engine builder magazine feb 2012

2012FEBRUARY SUPPLEMENT TO: MAGAZINE

FORD PG 2GENERAL MOTORS PG 6

CHRYSLER PG 11IMPORT PG 16

PERFORMANCE PG 18SHOP TIPS PG 23

C1 Tech BULLETINS 12_Cover Temp_2006 2/16/12 7:59 AM Page c1

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http://www.cloyes.com

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Circle 101 on Reader Service Card for more information

C2 Cloyes_Layout 1 2/16/12 8:08 AM Page c2

http://www.cloyes.com

Year Engine Problem Page #

All 3.0L Duratec Timing Chain Service 2

2003-2004 3.8L, 3.9L and 4.2L Balance Shaft Gear Clarification 4

1990-1993 4.0L Oil Leak Repair 4

1999-2002 4.0L Rattle Noise From Primary Chain Drive 5

1990-2002 2.2L/134 cid Deciphering The Differences In The Chevy 2.2L Engine 6

1988-2002 2.3L “Quad 4” Timing Chain Installation Caution 6

1993-1994 3.1L/191 cid Chevy 3.1L/191 Cam Bearing Bore Issues 8

2004-2005 3.6L Noise Complaints on 3.6L Cadillac Engines 8

All All Close-Coupled Catalytic Converter Caution 9

All 4.6L Cadillac 4.6L DOHC Aluminum Head, Block Cracks 9

All All supercharged engines GM Belt Tensioner Failure May Cause Supercharger Failure 10

1995-2006 2.4L Chrysler 2.4L Cylinder Block Casting Identification 11

2004-2006 3.5L Multiple Cylinder Misfire or Rough Idle 14

All 3.7L Keeping Your Balance With 3.7L Chryslers 15

1988-1995 EA827 VW 16-Valve Cylinder Head Ticking Noise 16

1996 2.8L Audi 2.8L V6 Rear Crankshaft Seal Leaks 16

1999-2001 VGS33E Repairing Nissan Exhaust Manifold Cracks 16

2006-2007 MZR Mazda Variable Valve Timing Noise 17

All All Understanding Spark Plug Heat Range 18

All All Influence of Grooved Main Bearings on Performance 20

All Carbureted engines Holly Power Valve Myths 21

All All Tips For Selecting The Proper Circle Track Cam 22

All All Quick Test For Water in Methanol 23

All All Oil Pump And Engine Priming 23

All All Vacuum Check Engine Inspection Procedure 24

All Small-block Chevy Keeping Chevy 4-Bolt Mains From ‘Walking’ 24

ADVERTISER CIRCLE NUMBERS PAGESAMERICAN CYLINDER HEAD 103, 109, 111, 118 3, 9, 11, 18APEX AUTOMOBILE PARTS 113 12-13CLOYES GEAR & PRODUCTS 101 2CENGINE & PERFORMANCE WAREHOUSE 108, 117, 123, 126 8, 17, 23, 4CMAHLE CLEVITE, INC. 105, 107, 114, 122 5, 7, 14, 22MOTOR STATE DISTRIBUTING 104, 119, 121, 124 4, 19, 21, 24SUNNEN PRODUCTS CO. 102, 110, 120, 125 2, 10, 20, 3C

NOTE: All tech bulletins, unless otherwise noted, have been provided by Automotive Production Remanufacturers Association (APRA).

GENERAL MOTORS

CHRYSLER

PERFORMANCE

SHOP TIPS

IMPORT

FORD

www.enginebuildermag.com | ENGINE BUILDER 1

1 index_Layout 1 2/16/12 7:47 AM Page 1

Timing Chain Service onFord 3.0L Duratec EnginesIf you have to remove or replace a cylinderhead for any reason, or replace the timingchain on a 3.0L Duratec, it can be a bit ofa challenge because Ford doesn’t provide aTop Dead Center (TDC) timing referencemark on the crankshaft.

You will have to use a dial indicator tofind the TDC position of the number onecylinder on Ford’s 3.0L Duratec to makesure the crank and camshafts are all proper-ly aligned.

Ford says that when the crankshaft key-way is positioned at roughly the 11 o’clockposition, the number one cylinder shouldbe at TDC.

Before you can remove the timingchain, the front cover has to come off theengine. Then you have to remove the cranksensor pulse wheel. Note the sensor wheel’slocation before you remove it.

Rotating the crank until the keyway is

at the 3 o’clock position will move theright cylinder head camshafts to the neutralposition. The timing mark on the intakecam should be pointing to the right whenviewed from the front, and the timing markon the exhaust cam should be pointing

straight up if both cams are in the correctposition. You can now remove the chaintensioner arm, chain guide and right tim-ing chain.

To remove the left timing chain, rotatethe crank clockwise 600° (1-2/3rds turn)until the keyway is again at the 11 o’clockposition. This will position the left cylinderhead cams in the neutral position. Thistime, the timing mark on the intake camshould be pointing to the left when viewedfrom the front, and the mark on theexhaust cam should be pointing straightup. As before, you can now remove thechain tensioner arm, chain guide and lefttiming chain.

Before you can reinstall the timingchains, you need to compress the left andright chain tensioners in a vise. Compressthe piston until it is fully bottomed, thentemporarily lock it in place with a pin orpaper clip.

If the replacement timing chain doesnot have timing marks for aligning withthe cam gears, you’ll have to mark the leftand right side chains. Start with the leftchain, and mark one link as the startingcrankshaft timing mark. Then count 29links and make a second mark (for theexhaust cam). Continue counting to linknumber 42 and make a third mark (for theintake cam). The second and third marksshould align with the timing marks on theintake and exhaust cams when the chain isslipped into place. The chain tensioner andarm can now be installed.

Next, you do the same procedure forthe right cam. But first, you need to rotatethe crankshaft 120° clockwise so thecrankshaft keyway is at the 3 o’clock posi-tion. Mark the right timing chain andinstall it the same as before.

Once both chains are in place, removethe locking pin or paper clip from the leftand right chain tensioners.

Rotate the crankshaft 120° counter-clockwise so the keyway is back at the 11o’clock position and number one piston isat TDC. Check to make sure all the tim-ing marks are aligned as shown in theillustration (Figure 1).

There should be 12 chain linksbetween the right and left intake andexhaust cam sprocket marks, 27 chain

2 ENGINE BUILDER TECH SOLUTIONS GUIDE | February 2012

Figure 1 You will have to use a dial indicatorto find the TDC position of the number onecylinder on Ford’s 3.0L Duratec to make surethe crank and camshafts are all properly aligned.

Circle 102 for more information

For fast, precisionalignment of mainbearing bores Sunnencan’t be beat. TheCH-100 handles thecomplete job of align-ment and sizing ofmain bearing bores inabout 30 minutesfloor-to-floor time foran average passenger

car block and it takes just a few minutes longer for truck blocks. With the CH-100, you will see stock removal, usually less than .003˝

(.076 mm) off the caps compared to as much as .010˝ (.254 mm) withboring.

For more information, visit www.sunnen.com or call 1-800-325-3670.

Sunnen CH-100

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3 ACH_Layout 1 2/16/12 8:05 AM Page 3


links between the cam gears and crank onthe non-tensioned side of each chain, and30 links between the cam gears and crankon the tensioned side of each chain.

