horsepower or more will work well. The air systemshould be equipped with an adjustable pressureregulator. The abrasive products' safe speed rating is18,000-20,000 rpm. If an air grinder's maximum speedexceeds that, you must reduce it by using the regulator.

While the never-exceed speed is 18,000-20,000 rpm,the majority of the abrasive products in the Block PrepKit will have best durability when the grinder runs at10,000- 12,000 rpm. Measuring the die grinder's speedis difficult, however, most tools cite their maximumspeed either in the unit's instructions or on aspecification plate attached to the tool. Supposemaximum speed of your unit is 20,000 rpm, but youwant to run it at 10,000. Operate the grinder at halfthrottle and listen to the noise it makes. Then, run it atfull throttle and adjust the pressure regulator such thatthe noise is about the same as before. That willapproximate 10,000 rpm.

The pressure regulator is important for another reason.It is easier to manipulate a die grinder with the throttlewide open than it is to control the grinder and modulatethe throttle at the same time.

You may be using an electric die grinder. That isacceptable as long as its maximum rpm is below the18,000-20,000 rpm limit. Because electric grinders areoften capable of exceeding that by a significant margin,an electrical device allowing the user to reduce the tool'sspeed is necessary. Additionally, speed regulation of anelectric grinder will be necessary if you want to use theabrasives at 10,000-12,000 rpm.

© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 1

What is Included in the Standard AbrasivesBlock Prep KitThe Block Prep Kit contains six types of abrasiveproducts: Surface Conditioning Discs, Grinding Discs,Cartridge Rolls, Cross Buffs™, Flap Wheels and a 3-foot by 2- in., 320-grit Handy Roll. There are enoughabrasives in the kit to perform basic deburring andpolishing on a V8 cylinder block, crankshaft, connectingrods and pistons.

Also included in theStandard Abrasives BlockPrep Kit are holders andmandrels for all the abrasiveproducts. These componentsare designed for mounting ina die grinder having amaximum speed of 18,000-20,000 rpm and a 1/4-in.diameter collet or "chuck".

1. Tools and RPMSpeedsAn air-powered die grinderis desirable because of itsrelatively low cost andvariable speed. It requiresan air source and most aircompressors powered bymotors rated at 2.5

Engine block preparation is the cleaning and abrasive operationsperformed to an engine's cylinder block prior to the machiningoperations (boring, honing, align boring, balancing, etc.) that set theblock's critical dimensions. For the purposes of this Guide, we'regoing to look at block preparation in a wider sense and includework on the crankshaft, the connecting rods and the pistons.

All of the block preparation techniques discussed in this Guide,surface conditioning, deburring and polishing, can be done by anydo-it-yourselfer using the Block Prep Kit (p/n 260003) from theStandard Abrasives Motor Sports Division along with a die grinderand a few common hand tools.

The Kit also includes all ofthese tools. Top is the holder forDiscs. Middle is the mandrel forCartridge Rolls. Bottom and leftare the mandrel pieces for FlapWheels and Cross Buffs™.

Everything the DIY needs to prep a V8 cylinderblock is in this kit.

D . I . Y .

E n g i n e B l o c k P r e p a r a t i o n

This is a typical die grinder with aright-angle head and a 1/4-in.chuck. A die-grinder with astraight head works acceptably. Aright-angle head can make certaindeburring operations lessawkward.

If you are working with an aluminum cylinder block, usegrades of abrasives suitable for aluminum and,regardless of the grade, use a more gentle touch thanyou would if you were working on cast iron. Becausealuminum is softer than iron, it abrades faster. If you usethe same grinder pressure you would with iron, beforeyou know it; you will have shaved off too much material.Additionally, when working on aluminum under mostconditions, the abrasive tool will "load-up" with caked onaluminum. Spraying the tool frequently with a lightlubricant, such as WD-40, reduces this problem.

3. Block Cleaning andSurface ConditioningIf your project starts with aused cylinder block, you'reprobably going to have toclean it before any abrasiveprocedures begin. If a usedblock comes from an enginethat was fairly clean inside, itmay just need to be washedwith solvent, then scrubbedwith hot soap and water(Tide laundry detergentworks well) and blown drywith compressed air.Shooting the solvent andhot, soapy water throughsome kind of pressureblaster makes the job easy.

