Ford Racing BOSS Blocks

WE THOUGHT YOUOUGHT TO KNOWThis is not a how-to book. It’s basically a listingof currently avail able Ford Racing PerformanceParts. The pieces can be bought by professionals,professional amateurs, weekend hobbyists orrank beginners. A certain amount of automotiveskill is assumed in presenting the parts. Modifyingan engine, be it a complete assembly or a bareblock, requires experience and know-how. If youdon’t know, ask someone who does. Read upand find out all you can before putting downyour bucks for those long dreamed of pieces. Andif at all possible, consult an experienced enginebuilder. You may find it to your advantage tohave him do a portion or all of the heavyma chin ing and wrenching.What we have here are just a few of the keybits of information and specs. The idea is to helpkeep midnight thrashing to a minimum, becauseparts don’t go together right, or there’s more to ajob than you imag ined.COMPRESSION RATIOIncreasing the compression ratio (CR) is oftenone of the first en gine performancemodifications. Squeezing the air-fuel mixtureinto a smaller space increases its temperatureand ease of ignition; thus the rate at whichheat is ex tracted from the fuel. Engineers callit “thermal efficiency.” Sim ply put, it meansthat increasing the compression ratioincreases horsepower.Henry Ford’s Model “T” has a CR of 3.6:1.High-performance engines operate in the areaof 12.5:1. Most of today’s stock pro duc tionengines are about 8.5:1.NOTE: Turbocharged engines typically havea lower CR than normally aspiratedengines. Thus, if you add a turbo,you may want to lower the CR,de pend ing on performance level.DETONATIONIncreasing the CR changes the rate at whichfuel burns. Spark knock (detonation) will occurif certain modifications are not per formed.Here are two of the most important:Ignition Spark Timing—In creas ing the CRrequires in stal la tion of new distributor springsto change advance curve.Fuel Octane Rating—Increasing the CRrequires gasoline with a high octane rating(with anti-knock components to controldet o na tion). This is not a prob lem with enginesthat burn al co hol, because it has a naturallyhigh octane number. Engines that run on alcoholrequire a high CR to compensate for the factthat they generate less heat.MODIFICATION TECHNIQUESCommon techniques to increase CR include:(1) Installation of a thinner head gasket.(2) Installation of “domed” or “pop-up” pistons.Check for adequate “piston-to-valve” clear ance at TDC. Camshafts with more overlaprequire more clear ance. A good rule of thumbis 0.080" for intakes and 0.100" for exhausts.(3) Removal of metal from deck face of block orcylinder head. You can safely mill off 0.010"to 0.040" (0.050" max.) from most VALUEBBore4.000 inGGasket Bore4.100 inPPiston Top Land Diameter3.965 inSStroke3.500 inS/2Crank Throw1.750 inLCon Rod Length6.000 inHCompression Height1.440 inDhDeck Height9.200 inrRing-to-Top Piston0.250 indPiston to Deck0.010 intGasket Thickness0.040 inVCylinder Volume720.7ccVtVolume Above Top Ring.9ccVnValve Notches Volume4.0ccVdDome Volume10.4ccVpPiston-to-Deck Volume2.1ccVgGasket Volume8.7ccVhVolume Head60.2ccVclVolume Clearance65.5ccCRCompression Ratio12.0NOTE: 1) Math reduction; /4 x 16.387 12.87The precise amount is limited by block deckheight, casting thickness, valve-to-pistonclearance, etc.NOTE: Also modify the intake manifoldto maintain port alignment.COMPUTINGCOMPRESSION RATIOCompression ratio is defined as the ratiobetween the Total Volume (Cylinder Volume plusClearance Volume) above the piston at BDCand the Clearance Volume above it at TDC.Calculations for a 351 CID engine are illustrated.The formula is: CR V VclVclPay particular attention to the following points:Clearance Volume (Vcl)—This is the volumeabove the piston (actually above top piston ring)at TDC. It consists of several small volumes.Cylinder (Swept) Volume (V)—Determinedby cylinder bore and stroke (indicated bymovement of piston from TDC to BDC).REMARKSB2 4.000 x 4.000 16.000G2 4.100 x 4.100 16.810P2 3.965 x 3.965 15.721D h – H – l – S/2/4 x B2 x S x 16.387/4 x (B2 – P2) x r x 16.387/4 x B2 x d x 16.387/4 x G2 x t x 16.387Vt Vn Vp Vg Vh – VdV VclV clCylinder Head (Combustion Chamber)Volume (Vh)—The irregular shape of thecombustion chamber requires measurement(popularly called “cc”ing) with a glass buretteand colored liquid, such as A.T. fluid. This cataloglists “nominal” values for Ford Racing heads.Valve Notches Volume (Vn)—Fill notcheswith soft clay and make level with top of piston.Remove clay with small knife and drop intograduated cylinder (filled with liquid toconvenient point). Note change in level of liquid(indicating volume of notches made by clay).Domed Piston Volume (Vd)—Dome valuesare combination “net” values of Vd and Vn.For compression ratio calculations, they shouldbe used as follows: Pop-Up pistons have a “positive” domevalue, which reduces the volume abovethe piston and thus must be subtracted(see example above). Dished pistons have a “negative” dome value.It must be added to compute clearance volume.MAKE ALL CALCULATIONS WITH ACCURATE MEASUREMENTSOF ACTUAL PARTS. CATALOG VALUES ARE “NOMINAL”SPECIFICATIONS AND MAY VARY FROM ACTUAL SIZE.

