond the serviceable limitspecified in Section XVIII, and an accurate arborpress and boring machine are available, bore out thebushing to a thin shell and collapse it for saferemoval. Support the adapter, pump mountingflange down, on a smooth parallel faced metalblock. Lay combination of plate and adapter on anarbor press. Dip new bushing in engine lubricatingoil and place it on a pilot arbor. Center bushing onadapter bore and press in carefully until fullyseated. Remove adapter and plate from arbor pressand fasten the combination of adapter and plate in adrill press. Ream bushing to a diameter of 0.8145 to0.8155 in. Flange and bore must be concentric, flat,square and true to adapter to engine mounting facewithin 0.002 in. Coat a replacement seal withengine lubricating oil. Place adapter in arbor presswith oil seal counterbore upward. Lay a new seal onadapter with sealing lip downward. Press sealsquarely into counterbore until seated.

14-21. PROTECTIVE COATINGS14-22.The engine manufacturer protects all aluminumalloy parts of current production engines with"Alodine 1200". This material is a product of theAmerican Chemical Paint Co., Ambler, Pa.Although the protective coatings differ, theapplication, interchangeability and part numbers ofparts are not affected. "Alodine" coated parts areeasily distinguished by their gold color. In order tomaintain a uniform appearance, the manufacturer ispainting exposed steel and magnesium parts withgold heat resisting enamel. Refer to the parts catalogfor part numbers of gray, black and gold enamel.

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14-23. REFINISHING ENAMELED PARTSIf enamel was removed from any exterior part bycleaning, etching or in the course of other repair work,it should be replaced with a new coat of primer and afinish coat of baked engine enamel of the propercolor. The primer coat should be Zinc ChromatePrimer, preferably applied by spray. After the primercoat has dried the finish coat of engine enamel shouldbe sprayed to cover the primer, but not heavily enoughto cause runs or drips. Ferrous parts when paintedwith gold enamel will be baked with infraredequipment for 15 minutes at 275°-285° followingapplication of each coat. Magnesium parts will bepickled and primed; then baked in the same manner asferrous parts.

NOTE

If a part which was originally "Alodized" isto be refinished with enamel, it will not benecessary to apply zinc chromate primerexcept to the surface areas completelystripped of "Alodine".

CAUTION

Before application of primer and enamel to apart, carefully mask all connection jointsand mating surfaces. No primer or enamel ispermissible on interior surfaces of fuel pumpadapter, tachometer and oil pump housing,oil sump, crankcase or any other partscontacted by engine lubricating oil afterassembly.

14-24. "ALODIZING" AND REPAIR OF"ALODIZED" SURF ACESAluminum alloy castings, sheet metal and tubing areprotected from corrosion by treating all surface of theparts with "Alodine 1200" (American Paint andChemical Co., Ambler, Pa.). "Alodine", unlike enamelor primer, will not flake or peel off to contaminateengine lubricating oil; therefore, corrosion protectioncan be afforded to all interior aluminum surfaces andparts. If an enamel coating is required for a partpreviously treated with "Alodine", application of aprimer before painting is not necessary. "Alodizing"will be performed after all machining and/or repairoperations have been completed. The surface color ofan "Alodized" part may vary from light gold to darkbrown. When a part is treated with "Alodine 1200" thethickness of the film, or buildup, on the mating or

bearing surfaces is so fine that the effect ondimensional tolerances is negligible.

14-25. APPLICATION OF "ALODINE 1200"In the event the original finish of an aluminum parthas deteriorated or been removed, the part may be"Alodized" as described in "Alodine" manufacturersTechnical Service Data Sheet No. AL-1200-D.Wrought or die cast (smooth surface) parts, such asvalve rocker covers and intake tubes, should betumbled or sand blasted to roughen before treatment.

14-26. REPAIR OF ALODIZED SURFACESIf "Alodized" parts have been remachined, rubbedwith abrasives or scratched in handling so as to exposeareas of bare aluminum, the surface may be repairedby local application of" Alodine" solution in thefollowing steps:

a. Clean the parts' bare area thoroughly with carbontetrachloride. Do not under any circumstances usean oil base solvent such as General Specification.P-S-661, TT-291 or alkaline cleaner.

b. Mix a small quantity of hot water (180°F) with 1-1/2 to 2 ounces of "Alodine 1200" powder to forma paste, then gradually dilute with hot water until asolution of one gallon is attained. This solution isto be adjusted with nitric acid addition to a PHvalue of 1.6 (1.5 to 1.7).

c. Application shall be made, with a rubber set paintbrush, in a manner so the solution flows over thearea.

d. Allow solution to remain on the part from one tofive minutes or until color of the new film isapproximately the same as the original.

e. Flush part with clear water and dry with air. Donot blast or rub with cloth to dry new film area. Ifcolor is too light, repeat steps "c" and "d" untildesired color is obtained.

NOTE

If "Alodine" does not adhere to metal, amore severe cleaning method must be used.A solution of 12 to 16 ounces of Oakite No.61 per one gallon of water is preferred.Apply and remove the solution with cautionbecause an alkaline cleaner of this type willremove any" Alodine" film previouslyapplied. Remove cleaning solutionthoroughly with plenty of hot water andvigorous brushing.

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14-27. IGNITION CABLES

Refer to paragraphs 10-18, 10-19, 10-20, 10-21, and10-22 for repair and replacement instructions.

14-28. DELCO-REMY STARTER

Refer to paragraph 10-29 for testing data.

14-29. PRESTO LITE STARTER

Refer to paragraph 10-35 for testing data.

14-30. DELCO-REMY GENERATOR

Refer to paragraph 10-38 for testing data.

14-31. STROMBERG NA-S3A1 CARBURETOR

F or overhaul. instructions, address Aircraft TechnicalService, Bendix Products Div., Bendix AviationCorp., South Bend, Indiana.

14-32. MARVEL-SCHEBLER MA-3SPACARBURETOR

For overhaul instructions relative to these carburetors,address Service Department, Marvel-Schebler/Tillotson Division, Borg-Warner Corp.,2195 South Elwin Road, Decatur, IL 62525. C90carburetors are identified by manufacturers part no.10-4252 and the 0-200 carburetors by part no. 10-4115.

14-33. MAGNETOS

For Bendix magneto instructions, address BendixMagneto Div., Bendix Aviation Corp., Sidney, N.Y.For Eisemann magneto information, address Jack &Heintz Precision Industries, Cleveland, Ohio. ForSlick magnetos, write Slick Electro Inc., Rockford,Illinois. For slick Magneto instructions, address SlickElectro Inc., 530 Blackhawk Park Aye., Rockford,Illinois 61101.

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SECTION XVASSEMBLY OF SUBASSEMBLIES

15-1. GENERAL PROCEDURE

15-2. CLEANING AND LUBRICATIONImmediately before assembling the parts of anysubassembly they should be sprayed with cleansolvent to remove corrosion-preventive oil and grit.The parts should be dried with a blast of drycompressed air. All bare steel surfaces, bushingsand bearings must be coated generously with amixture of one part corrosion-preventive compound,of a type which will not adversely affect thelubrication system, and three parts of enginelubricating oil, if the engine will not be testedimmediately, or the surfaces may be coated withclean engine lubricating oil if the test is to beperformed at once.

15-3. NEW PARTS REQUIREDAll lockwire, palnuts, lockwashers, elastic stop nuts,gaskets and rubber connectors used in assemblingthe engine must be new parts. If any of these partsare removed after initial assembly it must bediscarded and another new part installed. Sets ofgaskets and rubber connectors, piston ring sets andmain bearing and thrust washer sets for the variousmodels are listed in the Parts Catalog. New sets ofthese parts for the model to be assembled should beprocured in advance. All other new parts requiredfor replacement of those discarded should be onhand.

15-4. DETAILED PROCEDURE

15-5. CRANKCASE COVER ASSEMBLYAssemble parts in the following manner:

a. Inspect the cover casting for any nicks ordamage incurred in handling, for thoroughcleanliness, condition of enamel or coating,freedom of machined surfaces and interior fromenamel and any other irregularity.

b. Install the pump impellers in their chambers,with the tachometer drive shaft end to the rear.Install the pump cover, and make sure that it fitsperfectly on the chamber surface.

No gasket paste may be used in this joint. Placeplain washers and bolts or slotted nuts on the pumpstuds and tighten to specified torque. Installlockwire to connect the studs or bolts in pairs. Thelockwire must lie flat against the sides of bolts ornuts and must not pass over their tops.