If a high-mileage, used block is your starting point, it'sprobably coated with black, gooey, sludge making thesolvent/hot-soapy-water method impractical. It is best tohave a block that dirty "hot-tanked," a process thatsubmerges the parts in a hot solvent or caustic solution.Typically, the block is left in this hellish brew for an houror so. If everything works right, it comes out of the tankdevoid of sludge, dirt and paint. Hot tanking is a serviceoffered by some auto parts stores, automotive machineshops and engine rebuilders. Use caution if you areworking with an aluminum block. Some cleaningprocesses and solutions that are safe for iron blocks arenot compatible with Aluminum. When in doubt, ask thefacility doing the cleaning if the process they use is safefor aluminum parts.

The majority of DIY engine builds will probably be donewith cast iron blocks. If that's the case with you,whatever cleaning process was used on your block, youwill probably be confronted with a thin coating of rust onmachined sealing or mounting surfaces, such ascylinder head decks, oil pan rails, timing chain covermounting surface and accessory mounting pads. Eventhough the block has been cleaned, these surfacesshould be conditioned to remove rust and any traces ofold gaskets, paint, gasket sealer, and dirt left after hot-tanking. Aluminum blocks will have no rust, of course,

Additional tools required are: a 5/64-in. hex key (Allenwrench), the die grinder's chuck wrenches, a medium-sized ball peen hammer, a medium-sized flat nosepunch, a medium- sized cold chisel, taps to fit the boltholes in your block and a roll of good-quality, duct or"racer's" tape.

None of the techniques used in a block preparationproject are dangerous as long as proper safetyprocedures are followed, however, misuse of the tools orfailure to observe a few safety rules may result in injury.Deburring and surface conditioning work throws lots ofmetal chips around, so the first thing you need to protectare your eyes. The minimum protection is shatterproofeye wear designed for industrial use. Better is a faceshield made of shatterproof material.

Next, you need snug-fitting work gloves. We recommendthe Mechanix Wear brand since they allow a good senseof touch while still offering protection. An alternative is ageneric leather work glove of medium thickness. Avoidthin leather gloves or the very thick units intended forwelding and do not use rubber gloves.

People sensitive to airborne dust may want a respiratormask such as the type used by paint and body shopworkers. These inexpensive, white cloth masks are heldto your face with an elastic string.

The noise some air grinders make is quite loud. If loudpower tools are a discomfort, do your block preparationwork wearing ear protection. Best are the muffs airportworkers wear around jet engines. Acceptable are a setof ear plugs intended for industrial use.

Mechanix Wear gloves can be found anywhere racersbuy parts and supplies. You should be able to find therest of this safety equipment at a hardware store.Dedicated safety vendors, such as Lab Safety Supply,are also good sources.

2. Die GrindersThe first die grinder operation to learn is changing tools.Virtually all die grinders come with a set of wrenchesused to loosen and tighten the chuck. Typically, onewrench holds the air grinder shaft and the secondwrench turns the chuck's nut. You loosen the nut, insertthe abrasive product's holder or mandrel, then tighten it,again. Finally, you will attach the abrasive to the holderor mandrel. In the process of your block preparationwork, you will change the abrasive product severaltimes. Always disconnect the air grinder from the airsource and the electric grinder from the power sourcewhen making the change.

Once you start working, move the grinder as smoothly aspossible. Grinding in one place will result in removal oftoo much material and uneven surfaces. Also, don't forgetto set the speed of the grinder at 10,000-12,000 rpm.

© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 2

If you start with a used block,here is an example of a near-worst-case-scenario and a greatillustration of why used blocksneed to be hot tanked. Sludge?You got lots of it here.

chuck and install an 80-grit Cartridge Roll. Use that toclear the water holes in the cylinder head decks of rust,scale and casting flash. Doing this will improve coolantflow.

After you're done with the decks, reinstall the SurfaceConditioning Disc and abrade the rest of the block'sgasket surfaces, accessory pads and other machinedsurfaces.

4. Deburring the BlockYou deburr a block forseveral reasons: 1) deburrthe inside surfaces of theengine block to improve oilreturn. 2) deburr or radiusother inside surfaces thatare under high stress, suchas sharp edges and castingflash around the mainbearing webs, to make itmore difficult for cracks tostart 3) deburr the outside of the block or appearancepurposes and to reduce the amount of nicks and cutsyou get from handling the block.

