Metric Mechanic M42 M44 Engine Series - BMW E30 Club

Page �Copyright© November 2006 by Metric Mechanic Inc™ 505 East Main, Richland, MO 65556PH: 573-765-1269 FAX: 573-765-4216, Email:[email protected], www.metricmechanic.com

Metric Mechanic M42 M44 Engine SeriesOne of Metric Mechanic’s NEW Engine Series

Oftenthe4CylinderBMWsare overshadowed by their 6Cylinder cousinsof the samemodel.Forexample,the1990318is can get over-looked infavorof the325iorM3.Thesame goes for the 318ti and1.9 liter Z3. But at MetricMechanic, we look at the 4CylindersasjuniormodelsoftheMcars.TheE30318iuseslighterscaleddowndrivetraincomponentsthantheE30M3.TheE36318ti&Z3continuethis theme through smallermorecompactbodies.Allthe4 cylinder car models havelightweight bodies with light-weight engines, transmissionsanddifferentials.Weightisnotonlytheenemyofaccelerationbutalsohandlingandbraking.The M42 and M44 DOHC(doubleoverheadcam)enginesusedinthesemodelshaveexcellentpowerpotential.Currently,our2100RallyEngineisgoodforjustover200HPandcanripthroughthe1/4milesin14.5sec.at98mphinanE30318is.FASTfora4banger! The power note (the sound the engine makeswhenitapproachespeakcylinderfilling)comesonat4300rpmsandtheenginegeneratesverystrongpulltoits7700rpmredline.Evenbelow4300the

Introduction

2100 Rally engine on the hook ready for installation

Metric Mechanic 2000 Sport Engines use ourlightweightforgedalusilpistonsalongwiththestockconnectingrodand81mmstockcrankshaft.MetricMechanicRallyEngines are designed andbuilt tobe the fastest street engines thatwe sell. They arebasicallyfullraceenginesde-tunedbydroppingthecompressionandcammingslightly. Theinternalsarebeefedupbyagainusinglight-weight but strong forged alusil pistons as well asforged4340ChromeMolycustomrodsof“H”or“I”Beamdesign,and88mmforgedsteelcrankshafts.These components greatly extend the life of theengineandmakeitvirtuallybulletproof.

Anatomy of our M42 Engine

enginehasadecentamountoftorquewhichmakesitagreatdailydrivercapableof30mpginhighwayuse.Nowforacloser lookatthenewMM“BabyM3KillerEngine”.

Page �Copyright© November 2006 by Metric Mechanic Inc™ 505 East Main, Richland, MO 65556

PH: 573-765-1269 FAX: 573-765-4216, Email:[email protected], www.metricmechanic.com

2100 Rally Acceleration Graph1991 E30 318is with Metric Mechanic 2100 Rally M-42 Engine

“Baby M3 Killer!” Weight is the enemy of acceleration, braking and handling. The M42 engine is already light - but we make it POWERFUL! The Metric Mechanic gang couldn’t stop talking about this car! Our comments were:“More power than the factory ever intended!” “How many cars can do almost 100 mph in a 1/4 mile and 30 mpg in highway driving?” “The Lotus of BMWs, a powerful engine coupled to a lightweight body and drive train.”


Piston and Rod

By lightening up thereciprocating mass, anengine’s longevity canbe greatly increased. Ina Sport Engine, this isdone by reducing thepiston and pin weightby15%overstockwhichinturnincreasesrodlifebecauseitisnotbearingsomuchweight.Alsoitreducestheloadontherodbearingsandcrank-shaft. With the M441.9 liter rod and MMSport piston shown tothe left, the reciprocat-ing mass is only 965grams.ButwithastockM42, 1.8 liter rod, the

massis1015grams-50gramsmore!Usingthe1.9literrodisaneffectiveoptiontowardsreducingthereciprocating mass in an M42 engine. These rodshaveabearingcapthatmeasures.275”(7mm)atthethinnestpoint.Wechecktheirconditioncloselyfor“outofroundness”becausethethinbearingcapcancausethebigendoftherodtoknockoutofround.Onceoutofround,therodbearingcapwillusuallyfitlooselyontherod,whichleadstofatigue.

Anatomy of the M42/M44 2000 Sport Engine

MM M42/M44 2000 Sport Bottom End Components (see below for M44 crankshaft)

Description Top:the2000Sportbottomendcomponentsincludeeitherthe M42 81mm forged steelcrankshaftortheM4483mmcastcrankshaft. Shown right: M42 rods at610grams,optionalM44rodsat 540 grams on the right.Bothare140mmlong. LeftCenter:ourMMslittedlightweight forged alusil pis-tonsat310gramsandtaperedwall wrist pins at 89 grams.The ring pack uses a 1.5mmMoly compression ring, a1.5mmironscrapperringanda3mmthreepieceoilring.

Left: M44 2000 Sport Engine crankshaftRight: M42 2000 Sport Engine crankshaft

M42/M44 Cranks Thecrankshaftontheleftisusedinthe‘96,1.9literM44engine,has4counterweightsandweighs28.5lbs.ThiscrankisusedinOBDIIenginesandemploysa60toothtimingwheelthat’sattachedtothe4thcounterweight.Thecrankontherightisthepre’96M42forgedsteelcrankshaft,has8counter-weightsandweighs29.5lbs.

M44 2000 Sport Piston Rod Assembly

Lightweight yet High Quality Strong Internals



M42, M44 PistonsDecades of Experience & Research have led to MM’s Piston Designs

Left: M42/M44 2000 Sport Piston for use withthe stock rod

Middle:A 2100 Turbo Piston used with our MM “H” Beam Rod

Right:The 2100 Rally piston used with MM Ultralite “I” Beam Rod

A high quality properly designed forged piston,morethananyotherenginecomponent,cangreatlyincrease the life of a High Performance or RaceEngine.Enginelife,iscurtailedbytheuppercom-pression ringhammeringout the ring groove andpartsfatiguecausedbyaheavyreciprocatingmass.Aforgedpiston is40%strongerandcanbemade15%-20%lighterthanacastpiston-whendesignedproperly. Although a forged piston is the perfectsolution,averageforgedpistons(notours)dohavedisadvantages. Their expansion rate is 35% - 50%more thanacastpistonand requires .0040”clear-anceormore.Thismuchclearancecreateshighoilconsumption (250-500miles/quart)andcauses thepistontorattleoncoldstart-up. Considerthisinlightofthefactthathighrevvingheats up the piston, requiring more cylinder wallclearancetoaccommodatetheexpansion.WhenwebegandevelopmentofourHiPerformanceEnginesin1984,wequicklyunderstoodthebenefitsofswitch-ingtotheForgedAlusilPiston.Theseearlypistonswere graphite coated to reduce cylinderwall scuff-ing.Duringtheenginebreak-inperiod,thecoatingeffectivelyworeoff.Manysuchengines,underharduse,arestillperformingwithover200,000milesonthem.Despitethissuccess,wefeltcertainthattheremustbeanevenbetterwaytoachievetighterpistontocylinderwallclearance.