NOTE

If the slots of any slotted engine nut orcastle nut will not align with the stud holewhen the nut is tightened to minimumspecified torque, continue tightening untileither the slot and hole align or themaximum allowable torque is reached,whichever occurs first. If alignment of theslots cannot be obtained within torquelimits, substitute another serviceable nut.

c. Test the oil pump impellers for free rotation. Ifany binding occurs, disassemble the pump forfurther inspection.

d. Insert the oil pressure relief valve plunger in itsguide; place the spring in the plunger; place anew copper-asbestos gasket on the cap, andscrew the cap into the cover boss over thespring. Tighten the cap securely.

e. Inspect the new oil seal in the tachometer drivehousing. The seal lip must be outward. If theengine is a -8 model, place a new copper-asbestos gasket on the housing. Insert a strip offiber in the tachometer drive shaft slot to fill theentire space and to protect the housing seal lip.Screw the housing into the left hand tapped holeover the tachometer drive shaft, being carefulnot to reverse the seal lip, and tighten thehousing securely. Remove the fiber strip. If theengine is -12, -14, -16 or O-200 model thehousing should be installed later.

f. If the engine is a -12, -14, -16 or O-200 modelprepare the oil screen housing gasket byworking into its surfaces a small amount of non-hardening gasket paste. Place the gasket on the

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crankcase cover pad. Place a new copper-asbestos gasket on the oil screen, and screw thescreen into its housing loosely. Place thehousing and screen on the crankcase covergasket, and attach it temporarily with a plainnut. If the engine is a -8 model tighten the oilscreen in its crankcase cover housing.

15-6. CRANKCASEInstall the following parts on the castings:

a. Spread a light film of Led plate No. 250 on thetwo front oil gallery plugs, and screw them intothe crankcase holes. Tighten both plugssecurely.

b. If no fuel pump is to be installed work a smallamount of a non-hardening gasket paste intoboth surfaces of the pump pad gasket, and placethe gasket and cover on the pad. Install twolockwashers and two plain washers and plainhex nuts. Tighten the nuts to specified torque.

c. If the engine is a -12, -14, -16 or O-200 model,and if no oil cooler is to be installed, treat thecover pad gasket with non-hardening gasketpaste, and place the gasket and cover on thesmall pad behind No.2 cylinder pad. Attach thecover with two plain washers, two lockwashersand plain hex nuts.

d. Spread a film of Led plate No. 250 on thebreather elbow thread, screw the elbow into thecrankcase 1, 3 side boss ahead of No.3 cylinderpad. Tighten the elbow enough to preventloosening. Position elbow 15 degrees rearwardfrom its downward position on O-200 engines.

e. Check the main bearing seats in both crankcasehalves for nicks, and make sure that they are dryand clean. Place a new main bearing insert ineach seat with the tang in the case notch and theends projecting very slightly and equally abovethe parting surface. The flanged front mainbearing inserts are used only on the O-200.Make sure that the set of inserts installed is thecorrect type for the crankcase being assembled

and of correct size for the standard or regroundcrankshaft to be installed. If there's an oilgallery for the starter clutch adapter, make surethe bearing shell has a hole and is properlyinstalled.

15-7. CRANKSHAFT AND CONNECTINGRODSFor maximum ease of working, the crankshaft, if atapered type, should be held in a fixture, asillustrated in Figure 30. A fixture may beconstructed for holding flange type shafts in thesame position. Assemble parts as follows:

a. If the shaft is a tapered type, screw the front oilplug into the front bore thread. For this purpose,a special type of screwdriver should be made toexactly fit the plug slot. The driver must have awrench square or hex on its stem. Tighten theplug enough to hold oil, being careful not todamage the slot.

b. Install the crankshaft in the holding fixture, andsecure it.

c. Layout the four sets of connecting rods, capsand bolts in numerical order, according to thecylinder numbers stamped on their bolt bosses.

d. Insert two bolts in each rod bearing cap with thehead flats against the cap shoulders.

e. Obtain a set of new bearing inserts of the correctsize for the crankshaft. Place an insert in eachrod and cap. The inserts must seat fully, andtheir ends must project very slightly and equallyabove the parting surface.

f. Coat the crankpins and bearings with engine oil.Install each rod and cap on the proper crank pin,according to cylinder numbers, and be sure thatthe numbers on rod and cap bolt bosses will beon top when the crankshaft and rod assembly isinstalled. Run on the slotted nuts as each rod isinstalled, in turn, and tighten to specified torque,and secure each with a cotter pin. Torque nuts tolow limit. If cotter pin will not enter increasetorque gradually up to high limit only. If cotterpin will not enter in this range replace nut and

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repeat. In no case shall nuts be torqued below lowlimit or over high limit. (Refer to Section XVIII forTorque Limits.)

NOTE

When connecting rods and caps areinstalled correctly, the bearing cap squirtholes will point to the opposite cylinders.

CAUTION

With C90 and O-200 connecting rods, useonly the bolts and nuts listed in the currentParts Catalog. Early production engineshad longer bolts and taller hex nuts. Theseshould not be used.

15-8. INTAKE PIPES AND HOSECONNECTORSInspect all pipe ends for roundness. Obtain a newset of inner and outer hose connectors, and centerone inner hose in each outer hose. Push the outerhoses on the ends of the pipes. Place two clamps oneach connector. Tighten one clamp to hold oneouter hose on each pipe securely. Push the oppositeouter hose on each pipe backflush with the end ofthe inner hose, and tighten the remaining clampsonly enough to prevent falling off.

15-9. INTAKE AIR FILTERObtain a new air filter of the proper type and a newgasket to match. Obtain four new locking studs andfour cross pins. Insert the studs through the filterfrom the front side and through the gasket. Supportthe drilled rear end of each stud, in turn, and drivethe cross pin through to centered position.

15-10. GENERATOR DRIVERefer to paragraphs 10-33 thru 10-36 for procedureand precautions to be observed in assembly of eithertype of generator drive.

15-11. OIL COOLER ADAPTERIf an oil cooler is used with the engine, spread afilm of Led plate No. 250 on the three socket headpipe plugs. Install the 1/4 inch plugs tightly in thefront and lower rear holes of the adapter, and installthe 1/8 inch socket head plug in the bottom adapterhole. In the upper rear adapter hole insert the check

valve ball, then the spring. Place a new copper-asbestos gasket on the 5/8-18 hex head plug, andscrew it in tightly on top of the spring.

15-12. MAGNETOSInstall the proper drive gear, according to the enginemodel, on the impulse coupling, or tapered shaft, ofthe two magnetos. Install the woodruff key beforethe gear on the tapered shaft of a right sideEisemann AM-4 magneto. Screw on the shaft nuttightly, and secure it with a cotter pin.

15-13. CYLINDERSAssemble valves and springs in cylinders in thefollowing manner, taking care to use the propersprings for the engine model.

a. Lay the cylinder on its side. Coat each valvestem with a film of Shell grease, Alvania No. 2,and insert each valve through the cylinder andinto its guide. Seat the valves, and check forcorrect positions.

b. Lift the cylinder by the valve stems and place iton a fixture which will hold the valve heads ontheir seats.

c. Place the two inner spring seats over the valveguides.

Figure 30. Tightening No. 1 Connecting Rod Bolts.

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d. Place the proper set of inner and outer, or inner,intermediate and outer springs over each valvestem.

e. Place an outer spring retainer on each set ofsprings.

f. If a lever type valve spring compressor is used,push the rocker shaft through its supports, andpivot the compressor on it.

g. Compress either set of springs. Insert two locksin the valve stem groove, small ends inward,and release the springs. Make sure that the locksseat perfectly in the spring retainer and the stemgroove.

h. In the same manner, assemble the retaining partson the other valve springs; then lift the cylinderfrom the fixture.

CAUTION

Never exert lifting or other force on thepushrod housings. They must remain firmand tight in the rocker box.

i. Slide out the rocker shaft, and install the tworockers in their original positions. Be sure to usethe correct parts.

CAUTION . . . Exhaust rocker has an oil orifice inthe valve stem end for valve stem lubrication.

j. Invert the cylinder, and place a new basepacking ring on the cylinder skirt. Push itagainst the flange, and remove twists.

k. Place two clamps and a new pushrod housingrubber connector on each housing, pushingconnector back flush with the housing end.

15-14. PISTONSInstall C-90 and O-200 piston oil control rings withthe pistons inverted on the bench. Install all otherrings with the pistons upright. The upper side ofeach ring bears the part number. Be sure that thecorrect size rings for the cylinders are installed.Spread each ring, as it is lowered into position, toavoid scratching the ring lands. Install removableplugs in piston pins, and start the pins into theirmating pistons.

15-15. PUSHRODSLay all pushrods in logical order in a pan of clean,light oil with crankcase ends raised to permit filling.Pushrods are numbered to avoid interchanging themat assembly.

15-16. VACUUM PUMP ADAPTERLubricate the gear shaft with engine oil; then pushgear slowly into adapter. Use care when installinggear to prevent reversing oil seal lip.

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SECTION XVIFINAL ASSEMBLY

16-1. GENERAL PROCEDURE

16-2. ASSEMBLY STAND

The engine should be assembled on a standequipped with a bed which can be rotated to placethe No's 2, 4 cylinder side of the crankcasedownward, so that the crankshaft and camshaft canbe laid in place in the horizontal position, and canbe turned to place the crankshaft in two verticalpositions, with the front end of the shaft upward ordownward. The stand should be constructed so thatall sides and both ends of the crankcase areaccessible, with sufficient clearance for installationof all parts and accessories.

16-3. NEW PARTS REQUIREDOnly new parts of the types named in paragraph 15-3 should be used in final assembly work, if removedfor any reason, they should not be reinstalled.