You'll be deburring with the Block Prep Kits' CartridgeRolls or its Grinding Discs and the Cartridge Rolls willbe used most of the time. Deburring to improve oil returnis done to two areas: 1) the oil return holes in the"valley" between the cylinder banks and 2) the surfacesof the cylinder bank walls that make up the sides of thevalley.

Oil is delivered to most of the engine's moving partsunder pressure but flows back to the oil pan over theengine block's internal surfaces by force of gravity. Ironblocks are sand castings and the rough finish left by thatprocess impedes oil flow. This is seldom a problem for aproduction engine in normal passenger car duty,however, in street high-performance or racing engines, itcan cause trouble. At high engine speeds oil can bepumped up into the top of the engine faster than it candrain back. This causes two problems: 1) a shortage ofoil in the oil pan resulting in occasional inconsistenciesin oil supply and 2) an excessive volume of oil in the topend of the engine resulting in oil leaks and oil ingestioninto the intake tract. One way to reduce the severity ofthose problems is to remove casting flash inside of theoil return holes, then deburr the holes and the inside ofthe block valley.

If the oil return holes have a lot of casting flashrestricting them you may need to knock large pieces outwith the ball peen hammer and a flat-nosed punch orcold chisel. Once that's done or if there are no large oilreturn restrictions, open up the Standard AbrasivesBlock Prep Kit and select either a 40-grit, straightCartridge Roll or a 40- grit, full-tapered Cartridge Roll.The type of roll you select will be dictated by the size of

but may have corrosion, gasket remnants or otherresidue left after the cleaning process.

Using a putty knife or scraper to removing this stuff isnot acceptable because neither will clean those surfacescompletely. If your block isaluminum, putty knifes orscrapers may even damagethose surfaces. The firststep in block preparation isto clean those surfaces witha Standard AbrasivesGeneral Purpose SurfaceConditioning Disc. The BlockPrep Kit contains twodifferent types of them. TheMedium grade discs are foriron blocks and the Very Fine grade discs are foraluminum blocks.

Disconnect the grinder, install the Standard AbrasivesQuick Connect, 2-in. holder pad into the chuck andtighten the nut. The conditioning discs use StandardAbrasives' unique SocAtt® locking system, so installingthe disc on the holder is as simple as a twist of yourwrist.

One of the best features ofStandard AbrasivesSurface Conditioning Discsdriven by a die grinder istheir ease-of-use. Little orno downward pressure onthe die grinder isnecessary. Thecombination of the SurfaceConditioning Discs' uniqueabrasive material and thehigh-speed rotary motion ofthe die grinder will do thework. If you apply anysignificant pressure to thedie grinder while usingSurface Conditioning Discs,damage to the surfacebeing abraded may occur.

If the work surface is aluminum, additional care with toolpressure and abrasive grade must be observed. Useonly the Very Fine grade discs and make suredownward pressure on the tool is almost non-existent.

After installing the proper Surface Conditioning Disc,reconnect the grinder, put on your gloves and eyeprotection, then start conditioning the head decks theeasy, Standard Abrasives way. Once the gasket surfacesare down to bare metal, disconnect the grinder andremove the conditioning disc set-up.

Install the Cartridge Roll mandrel into the die grinder© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 3

Cartridge Rolls are themainstay of many automotiveabrasive operations. The BlockPrep Kit has four differenttypes: 40- grit, full-tapered; 80-grit, full-tapered, 40-grit,straight and 80-grit, straight.

These are BriteRite® SurfaceConditioning Discs. Themaroon disc (left) is MediumGrade and the blue disc isVery Fine Grade.

The key to good work withpower-driven abrasive productsis to control the grinder with bothhands and let the rotating actionof the abrasive do the work. Useonly limited downward pressure,if any at all.

Block Prep Kit, lifter borefinishing becomes easy.Install the CombinationMandrel used for both CrossBuffs™ and Flap Wheels,add the hex-socket screw,tighten with a 5/64ths in. hexkey, then screw the CrossBuff™ on that.

Of the abrasives in the BlockPrep Kit, Cross Buffs™ aremost sensitive to grinderspeed and should be run at 10,000 rpm for best results.Also, Cross Buffs™ must be used with a light lubricant,such as WD-40 or automatic transmission fluid. Dip theCross Buff™ in the lube or spray it on. Place the CrossBuff™ at the top of the lifter bore then turn on the diegrinder. All that is required is one or two passes throughthe lifter bore and its surface will be free of corrosionand properly conditioned.