How MM Pistons Greatly Extend Engine Life! Metric Mechanic Slitted Pistons

Thenintheearly‘90s,wecompleteddevelopmentof our “Slitted Piston” technique which involvesmachiningahorizontalslitintothepistonjustundertheoilringgroove.Thisslitkeepspistoncrownheatfromtransferringdirectlytotheskirtbyconductingitinitiallytothequitemassivepinbosswhichactslike a heat sink. This interruption along with thelongertraveledpath,helpstheheatdissipate;allow-ingforcoolerskirtsthatexpandless.ThisMMslitalsoreducestheexpansionrateofourForgedAlusilPiston from35%toonly5%over thatofa stockpistonandistheprinciplereasonforourtightclear-ances.Generally,werun.0020”-.0025”clearanceonourSportEnginesand.0023”-.0028”ontheRallyEngines.Thiskeepsoilconsumptionlowandpistonrattlingtoaminimumoncoldstart-ups.

Metric Mechanic Boosted Pistons

AprimaryconcernwithBoostedenginesispistonmeltdown. In order to avoid pistonmeltdownweincreasethecrownthicknessby2mm,lowerthetopringgroove,anduse4mmwidehighradialtensionoil rings.Thepistonpinwall is thicker for addedstrengthanditweighs105grams.Thetotalpistonandpinweightisapproximately90gramsmorethanaRallypistonusedinanormallyaspiratedengine.


M42/M44 Cylinder Head & Components

Currently our M42/M44 heads flow 6% overthe stock head. Pre ’93 M42 heads are convertedfrom7mmto6mmvalvesforaddedflowandlighterweight.Ourshortervalveguideincreasesflowoverthehighsideradiusoftheport.Seatsaremachinedwiththreeselectseatanglesdeterminedduringflowbenchtesting.A45°anglemachined intotheseatmatches the valve head diameter. We also modifytheintakevalveback-cutangletoincreaseflow.Andweaddourpatentedsurfaceturbulenceconcentricgrooves to the valve itself. For over 16 years, thistreatment has proven to increase flow at low lifts.Anaddedbenefitisthattheyhelpatomizefuelbytumblingairflowoverthevalvesurfaceandpullingfuelparticlesoffthebackofthevalve.

M42 Head with Metric Mechanic modifications, ready for final assembly. Shown left to right is an Hydraulic Lifter Bucket, “Bee Hive” Valve Spring topped with Retainer, a Viton 6mm Valve Guide Seal with 6mm Keepers and Spring Perch,

Manganese Bronze Valve Guide shortened to 6mm and a pair of 6mm Surface Turbulenced Intake and Exhaust Valves

Tour of the MM Cylinder Head

Ported Head, Surface Turbulence Parts and Assembly Components

Weuseaspecial100mmlongsocket head bolt. The stocktorquetoyieldheadboltsare90mm long. We torque ourheadboltsdownto64ft.lbs.These longerboltsspreadtheload along the cylinder wallto reducewall distortion andunlikethefactoryheadbolts,theseboltsarere-usable.

MM 100mm Head Bolts

Left: MM 100mm long Socket Head, Head BoltRight: Stock 90mm longTorx Head, Head Bolt



M42 Sport Cam & Valve Train Components

Metric MechanicSport Cam for the M42 Engine

258°Intake

228°Exhaust

.005 258° 228° .010 246° 216° .015 242° 212° .020 238° 206° .050 224° 188° .100 202° 168° .200 166° 128° .300 124° 76° .400 64° --- Lift .439” .356” 11.15mm 9mm

Shrick 256 Camfor the M42 Engine

256°Intake

256°Exhaust

.005 256° 256° .010 242° 242° .015 236° 236° .020 232° 232° .050 215° 215° .100 194° 194° .200 154° 154° .300 112° 112° .400 30° 30° Lift .408” .408” 10.35mm 10.35mm

M42 Sport Cams OnanMM2000SportEngine,wecamupthe intakeside (258°Duration/11.15Lift)quiteabitmore than theexhaust.Usingahotterintakecam,increasesRPMsandenhancestopendperformancewhilekeepingthestockexhaustcams,maintainsthemidrangeandbottomendtorque.Intheend,thiscamcombinationmakesforanenginewithabroadpowerband.Seecamchartlowerleft.

M42 256° Shrick Cams TheShrickcamsetshownlowerrightisbasicallyanE36M3intakecamcopy.

Comparing the MM Sport Cams with Shrick Cams On the surface,by simplycomparingintakedurationat.005”,ourcamdoesn’tlookthatmuchhotterwiththeMMat

Comparing Intake and Exhaust Cams used for a Broad Power Band

258°andtheShrickat256°-amere2°advantage. But an engine takes inmostof it’s airwhen the camhas the intakevalve open to .300” lift or more. Duetofasterrampspeeds,ourcamhas124°durationversustheShrick112°durationat.300”lift.Byhavinganadditional10%moredurationatthenoseofthecam,theenginewillcontinuetomakepower10%higherinRPM.Also,alargerenginewillneedmorecamdurationandlift.A10%larger engine will need 10% more nosedurationonthecamat .300” lift tohitthesamepeakRPMpoint. In the past, most manufacturers ranthesamecamontheintakeandexhaustside. But, when the ‘95 M3 came out,BMWchosetoruntheirintakecamwithmoredurationandliftthantheexhaustcam.Theyusedanintakecamwith256°durationand10.35mmlift (sameas the

Shrick) but it alsohad25°ofVANOSaddedtotheintakecam. And theyusedmildera235°exhaust cam with9.7mm lift alongwith VANOS toincreasethelowandmidrangetorqueoftheengine. So by runningtwodifferent lobeswhere the intakecam is larger byabout 15% overthe exhaust cam,theenginedevelopsa much broaderpowerband.Thisisalsowhatwedo.


Metric Mechanic - M42 Sport Cam Timing MapIntake Cam - 258° Dur. / 11.15mm Lift at .005” - Opens 10° BTDC - Close 68° ABDCExhaust Cam - 228° Dur./ 9.0mm Lift at .005“ - Opens 41° BBDC - Close 7° ATDCValve Opening During Overlap at TDC ........................... Intake .020” (.5 mm).......................................................................................................Exhaust .015“ (.4 mm)

TDC

BDC

IntakeOpens at10° BTDC

Intake LiftOff Seat

.020” ATDC

Exhaust LiftOff Seat

.015” ATDC

IntakeCloses at 68°ABDC

ExhaustOpens at41° BBDC

ExhaustCloses at7° ATDC

TDC Top Dead CenterBDC Bottom Dead CenterBTDC Before Top Dead CenterATDC After Top Dead CenterBBDC Before Bottom Dead CenterABDC After Bottom Dead Center

Exhaust Cam - 228

Intake Cam - 258

No Valve AdjustmentUses Hydraulic Lifters

Exhau

st

Intake

Crown Treatment Nitrided Heat Heat Treated Treated

Rockwell Hardness 54c 48c (C-Scale)

Crown Thickness .0957” .0933”

Wall Thickness .039” .035”

Lifter Spring .038” .031” Wire Diameter

35mm Lifter BucketsComparisons

MM Lifter Stock

Metric MechanicBee Hive Spring & Retainer

Metric Mechanic’s use of the “BeeHive”isapreferencethatevolvedoutofexperience with three previous springschoices.Becausespringrateisverycriti-calinmakingthehydrauliclifterworkathighRPMs.Whenusingcamswithhigherliftsandfasterrampspeeds(likeourcamdesigns) we are continually researchingforbettersprings. Our “Bee Hive” springs and retain-ers are 25 grams lighter than the stockdual spring set-up. The 6mm retainerweuseismuchstrongerthantheBMWfactory6mmretainer.Forinstance,our6mm retainer can take up to a 310 lb.loadbeforethekeeperspullthroughtheretainer.ThefactoryBMW6mmretainerfailsat185lbs.Wehavetapedamissedshiftwherethetachwasjustshyof9,000RPMwithnoincidentofbentvalves.

