It's been a while but here it is.... a basic recipe for a 600ft/lb stroker. I do feel the need to add a disclaimer:
Warning, the output of this engine WILL be less if you deviate much from this basic recipe, listen to just anybody on an internet forum, do not approach the build with common sense :)
With that said, let's get to it!
Block - Any two bolt 400 block will suffice for a 4.25" stroke but for a 4.5" stroke, play it safe and 4 bolt it. Be sure to have a qualified shop magnaflux it. Be sure to look for any obvious signs of core shift. Offset lifter bores within the lifter bosses are a sign, while you are at it, check them for any signs of erosion. A lot of block have been sitting out doors for lord knows how many years and we all know how the seasons can take their toll on cast iron, especially up north. Bore the block for a good lightweight premium forged piston. Hone with a torque plate, align hone for studs, and zero deck ( a few thousandths is fine but you don't want the pistons more than about .010" down the hole. One last thing... MAKE SURE THE CAM SPINS FREELY.
Pistons - I like a premium forging like an Srp, Icon, or Probe because of the quality, the ability to use a floating pin, and they use a thinner ring pack for less friction.
Piston rings - Use a quality 1/16, 1/16, 3/16 ring pack (you will have to anyway with those pistons), gap them according to typical street/strip specs; .0045" per inch of bore diameter unless you are using a power adder like nitrous. Gap the 2nd rings ,005-.010" larger so as not to build pressure BETWEEN the 1st and 2nd rings. The top ring works on PRESSURE DIFFERENTIAL, NOT TENSION. The 2nd ring is acts as a scraper... ONLY.
Connecting Rods - I like the Eagle, Ohio Crankshaft, or Scat H-beams for this combination. Check them for sizing, of course, and use the stretch method for tightening the rod bolts. I like a moly based lubricant on the threads and the underside of the bolt head. Do not be surprised if you check stretch vs torque, and you find the torque value drops(for the given stretch value) after repeated tightening due to the threads burnishing.
Clearances - I like .003" for the mains and .0025" for rods. Better a little too loose than too tight.
Cylinder heads - Ported Edelbrock aluminum Performer RPM cylinder heads. Open them up to flow 300 or more CFM... you really can't go too big in a non-"wideport" configuration. The piston speeds brought on by a 4.25" or 4.5" stroke ensure good velocity. In comparison, the 454 Chevrolet uses a 4" stroke and more than 280cc's of port volume... so our miniscule 230 or so is nothing to worry about. The substitution of ported cast iron factory heads will impede top end performance, but low end torque and throttle response will be SUBSTANTIAL!
Intake manifold - Victor manifold flanged for a 4150 Holley, ported to match the 300+ cfm E-heads and topped with an open spacer for more plenum volume.
Carburetor - A minimum of 850 cfm Holley HP.
Camshaft - Let's not play around, go solid roller unless you have a handle on your hydraulic lifter setup. Mid 240's @ .050" with .600" lift on a tight Lobe Separation Angle (LSA). Go aggressive. E-mail us for a custom ground solid or hydraulic roller for this combination.
Rocker arms - Go American made aluminum or stainless steel. Harland Sharp aluminum with a 1.65 ratio or Crower stainless, also a 1.65 ratio.
Valvetrain - Heavy duty chromemoly pushrods, lightweight retainers, and valvesprings with the proper tension at the seat and the open positions.
Oil pump - Melling m54ds. Disassembled and inspected. Use the proper pickup for the pan used and space it 3/8-1/2 inch from the pan floor.
Oil pan - Canton, Milodon, or Moroso. Pick the biggest one that fits your chassis because you don't want oil entrained in the spinning rotating assembly.
Gaskets - Felpro 1016 head gaskets, SCE intake manifold gaskets that fit your ports, and SCE pan gaskets with a Felpro cork pan-to-main cap seal.
With a tight LSA and aggressive lobes, this is a low rpm engine that WILL have an aggressive idle. Attention to detail is a MUST.
QUESTIONS OR COMMENTS? E-MAIL ME @ PSPERFORMANCE@COMCAST.NET
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