Though cylinder block crackingdue to the stresses of high rpmoperation is not common withstreet high-performance andmany race engines, it doeshappen. If it does, it is morelikely to occur in the structuralareas of the crankcase aroundthe main bearings.

It is not necessary to deburr allof the crankcase surfaces. Youwant to grind a small radius ontosharp edges and deburr placeswhere casting imperfections are

obvious places for cracks to start. You may even findcasting imperfections in the sharp-edged part of themain webs that are actually tiny splits or gaps in thecast iron that surely could become cracks. Thoseproblem areas need to be carefully deburred.

Don't forget to lightly deburr thesharp edges and corners of themain bearing caps. In the caseof engines that have the oilpump bolted to the bottom ofthe block and the main oil feedrunning from the oil pump andinto a main bearing cap or theblock itself, inspect the areaswhere that main oil feed goesinto the main cap or blocksurface. Those entry and exitholes may need to be slightly deburred or chamfered toremove flash or sharp edges that will impede oil flow.

For the most part, deburring or radiusing to eliminatestress risers can be done with 80-grit Cartridge Rolls but

the oil return hole you areworking on. If it's a largehole, the straight CartridgeRoll will work best. A smallhole will be better "de-flashed" with a 40-grit,tapered roll. Typically, onestarts from the top or "valleyside" of the block but, don'tforget to roll the block overand look at the other ends ofthe oil returns as they exitinto the crankcase. In manycases these passages, asthey dump into the roof ofthe crankcase around themain bearing webs, will needdeburring work, too. Once

the oil passages have been cleared with the 40-grit rolls,then go over everything again with 80- grit rolls tosmooth the surfaces.

The next step is to turn theblock back over and deburr theareas in the valley over whichoil flows on its way to the oilreturn holes. Generally, this willbe the cylinder block wallsabove the valve lifter boresand the surfaces surroundingthe lifter bores. You may beable to deburr most of thesesurfaces using the 80-gritCartridge Rolls but, some ofthe rougher areas will go fasterand your abrasives supplieswill last longer if you start withthe 40-grit rolls then finish withthe 80s. Also, there may besome large, flat or nearly-flatareas where the 100 grit Grinding Discs may workbetter. If you are working on an aluminum cylinder block,use only the 80-grit rolls and the 150-grit Grinding Discswith a soft touch.

The final block preparation task done in the valley is toCross Buff™ the valve lifter bores. The StandardAbrasives Cross Buff™ is unique in the industry. It wasdesigned exclusively for automotive use and is theperfect solution to a block preparation challenge:refinishing the valve lifter bores. Typically this is done

with a clumsy brakecylinder hone which, if youcan even find one thesedays, sometimes can domore damage to the lifterbore finish than good.Using one of the High-Strength, Very Fine gradeCross Buffs™ from the

© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 4

These are Cross Buffs™, a veryspecialized type of automotiveabrasive product developed byStandard Abrasives Motor SportsDivision

In block preparation work, themain application of CrossBuffs™ is the surfacepreparation of the valve lifterbores.

Both Cross Buffs and FlapWheels require the long,silver mandrel. WhenCross Buffs are used, theblack set screw isattached to the mandreland the Cross Buff goeson the end of the screw.

Lightly round sharp edgeson all the main caps,however, do not heavilyradius these edges.

After the oil hole work,depending on the surface,use tapered or straightcartridge rolls, to deburr andsmooth valley areas.

It's best to use taperedCartridge Rolls to clear the oilreturn holes because most ofthese holes will be fairly small.Some engines will have somuch casting flash and crud inthese holes that a cold chiseland a hammer may benecessary to remove heavyconcentrations. Two hands onthe grinder makes for bettercontrol.

© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 5

in some cases the 100-grit Grinding Discs maywork well. If you areworking on analuminum block, useonly the 80-grit rollsand the 150-gritGrinding Discs with alight touch.

Some of the surfacesinside the lower end ofmost cylinder blockscan be anything buteasy to access, but witha compact die grinder and the variety of abrasiveproducts in the Standard Abrasives Block Prep Kit, youshould have little trouble in working on the most difficult-to-reach spots.