MM Heavy Duty Lifter Bucket Our 35mm Lifter Buckethas a harder nitrided crownmakingitmorewearresistant.The lifter spring is stiffer (see spring on left in Photo) to reducelifterbleed-downandhelpthelifter track thecamprofileathigherRPMs.Whenanengineexceeds150,000milesandit’srebuild time,we suggest con-sideringnewhydrauliclifters.

MM “Bee Hive” Valve Spring with Lightweight 6mm Retainer and MM Heavy Duty 35mm Lifter Bucket

M42 Sport Cam & Valve Train Components

Shows the hydraulic lifter and spring removed from the lifter bucket.

MM to left, stock to right.

Upgraded Valve Train Components



Anatomy of the M42 2100 Rally Engine Rally Engine Part Descriptions

MM’s 2100Rally engine isbuiltwithan88strokecrank,chainsprocket,harmonicbal-ancer hub, plus larger crankbolt&washer.Rodsarelight-weight forged 4230 ChromeMoly Steel, shot peened andfullyCNCmachined. Shownhereare525gram“H”beamrods.MMUltralite “I”BeamRodweighs475grams-stockrod610grams.Pistonsare310gram forged Alusil (13% sili-concontent)310grams.Stockpistonsweigh360grams.

Boththesecranks,originallyfroma2literEuropeanDiesel,needmodificationsbeforetheycanbeinstalledintheM42orM44Block.Shownleftistheearlierver-sion,an88strokewith8counterweightswhich is easier to adapt for the engine.Thelatercrankontherighthasan89.6mmstrokewith4smallercounterweights.Because this crank runswith a counter-balancesystem,itisfarmoredifficulttoadaptin.Theneededadaptorsareshownabovewiththecranks.

The 88 stroke crank musthave the nose turned downand a second keyway addedto secure the chain sprocketand front harmonic balancerhub. Close-ups are shown ofthemachiningprocess(above)andtheendresulttotheleft.

2100 Rally Crankshaft, Pistons and Rod Bearings

Left: 88mm Crankshaft, Right: 89.6mm Crankshaft

Adding an extra Keyway Groove to the 88mm Crankshaft

Crankshaft Nose adapted to accept the Stock Crank Sprocket


M42 M44 RodsMetric Mechanic Rod Line-Up: the usual prospects!

Far left at 140mm long istheM44540gramrod.Next,an 140mm long M42 Rodthatweighs 610 grams. Theseare used in our 2000 SportEngines.ThethirdrodisMM’sUltralite“I”Beamrod,138mmlongandonly475grams,usedin our 2100 Rally engines.FourthonthefarrightistheMM“H”Beam rod. It’s also138mm long, weighing in at525grams.Thisrodsisgener-allyusedinboostedengines.

OurMMRallyrodsshowntotheleft,aremuch lighter and twice as strong asthe stockproduction rods.Forged from4340 chrome moly steel, makes themsuperiorinstrengthtobilletrods.Thenthey are fullyCNCmachined to sculp-turedownexcessweightandfinallyshotpeenedtoimprovesurfacestrength.Theyarecappedoffwith3/8”ARPbolts.Thesmall ends of each rod are coupled tothe piston with a 21mm lightweight 80gramwristpin.Bycomparison,thestockpistonpinweighs105grams.

Wrist Pins: Left 21mm, 105 gram Turbo, Middle 21mm 80 gram Rally,

Right 22mm tapered wall 89 gram Sport

Reducing reciprocating mass weight(piston&rodassembly)hasafargreatereffectonaccelerationthanreducingtherotational mass. Lightening a rotationalmass component such as a flywheel,comesintoplayonlyunderaccelerationbut the reciprocatingmass isconstantlyaccelerating and decelerating. At 7000rpm,thepistonandrodassemblyisgoingfrom0mphto100mphandbackto0mph-14,000timesinoneminutesincethepistonchangesdirectiontwiceatthetop andbottomduring one revolution.The jerking motion against the pistongoesto1500G-Force.Usingalightweightreciprocatingmassassemblywillnotonlymakeanenginespoolupquickerbutitwillgreatlyincreaseitsreliability.

Benefits of Reducing the Reciprocating Mass

Left: MM Ultralite “I” Beam Rod Right: MM “H” Beam Rod

From Left: M44 Stock Rod, M42 Stock Rod, MM Ultralite “I” Beam and MM “H” Beam Rods

Page �0Copyright© November 2006 by Metric Mechanic Inc™ 505 East Main, Richland, MO 65556


M42, M44 Oiling SystemAmple Oiling - the “Life Blood” of a Healthy Performance Engine

Oil Pressure Loss from Failed Pan Gasket Theoilpumpisdrivenoffthefrontofthecrank-shaftandsitsinthefronthousing.Theoilpansealsbetween the oil pump and the oil pumppick-up.Oilpanboltsarehiddeninsidetheoilpan.Some-timesthey’llcomelooseandfalldownintotheoilpan.Whenthishappens,airgetsdrawninbetweenthepumpandthepick-up fromthe looseoilpangasket(loosenedbythedislodgedbolts).Intheendtheengineloosesit’soilpressureandtheoilpumpwon’tprimeup.MM Solution for Failed Pan Gasket Ouroilpangasketisreinforcedbyasiliconseal-ingbeaddirectlyonthiscriticalpick-uppoint.WealsouseBlueLoctiteontheinternaloilpanboltstopreventthemfromworkinglooseinthefuture.

Worn out stock thrust bearing from an M42 engine. 360° Main Bearing Oiling System: double thrust bearings.

The bottom main bearing cap has two narrowlock tang grooves. The 360° Main Bearings thatweuse,haveasinglelocktangthatis3.5mmwide.Thereforethestockbearingcapmustbemodifiedtoacceptthewiderlocktang.

Usingamillingmachineandcustomkeywaycutter.140”wide,wemachineinthenewlocktanggroovetoacceptthe360°oilingmainbearings.

360° Oiling Main Bearings Installed.