16-4. DETAILED PROCEDURE

16-5. CRANKCASE AND ENCLOSED PARTSAssemble and install parts in the crankcase in thefollowing order:

a. Attach the upper and lower mounting arms ofthe No's 2, 4 side crankcase casting securely tothe assembly stand bed, and turn the bed so thatthe open side of the casting is upward.

b. Place the No's 1, 3 side crankcase casting on thework bench, with the open side upward.

c. On the parting flange contact surfaces of thecastings, and on the small surface immediatelybelow the rear camshaft bearing (around the 3/8inch stud) spread a thin, uniform film ofAviation Permatex. Do not allow the liquid torun into the interior of the case. Do not applyPermatex on the other camshaft bearing bossesor on any main bearing bosses. Use it only onthe surrounding flange and around the 3/8 inchstud.

d. When the Permatex has become tacky, place astrand of No. 50, Grade "A" silk thread alongthe upper, lower and front flanges of the No's 2-4 side casting. Place the thread inside the upperand lower flange screw holes and inside thelower front flange hole. Place a loop of threadaround the 3/8 inch stud on the surface belowthe rear camshaft bearing.

e. In succession, dip each valve lifter body in lightengine oil or in a corrosion-preventive oilmixture, and install it in its original crankcaseguide from the inside. As each lifter body isinstalled in the 1, 3 side casting, push a usedpushrod housing rubber connector over its outerend to prevent it from falling.

f. If the engine being reassembled is a C90-16 oran O-200, a driving bevel gear must be installedon the front end of the camshaft before it isinstalled. Install gear on camshaft and install sixretaining screws tightly. Safety the screws inthree's with lockwire. Coat the camshaft withoil, and place it in the bearings of the crankcase2, 4 side. Measure clearance between eithercamshaft rear bearing flange and the bearingend. (Refer to Section XVIII.)

Figure 31. Installing Crankshaft Bearing and OldType Thrust Washer

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Figure 32. Installing Crankshaft and ConnectingRods.

CAUTION

Some early production O-200 enginesrequire shims behind vacuum pumpdriving bevel gear. Reassemble originalparts with same shims. Replacement partsmayor may not require shims asdetermined by backlash. Refer to SectionXVIII for proper backlash.

g. Spread a very thin, uniform film of lightweightTiteSeal, or an equivalent gasket paste, on thesurface of the recess around the crankshaftopening at the front of each crankcase casting.Coat the sealing lip of a new crankshaft oil sealwith a film of Gredag No. 44, or an equivalentlubricant. If the seal is a split type assembly fora flange type crankshaft, remove the helicalspring from its inner recess, and unhook theends.

h. If the crankcase is the older type, equipped withdowels in the front main bearing boss to retainthe thrust washers, obtain new washers of theproper type, and spread a very thin film of softgrease on their shouldered sides, so that theywill adhere to the ends of the boss. place eachwasher in position, as shown in Figure 31. Fouridentical notched washers are required.

i. If a flange type crankshaft is to be installed,spread the split oil seal ends by twisting, and

Figure 33. Installing Dowel Type Thrust Washersand Split Oil Seal.

place the seal on the shaft behind the propellerflange with its recessed side toward the rear.Pass the oil seal spring around the shaft behindthe seal, and hook its ends to make a loop.Place the spring joint opposite the seal split.Lift the spring into the seal recess at one point,using a wire hook, and work the entire springinto the recess progressively. Make sure thatthe spring lies in the groove inside the recess.

NOTE

If a flange type crankshaft is to beinstalled in an old type crankcase (withsmall shoulder behind oil seal recess) aspecial spring (part number 25386) may beinstalled behind (and not touching) the oilseal to act as an oil slinger.

j. Spread a generous coat of light engine oil orcorrosion-preventive oil mixture on allcrankshaft main journals. Lift the crankshaft andconnecting rod assembly by the No's 1 and 3rods, and place it carefully in the 2, 4 crankcaseside bearings. If it is a flange type crankshaftturn the oil seal, before seating the shaft frontend, so that the split will be within the 2, 4 siderecess and 20° from the parting surface towardthe top of the case. The seal must be against theshoulder of the recess. (See Figure 33.)

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Figure 34.

Installing Adapter Electric Starting Engines.

k. If the crankshaft is a tapered type, pass the steelcased oil seal over the front shaft end with itssealing lip toward the rear. Lift the shaft endslightly, and push the seal into the case recess asfar as it will go, with its drain hole toward thecamshaft.

1. Early crankcases for all "C" models arenotched at the lower front and upper rearedges of the No.2, 4 side front main bearingto accept the pins installed in two thrustwashers. Obtain two plain thrust washersand two with the short dowels installed atthe center. Slide the plain half washers intothe 2, 4 side crankcase recess; then place thedowel half washers against the crankshaftthrust flanges, and rotate each completewasher until the short dowel lies in acrankcase notch. (See Figure 35.)

NOTE

On the O-200 the front and rear thrustflanges are manufactured on the front mainbearing. Before torquing the through bolts orthe backbone bolts, pull the crankshaft upagainst the rear of the front main bearing toseat the front main bearing to seat the thrustflange of bearing against the bearing supportboss. Torque through bolts and backbonebolts.

Installing Starter Pinion PivotManual Starting Engines.

The current "C" and O-200 models have thecrankcase assemblies machined at the front mainbearing bosses to accommodate a plain mainbearing and flat, or tang-type thrust washers.Crankcases not machined for the above type thrustwashers must use the available flange type mainbearing.

m. Insert a thickness gauge between the crankshaftfront thrust flange and the thrust washer orbetween the front thrust flange and the flange ofthe front main bearing of the O-200. With thecrankshaft drawn forward, measure the endclearance. (Refer to Section XVIII.)

Figure 35 Installing Crankcase 1,3 Side on 2,4Side.

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n. If the engine is a -12, -14, -16 or any early O-200 model, install the pinion pivot in its recessabove the rear main bearing. If the engine is anO-200 using a Prestolite Starter, install thestarter jackshaft adapter. (See Figure 34.) Makesure crankcase has been modified per para. 14-13 A.

o. Place No's 1 and 3 connecting rods upright.Invert the 1, 3 crankcase side, and lower itcarefully into place on the 2, 4 side, keeping theparting flanges parallel to prevent binding as thethrough studs in each casting pass through theopposite half.

p. Make sure that the case parting flanges makecontact all around. See that the starter pinionpivot is correctly seated and retained by the casedowel. If a split oil seal is installed, checkposition of the joint, and see that the ends areflush. Either type of seal must be against therear shoulder of the recess, and the seal lip musttouch the crankshaft at all points.

q. Place a plain washer next to the head and installthe three 5/16 inch dowel screws through thecrankcase flange holes to align the case halves.In addition to the dowel screws, install the twothrough bolts in the O-200 crankcase and any Cmodel whose crankcase is machined at thecenter bearing bosses to accept through bolts. Ifthe engine is a -8 model, the dowel screws willall be the same length. For the -12, -14 or O-200models the longer screw is installed in thesecond hole from the rear of the upper flange.Install a 1/4 inch hex head screw in the holeahead of the upper flange dowel screw. Place aspacer washer on each of the upper flangescrews, then the engine lifting eye. Secure thefour screws with a plain washer and hex nut onall C models. On the O-200 models secure thetwo lifting eye attaching screws with alockwasher and plain hex nut and the remainingtwo dowel screws with a lockwasher, plainwasher and hex nut. Tighten the nutsmoderately.

r. Install protectors on all connecting rods toprevent the rods from touching the crankcase.

s. Test the crankshaft and camshaft for freerotation. If they turn freely, attach the 1, 3 sidemounting arms to the assembly stand.

t. Place plain washers and hex nuts on the twofront through studs ahead of No.4 cylinder padand on the through stud above the lower rightmounting arm. Tighten these nuts to specifiedtorques for their respective sizes.

u. Insert the two longer crankcase flange screws inthe holes immediately ahead of the upper dowelscrew on -8 models, then install the lifting eyespacers, the lifting eye, plain washers andattaching nuts. On all C75, C85 and C90 modelsinstall the remaining crankcase flange screws,with plain washers under their heads and securethem with plain washers and hex nuts. On theO-200 install the remaining crankcase flangescrews, in the same manner as the other modelsand secure them with a plain washer,lockwasher and hex nut. Tighten all flangescrews to the standard torque specified for 1/4inch nuts and screws.

v. Remove rubber connectors from the outer endsof 1, 3 side valve lifter bodies.

w. If the engine is a C model and is to be equippedwith a carburetor, and if the mount pad at thebottom front of the crankcase is machined andstudded, install on the pad a gasket treated withlight weight TiteSeal. Install either the lowerfuel pump adapter, with its pump pad to therear, or a cover plate. Attach the adapter orcover with spacers, if required, plain washersand castle nuts. Install lockwire to connect andsecure the nuts in pairs. If the engine is an O-200 or C90-16, install a gasket treated withlightweight TiteSeal on the pad at the bottomfront of the crankcase. Install the vacuum pumpadapter. One stud set in the crankcase is largerin diameter than the other three. Line upmatching holes in adapter and install theadapter. Secure it with three 1/4 inch plainwashers, lockwashers and plain hex nuts andone 5/16 inch plain washer, lockwasher andplain hex nut.