Once the work inside thecrankcase is complete, youshould turn your blockpreparation efforts to theoutside of the block. Allcasting flash should beremoved and all sharp edgesshould be radiused. You'dthink most of the work on theblock's exterior will be forascetic purposes-you wantyour engine to look as goodas it runs. There is a safetyreason, as well. Blocks withlots of sharp edges andcasting flash can cut oneshands during the inevitablehandling that will occur

during an engine building project. A good blockdeburring job will greatly reduce the chances of cuts andnicks. A third reason to deburr the outside of the blockis, like the main bearing webs inside the crankcase,there will be some areas of the block's exterior wheredeburring will eliminatestress risers and defraycracking.

The exterior of a cast ironblock will be done mostlywith 40- and 80-grit, straightCartridge Rolls and 100-gritGrinding Discs.. If you areworking with an aluminumblock, use only 80-grit rollsand the 150-grit GrindingDiscs and a light touch.

Once the deburring andradiusing work on theoutside of the block is

complete, get outyour taps and runthem into each bolthole on the block.It is especiallyimportant to do thisto the cylinderhead bolt holes.This removes anydebris and repairsthe threads in anyholes that havebeen damaged.Either of those problems interferes with proper bolttightening during the assembly process.

5. CrankshaftThe crankshaft is thelargest moving part inthe engine and is thedevice that converts thereciprocating motion ofthe pistons into therotary motion thatmoves the vehicle.Crankshafts are eithercast of nodular iron orforged from high-strength steel.

Regardless of the material, most crankshafts have sharpedges that need to be radiused and rough surfaces thatneed to be deburred.

Like the block the first step is to clean the crank. Run awire-bristle brush though the crankshaft oil passages.Many "engine cleaning" kits have specific brushes forthis purpose. A excellent and perhaps more easily-obtainable substitute is a 22-caliber pistol cleaning kitwhich usually contains both the brushes and a cleaningrod that comes in handy for this purpose. Next, you wantto clean the crank's exterior. This can be done with acold solvent washing or dipping or with a hot-tanking.

The crankshaft's sharp edges need to be radiused. It isnot necessary to significantlygrind down these edges. Justput a small radius on themusing either the Standard

This is what you call "heavydeburring". Major casting flashareas on the outside of theblock should be attacked with a40-grit, straight cartridge roll.

Our finished demo block showsthe comprehensive deburring jobone can do with the StandardAbrasives Block Prep Kit.

Part lines left by the mold (for a castcrank) or forging die (for a forged crank)should be deburred away. A CartridgeRoll is best for this.

Crankshafts, especially nodular ironunits, have a multitude of sharpedges, flash and part lines that needto be removed.

Edges of counterweightsare best removed with astraight cartridge roll. It isnot necessary to heavilyradius the counterweightedges, just remove thesharpness.

Some engines, like Chevrolets, thatmount the oil pump to the bottom ofthe block or to a main bearing cap,need to have the main oil feed linetransition from the pump body to theblock deburred to remove sharp edgesthat restrict oil flow.

RoundedEdgesRoundedEdges

Once painted, the outside of the block looksprofessionally detailed. No sharp edges tocut your hands and no flash nor casting crudto make you look bad.

© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 6

Abrasives Block Prep Kit's 80-grit Cartridge Rolls or the100-grit Grinding Discs. You may find some big holes inthe counterweights and the edges of those holes needto be radiused using a tapered Cartridge Roll.

There are parts of the crankshaft deburring processwhere you will have your abrasive tool very close to thebearing journals. You absolutely do not want to abradethose surfaces. To protect them,wrap each journal with severallayers of good-quality duct tape.If you do nick a taped-overjournal, stop deburring, removethe tape from that journal and puta fresh wrapping on it.

If you make a mistakeby touching one of thejournals and theabrasive cuts all theway through your layerof tape, immediatelystop working and re-tape the journal, thencontinue the deburringprocess. After the

deburring is complete, strip the tape off the nickedjournal and use the 320-grit Handy Roll to deburr thenick. You will be able to tellthen the nick is properlydeburred by running yourfingernail over the damagedarea. When you can't feelanything, the nick has beendeburred.

Once you've radiused all thecrank's sharp edges, you mayfind the flat surfaces of someof the counterweights to berough or scarred from thecasting and/or machining

process. The rough areas should be deburred using the100-grit Grinding Disc or an 80-grit Cartridge Roll.

Lastly, run a tap through all the crankshaft's bolt holes toclear them of debris and repair any minor thread damage.

