Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - do i really need forged?
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Old 07-15-2010, 01:46 PM
PatM PatM is offline
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I agree totally with just about all of that. Cast cranks (SCAT, for instance) claim to be able to handle 500 HP. That of course will depend on the weight of the pistons and rods, as well as the power being produced. Lunati Street Race rods used to be rated (don't think they make them anymore) for 450 HP at 7000 RPM. Since RPM increases drive increases in acceleration forces, the rods should be more capable at lower RPMs. Like maybe 475HP at 6200-6500 RPM. With Rods, it's not the force from combustion, it's the inertial acceleration and deceleration created by higher RPM that makes the difference. Naturally, piston weight comes into play here as well as RPM. So, very light hypereutectic pistons, light weight forged high-strength (say, 4340) rods with good (like ARP) bolts, and a quality cast crank contribute to a bottom end that is likely to survive into the 475-500 HP arena.
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