By Larry Carley

2003-2004 Ford 3.8L, 3.9L and 4.2L Balance Shaft Gear Clarifications To deal with certain engine harmonics(particularly, inherent second-order ortwice engine rpm vibration), enginedesigners often incorporate two balance

shafts rotating in opposite directions attwice engine speed. Equal size eccentricweights on these shafts are sized and phased

so that the inertial reaction to their count-er-rotation cancels out in the horizontalplane, but adds in the vertical plane. Thisgives a net force equal to, but 180 degreesout of phase with, the undesired second-order vibration of the basic engine, therebycanceling it. In a “V” configuration thesame may be accomplished by oppositecounter weights on the same/single shaft.The ultimate result is to eliminate NVH(Noise Vibration Harshness).

This fact is understood, and the Ford3.8L, 3.9L and 4.2Lengines in the same fam-ily configuration havehad these shafts at vari-ous times and in differ-ent vehicles – howeverrecognizing changes inthe amount of teeth ofthe drive and drivengears of certain vehiclesis critical.

The drive and drivengears of the balance shaft

appear to have changed in August of 2003for vans and August of 2004 in the truck.The driven gear on the balance shaft

changed from 31 to 38 teeth, and as youcan see in the illustrations (Figures 2, 3) itwould not be hard to confuse the two.

The change in teeth was to furtherreduce the NVH of the gears that drive thebalance shaft. Obviously a mix up wouldresult in a catastrophic failure. However,what I have found is that as long as youkeep the camshaft drive gear and balanceshaft gear matched it makes no differencewhich ones you use.

By Roy Berndt

Oil Leak Repair for 1990-1993 4.0L Ford V6 Engines The 4.0L Ford V6, used in theAerostar, Explorer and Rangerpickups, has been a problemengine for oil leaks for years.

The most common oil leakon ’90-’93 4.0L engines is oftendiagnosed as a rear seal leak, but inmost cases, the problem is usuallyfound to be the rear of the oil pangasket. Since 1990, when the 4.0Lwas first introduced, Fordredesigned the gasket twice andeven the oil pan casting to elimi-nate the leaking issue.

The following installationtips from Canada Enginesshould help to prevent this cost-ly and aggravating oil pan gasketleak.

The ’90 to ’93 gasket set willinclude a plastic wedge seal thatgoes into a groove in the maincap (see Figure 4).

The oil pan was redesigned in1994 and so was the gasket(Figure 5). The wedge seal is nolonger used because its shape is

4 ENGINE BUILDERS TECH SOLUTIONS GUIDE | February 2012

F O R D

Figure 3 It’s easy to confuse the two gears, butputting the wrong driven gear into a Fordengine will cause real problems.

Figure 2 Ford increased the number of teeth in the drive anddriven gears on several Ford engine balance shafts in 2003 and2004.



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built into the gasket. Silicone is still neces-sary across the main cap and in the cavitiesbetween the cap and the block.

The oil pan must be aligned with astraight edge to the back of the blockbefore it is torqued down.

Source: Canada Engines LTD

Rattle Noise From Primary Chain Driveon Ford 4.0L SOHC EngineThere have been complaints of a rattlecoming from the primary timing chaindrive area on some 1999-2002 Ford 4.0LSOHC engines during cold engineoperation.

The 4.0L SOHC engine is one ofFord’s Cologne V6 engines, a line of 60º,cast iron block, V6 engines produced con-tinuously by Ford in Cologne, Germanysince 1968. It uses a jackshaft in place of acamshaft to drive a timing chain to eachcylinder head. The patented “Offset Y-drive” (see Figure 6) uses three timingchains, one from the crank to the jackshaft,one in the front of the engine to drive thecam for the left bank and one on the backof the engine to drive the cam for the

right bank.The noise is audible during hot and

cold engine operation (but predominantlyfound on cold engines) under accelera-tion, typically at 2,400-2,500 rpm. To con-firm presence of this noise, accelerate in2nd gear between 2,000-3,000 rpm andlisten for a rattle noise that sounds similarto spark knock. This may be caused by theprimary timing chain tensioner system.

Replace the primary timing chain ten-sioner, chain guide, jackshaft, and crank-shaft sprockets with a primary timingchain tensioner kit. The kit includes animproved primary chain Ttensioner, aswell as updated primary chain guide, jack-shaft, and crankshaft sprockets. Requiredfasteners, primary timing chain, and frontcover gaskets are also included.

Use kit 2U3Z-6D256-AA (balanceshaft engines) for:• ’99-’01 4x4 Explorer/Mountaineers;• ’01-’02 4x4 Sport/Sport Tracs; and• All ’02 Explorer/Mountaineers, exceptengine codes 2G-960-AA and 2G-964-

AA.Use kit 2U3Z-6D256-BA (non-bal-ance shaft engines) for:• ’99-’01 4x2 Explorer/Mountaineers;• ’01-’02 4x2 Sport/Sport Tracs;• ’02 Explorer/Mountaineers withengine codes 2G-960-AA and 2G-964-AA; and• All 2001-02 Rangers. TSG


F O R D

Figure 5 The oil pan was redesigned in 1994and so was the gasket. The wedge seal is nolonger used because its shape is built into the gas-ket. Silicone is still necessary across the main capand in the cavities between the cap and the block.


Figure 6 The patented “Offset Y-drive” usesthree timing chains, one from the crank to thejackshaft, one in the front of the engine todrive the cam for the left bank and one onthe back of the engine to drive the cam forthe right bank.

Figure 4 The oil pan gasket for the ’90 to’93 4.0L Ford engine (top) will include aplastic wedge seal (bottom) that goes into agroove in the main cap



Deciphering The Differences In The Chevy 2.2L EngineThe very popular Chevrolet 2.2L/four-cylinder engine has been a solidsteed in GM’s FWD/RWD stable. Buteven after all these years, it still managesto raise questions surrounding the Gen

II engine casting configurations, in par-ticular the cylinder head.

Since its birth in 1990, when the oldChevy 2.0L engine was upgraded with astroke increased from 3.15˝ to 3.46˝, the2.2L/134CID, OHV four-cylinderengine powerplant has been upgradedseveral times: the block has been revisedfour times and the head has beenchanged three times (it was discontinuedafter 2003, replaced by the 2.2L Ecotec).Let’s start in 1994 and see if we can’tclear up some of the confusion.

In 1994 the 2.2L Chevrolet becamethe base engine in the S-series truck line,replacing the 2.5L Pontiac engines. This

presents us with the 2.2L now beingboth FWD and RWD, which you wouldthink would mean numerous differences.Actually, that’s not so. GM used two dif-ferent head gaskets through 1997, and in1998 went to a common head gasket forboth FWD and RWD. Using the incor-

rect head gasket willresult in almost immedi-ate overheating. Thecastings made changes inthose years but they fol-lowed suit in both FWDand RWD configura-tions.

In 1994, the valvestem diameter went from8 mm to 7 mm as well asgoing to a roller lifterand assembled camshaft.

The FWD versionrequires the use of a34.4 mm soft plug infront of the headwhile the RWDmodel is open andmust have the boltholes drilled andtapped (see Figure1). The 1994 motorcould have castingnumber 10112391 or10112391S that is theservice replacement.This same pattern wasfollowed throughout

the 1997 production cycle.In 1998, a new cylinder head (c/n

24575507) arrived with a heart-shapedcombustion chamber against a D shape.The engine also had smaller 1-1/8˝diameter exhaust ports vs. 1-3/8˝, and atriangular top of the intake ports vs. asmaller eyebrow top. This version of theGM 2.2L engine – a single-year config-uration – must have an open and drilledEGR port.