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16-6. GEARS AND CRANKCASE COVER

Rotate the engine bed so that the front end of thecrankshaft is downward, and lock it in position.Install parts at the rear of the crankcase in thefollowing order:

Rotate the engine bed so that the front end of thecrankshaft is downward, and lock it in position.Install parts at the rear of the crankcase in thefollowing order:

a. Install the proper type of gear on the rear pilotof the crankshaft, and run in the four hex headscrews with fingers.

b. Turn the crankshaft until No.1 crankpin is atT.D.C. The gear tooth timing marks will betoward the camshaft.

c. Turn the camshaft counterclockwise until No. 1exhaust lobe (rear) approaches its closingposition and No.1 intake lobe is beginning itslift. Install the camshaft gear on the camshaftpilot with its punch marked tooth meshedbetween the marked teeth of the crankshaft gear.Install four hex head retaining screws.

CAUTION

Use screws of correct length on each gear.Refer to Parts Catalog for lengths requiredby each model.

d. Tighten the eight gear retaining screws totorques specified in Section XVIII.

e. Install lockwire through the drilled heads of theretaining screws of both gears to connect themin pairs. The wire must pass around the sides ofall screw heads, not over their ends, and it mustbe twisted in the direction necessary to preventthe end loops from rising and led from onescrew to the next in the direction necessary toprevent either screw from loosening. Draw thetwisted lockwire tight, and bend the twistedends down.

f. Work into both surfaces of the proper covergasket a small quantity of a non-hardeninggasket paste, and place the treated gasket overthe studs and on the crankcase rear surface.

The dowel holes in the gasket must fit over thecrankcase dowels.

NOTE

The cover gasket for -12, -14, -16 and O-200 model crankcase does not have orneed a hole for the left oil gallery.

g. Lower the crankcase cover subassembly overthe studs, and seat it on the cover gasket, asshown in Figure 36, for -12, -14, -16 or O-200models, turning the crankshaft slowly to alignthe oil pump drive.

h. If the engine is a -12, -14, -16 or O-200 modelplace plain washers, lockwashers and plain hexnuts on all crankcase cover retaining studs,except the one through the generator mount pad.Tighten to specified torque these seven nuts andthe third retaining nut of the oil screen housing.Loop a length of lockwire around the nearestcover retaining studs to the oil screen housingand oil pressure relief valve cap, and twist thewire. Twist the two lockwires and lead them tothe oil pressure relief valve cap and the oilscreen cap, respectively, in a counterclockwisedirection to engage the cap corner holes. Installa drilled hex head plug and new copper-asbestosgasket in the oil screen cap hole. Tighten theplug, and secure it with the ends of the lockwirein the screen cap. If the engine is a -8 modelinstall all of the ten retaining washers, nuts andsafety the oil screen and pressure relief valve-cap in the same manner as described.

i. With a sharp knife, cut out the strip of thecrankcase cover gasket which crosses the oilsump pad opening, then trim the lower ends ofthe gasket flush with the sump mounting pad.

16-7. VALVE LIFTER UNITS AND PUSHRODHOUSING FLANGESRotate the engine bed so that the front end of thecrankshaft is upward. Then:

m. Install hydraulic units in the valve lifter bodieswith their plungers outward. Before installingeach unit, make sure that its spring is snappedinto the cylinder counterbore and that theplunger can be depressed fully. Place theoriginal socket in each lifter.

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b. Work a small quantity of a lightweight TiteSealinto both surfaces of each pushrod housingflange gasket, and place the gaskets on thecrankcase pads. Place the housing flanges on thegaskets. Install plain washers and hex nuts on allstuds of the C models. For the O-200, install aplain washer, lockwasher and hex nuts on allstuds. Tighten the flange retaining nuts tospecified torque.

16-8. PISTON ASSEMBLIESPlace each piston assembly with the matingcylinder, and preferably in numerical order. Beforeinstalling each piston, coat its skirt, rings and pinwith a light mineral oil or with a corrosion-preventive oil mixture. If the pin has removable endplugs place them with the cylinder. Push the pinpartially into the piston bore, but clear of theconnecting rod cavity. Make sure that piston ringpart numbers are toward the piston heads.

16-9. PISTONS AND CYLINDERSInstall these sub-assemblies as follows:

b. Turn the crankshaft until No.1 connecting rod isat T .D.C., with both valve lifters on the heels oftheir cam lobes.

c. Lay the cylinders on their sides, and coat thebores generously with light engine oil orcorrosion-preventive oil mixture.

d. Install No.1 piston with the cylinder number onits head toward the front of the engine. Push thepin through the connecting rod bushing to thecentered position.

e. Remove the protector from No.1 connectingrod. Hang the piston ring compressor on theconnecting rod. Stagger the piston ring gaps 90°apart, with no gap in line with the pin.

f. Hold No.1 cylinder on the left arm. Do not holdthe pushrod housings. Take the two pushrods forNo.1 cylinder from the oil pan, and insert themin the pushrod housings, seating their ends inthe rockers. Make sure that each pushrod is inits original position.

f. See that the No.1 valve lifter sockets are in thelifters. Make sure that No.1 cylinder basepacking is not twisted. If removable piston pinplugs are used pick up the two for No.1 pistonpin.

g. With the right hand, apply the ring compressorto the No.1 piston rings above the pin. Push thecylinder skirt over the rings. Remove thecompressor, and install the piston pin plugs. Ifthe engine is a C90 or O-200 model, compressthe bottom piston ring. Push the cylinder inwardover the piston. Remove the ring compressor,and seat the cylinder on its crankcase pad.

h. Install six flanged nuts on the cylinder basestuds, and tighten them to specified torque.

i. Fully depress each rocker of No.1 cylinder, inturn, and measure the lash in the -deflated valvetrain between the rocker and the valve stem.This lash must be .030-.110 inch. If the lash isexcessive, either rockers, pushrods, liftersockets or valves must be replaced.

j. In the same manner, install No.2 cylinder, afterturning the crankshaft one revolution, and checkits valve lash.

Figure 36. Installing Crankcase Cover on –12, -14,-16 and O-200 Models.

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k. Repeat the installation procedure for No's 3 and4. cylinders, with the crankpin at T.D.C. and thevalve lifters on the heels of the cam lobes ineach case. Check lash in each of their valvetrains.

l. Treat each rocker cover gasket with lightweightTiteSeal and install each gasket and rockercover on a cylinder head. Install plain washers,internal tooth lockwashers and fillister headscrews in all covers.

m. Push the rubber pushrod housing connectorsinward over the flanges, and install a hoseclamp in each connector groove.

16-10. AIR INDUCTION SYSTEMInstall parts required for the carburetor inductionsystem, as required, in the following order:

a. Place a new gasket on the studded intake flangeof each cylinder head, and place the correcttypes of elbows on the gaskets. When correctlyinstalled, the elbows point to the manifoldattaching studs.

b. Install lock-o-seal washers between thecrankcase and intake manifold and below the in-take manifold. When required, install thecarburetor air box support assembly on theforward stud. Install castle nuts and tighten

Figure 37. Installing No. 3 Cylinder.

finger tight. Advance as required to install cotterpin. Do not use wrench on castle nut. (SeeFigure 38.)

c. Make sure that inner hoses are in position withinthe outer hose connectors at both ends of allintake pipes and that all hose clamps are inposition. Push the projecting hose of each intakepipe over a manifold outlet, and push the hoseconnectors at the opposite ends over thecylinder intake elbows. Tighten all hose clampsto hold the pipes firmly.

Figure 38. Install "O" Rings on Intake ManifoldStuds.

16-11. CARBURETOR AND INTAKE HOUSINGIf the engine is to be equipped with a carburetormake sure it is the right model for the engine beingreassembled. Place a new gasket on the manifoldlower flange over the four studs. Install thecarburetor with its throttle lever on the right side,and attach it with four plain washers, lockwashersand hex nuts. In the same manner install and attachthe air intake housing with its scoop forward. Besure to install the proper housings since enginesequipped with Marvel-Schebler carburetors requirea different air intake housing. Refer to the PartsCatalog for applicable housing required. Attach thehousing support under the manifold front retainingnut and to the housing with two fillister headscrews.

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16-12. AIR FILTERPlace the gasket assembled to the air filter againstthe flange of the air scoop or intake housing, andwith the filter locking studs entering the lockingplate holes. Press the filter firmly against the scoopand turn the four studs to lock.