Oiling Problems Inherent in the stock M42 M44 EnginesThrust Bearing Failures StockM42M44enginesonlyhavea thrust sur-faceonthetopMainBearing.Becauseofthislim-itedthrustarea,thethrustsurfacecanwearout.MM Solution for Thrust Bearing Failure We use main bearings with a thrust surface onboththetopandthebottom.

High RPM Oil Starvation Thestockmainbearingshaveabouta200°oilinggrooveandoilisshutofftotherodbearingsfrombottomdeadcentertotopdeadcenter.Thiscausesoilstarvationathighrpm.MM Solution for High RPM Oil Starvation Thesebearingsalsofeaturea360°oilinggroovesotherodbearinghasaconstantsupplyofoil.

Page ��Copyright© November 2006 by Metric Mechanic Inc™ 505 East Main, Richland, MO 65556PH: 573-765-1269 FAX: 573-765-4216, Email:[email protected], www.metricmechanic.com

Rod Bearings, Timing Chain & Windage Tray Scrapper System

Oiling System continued & the Timing Chain

Upgrading the Rod Bearings Currently, we use one of three rod bearings inourM42/M44engines.ThestockaluminumfacedbearingontherightworkswellinourSportengines.Next is a heavy duty tri-metal rod bearingwith athinBabbitfacing,copperunderlayandasteelback-ing. This bearing is used in our daily driverRallyengines.Shownright is thesamebearingbutwithaTefloncoatedfacewhichincreasesbearinglifebythree times under race conditions. These bearingsareusedinourDriver’sSchoolMMRallyengines. Remember,uponrequesttheseTeflonCoatedbear-ingscanbeusedinanyMetricMechanicengine!

Single Row Timing Chain Conversion ForyearswehaveusedsinglerowtimingchainsontheM10,M30singleoverheadcamengines.Theyhave proven to be extremely reliable to the pointwhere we trust them more than the Double rowchain.Yesthedualrowisphysicallystrongerbutdueto thecentrifugal forceof the spinningchain, thesheermassof thedoublerowchaincancausethechainlinkstostretchandwearoutandthechain’swhippingactioncanalsocauseexcessivewearontheguide and tensioner rail. Converting to the singlerowchainreducestherotatingmassofthechainandsprocketbyabout2lbsandto-datewehaveneverhadachainfailurefromthismodification. Adds$200tothecostofanyM42M44engine.

E30 2100 Rally Windage Tray/Scrapper Awindagetray’sfunctionistoseparatethecrank-shaftfromtheoilinthesumpandthebuiltinscrap-perisusedtopulloffoilsprayfromthecrankshaftanddeposititbackintotheoilsump.Thewindagetray also keeps the oil level in the pan calm andinsures that the pick-up remains submerged. Fur-thermore, by reducing oil drag on the crankshaft,theenginegainsacouplemoreHP.OurWindageTray/ScrapperBarSystemisanadditional$350andavailableonlytothosewhopurchaseanenginefromus.We cannot sell it as a separate unit because itrequirescustommachiningandfitting.ThewindagetrayshownbelowdoesnotapplytotheE36M42/M44 because they come stock with oil pans thathaveamagnesiumwindagetraybuiltrightin.

Frontal View of reversed Block showing Windage Tray on underside.

Left is the MM Single Row Sprocket and ChainRight is a Stock Double Row Sprocket and Chain

Machined single row sprocket set for use in our M42 M44 engines.

Left to Right: Stock Aluminum Faced Bearing, Heavy Duty Tri-Metal, Heavy Duty Tri-Metal Bearing with Teflon Coated Face

Page ��Copyright© November 2006 by Metric Mechanic Inc™ 505 East Main, Richland, MO 65556


Metric MechanicRally Cams for the M42 Engine

272°Intake

258°Exhaust

.005 272° 258° .010 260° 246° .015 254° 242° .020 252° 238° .050 234° 224° .100 212° 202° .200 174° 166° .300 132° 124° .400 76° 64° Lift .448” .439” 11.4mm 11.15mm

Intake Cam - 270° Dur. / 11.4mm Lift at .005” - Open 20° BTDC - Close 70° ABDCExhaust Cam - 250° Dur. / 11.15mm Lift at .005“ - Open 55° BBDC - Close 14° ATDCValve Opening During Overlap ...................Intake .025” (.63 mm).................................................................................Exhaust .020“ (.51 mm)

TDC

BDC

IntakeOpens at20° BTDC

Intake LiftOff Seat

.032” ATDC

Exhaust LiftOff Seat

.028” ATDC

IntakeClosesat 70°ABDC

ExhaustOpens at55° BBDC

ExhaustCloses at14° ATDC

TDC Top Dead CenterBDC Bottom Dead CenterBTDC Before Top Dead CenterATDC After Top Dead CenterBBDC Before Bottom Dead CenterABDC After Bottom Dead Center

Exhaust Cam - 240

Intake Cam - 264

Valve AdjustmentIntake .011” ± .101 Exhaust .013” ± .001

Metric Mechanic - M42 Rally Cam Timing Map

Exhau

st

Intake

Rally Cam Description

OurRallycamspullstrongallthewayto their 7700 redline in our 2100 RallyEngine. These cams are rather top endhappybutwillpullstrongfrom4300rpmswhencombinedwithourpulsechamberintakemanifold.Thesecamsneedtobeusedwith our “BeeHive” valve springsandlightweight6mmretainers.Thevalvetrain shouldbe lightenedupwith6mmvalves.MM’sheavydutyhydraulic lifterbucketsworkwellwithourRallycamsforhigh RPM maintenance free operation.For extreme high RPM running, switchovertoourMMMechanicalLifterBucketSystem.ShimpadsarefromanE46S54engine.Valveadjustmentis.004”to.005”whenusedwithahydrauliccam. Bee Hive Spring, Retainer

& Stock Spring PerchLeft: MM Heavy Duty Hydraulic Lifter

Right: MM Mechanical Lifter with shim pad

MM Rally Cam & Valve Train ComponentsUpgraded Valve Train Components


Lightening the M42 Valve TrainReduced by Over 50 Grams per Valve Assembly!



M42 E30 Pulse Chamber Intake Manifold Increasing Bottom End and Mid Range

M42/E30 Pulse Chamber Intake Manifold

Our MM PulseChamber Intake Mani-fold greatly increasesbottom end and mid-rangetorqueintheM42engine. When lookingclosely at the base ofthe “C” runners on anM42 E30, capped offtube extensions are vis-ible.Wecallthesepulsechambers.

How Does the Manifold Work?

After the intakemix-ture (fuel and air mix-ture) enters a cylinder,the intake valve slamsshut.Inthestockmani-fold, the intake mix-ture starts to recoil offthe back of the intakevalveandback-flowsuptheintakerunnertotheplenum.Butwithapulsechambermanifold,theintakemixturegoesstraightbackintothepulsechamberbecausethatisthepathofleastresistance.Nextthemixturerecoilsofftheback of the capped-off tube (the pulse chamber)and heads for the back of the intake valve readyto enter the engine when the intake valve opens.Sincetheintakemixtureisreadytogointothecyl-inder,thecylinderfillingisincreasedandtheenginemakesmorepower.FrompastDynotesting,wecanclaima15%increaseinmidrangetorquewiththismanifold.