Since 1999 to present, the samecylinder head (c/n 24576146) has beenused. It is basically the same as c/n24575507 except for crucial long flatbosses that are now between the first

two and last two exhaust ports (seeFigure 2). The latest exhaust manifoldshave a balance channel that runsbetween ports 1-2 and ports 3-4 thatmust seal against the cylinder head. Asyou can see, that exhaust manifold con-figuration assembled against the 507head would leak.

One last quirk: the 146 head may alsobe drilled for the EGR port as a servicereplacement for the 507 head in 1998.All later applications would require theuse of an EGR block-off plate (GM p/n24575919) when used without EGR.

Special Note: 1998 applications allrequired an open EGR port; 1999-2002are closed EGR, w/exhaust manifoldport balance mounting face, (seeIllustration D and observe area thatarrows are pointing to). P/N 24576146cylinder head may also have open EGRport and will retro for 24575507 in1998, or may be used 1999-2002 withthe use of EGR block off plate partP/N24575919.

– By Roy Berndt

Timing Chain Tensioner InstallationCaution on GM 2.3L Quad 4 The timing chain tensioner on GM's2.3L “Quad 4” engine is of the spring-loaded ratchet design (See Figure 3).The tensioner assembly consists of ahousing, spring, and ratcheting plunger.The plunger is locked into the housingand plunger to prevent the accidentalrelease of the spring before or duringinstallation.

Once the tensioner is installed andthe chain is in place, the anti-releasedevice must be removed and the plungermanually depressed into the housing tounlock the plunger and release springtension on the chain.

Inadequate tension placed on thechain will eventually result in chainbreakage and the consequential piston tovalve contact.

Failure to perform this importantfinal step can lead to severe engine dam-age.

– From MAHLE Clevite


Figure 1 The FWD 2.2L engine (left) requires the use of a softplug in the front of the head. The RWD model is open and musthave the bolt holes drilled and tapped.

Figure 2 The GM 2.2L cylinder head in use since 1999 has long flatbosses between the exhaust ports (top). The latest exhaust manifoldshave a balance channel that runs between ports 1 - 2 and 3 - 4.

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7 Mahle_Layout 1 2/16/12 8:13 AM Page 7


Chevy 3.1L/191 Cam BearingBore Issues Some of the later roller cam 3.1L blocksfor the ’93-’94 Chevy VIN M are show-ing up with oversize cam bearing boresthat appear to have been caused by spuncam bearings.

If a new cam bearing is installed ina bore that has been damaged, it willspin in the block, cut off the oil to thecam, and cause an immediate failure(Figure 4).

Inspect the cam bores in all of the late3.1L castings (10137093/ 10191737/24504089/ 24504150/ 10224227) verycarefully, paying special attention to the#2 bore that seems tobe the most prone tofailure.

If the cam bore isoversize, there are onlytwo choices:

1) You can eitherknurl the O.D. of thecam bearing to getenough press fit, or 2)you can junk theblock.

– By Doug Anderson

Noise Complaints with 2004-20053.6L Cadillac Engines If a whine, ringing or whistling noise isreported in several 3.6L Cadillacengines, replacement of the crankshaftharmonic balancer is recommended if

noise is isolated to the front of engineand balancer is three-spoke design.

Models affected include the 2004-2005 Cadillac CTS and SRX; and2005 Cadillac STS with 3.6L engine

(VIN 7 - RPO LY7) and without heavyduty cooling (RPO V03tV92).

Other complaints of a faint enginewhine-type noise have been reported atspeeds of 0-30 mph (0-48 km/h) at1,000-2,500 rpm and may be caused bythe primary camshaft drive chain. Thistype of noise may be amplified by thevehicle's body structure.

Some installers/customers may com-ment on a whine, whistle, or ringingtype noise from the front of the enginethat increases in intensity as engine rpmincreases. This noise is most audiblestanding in front of the vehicle with thehood opened. If the noise fades into theambient engine noise by 2,000 rpm theharmonic balancer may be the culprit.

Refer to Figure 5 and inspect the


G E N E R A L M O T O R S


Figure 5 Refer to the above graphic illus-tration and inspect the crankshaft harmonicbalancer for design type. After the inspec-tion, if the vehicle was built with threespoke (1) design crankshaft harmonic bal-ancer, replace the harmonic balancer withp/n 12597654.

Figure 4 Some of the later roller cam 3.1LChevy blocks have oversize cam bearing boresthat may have been caused by spun cam bear-ings. Inspection will reveal if you can repair thedamage or junk the block.

Figure 3 GM 2.3L Quad 4 Timing ChainTensioner Assembly. This is the late produc-tion piece, although early production is simi-lar. Components include: A. Plunger assem-bly; B. Long end; C. Peg; D. Nylon Plug;E. Spring; F. Restraint cylinder; G. J-36589Anti-release device; H. Tensioner body.


http://www.epwi.net

crankshaft harmonic balancer to deter-mine the design type. If the vehicle wasbuilt with a three-spoke design crank-shaft harmonic balancer, replace the har-monic balancer with a new unit (P/N12597654.)

However, if the vehicle is equippedwith the V03N92 Heavy Duty Coolingpackage, DO NOT replace the six-spokedesign crankshaft harmonic balancer (seeFigure 6). Continue with routine diag-nosis to isolate the noise.

Close-Coupled Converter CautionOn Late Model GM VehiclesCertain late model General Motorsvehicles may be equipped with a newstyle of catalytic converter, technicallyknown as the close-coupled catalyticconverter (see Figure 7).

This new-style converter providesquick catalyst warm-up, resulting inlower tailpipe emissions earlier in theoperating cycle. If an engine failureoccurs (such as a broken intake/exhaustvalve or piston), debris may be depositedin the converter through the engineexhaust ports.

If the engine failure is due to a severeoverheating event, damage to the ceram-ic “brick” inside of the catalytic convert-er may occur. This could then result inceramic debris being drawn into theengine through the cylinder head

exhaust ports.If a replacement engine is installed

due to either of these instances, thereplacement engine may ultimately faildue to the debris being drawn into thecombustion chamber upon startup.

Remind your installers that whenthey replace an engine due to a failure ofthis type, they must inspect the convert-ers and ALL transferred componentssuch as the intake and exhaust manifolds.Remove any debris that is found.

In cases where engine failuresoccurred as a result of severe overheat-ing, installers should inspect each cat-alytic converter for signs of melting orcracking of the ceramic “brick.” If dam-age is observed, the converter should bereplaced.

Cadillac 4.6L DOHC Aluminum CylinderHead and Block Crack Cautions Cadillac 4.6L DOHC engines may beprone to cracking of the aluminumblock casting around the cast iron liner

(Figure 8). Knowing that this possibili-ty exists, make a close examination ofthe deck prior to doing any machiningat all – and before you then spend

www.enginebuildermag.com | ENGINE BUILDER 9Circle 109 for more information


Figure 6 Refer to the above graphic illus-tration and if the vehicle was built with theNEW DESIGN six spoke (1) crankshaftharmonic balancer, DO NOT replace it.Continue on with routine diagnosis to iso-late the noise.

Figure 7 Certain late model General Motorsvehicles may be equipped with a new style ofcatalytic converter, technically known as theclose-coupled catalytic converter. Engine fail-ures can damage the converters which, if notinspected properly, can then cause subsequentdamage to a replacement engine.