16-13. OIL SUMP AND SUCTION TUBEMake sure that the sump to be installed is thecorrect type for the engine model and for theaircraft installation; then proceed in the followingmanner:

a. Place a new copper-asbestos gasket on thethreaded end of the oil pump suction tube.Screw the tube thread into the crankcase coverhole within the sump mount pad circle, andtighten the hex. Install lockwire in the holeacross a corner of the hex; twist it, and lead itclockwise to the nearest of two holes providedin the casting. Insert one end of the wire, andtwist the two ends to pull the wire tight.

b. Spread a thin film of non-hardening gasket pasteon both surfaces of an oil sump gasket, andplace it on the crankcase pad. Ascertain whetherthe sump filler neck should extend to the left orto the right side to suit the aircraft; then placethe sump on the pad, and check the fit of thefiller neck bracket on the lower mount arm. If itdoes not make contact install one or two plain

Figure 39. Placing Crankshaft in Firing Positions ofNo. 1 Piston.

Figure 40. Placing Flange Crankshaft in FiringPosition of No.1 Piston.

5/16 inch washers as spacers. Attach the sumpand filler neck to crankcase plain studs withelastic stop nuts or to drilled studs with castlenuts and lockwire. Install the oil gauge and capassembly.

16-14. IGNITION SYSTEMInstall on the two magnetos the proper type or typesof gear for the engine model. Tighten the magnetoshaft nut, and install a cotter pin to retain each gear.To install the magneto, turn the engine crankshaft inthe direction of engine rotation until No.1 cylinderis in its correct firing position on the compressionstroke (See Table X). Insert the magneto with thedistributor rotor in position to fire No.1 ignitioncable (after tripping the impulse mechanism if any).For the Bendix Magneto, timing to the engine isobtained by turning the magneto through therequired angle until the breaker points just open.Use a timing light preferably. For the SlickMagneto only the removal of the timing key isrequired after installing the magneto on the engine.

a. SLICK MODEL 4001 MAGNETOS. Currentproduction Model O-200 engines are equippedwith non-adjustable Model 4001 slickMagnetos. Remove the bottom vent plug and"Spark Out" the magneto. This magneto cannotbe overhauled and the breaker assembly, coiland capacitor are non-replaceable. Exchangemagnetos are available through yourContinental Distributor.

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To "Spark Out" the magneto, hold the lead withT1 or B1 on the spark plug nut 1/8" to 1/4"away from the magneto frame, and turn theimpulse coupling or gear one (1) click at a timeuntil a strong spark jumps between the wire andthe magneto frame. Use care to hold themagneto firmly so the coupling will not movebeyond the point where it trips and the sparkoccurs. Reverse the operation approximately25° until the white line appears in the center ofthe hole. Hold the rotor with the index finger sothe white line is in the center of the hole andinstall the magneto on the engine.

b. For unshielded systems, install the front cablebrackets on the front attaching bolt of the liftingeye. On -8 models, install the rear cable bracketsunder the outboard magneto flange nuts, and on-12, -14, -16 and O-200 models under the lowerof two crankcase cover retaining nuts in front ofeach magneto. Install the upper ignition cablebrackets of radio shielded systems under theupper center base nuts of cylinders No's 1 and 2.Install the lower shielded cable brackets of -8models under the crankcase cover retaining nutsin front of the magnetos. Install the two lowercable brackets of Eisemann LA-4 shieldedsystems on -12 and -16 models under the lowerof two crankcase cover retaining nuts in front ofeach magneto, and install the loose, unattachedbracket under the lower starter retaining nut.Bendix shielded cable assemblies for -12, -14, -16, and O-200 models have a twisted cablebracket on each pair of upper and lower ignitioncables. These are installed under the twocrankcase cover retaining nuts in front of eachmagneto. The brackets on the two pairs ofcables for lower spark plugs of cylinders No's 1and 3 and No's 2 and 4 are installed under thepushrod housing nuts. ; Install the upper andlower spark plugs with serviceable gaskets.Tighten all plugs to specified torque. Withshielded systems, install the spark plug contactsleeves carefully, and tighten the elbow unionnuts only enough to prevent the elbows fromturning. Install ignition cable terminals in themagnetos as described in paragraph 10-13.

16-15. GENERATOR/ALTERNATORSpread a film of non-hardening gasket paste on bothsides of a generator and tach drive housing gasket.Place the gasket on the crankcase cover pad. Installthe generator, with the wire terminals to the left,meshing the drive gear with the camshaft gearinternal teeth as the mounting flange approaches thecase pad. Install three elastic stop nuts on retainingstuds and tighten them securely. Insert a fingerthrough each of two openings in the drive endframe, and attempt to oscillate the armature tocheck gear backlash. A noticeable backlash mustexist. If none is felt, loosen the retaining nuts andshift the generator upward slightly. Tighten the nutsand recheck for backlash. If none can be obtained inthis manner, it will be necessary to remove thegenerator and to substitute another drive gear.

16-16. TACHOMETER DRIVE HOUSING (-12, -14, -16 and O-200 MODELS)Insert a strip of fiber to completely fill thetachometer drive shaft slot and project beyond therear end of the shaft. The surface of the strip mustbe smooth to protect the housing oil seal lip. Makesure that the oil seal is installed in the tachometerdrive housing with the lip outward. Work the seallip over the shaft end, and push the housing over thecase studs onto the gasket. Install the three elasticstop nuts, and tighten them evenly. Remove thestrip from the tachometer drive shaft slot, and installa shipping cover.

16-17. STARTERWork non-hardening gasket paste into both surfacesof a starter' gasket, and install it on the crankcasecover pad. Lubricate the starter pinion andintermediate gear. Hold the starter assembly inposition to align the clutch bore with the crankcasepivot, and push the clutch over the pivot, holdingthe assembly in line as it approaches and seats on itspad. Place two lockwashers and plain washers onthe upper through bolts, and install them throughthe crankcase rear flange holes. Align the starterbolt holes and screw in the two bolts. Install plainwashers, lockwashers and hex nuts on the threelower retaining studs on all model engines. Tightenthe nuts and bolts evenly.

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SECTION XVIITESTING AFTER OVERHAUL

17-1. TESTING EQUIPMENT

17-2. TEST STANDAfter each major overhaul, engine performanceshould be tested and new parts run in while theengine is mounted on a rigid test stand, preferablyenclosed in a cell of such a design that cooling airrecirculation will be held to a minimum. The enginestand should be constructed in such a way as topermit accessibility to all engine line and instrumentconnections and to permit frequent inspection of allpoints of possible leakage. All tubes, wires, rodsand cables used to connect instruments and controlsto the engine should be well supported, yet ofsufficient flexibility to permit them to be moved outof the way during installation and removal of theengine.

a. The aircraft can be considered a suitable teststand for running-in overhauled enginescontingent on the following conditions:

1. Install engine cowling.

2. Each cylinder must be equipped with atemperature sensing device to monitor thehead temperature.

3. The flight propeller may be used contingenton careful observation of cylindertemperatures. Head the aircraft into the windfor this test.

17-3. INSTRUMENTSIn order to obtain a satisfactory report of engineperformance, permanent instrument and controlboard should be installed in a separate enclosure,and it should be as free as possible from vibration.Instruments should be of the most ruggedconstruction available, and they should be checkedperiodically to assure continuous accuracy. Thefollowing instruments will be needed to indicateengine operating conditions.

a. Tachometer (mechanically driven) (See TablesXIV and XV).

b. Cylinder Head Temperature Gauge.

c. Oil Temperature Gauge.

d. Oil Pressure Gauge.

e. Fuel Flow Meter (or accurate means ofweighing the supply).

f. Fuel Pressure Gauge, 10 p.s.i., capacity (forcarburetor engines equipped with fuel pumps).

17-4. TEST CLUBManufacturers of wood propellers supply wood testclubs of various sizes. A club of this type should beused for all engine testing. Flight propellers do notdirect cooling air over the cylinders. For the fullrange of C series engines, three diameters of testclub are required to absorb 75, 85 and 90horsepower at 2275, 2575 and 2475 R.P.M.,respectively. O-200 engines will require only onetest club which will absorb 100 horsepower at 2750R.P .M. Two test clubs of each size will be requiredto fit the two types of crankshafts of the C seriesengines. For tapered shafts, the clubs should befitted with hub assemblies, as listed in the partscatalog. After installation of the hub, the club mustbe balanced statically. For flange type crankshafts,the test club bolt holes must be counterbored at therear ends to fit over crankshaft flange bushings.

17-5. ENGINE TEST AFTER OVERHAULa. After a partial or complete disassembly and

repair of an engine, the engine will be tested inaccordance with Tables XXI and XXII.

b. Extend the second period of each test schedule,if necessary, to raise the oil temperature to thedesired minimum in Table XXI.

c. Take instrument readings at the beginning, inthe middle, and at the end of the full throttleperiod. Take one reading during each of theother periods as soon as conditions havestabilized.

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d. After completion of oil consumption test run,make one check on performance of eachmagneto alone at the R.P .M. specified in TableXXI prior to cool down period.

NOTE

If tests must be conducted in extremelycold weather, it may be necessary to coverthe oil sump with an oil-proof lagging.

NOTE

The following procedures should befollowed to insure that adequatelubrication is being provided to newlyinstalled components and that the pistonring seating will occur as soon as possible.

e. Servicing and Pre-starting Procedures.

1. Service the lubricating system with mineraloil (MIL-C-6529 Type II.)

e. Servicing and Pre-starting Procedures.