VALVE TRAINWhen modifying production engines for performance,here are a few things to keep in mind.CAMSHAFTS When replacing a cam, it’s a good practiceto install new related components such as adistributor gear, tappets, springs, retainers,etc. It’s especially important that new tappetsbe installed. Never use hydraulic lifters with a mechanicalcam or solid tappets with a hydraulic cam.The ramps are not compatible. Be sure your valve train can handle the timingevents and lobe lift of your performance cam.Check for adequate piston-to-valve clearance,spring bind and retainer-to-valve clearance,spring bind and retainer-to-valveseal clearance. Be sure to use camshaft and lifter prelubewhen installing the cam to prevent scoringthe lobes during break-in. Engine oil by itself(regardless of quality or viscosity) isnot enough! Mechanical cams require lash adjustment. If production head is designed for hydrauliccam, modification is usually required. Many design changes have occurred overthe years, which affect the front of the block—especially the small V8s. Be sure you checkitems such as the cam thrust plate, camspacers, cam gear, fuel pump eccentric,timing chain, cam gear alignment and frontcover clearance. Refer to the Ford Racing “Camshaft Usage”chart for performance characteristics of camsbased on their duration. Refer to the “Camshaft Specifications”chart for detailed data on FordRacing camshafts.FORD RACING CAMSHAFT USAGEThe durations shown in this chart are S.A.E. durations. The descriptions within each group of camsshow performance characteristics and basic modification recommendations required to achievedesired performance.DURATION PERFORMANCE(SAE)CHARACTERISTICSENGINE/VEHICLE USAGEAND MODIFICATIONS270-290 Good idle qualityand low rpm torque.Use with stock or slightly modified engine,stock axle gears and with A.T. or M.T.290-300 Fair idle quality. Good low-toWill work with stock or modified en gine.mid-range torque and horsepower. Can use stock axle gears and with A.T. or M.T.300-320 Rough idle quality. Good mid-to- Use with M.T. or high stall A.T. Requires improvedhigh rpm torque and horsepower. carburetion, ignition and exhaust systems.Engine will have lower vacuum than stock.320-340 Rough idle quality. Good mid-tohigh rpm torque and horsepower.For all-out competition only.Use with M.T. or very high stall A.T. Re quiresimproved carburetion, ignition and exhaust systems.Engine will not provide enough vacuum foraccessories. Axle gear ratios must be properly selected.ROLLER TAPPET CAMSHAFTMost engines are designed with hydraulic ormechanical flat tappet camshafts, which meetthe needs of regular production engines thatseldom see 6000 rpm. Flat tappet cams aremore than adequate for many competitionengines. For ultra-high-performance applicationswhere durability and high rpm capability areparamount, however, roller tappet camshafts arevery popular. As the name implies, a cylindricalroller “rolls” over the cam lobe, instead of “sliding”as does a conventional flat tappet. This not onlyallows a roller tappet to follow a more radicalcam lobe profile, but it reduces friction andlessens tappet scuffing of the cam lobes.Ford introduced hydraulic roller tappet camshaftson the 1985 Mustang (and Mark VII LSC) with302 (5.0L) High Output engine. Here is a briefdescription of components.Roller Tappet—Longer than flat tappet,because of roller. Hydraulic portion functionslike a standard flat tappet.Roller Tappet Camshaft—Machinedfrom steel, instead of typical iron used for flattappet cam. Cam lobes specially ground andhardened to withstand loads of roller tappets.Do not attempt to use with flat tappets!Roller Tappet Block—Longer, production5.0L hydraulic roller tappet requires highertappet boss than block for flat