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Heads from

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Look to American Cylinder Head for quality built on a her-itage of nearly a half-century of experience. Continual

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numerous hours on cylinder head bolt repairs.The second tip involves cylinder head c/n 3533989

and 12554607, which would be the left head (or front, inthe transverse mount engine) that has an alternator brack-et bolted onto it in some applications. This head willalways have the bosses for this mounting bracket but bothof them may or may not be drilled (see Figure 9).

If you want to avoid problems I recommend that youdrill all of the bosses, thereby eliminating the possibilityof having a warranty problem upon installation and also

reducing head proliferation.– By Roy Berndt

GM Belt Tensioner Failure MayCause Supercharger FailureAll GM vehicles equipped with super-chargers may be prone to premature fail-ure of supercharger bearings.

When the belt tensioner starts to fail,belt tension increases as side-loading inthe supercharger rear bearing.

Periodic inspection of the belt ten-sioner should be part of the regular main-tenance routine. Before operating thereplacement supercharger, the tensionermust be inspected and replaced if defec-tive. Unless the tensioner is checked andreplaced as needed, supercharger-bearingfailure will occur, causing premature cata-strophic failure.

While this problem is prevalent onGM vehicles, this inspection should beperformed on all belt-driven super-charged vehicles. Please check the servicemanual for the recommended inspectionand service.

Note: This bulletin is supplied as tech-nical information only and is not anauthorization for repair.

– By CARDONE Industries TSG

10 ENGINE BUILDER TECH SOLUTIONS GUIDE | February 2012Circle 110 for more information


For precision rod reconditioning and pin fitting, theSunnen LBB-1660 manual hone can turn old rodsinto like-new rods. For added flexibility, theLBB-1660 also handles King Pins, aircompressors and small bore engines.

The LBB produces a round andstraight honed bore, equal to orbetter than manufacturers’new rods, and it helps keepyour rod inventory to a min-imum by enabling you to giveover-the-counter service oncustomers’ own rods.

For more information, visit www.sunnen.com orcall 1-800-325-3670.

Sunnen LBB-1660 Manual Hone

Figure 8 The aluminum 4.6L Cadillac block may crackoutside the cast iron cylinder liner and is extremely hard todetect. The above crack became visible only after the deck facewas machined.

Figure 9 The cylinder head on the top has the bolt holes drilled and tappedfor the alternator bracket when used. The head below does not but both havethe same casting number. To avoid potential warranty issues drill and tap allheads.



1995-2005 Chrysler 2.4L Cylinder Block Casting Identification

Chrysler replaced its old SOHC fourcylinders with an all-new family ofSOHC and DOHC engines in 1995.

There were 2.0L SOHC and DOHCversions, along with a 2.4L DOHC thatwas installed in the FWD cars and mini-vans. Over the years, this engine hasbeen used in several other applicationsincluding the PT Cruiser, the RWDLiberty and Wrangler, and the SRT4Neon. It has evolved over the years, too,so there are seven short blocks that usesix block castings. So, let’s take a lookand see if we can make some sense outof all the changes to the blocks.

1995-2000: The original casting wasa 4621443 block that had a 4621445bedplate. It was used up through 2000.

2001: The hole for the oil pressuresender on the passenger side was movedback about 6˝ in 2001 so it was muchcloser to the bell housing. It’s a4621443AB casting.

2002: The oil drainback hole in thehead was enlarged in ’02 so there wasanother “bulge” added to the block onthe driver’s side, between the third andfourth cylinders. It’s an all new castingthat has 4781655AA on the driver’s side.

2003-2006: There was another allnew FWD block in ’03 that incorporat-ed several more changes, but the mostnoticeable one was the change in thelocation of the hole for the crank sensor;it was moved from the front of the block

on the passenger side to the back of theblock on the driver’s side in order toaccommodate the new, bolt-on “targetring” for the crank sensor.

There were some other changesmade to accommodate the turbo motor,

too, including a boss on the pas-senger side that can be drilledfor the oil return from the turboand an additional oil galleyinside the block that’s machinedfor the four “oil squirters” thatare used to help cool the pistonson the turbo motors. Look for a4781632AA/AB casting.

2003-2004 RWD: Chryslerinstalled the 2.4L motor in boththe RWD Jeep Wrangler andLiberty beginning in 2003. TheRWD block is a unique casting(53010502AA) that doesn’t havethe “ear” that sticks out from thefront of the block down by the

pan rail on the passenger side of theFWD blocks.

These blocks have “RWD” cast onthe passenger side so they’re easy to spot.The Catch-22 is that this block was usedfor both the Wrangler and Liberty in’03, but only for the Wrangler in ’04because the Wrangler platform contin-ued to use the old style computer andcrankshaft (without “NGC”) through’04 even though the Liberty got the“NGC” computer along with a newblock and crank in ’04.

2004-2005 RWD: The RWD blockwas revised in 2004 to accommodate thebolt-on “target ring” with more notchesthat was used with the new “NGC” com-puter so the hole for the sensor wasmoved over to the driver’s side and backtoward the bell housing, just like it was onall the ’03 cars. The revised 53010502ABcasting was used for the Liberty in ’04 and’05 and the Wrangler in ’05 and ’06.

Figure 1 The hole for the oil sender on the passengerside of the 2.4L was moved back about 6˝ in 2001 soit’s much closer to the bell housing.


Why Cylinder

Heads from


Heads from

American?Service

Count on American Cylinder Head to deliver standard-setting service atevery step. From the moment you explore our electronic or hard-copy

catalog you’ll find user-friendly data and comprehensive coverage for thefull range of vehicles you service, including domestic and import models,as well as marine, H-D, ag, and industrial applications. Once you order,our three warehouses will ship your order promptly since we stock 96%of our part numbers. And we support you after the sale with technical

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Multiple Cylinder Misfire or RoughIdle on 2004-'06 Chrysler 3.5L Engines

This information for installers applies toChrysler models built after Feb. 1, 2004(MDH 0201XX) equipped with a 3.5Lengine.

This bulletin involves rotating all engine exhaust valves, replacing thevalve spring retainer locks with a newdesign to increase valve rotation at lowerrpm, inspecting/replacing the MAP sen-sor (as necessary) and decarbonizing thecombustion chamber.

The customer may experience occa-sional engine misfire (rough-runningengine) during certain vehicle operatingconditions.

In addition, MIL illumination mayalso have occurred due to DTC P0300 -Multiple Cylinder Misfire. Various singlecylinder misfire DTCs may also be pres-ent. If the frequency of misfire is high,the powertrain control module (PCM)may place the engine in “limp-in” mode.

The misfire condition may be causedby one or more engine exhaust valvesthat are slow to close due to a buildup ofcarbon on the valve stem.

Diagnosis1. This condition may occur when

the engine is not allowed to run atengine rpms that are greater than 3,500.At 5,000 rpm or higher, the engineexhaust valves will rotate if not impededby high carbon deposits. Low enginerpms and high carbon deposits are asso-ciated with short-trip driving where theengine is not allowed to fully warm tonormal engine operating temperatures.

Cold ambient temperatures will

increase engine warm-up timeand increase the likelihood of car-bon deposit buildup on the stemof the engine exhaust valve. Fueldetergent quality may also con-tribute to the condition; the cus-tomer may want to try a differentbrand of fuel.

2. Verify that the engine misfirecondition is not caused by faultyengine mechanical or electricalcomponents.

3. If the engine mechanicaland electrical systems are operat-ing properly, perform the Repair

Procedure.

