Revenge Of The 350
Despite the fact that the 350 Pontiac engine generally garners little attention in the hobby, HPP still receives a fair amount of questions regarding building them up. Some owners want to retain numbers-matching block status and add some tire-smoking power, and others desire to be different and not simply perform a traditional 400 or 455 swap in an effort to increase performance.
For those who fit into either category, Ken "Ace" Brewer from Pacific Performance Racing (PPR) has an answer. PPR, home of Tomahawk Performance Products, has just released a brand new 4.00-inch stroker package for the plentiful and very-inexpensive-to-buy 350 engine that transforms it into a 383-cube thumper. Follow the recipe outlined here, and you can look forward to 462 horsepower at 6,100-rpm and 436 lb-ft of torque at 4,400 rpm. The beautiful part is that the combination employs a lightweight reciprocating assembly for a quicker rate of rev, a 9.6:1 compression ratio for pump gas, valve sizes that quiet the old complaint of too much shrouding in the small bores, and it's affordable. How affordable? Does $1,595.95 (under $1,400 with 5140 rods) for a complete balanced Ultra Lite rotating assembly with forged pistons and forged steel rods ring your bell?
Some of you may be asking, why not just build a 400? That's a reasonable question, assuming you have one at the ready. But the fact that few Pontiac hobbyists seem to want 350s makes cores very cheap, if not free, and the 350/383 could be considered the underdog in any race against a larger engine from any camp, so there is the spoiler factor as well. If nothing else, Pontiac fans have a new number to play with.
Think how much fun it will be upstaging the Bowtie and Mopar brigades, who owned exclusive 383 bragging rights...until now. Remember, this thing actually cranks out some power. If it didn't, we wouldn't waste time telling you about it. Now go pull a 350 out of the scrap bin and get started!
HPP ENGINE BUILDUP WORKSHEETEngine Displacement383Horsepower462Torque436 lb-ftBore/Stroke3.905/4.00Block/Crank Combo350 Block/428 crankBore/Stroke Ratio0.976:1Rod/Stroke Ratio1.7:1
Bottom EndBlock'73 350 2-bolt mainPreparationBottom fill with block filler, thermal clean, bore and hone with torque plate, line hone mains with studs, surface to zero deckDeck Height10.16-inCrank428 Tomahawk Performance Products crankshaft, 3.00-in mains and BBC 2.200 rod journalsPreparationRifle brush and cleanBalancerProfessional Products Powerforce ElastamerRods6.800-in, Tomahawk Performance Products Ultra-Lites, 756gBearingsKing HP series rod bearings std, King AM series main bearings stdPistonsForged, Probe/PPRPiston-to-deck HeightZeroPiston Pins0.990-in, Probe, tool steelMethod Used to Retain Piston Pins in PistonsDouble Spiro-locksRings1/16, 1/16, 3/16 Total Seal, plasma molyPreparationFile fit
BalancingTypeNo hole balance for less windageSpecs:Piston and Pin539.5gPiston Rings48.4gPin Locks4.7gTotal Rod756gRotating Rod524.5gBearing50.6gBobweight1,979.3gOiling SystemWindage TrayTomahawk Performance Products, 3/4 stock typeCrank ScraperIshihara-Johnson, Zero-Tolerance Teflon, dual sidesOil PanMilodon, Road Race, four trap doorsOil Pump10540 Melling Select High Performance, 60 psi, 3/4 pickupPreparationInspect prelube
HeadsCasting Number#16 small valveChambersOpenHead ModsCNC-Ported at SD PerformanceCombustion Chamber Volume77 ccsCompression Ratio9.6:1ValvesFerrea 2.08/1.71-inAngles Used in Valve JobIntake: top-30-deg, seat-45-deg, bottom-70-deg;
Exhaust: top-30-deg, seat-45-deg, bottom-75-degModsCNC-PortingRetainersManleyKeepersComp CamsValve GuidesBronze linersValve SealsViton RubberRocker ArmsTomahawk Performance Products Rocker Shafts System, 1.6:1 rollerPushrodsPRW chrome molyDiameter5/16-inLength8.800-inHead BoltsARP
CamBrandCrower hyd. rollerDuration at 0.050234/242-degLift0.549/0.573Lobe Separation Angle112-degInstalled Position108-degLiftersCrower hyd rollerValve SpringsCrower doubleSeat Pressure130 lbsOpen Pressure330 lbsTiming ChainS/A 9 Keyway true roller with removable bronze bushing
InductionCarbHolley Street Avenger, 770 cfm, vac sec,Jets#71/#75Fuel PumpDyno Pump/Magna Flow 500 gphFuel RegulatorAeroMotive High FlowFuel Lines1/2 and 3/8Intake ManifoldTomahawk Performance Products, single-planeModsNoneIgnitionDistributorWAPP HEIWiresDyno/ACCEL Graphite for no computer interferenceTotal Timing34-degInitial Advance13-deg
ExhaustHeadersDoug'sPrimary Tube Diameter1.75-inCollector Size3.00-in
Cylinder Head FlowLiftIntake CFMExhaust CFM0.10071.759.10.200143.8107.80.300197.2147.10.40023 3.6174.90.500248.4197.70.550255.7--0.600--212.7

Photo Gallery: Small-Bore Pontiac Performance Engine Build - Revenge Of The 350

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