tappet cam.Thus, 5.0L hydraulic roller tappet cam cannotbe used in block designed for flat tappet cam.However, flat tappet camshafts can be usedin roller tappet blocks.Roller Tappet Distributor Gear—Machinedfrom steel and specially hardened to becompatible with billet-steel roller camshaft.Do not attempt to use cast iron gears designedfor flat tappet cams.Roller Tappet Push Rod—Push rods areshorter than those designed for flat tappet camengine, because of longer roller tappet. Rockerarm end has hardened ball that is copper platedto resist wear by rocker arms rubbing on push rod(which don’t rotate). A small bracket encirclesone end of push rod as reminder to install thatend upward (on 1985-1986 models only).Roller Tappet Guide Plate—Holds rollertappets in alignment with camshaft lobes(flat tappets rotate). Must be installed with“UP” marking upward.Roller Tappet Guide Plate Retainer—Made ofspring steel. Fits in valley cover area to holdguide plates in position.ROLLER ROCKER ARMSMost production engines use stamped steel orcast iron rocker arms. As the push rod movesone end upward, the rocker arm pivots on aball or sled-type fulcrum—and the other endpushes the valve downward. Although “sliding”friction exists at each point, this design isokay for street engines and even manyperformance applications.

ROLLER ROCKER ARMSLight-weight aluminum roller rocker arms,however, provide many advantages for continuoushigh rpm operation. They’re mounted on needlebearings and feature a cylindrical roller that“rolls” over the valve tip to move it downward.This reduces friction, heat and wear, and onlyrequires about half the horsepower to operatethe valve train. And valve train stability is greatlyincreased. Roller rockers reduce valve stem wearand valve guide wear to an absolute minimum,because the roller doesn’t push the valvefrom side to side as it is opened, as occurswith standard rocker arms, as they “slide”over the valve tip.POSITIVE-TYPE OIL SEALSPositive-type oil seals are recommendedon OHV performance engines to preventoil from running down the valve past thevalve guide and into the combustion chamberand contaminating the air-fuel mixture.The cylinder head must be machined asillustrated to accept the oil seal.VALVE PUSH RODSHardened push rods are required on valve trainsthat use a guide plate (because they rub againstthe plate). Do not use non-hardened push rods.Push rod length is important to maintain correctvalve train geometry. The process of drilling anoil hole down the center removes some materialfrom the spherical ball at each end. Push rodsare described by “gauge” length (the distancebetween the ends before drilling the oil hole).The actual “measured” length is usually about0.025" shorter than the gauge length.Ford Racing offers roller rocker arms in severalratios for the Ford Racing V6, small block V8sand big block 429/460 V8s.VALVE SPRING RETAINERSAND KEEPERSCurrently Ford Racing only offers retainersand single-lock groove keepers in a 7-degreedesign. They are compatible with all Ford Racingvalve springs for the Ford Racing V6, small blockV8s and big block 429/460 V8s. 10-degreeretainers/keepers are available from aftermarketsuppliers. Do not attempt to interchange 7-degreeretainers with 10-degree keepers and vice versa.Single-lock groove keepers are recommendedfor high-performance engines. Production 351C(except BOSS and HO), 351M and 400 enginesuse multi-groove keepers (to promote valverotation). If you modify for any extended highrevving performance, replace the valves, retainersand keepers with a single-lock groove design.CAMSHAFT TIMINGDEGREE WHEELNo camshaft installation is complete withoutchecking camshaft timing events. Use atiming degree wheel to check for correctcamshaft installation.