Repair Procedure1) Relieve the fuel pressure.2) Remove the upper intake mani-

fold.3) Remove the cylinder head cover(s).4) Remove the rocker arm and shaft

assembly.5) Clean and mark the tip of each

exhaust valve stem at the 12 o’clockposition with a paint marker. The paintmark will be used later to assist withdetermining the amount of valve rota-tion.

6) Remove the spark plugs.7) Rotate the crankshaft clockwise,

until the number 1 piston is at Top DeadCenter (TDC) on the compressionstroke.

8) Install the compression tester sparkplug adapter in cylinder #1 spark plughole. With the air hose attached to thespark plug adapter, apply 90 to 100 psiair pressure. This is to hold the valves

C H R Y S L E R

Figure 2 The oil drainback hole in the head on the2.4L was enlarged in 2002, so the block had a pro-nounced bulge on the driver’s side between the thirdand fourth cylinders.

Circle 114 for more information14 ENGINE BUILDER TECH SOLUTIONS GUIDE | February 2012

Figure 3 Using a valve spring compressor toolwith the valve spring adapter, slightly compressthe exhaust valve spring to release tensionagainst the valve and valve spring retainer on3.5L engines.



into place while servicing the compo-nents.

9) Using a valve spring compressortool (MD 998772A) with the valvespring adapter (6527 or equivalent),slightly compress the exhaust valvespring to release tension against the valveand valve spring retainer (see Figure 3).

10) Remove the valve spring retainerlocks and discard the locks.

Note: It is important that the valverotation section of this repair procedurebe performed.

Caution: Only grab the valve stemtip, being careful not to cause damage.

11) Using needle-nose pliers, grabthe tip of the valve stem and rotate theexhaust valve 90° (move the mark to the3 o’clock position).

12) Install two new valve springretainer locks (p/n 53022277AA).

13) After installing the locks, releasethe tension on the valve spring and ver-ify proper installation.

14) Remove Special Tool MD998772A (1) and the spark plug adaptertool.

15) Repeat steps 7-14 on the remain-ing five cylinders using the firingsequence 1-2-3-4-5-6. Make sure thepiston is at TDC in each cylinder of theexhaust valve spring retainer lock that isbeing removed. When all the exhaustvalves have been rotated 90° and all theexhaust valve spring retainer locks havebeen replaced, proceed to the next step.

16) Install the rocker arm and shaftassembly.

17) Install the cylinder head cover(s).18) Install the upper intake manifold

MAP Sensor Inspection1) Inspect the MAP sensor – Figure 4

for LX models or CS models. If the MAPsensor is the new style, no further actionis necessary for the MAP sensor. If theMAP sensor is the old style, proceed tothe next step.

2) Replace the MAP sensor with p/n05033310AC for LX models or p/n04896003AB for CS models. If the vehi-cle is a CS model, be sure the new sensoropening is facing a downward directionwhen installed and only use one fastener.

–From ALLDATA

Keeping Your Balance With 3.7L Chryslers

While an optimally balanced V6 enginewould have either 60 or 120 degree anglesbetween the two banks of cylinders, manycurrent V6 engines are derived from 90degree angle V8 engines. While this con-figuration gives an evenly spaced firingorder in an 8-cylinder engine, a 6-cylin-der engine develops a loping rhythm.

During each rotation of the crankshaftthree of the cylinders fire at 90-degreeintervals, followed by a gap of 90 degrees

with no power pulse. Much of this issuewas eliminated by the use of the split jour-nal crankshaft.

Recently many manufacturers havefound it wise to adapt the balance shaftconcept as well, using a single shaft withcounterweights spaced so as to provide avibration which cancels out the shakeinherent in the 90 degree V6. If you buy anew vehicle today, you most likely have anengine with a balance shaft.

One of those V6 engines that incorpo-rate the single balance shaft technology isthe 3.7L Chrysler engine that utilizes thesplit journal crankshaft. The single balanceshaft goes down the center of the block inan area that you may have thought thecamshaft would reside. Since the 3.7L is aSOHC engine it was a perfect spot todrop the single balance shaft unit.

What would happen if you put a bal-ance shaft into the engine out of time? Itwould just exacerbate the problem andthe result would be a shaker instead of asmoothie. Imagine if you did time it cor-rectly but you were actually duped intothinking that you were in time?Unfortunately, that is exactly what hap-pens if certain components don’t live upto expectations.

The 3.7L engine has a gear cluster inthe center of the engine that drives notonly the balance shaft but the two timingchains as well. And many say it is a braveman who takes on timing these engines –there are four chains: one “Morse” typechain for timing to the crank; two sprock-et type chains for the two camshafts; and aspline type gear for the balance shaft allinstalled simultaneously.

The spline gear drives that balance shaftand the two sprocket gears drive the tim-ing chains. On the spline gear side of thegear cluster there is a roll pin that locatesthe index of the gear. Numerous exampleshave been cited where the spline gear has“shifted” and the roll pin sheared.

It is not always easy to see but if youlook closely at Figure 5 you will see thatthe roll pin has been sliced in half and isnow out of time and will cause a vibrationrather than a counter measure to vibration.

Be aware of this situation because itcan be easily missed, especially when thegear cluster appears to be perfect in everyother way. TSG


Figure 5 The circle shows where the roll pin(arrow) and spline gear should be aligned forproper timing of the balance shaft on the3.7L. This assembly has spun on the centershaft over 90 degrees.

C H R Y S L E R

Figure 4 Inspect the MAP sensor for LX models (left) or for CS models (right). If the MAPsensor is the new style, no further action is necessary for the MAP sensor.


Diagnosing VW 16V Cylinder HeadTicking Noise at 2,000 RPM

Dimensional differences between thecamshaft sprockets and the cam timingchain create a rattling noise that canbe heard from the cylinder head atapproximately 2,000 rpm (Figure 1).

This bulletin refers to all MYVolkswagen 16-valve engines.

As of 11/88, starting with VIN 067722 a manufacturing tolerance changehas been made to the camshaftsprockets. If a customer complainsbecause of persistent noise, replaceboth camshafts with the following:

Intake cam p/n: 027 109 021 AJExhaust cam p/n: 027 109 022 F

1996 Audi 2.8L V6 Rear CrankshaftSeal Leaks After Replacement

Oil may leak from the rear crankshaftseal after seal replacement due to theseal lip rolling while installing thenew seal (Figure 2).

This condition affects 1996 A4with 2.8L V6 (engine code AFC).When replacing the seal, the new sealis supplied pre-installed in the flange.

• Seal/Flange P/N: 078 103 171H;• Flange gasket p/n: 078 103 181

(must be ordered separately).Caution: Part numbers are for ref-

erence only.1) Carefully remove installation

tool that comes with seal and apply asmall amount of engine oil to theinner lip of the seal.

Note: Lubricating the seal lip willease seal installation and reduce thetendency of the seal to roll as it isbeing installed.

2) Carefully reinstall the seal instal-lation tool.

3) Install oil seal and flange withnew gasket.

4) Torque reusable flange bolts to 7ft.lbs. (10Nm).

1999-2001 Exhaust Manifolds Crackedin Nissan VGS33E Engines

A ticking or exhaust noise has beenreported coming from the right-handexhaust manifold area of some 1999-2001 Nissan VGS33E engines.

If a cracked right-hand exhaustmanifold on a 1999-2001 NissanVGS33E engine is discovered when

the exhaust heat shield is removed,installers must replace the exhaustmanifold (Figure 3).

If one of these symptoms shouldoccur, use the following to diagnosethe condition, replacing the right-hand exhaust manifold and relatedparts as described.