Side View of the Pulse Chamber Intake Runner

Pulse Chamber Intake Manifold on a 2100 Rally Engine


M42/M44 Lightweight Flywheel & Clutch Assembly

Left to Right: Lightweight Flywheel & Bolts, 228mm Disc with Sprung Hub, 228mm Pressure Plate and Throw Out Bearing

Description

From the factory, M42/M44 engines use largeheavydualmassflywheelswith215mmclutchassem-blies.Inproportiontotheenginedisplacement,wethink this flywheel sets the record for being theheaviestBMWflywheelscalinginatamassive28.25lbs.Wereplaceitwithasinglemassflywheelweigh-ing11to11.5lbs.andupgradetoa228mmclutchassembly.The Significance Thestock215mmclutchcantakeuptoabout155ft. lbs.of torque.The228clutchassemblyweusecanhandleuptoabout230ft.lbs.oftorque.Goingtoa228clutchwillvirtuallyeliminateanyneedfora clutch replacement. This amount of “overkill”reducestheprobabilityofeverhavingtoreplacetheclutch.Forthemoney,alightenedflywheelwith228clutch assembly is thebest performancemodifica-tionyoucandotoanM42orM44.

How a Lightened Flywheel Works

Whileanenginerevs,theflywheelcreatesapara-siticdragontheengine’sabilitytoaccelerate.Thefaster the flywheel is accelerated, the greater thepowerlosstotheengine. Forexample,apairoftestsona3700,firstwiththestock23lb.andsecondwiththeflywheellight-eneddownto12.5lbs.revealedanimpressivegain.When accelerated at 1500 RPMs per second, theenginepickedup17HPwiththelightenedflywheel.Considerthis:1500RPMspersecondisequivalentto a 1st gear acceleration. Here’s another way tolookatit:everypoundremovedfromtheflywheel,iscomparabletotaking15lbs.offthebodyweight.Summary Installing a lightenedflywheeldoesnotgeneratemoreHPinanengine.It’smorelikethereductionofaloss.

Best Performance Modification for the Money



MM 2000 Sport Engine Displacement........................ 1925cc BorexStroke........................ 87mmx81mm CompressionRatio.............. 11.0:1 Horsepower........................... 170@6500 Torque.................................... 145@4500 Redline................................... 7000rpm

Block Components Crankshaft............................. Stock81mmstrokeforgedsteelwith8counterweights,29.5lbs.

Rods........................................ StockM42/1.8rod,595grams Optional:StockM44/1.9rod,540grams

Pistons MM87mm.................... LightweightForgedAlusilPistonventedskirts 11.0:1CompressionRatio/310grams StockCastPiston.......... 10.0:1CompressionRatio/360grams

Rings....................................... 1.5mmMolyTop,1.5mm2ndand3.0mm 3pieceOilRing(lowradialtensiondesign)

PistonPin.............................. 22mmtaperedwall,89grams Stock............................... 22mm/105grams

Oiling Block Modifications MainBearings....................... Stockmainbearingswith200°oilinggrooveand360°thrust

bearingsurface

RodBearings......................... StockaluminumfacebearingsOption:Tri-metalheavydutyTefloncoatedbearings

WindageTray(E30only)........Optional:Awindagetray/scraperassembleisinstalledtopeelslingingoiloffthecrankandsendittotheoilpick-up.

Head Assembly HeadFlow............................. 6%overstock

HeadBolts.............................MMsocketheadbolts100mmlongtorquedto64ft.lbs.reusable .......................................... Stocktorquetoyieldtorxheadbolts90mmlong-nonreusable

Cams.......................................MMSportCamsIntake:262°Duration/11.15mmLift

Exhaust:228°Duration/9.0Lift

HydraulicLifter....................MMheavydutyhydrauliclifterwithnitratedcrown

Valves...................................... 33.0mmintakeand30.5mmexhaustwithSurfaceTurbulenceand7mmstems

..........................................Optional:lighterweight33.0mmintakeand30.5mmexhaustwithSurfaceTurbulenceand6mmstems

ValveSpring...........................MM“BeeHive”springwithlight7mmretainerOptional:MM“BeeHive”springwithlight6mmretainer(25gramslighterthanthestockdualspringwith7mmretainer)

ValveGuide...........................MM7mmmanganesebronze ..........................................Option:MMshortened6mmmanganesebronze

2000 Sport M42 Engine - Spec Sheet For the Enthusiastic Street Driver


2000 Sport M44 OBDII/M42 Engine - Spec Sheet

MM 2000 Sport Engine Displacement........................ 1973cc BorexStroke........................ 87mmx83mm CompressionRatio.............. 11.0:1 Horsepower........................... 175@6500 Torque.................................... 150@4500 Redline................................... 7000rpm

Block Components Crankshaft............................. Stock83mmstrokecastwith4counterweights,28.5lbs. .......................................... withOBDII/60toothtimingwheel Rods........................................ StockM44/1.9rod,540grams

Pistons MM87mm.................... LightweightForgedAlusilPistonventedskirts 11.0:1CompressionRatio/310grams StockCastPiston.......... 10.0:1CompressionRatio/360grams


PistonPin.............................. 22mmtaperedwall,89grams Stock............................... 22mm/105grams

Oiling Block Modifications MainBearings....................... Stockmainbearingswith200°oilinggrooveand360°thrust

bearingsurface

RodBearings......................... StockaluminumfacebearingsOption:Tri-metalheavydutyTefloncoatedbearings

WindageTray(E36only)........ Stockaluminumwindagetrayinoilpan



Cams.......................................MMSportCamsIntake:262°Duration/11.15mmLift


HydraulicLifter....................MMheavydutyhydrauliclifterwithnitratedcrown

Valves...................................... 33.0mmintakeand30.5mmexhaustwithSurfaceTurbulenceand6mmstems

ValveSpring...........................MM“BeeHive”springwithlight6mmretainer

ValveGuide...........................MM6mmshortenedmanganesebronze

For the Enthusiastic Street Driver



MM 2100 Rally Engine Displacement........................ 2091cc Bore......................................... 87mmxstoke88mm CompressionRatio.............. 11.5:1 Horsepower........................... 205@7350 Torque.................................... 165@5150 Redline................................... 7700rpm Acceleration........................... 0-60-6.5sec. 1/4mile-14.5sec./98mph

Block Components Crankshaft............................. 88mmstrokeforgedsteelcrankwith8counterweights,29.5lbs. stock81mmstokeforgedsteel

Rods........................................MM138Ultralite“I”BeamRod,480grams orMM138mm“H”BeamRod,540grams‘95&newer

Pistons MM87mm.................... LightweightForgedAlusilPistonventedskirts 11.5CompressionRatio/310grams StockCastPiston.......... 10.0CompressionRatio/360grams


PistonPin.............................. 21mm/80grams Stock............................... 22mm/105grams

Oiling Block Modifications AntiDrainBackValve......... Valveaddedforhydrauliclifterbucketstokeeptheliftersfrom

drainingdown

MainBearings....................... 360°oilgroovetoinsureaconstantflowofoiltotherodbearings.Stockmainbearingshaveonlya200°oilinggroove.thispreventsoilfromfeedingtotherodbearingsfrombottomtotopdeadcenter.Alsohavea360°thrustbearing-thestockthrustbearingis180°

RodBearings......................... Tri-metalheavydutyTefloncoatedbearings

WindageTray.......................Optional:Awindagetray/scraperassembleisinstalledtopeelslingingoiloffthecrankandsendittotheoilpick-up.