VALVE SPRINGS AND THINGSROCKER ARMS AND STUDSInstalled spring height is the distance from thespring seat to the bottom of the valve retainer.Shims can be used under the spring to changespring height. If installed under stamped seat,shims and seat must have same outside diameter.Spring seats on most production engines consistof a boss machined in the head, on which thespring pilots. On stock performance engines(302 BOSS, 351C BOSS and HO, 429 CJ/SCJand BOSS) the head is flat and the spring sitsin stamped spring seat.This is a conventional rocker arm with closetolerance slot in head to guide push rods andmaintain rocker arm alignment. Can be usedwith mechanical or hydraulic camshafts.USAGE: All 289 high-performance and1963-1966 1 2 standard 289.Valve springs are a critical part of valve trainoperation. They’re designed to exert a specificload at a specific installed height, thus springselection and installation are important. A singlespring is generally used for stock engines. Dual ortriple springs are often necessary for performanceapplications to increase the load for a giveninstalled height. If installed height isn’t sufficientto handle camshaft lobe lift, coil bind may occur.429 BOSS, FE engines and some 4-cylinderrocker arms are shaft-mounted, while othersare individually mounted (in several ways), asshown in the illustration. A non-adjustable studis used in production engines with hydrauliccams. Mechanical camshafts require rocker armadjustment to set valve lash (hydraulic cams withanti-pump-up lifters also require adjustment).Ford Racing offers spring seats for use withFord Racing aluminum cylinder heads to preventdamage to the spring seat area.Shown here is a “rail” rocker arm with “loose-fit”hole in cylinder head for push rods. The U-shapedrocker arms maintain alignment. Can only beused with hydraulic camshafts.USAGE: 1966 1 2-1968 standard 2891968-1976 302 and 351W.Here is a modified valve train to convertrail rocker arm design for mechanical cam.Requires conventional rocker arms, guide plates,hardened push rods (they rub on plates) andthreaded adjustable rocker studs. Requiresdifferent guide plate than the one used witha similar 302 BOSS setup.USAGE: 289/302/351W with mechanical camshaft.The illustration above is typical of351C-351M-400 canted valve engines(429-460 engines are similar). The rocker arm ismounted on a slotted pedestal, moves on a“sled” fulcrum and is retained by a bolt. 351CBOSS engines use the 302 BOSS type valve train(also used on 429 CJ/SCJ), 1968-1972 429/460with hydraulic camshafts use a screw-in positivestop stud. 1973 and later 429/460 have the351C-type slotted pedestal.A modified pedestal is used on 1978 and later302/351W engines. A stamped fulcrum guideis used with each pair of rocker arms.

ROCKER STUD COMPARISON AND IF YOU HAVE 302/351FORD RACING ALUMINUM HEADS ➀These heads come with a tapped .75" pipethread hole in the combustion face, but no holein the intake manifold face.Press-in stud with adjustable rocker nut.NOT recommended with mechanical camshafts.If your application requires external wateroutlets, see diagram below.USAGE: Standard 289 and 1968 302.TO INSTALL ON WINDSOR-TYPEBLOCK (289/302/302 BOSS/351W)1.Install pipe plug in hole. Finish so it doesn’tprotrude above head face.2. Drill a 0.800" diameter hole in the intakeface as shown or use the .75" pipe threadexternal water outlet valve provided in thefront and rear ends of Ford Racing headsproduced after July 1984.Press-in positive stop stud. Cannot be adjustedto set lash with mechanical camshaft.USAGE: 1969-1976 302/351W.TO INSTALL ON CLEVELAND-TYPE BLOCK (351C/351M/400)Screw-in, positive stop stud.USAGE: 1968-1972 429 with hydraulic camshaft.1.Requires no special head work.NOTE:Heads produced after 6/1/1985 do not have .75" pipe threads at front and rearof head face and must be drilled and tapped as shown in illustration.HEAD MODIFICATION FOR MECHANICAL CAMPedestal-type cylinder heads for hydrauliccams can be modified to accept a mechanicalcam (351C/351M/400 shown). Machine at rightangles to the existing hole—not the bottomof the head. The valves operate at compoundangles. With 302/351W type pedestals,measure from the top of the pedestal.Screw-in, adjustable stud. Required formechanical camshaft (and hydraulic withanti-pump-up lifters).USAGE: 289 Hi-Performance, 302 BOSS,351C BOSS and HO and 429 CJ/SCJ.CYLINDER HEAD WATERPASSAGE MODIFICATIONAs described on this page, cylinder heads for351C/351M/400 engines have a water outletpassage in the combustion face, whereas289/302/351W heads have a water outletpassage in the intake manifold face of the head.Heads can be interchanged, if provision is madefor appropriate water passages.All 302/351W.230"All 351C/351M/400.300"1973-1995 429/460.300"1968-1972 429/460.230"TO INSTALL CLEVELANDTYPE HEADS (351C/351M/400)ON A WINDSOR-TYPE BLOCK(289/302/302 BOSS/351W)1.Drill a 0.800" diameter hole in the intakemanifold face of the head as illustrated.2. Plug square hole in cylinder head. Installheads with Cleveland-type head gasket.3. Use intake manifold gasket to matchintake manifold.NOTE: If BOSS-type heads (302 or 351C)are used in either procedure, rememberthey have larger rounded ports thanconventional heads; thus a unique BOSStype intake manifold gasket is required.1Crank throw times two equals stroke.Changing rod length or piston compressionheight only changes where stroke occurs incylinder bore— not length of stroke.2Use of crank with longer strokeand stock rods results in stockpiston being above top of block.Requires rod or new pistoncompression height.3Re-locatedpiston pin.4Shorter rod.