Diagnosis1) Installers should verify the

source of the noise with the enginerunning that it is coming from theright-hand manifold area.

2) If the noise is coming from theright-hand manifold area, remove theheat shield and inspect for cracksbetween the #1 and #3 ports on themanifold.

Repair1) Separate the catalyst from the

right-hand exhaust manifold andremove it to allow for clearance.

Caution: The nuts that attach thecatalyst to the exhaust manifold have aself-locking design and require someeffort to remove. Apply penetrating oilto the threads and allow it to soak inbefore attempting to remove the nuts.

Use a tight-fitting six-point socketto avoid rounding off the corners ofthe nuts during removal. If any of thenuts or studs are damaged duringremoval, replace them as needed.

2) Remove the exhaust manifoldfrom the head (See Figure 4 for loos-ening sequence of manifold nuts).NOTE: If any of the nuts or studs aredamaged during removal, replace them


Figure 1 Dimensional differences betweenthe camshaft sprockets and the cam timingchain may create a rattling noise on someVolkswagen 16-valve engines that can beheard from the cylinder head at approximate-ly 2,000 rpm.

Figure 2 When replacing the oil seal on1996 Audi A4 models with V6 engines,make sure the new seal is supplied pre-installed in the flange.

Figure 3 A ticking noise may be heard from a cracked exhaust manifold on certain Nissan engines.Typically, inspection for cracks between the #1 and #3 ports should be conducted.

16-17 Import_Layout 1 2/16/12 7:51 AM Page 16

as needed.3) Install the replacement manifold

with a new gasket onto the head. SeeFigure 5 for tightening sequence ofmanifold nuts. See Figure 3 for mani-fold nut torque specifications.

4) Re-attach the catalyst to theexhaust manifold. NOTE: Ensure that

all bolts securing the manifold and heatshields are installed and are torqued tothe specifications shown in Figure 3.

Variable Valve Timing NoiseComplaints When Starting 2006-2007 Mazda MZR EnginesCustomers may complain of a loudticking noise from the variable valvetiming (VVT). This is caused by thelock pin of the variable valve timingactuator not fully engaging.

Affected models with MZRengine:

• 2007 Mazdaspeed3 vehicles pro-duced before April 1, 2007;

• 2006-2007 Mazdaspeed6 vehiclesproduced before April 1, 2007;

• 2007 Mazda CX-7 vehicles pro-duced before April 1, 2007.

When the engine is first started,some vehicles may exhibit a loud tick-ing noise from the variable valve tim-ing (VVT). This is caused by the lockpin of the variable valve timing actua-tor not fully engaging.

Heat treatment has now beenadded around the hole of the variablevalve timing rotor lock pin to preventthis from happening.

Customers having this concernshould have their vehicle repairedusing the following repair procedure.

Repair1) Verify variable valve timing

noise.2) After the engine cools down,

replace the variable valve timing actu-ator.

NOTE: Do not use the printedservice manual as the procedure hasbeen updated online.

3) Change the engine oil (5W-30)only, then start and let the engine idlefor 5 minutes. This is to remove con-taminants from the engine.

4) Make sure there is no fuel leak-age around the high pressure fuelpump.

5) After the engine cools down,change the engine oil (5W-30) again,and the filter.

6) Verify repair. NOTE: This repair calls for the oil

to be changed two times. TSG


Figure 6 Location of the variable valve actuatorfor the Mazda MZR engine.


I M P O R T

Figure 4 Sequence for loosening the exhaustmanifold nuts on the Nissan VGS33E.

Figure 5 Sequence for tightening the exhaustmanifold nuts on the Nissan VGS33E.

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Understanding Spark Plug Heat RangeFinding the right spark plugs for a mod-ified engine is a little more involved thanjust looking in a catalog for make andmodel.

Depending on the engine modifica-tions you’ve made, you’ll need to take afew extra factors into considerationbefore settling on the right spark plugs(Figure 1). These factors include sparkplug seat design, thread length and diam-eter, and reach. One of the most impor-tant – and least understood – factors inchoosing aftermarket spark plugs is theheat range.

Heat range is the speed at which aspark plug can transfer heat from the fir-ing tip to the cylinder head water jacketand into the cooling system. Choosingthe right heat range is crucial for highperformance engines. If the heat range istoo cold, the spark plug will be unable to

properly self-clean by burning off car-bon deposits.

If it the heat range is too hot, your

engine could experience detonation,pre-ignition, or power loss. Most sparkplug manufacturers recommend that thetip temperature remain between 900° F(500° C) and 1,500° F (850° C).

Heat ranges are designated by eachspark plug manufacturer with a number.In broad terms, spark plugs are oftenreferred to as “hot plugs” or “coldplugs.” A cold plug has a shorter insula-tor nose length – the distance from tipto spark plug shell – and transfers heatrapidly from its firing tip to the cylinderhead water jacket.

Cold plugs are ideal for high rpmengines, forced induction applications,and other instances where the engineproduces high operating temperatures.Conversely, hot plugs are good for appli-cations that operate mainly at low rpms.Because they have a longer insulatornose length, heat is transferred from thefiring tip to the cooling system at slow-er pace. This keeps the spark plug tem-perature high, which allows the plug toself clean and prevent fouling.

Unfortunately, heat range numbersare not universal – each brand has itsown method for assigning heat ranges.You’ll need to talk with your sales rep orconsult with the manufacturer to findthe best heat range for your applicationand spark plug brand. Be prepared tosupply some basic vehicle information,including any modifications you’vemade.

As a rule of thumb, you can expect torequire one heat range colder than thefactory-supplied plugs for every 75-100horsepower you’ve added with yourmodifications, according to ChampionSpark Plugs. Here are some more basicguidelines to get you pointed in theright direction:

• Supercharging/turbocharging:For-ced induction leads to increasedcylinder pressure and temperature,which could lead to detonation.Depending on the exact application,you’ll need to go with a significantlycolder heat range (faster heat transfer)over stock.

• Nitrous oxide: The high cylinder

Figure 1 As a rule of thumb, you can expectto require one heat range colder than the fac-tory-supplied plugs for every 75-100 horse-power you’ve add with your modifications.

18 ENGINE BUILDER TECH SOLUTIONS GUIDE | February 2012Circle 118 for more information

Why Cylinder

Heads from


Heads from

American?The Future

Trust American Cylinder Head to constantly look to The Future by utiliz-ing cutting-edge parts, equipment, and technology to provide you themost precisely-engineered and durable cylinder heads in the industry.

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18-22 Performance_Layout 1 2/16/12 7:53 AM Page 18



19 Motorstate_Layout 1 2/16/12 8:08 AM Page 19

http://www.motorstate.com

temperatures caused by nitrous usuallyrequires a colder heat range over thestock plug.

• Methanol: Since it has a higheroctane level than standard gasoline,methanol delivers more complete com-bustion. As a result, you’ll need a colderplug to transfer more heat from thecombustion chamber.

• Increased compression ratio:Higher compression ratios mean highercylinder pressure and temperature. Onceagain, you’ll need a colder heat range torapidly transfer all that extra heat to thecooling system.

• Air/fuel mixture modifications:Lean air/fuel mixtures raise the operat-ing temperature, along with the plug tiptemperature, possibly causing knock orpre-ignition. Use a colder heat range forleaner air/fuel mixtures. Rich air/fuelmixtures can cause the plug temperatureto dip, allowing carbon deposits to buildup on the tip. Use a hotter heat range forrich air/fuel mixtures.