6. Connecting RodsThe rods are probably the most stressed moving partsin an engine. Most street-high performance engines andsome race engines will use production, forged steelconnecting rods. They will have sharp edges maybe

even some casting flashand a noticeable partingline along the rod's"beam". The edges andthe parting line are stressrisers and it's importantto radius all sharp edgeson the rod and rod capthen deburr and polishthe connecting rodbeams.

The first step is to cleanparts with either a solventspray or by the hot-tank

process. Next, understand there are three parts of eachrod from which you want to keep abrasive productsaway: 1) the rod bolts, 2) the rod cap mounting facesand 3) the rod bearing mounts. Take care to keep theabrasive tool away from those areas.

Radius sharp edges onthe rod and rod cap usingthe 80-grit Cartridge Rollsout of the StandardAbrasives Block Prep Kit.Generally you'll use astraight roll but some ofthe complex shapes onthe rod caps might requirea tapered roll.

Once the edges areradiused, it's time topolish the rod beams.Start with a 100- gritGrinding Disc and removeall traces of casting flash

and the parting line left bythe forging process.

Once you've removed theheavy stuff with the GrindingDisc, select the Flap Wheelmandrel from the Block PrepKit, install one of the 80-gritFlap Wheels and furtherpolish the beam surface. It isextremely important during

At left is a rod after preparationusing the Block Prep Kit. At right isthe production rod. The greatestvalue in deburring block partscomes when you do the rods.

Begin the process with a 100-gritGrinding Disc. Remember to let thegrinder's rotary motion do the work.

The second stage of the rodwork is done with the 80-gritFlap Wheel

Tapered Cartridge Rolls are best forcounterweight holes. Use a straightroll and the diameter of the rollmaybe too large to round the edgesof the hole without chattering ordestroying the Cartridge Roll. Forbest results, the diameter of the rollmust always be noticeably less thanthe hole and in many cases thatmeans a tapered roll

Duct tape greatlydecreases the threat of anicked journal if you catcha bearing journal with thetool.

Sharp edges just outside the bearingjournals must be approached with careusing a tapered Cartridge Roll. Do notheavily radius these edges. In somecases, such as this Chevrolet crank,you may be working near the crank'sthrust bearing surface. Take care not tonick the thrust surface.

In the unfortunate event youdo damage a crankshaftjournal or thrust surface, theBlock Prep Kit's Handy Rollwill usually repair theproblem.

© 2006 Standard Abrasives

E n g i n e B l o c k P r e p a r a t i o n 7

the Flap Wheel stage to movethe abrasive such that themarks it leaves are parallel tothe beam. The final step mustnot deburr or polish across thebeam.

7. PistonsThe final step in a blockpreparation project issome minor abrasive workon the pistons. Like theother engine parts we'vecovered in this DIY Guide,if you are working withused pistons, they'll needto be cleaned.

Lightly radius the edges of the piston skirts and tops.This must be done with care because the edges will bevery narrow and the material is aluminum whichabrades much faster than iron or steel. Use either the

80-grit Cartridge Rolls or 80-grit Flap Wheels for thispart of the job and remember-you need a very lighttouch with the abrasive. You only want to lightly radiusthe edges not grind them down substantially.

8. Closing Out the JobThough many of the parts we've worked on in this blockpreparation Guide will next go to a machine shop foroperations such as boring, honing, rod re-sizing andpiston pin- fitting, you want to send the machine shopclean parts.

We suggest you rewash everything with hot soapywater, give them a water rinse then blow them dry withcompressed air.

Typically, there will be enough abrasive products left inyour Standard Abrasives Block Prep Kit such that, if youget the parts back from the machine shop and find youmissed a sharp edge or a little casting flash somewhere,you can go back and remove it before the assemblyprocess begins.

For information on more advanced block preptechniques typical of that used on all-out racing engines,Standard Abrasives markets a video tape titled "RaceBlock Prep" (p/n 269847) which covers DIY methods forpreparing a block for extreme high output applications.

Copyright 2006 Standard Abrasives - All rights reserved - Anyunauthorized copying or distribution forbidden by law.

www.sa-motorsports.comQuestions? E-mail us at tech@sa-motorsports.com

Only use the Flap Wheel on pistons.The aluminum will abrade rapidly. Onlylight radiusing of the piston skirt edgesis necessary.

It is very important, toapply the Flap Wheel'srotary motion parallel tothe rod beam. Applying itacross the beam actuallycreates stress risersalmost as bad as the onesyou are trying to remove inthe deburring process.

This is how the rod beam shouldlook after the Flap Wheel work.