Cams.......................................MMRallyCamsIntake:272°Duration/11.4mmLift


HydraulicLifter.................... LighterLateModelM50tu35mmLifter

ValveSpring...........................MM“BeeHive”springwithlight6mmretainer(25gramslighterthanthestockdualspringwith7mmretainer)

Valves...................................... SurfaceTurbulencewith6mmstems, Stockvalveshave7mmstems

ValveGuide........................... Shorter6mmmanganesebronze Stockare7mmbrass

2100 Rally M42 Engine - Spec SheetFor Hard Street and Driver School Use


MM Forced Induction M42/M44 EnginesConsiderations in choosing Forced Induction

Forthosewanting200HPormorefromanM42orM44 engine, a Forced InductionEngine is theanswer.

Considerations Before Making the Move to Forced Induction

A2100Rallyenginewilldothe1/4milein14.5secat98.5mph.ThisisasfastasanE36M3.EquippedwithaPulseChamber IntakeManifold, it’spowerbandisfrom4300to7300RPM.Theenginepullslikeitsrunningon6cylindersandgets30mpgonthe highway. Forced Induction is more complexwithaboostapparatusandextraplumbing.ThecostofaForcedInductionSystem,onceit’sallplumbedupandtuned,canbeasmuchastheengineitself.

Two Camps

OK!Youreallywanttodoit?Thenthefirst decision is to determinewhich campyoubelongwith-theSuperchargecrowdortheTurbopeople.Bothsystemshavetheirmeritsanddrawbacks.

Bower Bands

A boost device such as the DowningAtlantic Supercharger, will be strong atmakingbottomendandmidrangetorquebut tends to fall off on the top end. Incomparison, aTurbo-Charged engine feelsratherflatdownlowbutmuchstrongerinthemid-rangeandtopend.Now,thepowerbandofeithersystemcanbemovedupordowndependingonhowthesystemissizedtotheengine.

Comparisons

Since the Supercharger is driven off the crank-shaft,it’spoweroutputisdictatedbyRPMwhereasaTurboisdrivenbytheengine’sexhaustoutputandisconsequentlydictatedbyengineload.BecausetheTurboisdrivenbyarelatively“free”powersource(exhaust),itismuchmoreefficientandsinceitreliesonengineload,ithasmorepowerpotentialthanaSupercharger. So,ifitisbottom-endandmid-rangetorqueyouare after, choose a Supercharger or small TurboSystem,butifyouareinterestedinasizeablepowerincrease,nothingbeatsaTurbocharger.

MM 1900, 2000 and 2100 Forced Induction Engines

ThisM42/M44Seriesisspecificallydesignedandengineeredtorunsuccessfullyunderboost.Theyarenotmerely decompressed stock engines which arelimited to about 7 lbs. (.5 bars) of boost and areshortlived.Aboostedenginelivesahardtoughlifeandneedstobebuiltstronganddurablesoitcantake thedemandsover time. Longevitymust be amajordesigngoalalongwithpower.

The Reciprocating Mass of Metric Mechanic’s Forced Induction Engines

Forced Induction Piston

The piston, more than any other component,receives the most abuse in a forced inductionengine.Heatgeneratedfromboostandparticularlydetonation can be so intense it can literally meltthepiston.Becauseofthis,ourforgedalusilpistonhasa.080”(2mm)thickercrownthanournormallyaspiratedpistons.Thetopofthepistonisintention-allymadeflatwithnovalvepocketsbecausevalvepockets create a thin eyebrow at the edge of thepistonandthisthinedgeistheveryfirstplacethepistonstartsitsmeltdown.Also,theuppercompres-sionringgrooveismovedfurtherdownthepistontoprotectthetopcompressionringfromheat.Ourforcedinductionpistonweighs380grams.

MM Forced Induction Piston, Pin and Rod Assembly

Page �0Copyright© November 2006 by Metric Mechanic Inc™ 505 East Main, Richland, MO 65556


MM Forced Induction M42/M44 EnginesCooling the Forced Induction Piston

Piston Pin

Weuseathickwall21mmwristpinweighing105grams.

Rod

Therodisan“H”beamdesignforgedandCNCmachinedoutof4340ChromeMolySteel.Atthebigend,wemachine4oilinggrooves,(seeclose-uponpage19)throughwhichoilsquirtstowardsthebottomofthepistontocooltheskirt.Threediffer-entrodsareusedintheseengines;the138mmrodfor1900FI engine, the137mmrod for a2000FIengineanda134.5mmrodfora2100FIengine.

Internal Cooling of the Forced Induction Piston

Thesamefouroilinggroovesalsohelpcoolthepiston internally. Oil coming off the rod bearingiscollectedintherod’ssidechamferandthendis-

Oil Cooling the MM Forced Induction Piston, Pin and Rod Assembly

charged out through these 4 oil squirter groovesonto the bottom side of the piston. Oil thensplashesthroughthehorizontalslitsmachinedintothepistonjustundertheoilringgroove.Theseslitsnotonlygreatlyhelp reducepistonexpansionbuttheyalsogivetheoilapathwaytowardstheupperportionofthepistonskirt, lubricatingit fromthecylinderwall.Evenwithatightfittingpiston(.003”),theskirtstayswelllubricatedwhichgreatlyincreasesthe skirt life and reduces the likelihood of a col-lapsedorseizedpistonskirt.Thelubricatingmethoddescribedabovedoesnotroboilpressurefromtheenginelikemoreconventionalblocksquirters.

Main Bearings

Thestockmainbearingshaveabouta200°oilinggrooveandoilisshutofftotherodbearingfrombottomdeadcentertotopdeadcenter.Thiscausesoilstarvationtotherodbearings.Themainbearingsweusehavea360°oilinggroovesotherodbearinghasaconstantsupplyofoil.Wealsouseadoublethrust surfacemainbearing.The stockmainbear-ingsonlyuseasinglethrustsurfacewhichtendstowearout.

Main Bearings with 360° Oiling Groove

Double Thrust Main Bearing Set


Left: Forced Induction Multi-layered Head GasketRight is Normally Aspirated Composite Head Gasket

Rod Bearings

The stock rod journal is only 45mm in diame-ter.Thisrathersmalljournaldiameterseesalotofloadunderboost.Totakethishigherload,weuseaTefloncoatedTri-Metalrodbearingthatcandeliverthreetimesthelifeofastockrodbearing.