• Advanced ignition timing: In

general, advanced ignition timing willraise the spark plug temperature. In fact,NGK estimates an increase of 70° to100° for every 10° advance in ignitiontiming. For this reason, you may need togo with a colder heat range to preventknock or pre-ignition.

• Prolonged acceleration/highspeed driving: Frequent and drawn-

out acceleration and high-rpm drivingraises combustion temperatures and gen-erally requires a colder heat range.

– From Summit Racing

Influence of Grooved Main Bearingson Engine PerformanceManufacturers are frequently asked whatdifference grooving makes. Various formsof main bearing grooving have beenused over the years.

It’s essential to understand that bear-ings depend on a film of oil to keepthem separated from the shaft surface.This oil film is developed by shaft rota-tion. As the shaft rotates it pulls oil intothe loaded area of the bearing and ridesup on this film much like a tirehydroplaning on wet pavement.

Grooving in a bearing acts like treadin a tire to break up the oil film. Whileyou want your tires to grip the road, youdon’t want your bearings to grip theshaft, so grooving is bad for maintainingan oil film. The primary reason for hav-ing any grooving in a main bearing is toprovide oil to the connecting rods.Without rod bearings to feed, a simpleoil hole would be sufficient to lubricatea main bearing.

Many early engines used fullgrooved bearings and some even usedmultiple grooves. Those choices werebased on what engineers knew at thetime. As engine and bearing technologydeveloped, the negative effect of groov-ing was recognized and bearing groov-ing was removed from modern lowermain bearings. The result is in a thickerfilm of oil for the shaft to ride on.

This provides a greater safety marginand improved bearing life. Upper mainshells, which see lower loads than thelowers, and hence don’t apply the sameload to the oil film, have retained agroove to supply the connecting rodswith oil.

In an effort to develop the best pos-sible main bearing designs for high per-formance engines, manufacturers haveinvestigated the effects of main bearinggrooving on bearing performance. Thegraph (Figure 2) illustrates that a sim-ple 180° groove in the upper main shellis still the best overall design.

While a slightly shorter groove of


P E R F O R M A N C E

Figure 2 As engine and bearing technologydeveloped, the bearing grooving was removedfrom modern lower main bearings creating athicker oil film.

Sunnen’s SV-10 Cylinder Hone combines the latest technology withthe consistency and dependability of the legendary Sunnen CylinderKing.

The SV-10 comes standard with two time and money savers – autodwell and rough and finish cycle. Auto dwell allows for unattendedoperation. The machine automatically dwells in the tightest part of

the bore – top, middle or bottom. The roughand finish cycle removes stock fast

and automatically switchesto finish for the correctcrosshatch angle.

With two motors, one forthe spindle and one for thestroker, the SV-10 has thecapability to run standardtools as well as Sunnen’sDH-series diamond honehead.

For more information, visit www.sunnen.com orcall 1-800-325-3670.

Sunnen SV-10 Cylinder Hone




140° provides a marginal gain, most ofthe benefit is to the upper shell, whichdoesn’t need improvement. On theother hand, extending the groove intothe lower half, even as little as 20° ateach parting line (220° in total), takesaway from upper bearing performancewithout providing any benefit to thelower half. It’s also interesting to notethat as groove length increases so doeshorsepower loss and peak oil film pres-sure, which is transmitted directly to thebearing.

Notes: You will still find some full-grooved main sets offered for olderengines where demand is low and theengineering cost to bring the sets tocurrent standards is not warranted(bearings generally represent the tech-nology of the time the engine wasdeveloped).

– From MAHLE Clevite Inc.

Holley Power Valve MythsThe power enrichment system suppliesadditional fuel to the main system dur-ing heavy load or full power situations.

There still seems to be a lot of miscon-ception about Holley carbure-tors blowing power valves.According to the manufacturer,this should be of no concern.Holley performance carburetorssince 1992 have utilized apower valve check system thateffectively eliminated this infre-quent problem. Consisting of aspring, brass seat and check ball,the check ball system is 100%effective protecting the powervalve diaphragm from damagedue to engine backfire.

The power valve check ballis designed to be normally openbut quickly seals to close off theinternal vacuum passage when abackfire occurs. Once closed,the check valve interrupts thepressure wave generated by thebackfire, thus protecting thepower valve diaphragm. Thisprevents the power valve’sdiaphragm from rupturing dueto an engine backfire, accordingto the company.

Holley carburetors utilize a

vacuum operated power enrich-ment system (Figure 3) and aselection of power valves is availableto “time” this system’s operation toyour specific needs. Each Holleypower valve is stamped with anumber to indicate the vacuumopening point. For example, thenumber “65” indicates that thepower valve will open when theengine vacuum drops to 6.5˝ orbelow.

An accurate vacuum gaugeshould be used when determiningthe correct power valve to use. Acompetition or race engine whichhas a long duration high overlap camshaftwill have low manifold vacuum at idlespeeds. If the vehicle has a manual trans-mission, take the vacuum reading with theengine thoroughly warmed up and at idle.

If the vehicle is equipped with anautomatic transmission, take the vacuumreading with the engine thoroughlywarmed up and idling in gear. In eithercase, the power valve selected should behalf the intake manifold vacuum readingtaken.

EXAMPLE: 13˝ Hg vacuum readingdivided by 2 = 6.5 power valve. If yourreading divided by 2 lands on an evennumber you should select the next lowestpower valve.

EXAMPLE: 8˝ Hg vacuum readingdivided by 2 = 4 power valve. Since thereis no #4 power valve you should use a 3.5.

Most of Holley’s “Street Legal” and“Street Performance” carburetors incor-porate a power valve blow-out protec-tion system. A special check valve is



Figure 3 Holley carbs use a vacuum operated powerenrichment system and a selection of power valves is avail-able to “time” this system’s operation to your specific needs.




located in the throttle body expressly forthis purpose. This check valve is designedto be normally open but will quickly seatto close off the internal vacuum passagewhen a backfire occurs. Once closed, thecheck valve interrupts the pressure wavecaused by the backfire, thus protecting thepower valve.

If you have a carburetor older than1992 (or you have experienced an extremebackfire) and expect a blown power valve,use this simple test. At idle turn the idlemixture screws (found on the side of themetering block) all the way in. If theengine dies the power valve is not blown.

– From Holley Performance

Tips For Selecting The Proper CircleTrack CamAn engine builder is only as good as hiscustomer’s information, and if your circletrack customer doesn’t give you the nec-essary answers, he may not be pleasedwith the cam you choose.

This isn’t always the builder’s fault, butis often followed by the racer selling thecam to another racer who thinks it’s thebest cam he ever ran. Why did this camwork so well for one racer and not foranother? The reasons can be many. Thefollowing are some tips for selecting theproper cam for circle track applications.

• Longer duration cams requiretighter lobe separation to have any poweroff the corner (not usually a preferablecombination in 2 bbl classes). Shorterduration cams with wider lobe separa-tions usually yield much flatter torquecurves. Longer rod engines seem to pre-fer shorter durations and wider lobe sep-aration (Figure 4).

• Stock exhaust manifolds or a highlyrestricted exhausts usually respond well toshorter exhaust duration and wider lobeseparation. Power increases are most evi-dent at higher rpm where exhaust back-pressure is greatest and reversion is mostprevalent.

• Most unported heads approach 85or 95 % of peak flow at .400˝ to .450˝ liftand do not need or want a maximumvalve lift over .540˝ to.555˝. Often a lowcam lift with 1.65 or 1.7 ratio rockers isvery helpful on the intake side as long aslift is kept to about .550˝. Exhaust is lesscritical with 1.5 or 1.55 being the mostpopular. Dyno testing doesn’t test dri-

vability or throttle response of theengine.