1. Service the lubricating system with mineraloil (MIL-C-6529 Type II.) of the appropriategrade depending on ambient temperature.

2. Rotate the propeller by hand through severalcycles with the spark plugs removed.

3. Pre-oil the lubrication system using anexternal pre-oiling pressure system.

4. Install the spark plugs and ignition harness.

f. Service and pre-starting procedures.

1. Service the lubricating system with mineraloil (MIL-C-6529 Type II) of the appropriategrade depending on ambient temperature.

2. Rotate the propeller by hand through severalcycles with the spark plugs removed.

3. Pre-oil the lubrication system using anexternal pre-oiling pressure system.

4. Install the spark plugs and ignition harness.

g. Engine starting and ground operation.

1. Assure that all engine and cylinder bafflingis properly installed and in good condition.

2. Start the engine and assure that oil pressurerises to within the specified limits within 30seconds.

3. Operate the engine at 750 RPM for oneminute, gradually increasing toward 1000RPM in three minutes. Check the magnetocircuit for grounding prior to a normal shut-down. Allow the engine to cool adequatelyand then make a visual inspection for anyirregularities.

4. Start the engine again and operate it at 750RPM gradually increasing to 1500 RPMover a period of four minutes. If the engineis equipped with a controllable pitchpropeller, cycle the propeller allowing onlya 100 RPM drop. Return to the idle rangeand make adjustments to the idle mixtureand RPM as required on carburetor enginesand to the low unmetered fuel pressure, idleRPM and mixture on fuel injected engines.Position the throttle to 1200 RPM to smooththe engine. Then do an idle mixture check.Refer to the appropriate service informationfor these fuel system adjustments. Runengine up to full power for a period not toexceed 10 seconds. Visually inspect andcorrect any discrepancies. Check the oilquantity. Cowl the engine in preparation fortest flight.

h. Test Flight.

1. Ambient air and engine operationtemperatures are of major concern duringthis test flight. Do a normal pre-flight run-up in accordance with the aircraft flight

108

manual. Conduct a normal take-off with fullpower and monitor the fuel flow, RPM, oilpressure, cylinder head temperatures and oiltemperatures. Reduce to climb power inaccordance with the flight manual andmaintain a shallow climb attitude to gainoptimum airspeed and cooling. Rich mixturefor all operations except lean for fieldelevation where applicable and lean tomaintain smoothness during climb inaccordance with airframe manufacturersoperating instructions.

2. Level flight cruise should be at 75% powerwith best power or richer mixture for thefirst hour of operation. The second hourpower settings should alternate between65% and 75% power with the appropriate

best power mixture settings. Engine controlsor aircraft attitude should be adjusted asrequired to maintain engine instrumentationwithin specifications.

3. The descent should be made at low cruisepower settings, with careful monitoring ofengine pressures and temperatures. A voidlong descents with cruise RPM and manifoldpressure below 18" hg.; if necessarydecrease the RPM sufficiently to maintainmanifold pressure.

4. Any discrepancies detected during test flightor any final adjustments necessary shouldnow be made. The engine can be operated innormal service in accordance with theaircraft flight manual.

109

TABLE XXI TEST OPERATING LIMITS

ValueFeature C75 C85 C90 O-200

Full throttle speed(RPM)

Fuel Consumption(at full throttle)

Oil ViscosityAbove 40°F.Below 40° F.

Oil consumption(maximum)

Fuel Rating(octane)

Idling Speed(RPM)

Manifold Vacuum atFull Throttle

Manifold Vacuum atIdling Speed

Magneto Drop atFull Throttle (RPM)

*Crankcase pressure(maximum)

Cylinder Head Temp.(maximum)

Oil Temperature(desired)

Oil Temperature(maximum)

Oil Pressure(at full throttle)

Oil Pressure(at idle speed)

2275-2325

38.5-41.5 lbs/hr

S.A.E. 4020 or 10 W 30

0.75 lbs/hr

80/87

475-525

0.5-1.3 in. Hg.

17 in. Hg.

75

1.0 in. H2O

525° F.

150°F. -200°F.

225° F.

30-45 psi

10

2575-2625

42.5-45.5 lbs/hr

S.A.E. 4020 or 10 W 30

0.75 lbs/hr

80/87

475-525

0.5-1.4 in. Hg.

17 in. Hg.

75

1.0 in. H2O

540° F.

150°F. -200°F.

225° F.

30-45 psi

10

2475-2525

**46-49 lbs/hr

S.A.E. 4020 or 10 W 30

0.75 lbs/hr

80/87

475-525

0.901.4 in. Hg.

#17.5 in. Hg.

†100

1.0 in. H2O

525° F.

150°F. -200°F.

225° F.

30-60 psi

10

2750-2800

51-55 lbs/hr

S.A.E. 4020 or 10 W 30

0.80 lbs/hr

80/87

475-525

0.5-2 in. Hg.

17.0-18.5 in. Hg.

†100

1.0 in. H2O

525° F.

150°F. -200°F.

225° F.

30-60 psi

10

* A sudden increase in in crankcase pressure and rapid fluctuation of manometer usually indicatedsticking of rings. Before removing cylinders, check, crankcase breather and manometer.

** 47-50 lbs/hr at 2625-2675 RPM; 42-46 lbs/hr at 2475-2525 RPM with No. 391090-1 or with Marvel10-4457 carburetors installed.

# Minimum with camshaft No. 531075 installed.

† At 1800 RPM. (Let temperature settle out before taking magneto drop.)

110

TABLE XXII TEST SCHEDULE

RPMPeriod Time (Minutes) C75 C80 C90 O-200

1

2

3

15

10

Warm up900-2000

2000

500±25Idle CoolingPeriod

Warm up900-2000

2300

500±25Idle CoolingPeriod

Warm up1200-2200

2200

500±25Idle CoolingPeriod

Warm up1200-2200

2400

500±25Idle CoolingPeriod

Stop engine, drain oil, weigh oil in for oilconsumption determination.

START OIL CONSUMPTION DETERMINATION

1

2

3

4

5

6

5

10

10

5

5

5

Warm upTo 2000

2000

2100

2200

2275-2325

Full ThrottleCheck Magnetos

500±25Idle CoolingPeriod

Warm upTo 2300

2300

2400

2500

2575-2625

Full ThrottleCheck Magnetos

500±25Idle CoolingPeriod

Warm upTo 2200

2200

2300

2400

2475-2525

Full ThrottleCheck Magnetos

500±25Idle CoolingPeriod

Warm upTo 2400

2400

2500

2600

2750-2800

Full ThrottleCheck Magnetos

500±25Idle CoolingPeriod

Stop engine, drain oil, weigh and recordengine oil consumption.

Magneto drop to be taken after completionof oil consumption run.

Oil consumption at rate of .35 lbs / ½ hr.Maximum acceptable rate for C75 and C85.Oil consumption .37 lbs / ½ hr. minimumAcceptable for the C90 and .39 lbs / ½ hr.Maximum acceptable for the O-200 .

111

Clear spark plugs by operating with both magnetoson for a few seconds between checks.

NOTE

The maximum cylinder head temperatureand the maximum allowable oiltemperature must not be exceeded at anytime during the test.

17-6. PRESERVATIONIf the engine is not to be installed in an aircraft andplaced into service immediately, the last 15 minutesof operation should be used to circulate a corrosion-preventive oil mixture (suitable for light operation).This will be an additional period, since the enginemust be stopped to change oil. Install dehydratorplugs in the spark plug holes which are in the topposition when the engine is mounted in the shippingbase. Seal all other openings leading to the interiorof the engine with shipping covers, suitable plugs ornon-hydroscopic tape.

17-7. FUEL AND LUBRICATING OILFor testing, the fuel used for each model must havean octane rating at least equal to that specified forthe model in Table XXI. Lubricating oil supplied tothe engine during the test run should be of aviscosity grade also recommended in Table XVIIIfor range of operating temperatures obtained.

TABLE XXIII OIL SUMP CAPACITY

Model Capacity (Quarts)

C75

C85

C90

O-200

4

4.5

4.8

6

17-8. TESTING ENGINES INSTALLED INAIRCRAFTDue to the inadequate air flow obtainable for enginecylinder and oil cooling when an engine is installedin an aircraft, it is recommended that no testing orrunning in of new parts be performed in thismanner. If it becomes necessary to run-in anoverhauled engine in the aircraft a wood test clubshould be used for ground operation. The cowlingshould not be installed, and the aircraft should beheaded into the wind to provide the best possiblecooling. A cylinder head temperature gauge must beinstalled, and a constant check must be made ofcylinder head and oil temperatures. The maximumcylinder head temperature for the engine asspecified in Table VI must never be exceeded andthe engine shut down frequently enough during thetest to assure this. After an hour of running has beenaccumulated, the flight propeller and cowlingshould be installed and the test completed in flightwithout "mushing".