MM Cylinder Head

OurM42/M44headsflow6%overstock.TheseheadshaveourpatentedSurfaceTurbulenceconcen-tricgroovesmachinedintothebacksideoftheintakevalve and theheadsof boththeintakeandexhaustvalves.Thishelps to reducedetona-tion in a boosted engine. Italsohelpspreventheadcrack-ing,increasesfuelmileageandhelpsreduceemissions.

Cams and Valve TrainThe stock cams areusedon the smaller 1900 and2000 Forced Induction Engines. The 2100 ForcedInductionEnginesusea258°duration/11.15mmliftcamonboththeintakeandexhaustcam.MM“BeHive”valvespringsandlighterretainersareusedalongwithMM35mmheavydutyhydraulic lifterbuckets.

Left to Right: Stock , Tri-Metal & Teflon Coated Rod Bearings

Multi-Layered Stainless Steel Head Gasket

Weuseathreelayeredstainlesssteelheadgasket.Thetopandbottomlayersareembossedandcoatedwith Viton for good sealing properties. A thickerinner stainless steel core isused forhigh strength.Thisgasketdoesnotrequireretorquingandcanbereusedifnotdamaged.

MM Head Bolts

Thesocketheadboltswebuildwithare100mmlong (10mm longer than stock) for deep anchor-ingpowerintheblock.Thisspreadstheloadmoreevenly over the cylinderwall and reduces cylinderwalldistortionevenundergreaterheadtorque(68ft.lbs.)Stockheadboltshitabout59ft.lbs.whentheyareangletorqued.

Main Bearings with 360° Oiling Groove

MM Forced Induction M42/M44 EnginesMore Parts Specialized for the Forced Induction Engine



1900 M42 Forced Induction - Spec Sheet For Boosting ... Supercharging or Turbocharging

MM 1900 M42 FI EngineIntroduction This engine is designed and engineered to rununderboostfromtheforcedinductionofaTurboCharger, Supercharger or Blower. The head bolts,headgasket,pistons,wristpins,rings,rodsandrodbearingsareallstrongerpartsspecificallydevelopedtorununderboost.Becausethisisalargerdisplace-mentenginewithbetterheadflowthanstock,thepower output will be much higher than a stockengineatthesameboostlevel.

1. DISPLACEMENT1881cc(86mmborex81mmstroke)

2. CRANKSHAFTThisengineusesastock1.8forgedsteelcrankshaftwith8counterweightsandan81stroke.

3. RODThese“H”beamrodsareforgedfrom4340ChromeMoly steel for strength, fully CNC machined forlightness, 138mm long andweigh only 525 grams.The“H”BeamRodsaremodifiedwith4oilgroovesmachinedintothebigendthatallowoilsquirtsintothebottomsideofthepistontohelpcoolitoff.

4. PISTONWeusean86mmForgedAlusilPistondesignedspe-cifically for boosted engines with 8.6 compressionratiothathasaflattopandnovalvepocketing.Thecrownthicknessat.080is2mmthickerthanournor-mally aspirated piston. To prevent heat damage tothetopcompressionring,it’smoveddownloweronthepiston.Mostboosted engines run a lotof cyl-inderwallclearance(usually.005”to.006”)tokeepthepistonfromstickinginthebore.Weuseaspe-cial13%highsiliconcontentpistontolowerpistonexpansionandreducescuffing.Ourpistonsalsohaveahorizontal slit justbelow theoil ring topreventthe heat that’s coming off the piston crown fromtransferringdirectly to the skirtof thepiston.Thisslithelpsreducetheexpansionrateattheskirt4-7%morethanacastpiston.Mostforgedpistonsexpand35-50%morethanastockcastpiston.Werun.003”pistontocylinderwallclearance.

5. RINGSTopis1.5mmMoly,secondis1.5mmandthe4mmoilringisahighradialtensiondesignwith3pieces.

6. PISTON PINSThe21mmpinweuseonboostedenginesweighs105gramswhileonanormallyaspiratedengineitweighs80grams.

7. MAIN BEARINGSWeusea360°oilgrooveonthemainbearings.Thestockmainbearingstopsfeedingoiltotherodbear-ingfrombottomdeadcentertotopdeadcenter,so,athighrpmstherodbearingsbecomestarvedforoil.Thiscircularoilgroovekeepstherodbearingswelllubricated.

8. ROD BEARINGSWe use tri-metal rod bearing with a teflon coatedbabbitfacing,acopperunderlayandasteelbacking.Inourexperience,theyare3timesmorereliablethanstock.

10. HEADCurrentlyourM42/M44headsflow6%overstock.We install our 6mm Surfaced Turbulenced valveswhichhelpreducedetonation,increasefueleconomyandminimizecrackingandthenpairthemwithman-ganesebronze valve guides for greatly increase life.MM“BeeHive”valvespringsandlightweightretain-ers reduce valve trainweight. Valves are capped ofwithMM35mmheavydutyhydrauliclifters.

10. HEAD GASKET & HEAD BOLTSOur choice is a Cometic multi layer metric headgasket withstronger 10mm socket-head bolts thatare100mmlongwhichis10mmlongerthanstock.

11. CAMMINGStockcams-228°durationwith9mmlift.

12. HORSEPOWER OUTPUT

200-250HP



MM 2000 M44 FI EngineIntroduction This engine is intended for OBDII M44/1.9enginesfrom1996onthatwillberununderboostfrom the forced induction of a Turbo Charger,SuperchargerorBlower.Theheadbolts,headgasket,pistons,wristpins,rings,rodsandrodbearingsareallstrongerpartsspecificallydevelopedtorununderboost.Becausethis isa largerdisplacementenginewithbetterheadflowthanstock,thepoweroutputwillbemuchhigherthanastockengineatthesameboostlevel.


2. CRANKSHAFTThisengineusesastock1.9castironcrankshaftwith4counterweightsandan83stroke.Thetimingwheelis mounted on the 4th counterweight for OBDIItimingreference.

3. RODThese“H”beamrodsareforgedfrom4340ChromeMoly steel for strength, fully CNC machined forlightness, 137mm long andweigh only 520 grams.The“H”BeamRodsaremodifiedwith4oilgroovesmachinedintothebigendthatallowoilsquirtsintothebottomsideofthepistontohelpcoolitoff.

4. PISTONWeusean86mmForgedAlusilPistondesignedspe-cifically for boosted engines with 8.6 compressionratiothathasaflattopandnovalvepocketing.Thecrown thickness at .080 is 2mm thicker thanournormally aspiratedpiston.Topreventheatdamagetothetopcompressionring,itsmoveddownloweronthepiston.Mostboostedenginesrunalotofcyl-inderwallclearance(usually.005”to.006”)tokeepthepistonfromstickinginthebore.Weuseaspe-cial13%highsiliconcontentpistontolowerpistonexpansionandreducescuffing.Ourpistonsalsohaveahorizontal slit justbelow theoil ring topreventthe heat that’s coming off the piston crown fromtransferringdirectly to the skirtof thepiston.Thisslithelpsreducetheexpansionrateattheskirt4-7%

morethanacastpiston.Mostforgedpistonsexpand35-50%morethanastockcastpiston.Werun.003”pistontocylinderwallclearance.