• The important numbers on a dynosheet are about a thousand RPM aboveand below peak torque and peak horse-power. Peak numbers are for braggingpurposes and high peak numbers do notwin races.

• The benefit of high ratio rockers isfaster valve movement and the added liftis frequently detrimental in unportedheads. It often helps to utilize a lowercam lift with high ratio rockers.

• Changing the valve lash is a goodway to get an indication of which way togo for your next cam change. You won’thurt anything by going too tight but tooloose will let the valves slam shut causingdamage to valves and seats. .004˝ to .006˝loose is usually OK.

• Look at the “major intensity” num-bers to get an idea as to how radical theprofile is (major intensity is the differencebetween the .020˝ duration and the .050˝duration). Lower numbers are more rad-ical but anything less than 26 or 27degrees may be very hard on the valvetrain.

• Camshaft Intensity is a measurementterm coined by Harvey Crane to com-pare ramp characteristics of camshafts.

- Hydraulic Intensity is the differencebetween .004˝ duration and .050˝ dura-tion.

- Minor Intensity is the differencebetween .010˝ duration and .050˝ dura-tion.

- Major Intensity is the differencebetween .020˝ duration and .050˝ dura-tion.

• Lower numbers indicate more radi-cal profiles, but too low can be too radi-cal and lead to noisy valve train operationand even to broken parts.

– From Camcraft Performance Cams TSG


Circle 122 for more information22 ENGINE BUILDER TECH SOLUTIONS GUIDE | February 2012

Figure 4 Longer rod engines seem to prefershorter durations and wider lobe separation.



Quick Test For Water in MethanolMost engine builders know thatmethanol absorbs water from the dayyou break the seal. But racers don’t usu-ally carry a specific gravity gauge to thetrack. Here’s what you may wish to tellyour customers. Once the motor is up tofull temperature with the ignition off,remove the air cleaner and open thethrottle all the way, holding it open forabout 30-45 seconds. With the throttleopen, take a light and look through thecarburetor to the floor of the manifold.With the motor being “hot” themethanol evaporates quickly and if youhave water in the fuel you will see dropsof water sitting at the bottom of themanifold. This is a quick way to tell howgood your methanol is.

Mark Those GuidesWhen installing more than one valveguide in an OHC cylinder head, it’soften difficult to see well enough to getthe depth correct every time, so I just lay

out all the guides in line, side-by-side,then use a piece of tape across all ofthem at the desired depth to be installedand spray them with a can of graphite.Remove the tape and you’ll have a lineto drive the guide to every time, and thegraphite helps to prevent galling duringinstallation.

Oil Pump and Engine PrimingA crucial step in any engine build is thepriming of the oil pump and the enginelubrication system prior to initial start-

up. Proper priming will help assure atrouble-free rebuild. There are two pre-ferred methods to prime oil pumps andnewly rebuilt engines. The first methodlisted covers oil pumps driven by thecamshaft and the second covers thosedriven by the crankshaft.

Priming camshaft driven oil pumps:These pumps are typically referred to aswet sump pumps since they sit low inthe engine oil pan and are partially sub-merged in the engine oil. To prime, firstsubmerge the inlet of the oil pump inclean oil and rotate the drive shaft in thecorrect direction. If it does not pump,change direction of shaft rotation untiloil flows from the pump outlet. Drainexcess oil from the pump and install iton the engine.

Fill the oil filter and install it; then fillthe engine with oil. Install the correctpriming tool, which can be a modified

distributor drive shaft into the engineand engage the oil pump drive shaft.Attach a 1/2˝ electric drill to theexposed end of the priming tool andspin the oil pump at a minimum of 500rpm. Continue to spin the oil pumpuntil oil reaches the rocker arms. It is agood idea to rotate the crankshaft 360degrees while spinning the oil pump


Figure 1 It’s often difficult to see wheninstalling guides in OHC heads. Markwith graphite spray for correct depth.


Figure 2 Attach a drill to the end of apriming tool and spin oil pump at a mini-mum of 500 rpm until oil reaches rockers.

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during priming. The oil pump andengine are now primed.

Priming crankshaft driven oil pumps:This type of oil pump cannot be turnedwith a priming tool so we recommendusing the Melling MPL-101 pressurepriming tank or a similar pre-lube tankto prime the engine with oil before ini-tial startup. Before assembling the oilpump to the engine, pour a smallamount of engine oil into the oil pumpand rotate the rotor set by hand to allowthe oil to coat the internal surfaces of thepump and rotor. Once the engine is fullyassembled fill the oil filter with oil andinstall it. Attach the pre-lube tank to theoil pressure port on the engine.

Now fill the pre-lube tank with up tofour quarts of engine oil and close thevalve on the top of the tank. Pressurizethe pre-lube tank with shop air andslowly open the valve on the tank whichwill release the oil and send it into theengine oil galleries. While the oil is beingtransferred from the pre-lube tank to theengine rotate the engine 360 degrees.Once the oil is transferred to the engineyou will hear a gurgling sound from thetank. The engine is now primed.

Vacuum Check That EngineWith the advent of foreign castings,some less than stellar, it is important tobe more critical than before duringinspection. One engine builder uses alarge vacuum pump to vacuum checkevery engine’s water jacket before itleaves his shop. His pump pulls around22 inches of vacuum. When it reachesthat point he closes the valve to checkfor leaks.

Some engine builders have found afew brand new castings to have porosity

holes in them after they were torqueddown. All of these heads were aluminumSB Chevy heads and were made over-seas. These heads were “good” prior toproper installation.

One a few occasions, brand newwater pumps have been found to haveleaking seals at the weep holes. Air ismuch less dense than water, so any smallleaks are easy to find. With a vacuumpump you can check all freeze plugs, gal-ley plugs, intake and head gaskets (forsealing) and block and head castings.

For a test, one engine builder drilleda .006˝ hole in a freeze plug – it failedmiserably. He says he even used thepump as a “reverse” pressure tester oncylinder heads where he couldn’t find anexternal leak, but knew the head wasbad. He says it’s sort of a “second opin-ion” that confirmed his suspicions.

How to Keep Chevrolet 4-Bolt Mains From ‘Walking’All four-bolt small block Chevy main caps“walk” when used with either studs orbolts. The factory cap or a splayed cap relieson the register to locate itself because boltsand studs don’t fit well enough to keep the

cap from walking. What oneengine builder does when work-ing with a stock block is to elim-inate cap walk altogether. Here ishow to do it:

Place 7/16˝ x 1/2˝ dowels asused in aftermarket connectingrods in the outer bolt holes.Since the O.D. of the dowel is1/2˝ it is easy to locate theproper reamer. No drilling isnecessary.

Set the block up and indicatehole locations. The bolt holesare already recessed. Ream toone half the distance of thedowel, and then do the samewith the caps. Be sure to sinkthe holes at least .015˝ to keepfrom bottoming the dowels intothe cap (Figure 3). This alsoleaves room for line honing.

Done correctly, the linehone should not change. Theblock that was used (pictured)required line honing anyway forthe proper tolerance. TSG


S H O P T I P S

Figure 3 Ream to one half the distance of thedowel, then do the same with the caps. Besure to sink the holes at least .015˝ to keepfrom bottoming the dowels into the cap.


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engine builder magazine feb 2012

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