17-9. INSPECTIONAfter completion of the test run, inspect thefollowing features:

a. Remove oil screen, and inspect for metalparticles.

b. Remove oil gauge, and check oil quantity andquality.

c. Remove all spark plugs, and measure electrodegaps. Readjust if necessary, and clean anyfouled plugs before reinstalling.

d. Using a flashlight for illumination, inspect allcylinder bores for scoring while the propeller isturning slowly.

e. Replace spark plugs, and test for uniformcylinder compression by turning the propeller,or use a cylinder pressure gauge beforeinstalling the upper set of spark plugs. Actualpressure values will depend on several variables,but they should be uniform among cylinders.

112

Figure 41. Fuel Flow Limits vs. R.P.M. at Propeller Load, Model C90.

Figure 42. Fuel Flow Limits vs. R.P.M. at Propeller Load, Models C75 and C85.

113

FUEL FLOW (GALS. PER HR.) (5.8 LBS./GAL.)

Figure 43. Fuel Flow Limits vs. R.P.M. at Propeller Load, Model O-200.

114

SECTION XVIIITABLE OF LIMITS

New PartsRef.No.

ChartNo. Description Minimum Maximum

ServiceMaximum

1234

1111

C75, C85 PISTONTop Land in Cylinder Bore. ................................................................Dia:2nd, 3rd & 4th Lands in Cylinder Bore. ..............................................Dia:Top of Skirt in Cylinder Bore. .............................................................Dia:Bottom of Skirt in Cylinder Bore. ........................................................Dia:

.034L

.030L

.009L

.007L

.038L

.034L

.013L

.010L.016L.013L

5678

9

1111

C90, O-200 PISTONTop Land in Cylinder Bore. ................................................................Dia:2nd & 3rd Land in Cylinder Bore. .......................................................Dia:Top of Skirt in Cylinder Bore. .............................................................Dia:Bottom of Skirt (above 4th groove)in Cylinder Bore. .................................................................................Dia:Deleted

.038L

.034L

.012L

.009L

.042L

.038L

.015L

.012L

.018L

.015L

10

11

12

13

1415

1

1

1

1

11

PISTON RINGSTop Piston Ring in Groove (C75 & C85) ..................................Side Clear:Top Piston Ring in Groove (C90 & O-200) ..............................Side Clear:2nd & 3rd Piston Rings in Groove (C75 & C85) ......................Side Clear:2nd Piston Ring in Groove (C90 & O-200) ...............................Side Clear:3rd Ring in Groove (C90 & O-200).......................................... Side Clear:Oil Control Ring in Groove. .....................................................Side Clear:Top Ring in Groove. ................................................................Side Clear:2nd Ring in Groove. ................................................................Side Clear:3rd Ring in Groove. .................................................................Side Clear:Oil control Ring in Groove. ......................................................Side Clear:Top Ring in Cylinder (C75 & C85). ....................................................Gap:Top Ring in Cylinder (C90 & O-200). ................................................Gap:2nd Ring in Cylinder (C75, C85, C90, O-200) ...................................Gap:3rd Ring in Cylinder (C75,C85,C90& O-200) .....................................Gap:4th Ring in Cylinder (C75 & C85) ......................................................Gap:4th Ring in Cylinder (C90 & O-200) ..................................................Gap:Compression Ring Tension (closed to specified gap) .............................. :Oil Control Ring Tension (closed to specified gap) .................................. :

.005L

.006L

.003L

.0045L

.005L

.002L

.006

.0045

.0025

.0020

.018

.021

.013

.013

.013

.0139.0 lbs.

11.0 lbs.

.0065L

.008L

.005L

.0065L

.007L

.004L

.008

.0065

.0045

.0040

.035

.040

.030

.030

.025

.03012.0 lbs.15.0 lbs.

.009L

.010L

.007L

.009L

.009L

.006L

.010 *

.009 *

.006 *

.006 *

.040 #

.045 #

.035 #

.035 #

.035 #

.035 #8.0 lbs.

10.0 lbs.

161718

19

111

PISTON PINSPiston Pin and Plugs No. 530830 in Cylinder. ......................... End Clear:Piston Pin in Piston (Pistons 40327 & 530348) ..................................Dia:Piston Pin in Connecting Rod Bushing(Rods A35160-A2 & 530184-Al) .........................................................Dia:Deleted

.010

.0001L

.0014L

.032

.0007L

.0021L

.080

.0015L

.004L

20

21

1

1

CONNECTING RODConn. Rods 530184Al & A35160A2 onCrankpin .................................................................................. End Clear:Conn. Rod Bearing No. 35897 on Crankpin .......................................Dia:Conn. Rod Bushing in Conn. Rod. .....................................................Dia:

.006L

.005L

.002T

.010L

.003L

.0045T

.016L

.006L --

* Chrome Plate# If necessary, use .005” oversize rings to maintain specified limits in cylinder bore to service limits.

115

New PartsRef.No.

ChartNo. Description Minimum Maximum

ServiceMaximum

22

23

1

1

Conn. Rod Bushing Bore Bushings .............................................. Dia:Conn. Rod Bearings & Bearings (out-of-round and taper) .........................................................................................Conn. Rod Bearings & Bushings ............................Twist or Convergence per in. of Length:Bolt in Conn. Rod. ........................................................................ Dia:

.9230

.0000

.000

.0005L

.9235

.0005

.001

.0023L

----

.0005

.001 ----

242526272728

29

30

222222

2

2

CRANKSHAFTCrankshaft to Thrust Washers ............................................ End Clear:Crankshaft in Front Main Bearing ................................................. Dia:Crankshaft in Center and Rear Bearings...................................... Dia:Crankpins ..................................................................................... Dia:Crankpins ...................................................................... Out-of-round:Run-out at Center Journal (shaft supported at front and rear journal) ............................................... (Full Indicator Reading):Run-out at Front End of Taper (shaft supported at front and rear journals) ...................................... (Full Indicator Reading):Run-out on Face of Flange, Near Edge (shaft supported at front and rear journals) .............................. (Full Indicator Reading):Main Journals ............................................................................... Dia:Main Journals. ............................................................... Out-of-round:

.004 .0005 .00051.9360 .000

.000

.000

.0001.8720 .000

.015 .0035L .0035L1.9370 .0005

.010

.006

.0051.8730 .0005

.004 .006 L .006 L1.934 † .001 †

.010

.006

.0061.870 † .001 †

31323334

35

2212

2

CAMSHAFTJournals in Crankcase Bearings ................................................... Dia:Rear Journal Flange to Crankcase .....................................End Clear:Valve Lifter in Crankcase Guide ................................................... Dia:Camshaft Journals ........................................................................ Dia:Cam Gear Pilot ............................................................................. Dia:Vacuum Pump Gear on Camshaft Pilot (O-200) .......................... Dia:

.001 L .004 .0005 L1.37252.8740 .0000

.003 L .008 .002 L1.37352.8750 .002 L

.005 L .012 .0035 L --- --- ---

3637

11

ROCKERSHAFTRocker Shaft in Rocker Bushing ................................................... Dia:Rocker Shaft in Cylinder Head Bosses ......................................... Dia:

.001 L .0002 L

.0025 L .0017 L

.004 L .002 L **

38

394041

1

111

VALVES AND GUIDESExhaust Valve in Guide (C75, C85, C90) ..................................... Dia:Exhaust Valve in Guide (0-200) .................................................... Dia:Intake Valve in Guide ................................................................... Dia:Valve Guide (Int. & Exh.) in Cylinder Head ................................... Dia:Valve Face (Exh.) (to stem axis) .............................................. Angle:Valve Face (Int.) (to stem axis) ................................................. Angle:Exhaust Valve Stem (PIN 3921) ................................................... Dia:Exhaust Valve Stem (PIN 629404) ............................................... Dia:Intake Valve Stem ........................................................................ Dia:Exhaust Valve Face .................................................................. Width:Intake Valve Face ..................................................................... Width:

.0035L .0030L .001 L .001 T45° 45’60° 45’ .4325 .4335 .3412 .1536 .1336

.0055L .0045L .003 L .003 T46° 15’61° 15’ .4335 .4340 .3422 .1602 .1478

.008 L .008 L .005 L --- --- --- --- --- --- --- ---

* If Camshafts bearings exceed this limit line ream and install .020 inch O.S. camshaft.** Install bushings in cylinder head bosses if this limit is exceeded. † If crankshafts are worn beyond these limits they may be repaired by grinding the crankpins and journals to 0.010” under newshaft limits and nitriding the crankshafts.

116

New PartsRef.No.