6. PISTON PINSThe21mmpinweuseonboostedenginesweighs105 gramswhile on a normally aspirated engine itweighs80grams.



9. HEADCurrentlyourM42/M44headsflow6%overstock.Weuse6mmSurfacedTurbulencedvalveswhichhelpreducedetonation,increasefueleconomyandmini-mizecrackingand thenpair themwithmanganesebronze valve guides for greatly increase life. MM“Bee Hive” valve springs and lightweight retainersreducevalvetrainweight.ValvesarecappedofwithMM35mmheavydutyhydrauliclifters.

10. HEAD GASKET & HEAD BOLTSOur choice is a Cometic multi layer metric headgasket withstronger 10mm socket-head bolts thatare100mmlongwhichis10mmlongerthanstock.

11. CAMMINGStockcams-228°durationwith9mmlift.

12. HORSEPOWER OUTPUT

200-250HP




MM 2100 M42 Turbo Engine Introduction For “boost junkies” seeking a 300 HP thrill,thisforcedinductionengineistheanswersinceitsdesignedandengineeredtorununderboostfromaTurboCharger, Supercharger or Blower. The headbolts, head gasket, pistons, wrist pins, rings, rodsand rod bearings are all stronger parts specificallydevelopedtorununderboost.Becausethis isourlargest displacement engine with better head flowandhotter cams (differentiating it fromour otherboosted engines) the power output will be muchhigherthanourotherboostedengines.


2. CRANKSHAFTWeuseamodifieddieselcrankwithan88mmstroke.Theboltthatretainstheharmonicbalanceradaptoris2mmlargerandwewouldneedthesuperchargedrivepulltoadaptittotheengine.

3. RODFortheboostedengineweusea134.5mmlong“H”BeamRodweighing500grams.The“H”BeamRodsaremodifiedwith4oilgroovesmachined into thebigend.Theseallowoil to squirt into thebottomsideofthepistontohelpcoolitoff.

4. PISTONWeusean86mmForgedAlusilPistondesignedspe-cifically for boosted engines with 8.6 compressionratiothathasaflattopandnovalvepocketing.Thecrown thickness at .080 is 2mm thicker thanournormally aspiratedpiston.Topreventheatdamagetothetopcompressionring,itsmoveddownloweronthepiston.Mostboostedenginesrunalotofcyl-inderwallclearance(usually.005”to.006”)tokeepthepistonfromstickinginthebore.Weuseaspe-cial13%highsiliconcontentpistontolowerpistonexpansionandreducescuffing.Ourpistonsalsohaveahorizontal slit justbelow theoil ring topreventthe heat that’s coming off the piston crown fromtransferringdirectly to the skirtof thepiston.Thisslithelpsreducetheexpansionrateattheskirt4-7%

morethanacastpiston.Mostforgedpistonsexpand35-50%morethanastockcastpiston.Werun.003”pistontocylinderwallclearance.


6. PISTON PINSThe21mmpinweuseonboostedenginesweighs105grams.



9. HEADCurrentlyourM42/M44headsflow6%overstock.Weuse6mmSurfacedTurbulencedvalveswhichhelpreducedetonation,increasefueleconomyandmini-mizecrackingand thenpair themwithmanganesebronze valve guides for greatly increase life. MM“Bee Hive” valve springs and lightweight retainersreducevalvetrainweight.ValvesarecappedofwithMM35mmheavydutyhydrauliclifters.

10. HEAD GASKET & HEAD BOLTSWeuseaCometicmulti layerMetricHeadGasketandstronger10mmSocket-headBoltsthatare100mmlongwhichis10mmlongerthanstock.

11. CAMMINGWeusea258°duration/11.15mmliftcamonbothintakeandexhaust.

12. HORSEPOWER OUTPUT250-350HP


M42/M44 Prices

M42 & M44 Engine Prices M42: E30 (90-91), E36 (92-95), Z3 ‘95 M44: E36/5 318ti (96-98) E36 318i (96-98) Z3 96-98 2000 SportM42......... 160HP........$6,495... 800 2100 SportM44......... 170HP........$6,795..1200 2100 RallyM42.......... 205HP........$8,495... 800 FORCED INDUCTION 1900 FIM42............. 225HP........$6,995... 800 2000 FIM44............. 225HP........$7,295..1200 2100 FIM42............. 300HP........$8,995... 800

Pistons & RingsMMSport87mmForgedAlusilPiston M421.0:1CR..$780MMSport87mmForgedAlusilPiston M441.0:1CR..$780MMSport87mmForgedAlusilPiston M421.5:1CR..$78078mmMolyRings...................................................$120

Rods & BearingsRodsMMRally138mm“Ultralite”“I”BeamRod(475 g)........$780MMRally138mm“H”BeamRod(520 g)......................$700MMForcedInduction“H”BeamRodswith4SquirterGrooves134.5mm, 137mm or 138mm...........................................$780Rod BearingsSportAluminumFaceBearings.................... $60perSetRally,ForcedInduction,Race:TeflonCoatedTri-Metal.............................. $140perSetMain BearingsMainswith360°Thrust&OilingGroove:Requires modifying lock tangs on the main bearing caps........ $120perSet

CrankshaftM42-88mmForgedSteelCrankKit:For 2100 Rally or 2100 Forced Induction................................... $1250

CamsMMSportIntakeCam258°Duration/11.15mmLift..... $780.. 250MMRallyCams:Intake272°Duration/11.4mmLift

Exhaust258°Duration/11.15mmLift.........................$900Pair 250MMTurboCams:IntakeandExhaust272°Duration/11.4mmLift..... $900Pair 250

Prices Subject to Change

Core Deposit

Core Deposit

HeadsInclude: 6% Flow Increase, Surface Turbulence Valves, Manganese Valve Guides, MM “Bee HIve” Valve Springs & Lightweight Retainers MMM42/M44Head................... $1,495....... 600Components MM35mmHydraulicLifters...... $30Each... $400Set

MM35mmMechanicalLifters.... $40Each... $600Set

ShimPads...................................................... $5Each

MM“BeeHive”ValveSpring andRetainer.......................... $20Each... $300Set

ManganeseBronzeValveGuide.. $12Each... $175Set

MMSocketHeadBolt(100MM)... $7.50Each......$70Set

MultilayerStainlessSteelHeadGasket For Forced Induction Engines......... $7.50Each......$70Set

Bolt-OnsMMLightenedFlywheel11lbs.&228mmClutchAssembly.................. $755.. 200(StockDualMassRingGearorFlywheelrequiredforcore)PulseChamberIntakeManifold(E30).... $995.. 250

Core Deposit

Core Deposit

Documents

Metric Mechanic M42 M44 Engine Series - BMW E30 Club