BASIC ENGINE DIMENSIONS (INCHES)Gasoline PACINGDIA.1.6L Kent1971-733.1883.0563.7802.12531.6L CVH1981-853.1503.1303.6142.3831.9L CVH1985-873.2303.4653.6142.3831.9L CVH1988-963.2303.4653.6142.3831.8L ZETEC DOHC 1991-963.2703.3503.5831.9662.0L I-4 Duratec 2005-TBD3.4453.2723.7802.0472.0L CVH1997-983.3393.4653.6142.3832.0L OHC ➀1971-743.5753.0294.0162.2442.0L OHC ➁1983-873.5203.1264.1732.3992.0L ZETEC 1995-043.3393.4653.6142.2832.0L V62001-043.2152.6314.0162.4792.2L Probe1988-923.3903.7003.8102.3602.3L I-4 Duratec 2001-073.4453.7013.7802.0472.3L OHC1974-973.7803.1264.1732.3992.5L OHC19983.7803.4014.1732.3992.3L HSC1984-943.6803.3004.0802.2492.5L HSC1986-913.6803.5834.0802.2492.5L V6 Duratec 1995-993.2453.1304.0162.480 2.5L V6 Duratec1999-073.2153.1304.0162.4802.6L V61972-733.5452.6304.7602.2442.8L V61974-803.6502.7004.7602.2442.9L V61986-923.6612.8354.7602.2443.0L V61986-073.5043.1504.3302.5193.0L V6 Duratec 1997-073.5043.1304.0162.4803.5L V6 Duratec 2006-073.6423.4134.1732.6583.0L V6 SHO1989-953.5003.1504.3302.5163.2L V6 SHO1993-953.6203.1504.3302.5163.4L V8 SHO19963.2453.1304.0162.4803.8L V61982-953.8103.3904.1932.5194 ➃3.8L V61997-033.8103.3904.1932.5193.9L V62004-073.8103.4654.1932.5193.9L V8 ➈2000-023.3863.3463.8582.4413.9L V8 ➈2002-073.3863.3463.8582.4414.0L V61990-003.9503.3204.7602.2444.0L V61997-073.9503.3204.7602.2444.2L V61997-073.8103.7404.1932.5194.5L Ford Racing➂4.0803.5004.4692.7494.6L V81991-073.5523.5433.9372.6575.0L V8➉3.7003.5433.9372.6575.0L V82011-123.6293.6473.9372.6525.4L V81997-073.5524.1653.9372.6575.8L V820133.6814.2303.9372.6567-2.65776.8L V101997-073.5524.1653.9372.6576.0L V121999-073.5043.1304.0162.657200 I-61963-833.6803.1264.0802.249250 I-61969-803.6803.9104.0802.399240 I-61965-724.0003.1804.4802.399300 I-61965-964.0003.9804.4802.399221 V81962-633.5002.8704.3802.249255 V81979-823.6803.0004.3802.249260 .3802.2493021968-964.0003.0004.3802.249302 BOSS1969-704.0003.0004.3802.249302 Ford 4.3803.000351W1971-964.0003.5004.3803.000351 Ford Racing➂4.0003.5004.3802.749351 Ford Racing➂4.0003.5004.3802.249351C * BOS

Compatable with factory 302 or 351W oil pan designs Retains clutch cross shaft pivot hole Original style oil filter location Original motor mount boss locations Original bell housing pattern Ford Racing BOSS Blocks Standard and Big Bore Versions Features: Engine: Blocks BOSS Blocks