ChartNo. Description Minimum Maximum

ServiceMaximum

4242

11

VALVES AND GUIDES (Con't)Exhaust Valve (max. tip regrind .015) ......................................Length:Intake Valve (max. tip regrind .015) .........................................Length:Exhaust Valve Guide Bore ........................................................... Dia:Intake Valve Guide Bore ............................................................... Dia:

4.0564.041 .4370 .3432

4.0724.057 .4380 .3442

4.0414.026 --- ---

4343434444

45464748

11111

1111

CYLINDERCylinder Bore (Standard) (at any point) ........................................ Dia:Cylinder Bore. ................................................................. Out-of-roundCylinder Bore (largest dia. at bottom if any) ............................. Taper:Cylinder Bore (reground to .015 in. O.S.) ..................................... Dia:Cylinder Bore Surface Roughness (in micro inches R.M.S.) ..................................................................:Cylinder Barrel in Crankcase ........................................................ Dia:Intake Valve Insert in Cylinder Head ............................................ Dia:Exhaust Valve Insert in Cylinder Head ......................................... Dia:Valve Seat (to valve guide axis) Exhaust ................................. Angle:Valve Seat (to valve guide axis) Intake ..................................... Angle:Exhaust Valve Seat. ................................................................. Width:Intake Valve Seat. .................................................................... Width:

4.062 .000 .0004.077

35 .003 L .0055T .005 T44° 45’59° 30’ .0608 .0828

4.064 .001 .0014.079

45 .012 L .0085T .008 T45° 15’60° 00’ .0820 .1001

4.069 †† .002 †† .002 ††4.084

30 --- --- --- --- --- --- ---

49505152

53

1111

1

ROCKER ARMSBushing in Rocker Arm ................................................................ Dia:Rocker Arm in Support Bosses ..........................................Side Clear:Pushrod Over-all Length .....................................................................:Clearance Between Rocker Arm and Edge of Valve Spring Retainer ......................................................................:Valve Stem to Rocker Clearance (lifter deflated)................................ :

.002 T .00410.797

.020 .030

.004 T .01110.827

.110

--- .01610.787 (min.) .020 ---

545556575859606162

222222244

OIL PUMPOil Pump Gear in Pump Housing ........................................End Clear:Oil Pump Gear in Pump Housing .................................................. Dia:Oil Pump Gear Shafts in Accessory Case and Plate .................... Dia:Gear on Crankshaft Pilot .............................................................. Dia:Camshaft Gear on Camshaft Pilot ................................................ Dia:Oil Seal in Tachometer Drive Housing .......................................... Dia:Magneto pilot in Accessory Case ................................................. Dia:Starter pilot in Accessory Case ..................................................... Dia:Generator Pilot in Accessory Case ............................................... Dia:Oil Pump Gear Cavity. .................................................................. Dia:Oil Pump Gear Shaft Bore ............................................................ Dia:Oil Pump Gear Cavity ............................................................... Depth:Drive Hub to Generator Shaft ....................................................... Dia:Coupling Retainer to Hub ..................................................Side Clear:Gear on Generator Sleeve ........................................................... Dia:

.002 L .003 L .0015 L .0005 T .0005 T .001 T .001 L .0005 L .001 L1.499 .5620 .624 .0002 T .005 T .001 L

.005 L .006 L .003 L .0015 T .0015 T .007 T .005 L .006 L .005 L1.501 .5630 .626 .0012 T .015 L .003 L

.007 L .008 L .0045 L --- --- --- --- --- --- --- --- --- --- .020 L .005 L

†† If limits are exceeded, regrind to .015 inch O.S. or rebarrel.

117

New PartsRef.No.

ChartNo. Description Minimum Maximum

ServiceMaximum

63

646566

2

222

VACUUM PUMPBushing in Adapter ....................................................................... Dia:Bushing Bore ................................................................................ Dia:Bushing Thrust Face to Pump Mounting Pad ..........................Length:Pump Driven Gear in Adapter Assembly ...................................... Dia:Oil Seal in Adapter ........................................................................ Dia:Adapter Pilot in Crankcase ........................................................... Dia:

.001 T .81451.113 .0015L .001 T .000

.004 T .81551.115 .0035L .007 T .004 L

--- ---1.111 .005L --- ---

67686970

4412

CRANKCASEStarter Pinion Pivot in Crankcase ................................................. Dia:Starter Pinion Pivot Shaft ............................................................. Dia:Hydraulic Tappet Bore in Crankcase ........................................... Dia:Camshaft Bearings ....................................................................... Dia:Main Bearing Bore ........................................................................ Dia:

.001T .5595 .71871.37452.0615

.001L .5605 .71971.37552.0625

--- .558 --- --- ---

717273

74

75

7677

3&434

4

4

3&42

GEAR TEETH BACKLASHCrankshaft Gear to Camshaft Gear ....................................................:Magneto Drive Gears to Crankshaft Gear (-8) ....................................:Magneto Drive Gears to Camshaft Gear (-12, -14, -16,0-200) .................................................................................................:Starter Gear to Crankshaft Gear (-12, -14, -16,0-200) .................................................................................................:Generator Drive Gear to Camshaft (-12, -14, -16,0-200) .................................................................................................:Oil Pump Gears ..................................................................................:Vacuum Pump Driven Gear to Driving Gear (0-200) ..........................:

.006

.0140

.012

.029

.010

.014

.002

.009

.017

.014

.043

.014

.022

.006

.013

.020

.016

.050

.019

.025

.010

118

SPRING PRESSURES

New PartsRef.No.

ChartNo. Description

PartNo.

WireDia.

Comp.To Min. Max.

ServiceLimit/Lbs.

78

79

80

81

82

1

1

1

1

3&4

Valve Spring (C75, C85, C90, O-200)

Valve Spring (C75, C85, C90)

Valve Spring (C90, O-200)

Valve Spring (O-200)

Oil Pressure Relief Spring

24029

24030

24031

625958

631706

.111

.142

.091

.148

.041

1.137

1.168

1.075

1.168

1.56

40

58

27

77

6.06

44

63

30

83

6.31

37

55

24

74

5.75

TIGHTENING TORQUES

TorqueRef.No.

ChartNo.

Description ThreadSize In. Lbs. Ft. Lbs.

T-1T-2T-3T-4T-5T-6T-6T-7T-8T-9T-10T-11

121111114221

Spark Plugs ............................................................................................Plug, Oil Sump Drain..............................................................................Nuts and Cap Screws (General).............................................................Nut, Cylinder Base .................................................................................Nut, Cylinder Base .................................................................................Nut, Crankcase Through Stud (C75, C85, C90).....................................Nut, Crankcase Through Stud (O-200)...................................................Nut, Crankcase Through Stud................................................................Nut, Generator Drive Shaft .....................................................................Screw, Gear to Crankshaft .....................................................................Screw, Gear to Camshaft .......................................................................Nut, Connecting Rod Bolt .......................................................................Bolt, Propeller Hub .................................................................................Nut, Engine Mount Bolt (-8, -12 and –16 Models) ..................................Nut, Engine Mount Bolt (-14 and O-200 Models) ...................................

18mm5/8-181/4-287/16-203/8-247/16-207/16-203/8-245/16-241/4-281/4-283/8-243/8-243/8-243/8-24

300 - 360Oil Tight90 - 110490 - 510410 - 430400 - 450490 - 510275 - 325175 - 200140 - 160140 - 160400 - 475200 - 220 60 - 80180 - 190

25.0 - 30.0

7.5 - 9.240.8 - 42.534.2 - 35.833.3 - 37.540.8 - 42.522.9 - 27.114.6 - 16.711.7 - 13.311.7 - 13.333.3 - 39.616.7 - 18.3 5.0 - 6.715.0 - 15.8

119

TABLE XXIV GENERAL USE – TIGHTENING TORQUES

BOLTS, NUTS & SCREWS DRIVING STUDSSize8-3210-32¼-20¼-285/16-185/16-243/8-163/8-247/16-147/16-20½-20

In. Lbs.22.0 - 30.036.0 - 50.075.0 - 85.090.0 - 110.0155.0 - 175.0180.0 - 220.0220.0 - 260.0275.0 - 325.0

400.0 - 450.0550.0 - 600.0

Ft. Lbs.1.9 - 2.53.0 - 4.26.3 - 7.17.5 - 9.213.0 - 14.615.0 - 18.318.3 - 21.722.9 - 27.1

33.3 - 37.545.8 - 50.0

In. Lbs.

50.0 - 70.0

100 - 150

200 - 274

300 - 424

Ft. Lbs.

4.2 - 5.8

8.3 - 12.5

16.6 - 22.8

25.0 - 35.4

NOTE

Torque loads are listed for use with oil onthreads, except for studs. Stud driving torquesapply when the threads are coated with Alcoathread lube if hole is blind, or with National OilSeal compound if hole is through to a cavitysubject to oil.

If cotter pin holes must be aligned set torquewrench at low limit and tighten nut to first holebeyond this torque. However, on connecting rodnuts the torque limits must be maintained.Replace nut and repeat as required. In no caseshall connecting rod nuts be torqued below lowlimit or over high limit.

TABLE XXV PIPE PLUGS

Size In. Lbs. Ft. Lbs.

18-271/4-183/8-181/2-143/4-14

60 - 80130 – 150185 – 215225 – 285310 - 350

5.9 – 6.610.9 – 12.515.4 – 18.021.2 – 23.825.8 – 29.2

Figure 44. Limits and Lubrication Chart (Sheet 1 of 4) – Cross Section View

Figure 45. Limits and Lubrication Chart (Sheet 2 of 4) – Longitudinal Section View.

Figure 46. Limits and Lubrication Chart (Sheet 3 of 4) – Rear View and Horizontal Section, -8 Model.

Figure 47. Limits and Lubrication Chart (Sheet 4 of 4) – Rear View and Sections, -12, -14, -16 and O-200 Model.