For long engine life the blower and applied boost should be matched to the quality of components inside the engine. Engines fitted with stock cast pistons, cast crankshaft, two-bolt main caps, and a small camshaft should run very low boost pressure (5 psi maximum). This is because higher boost levels can cause detonation and engine failure. If the fuel system, the ignition system, and the short-block are built with quality parts, 8-10 psi will work fine, depending on blower design and efficiency. Late-model computer-controlled ignition systems, automatic detonation retard, and EFI may permit running even higher compression ratios and boost pressures.
For engines run with boost levels from 6 to 10 psi* Forged pistons * Steel crankshaft * Four-bolt main caps * Steel harmonic damper * Stainless steel valves * Three-angle valve job * More aggressive (blower-designed)camshaft * Roller rockers * High-flow cylinder heads * Steel rods w/high-performance rod bolts * Chrome-moly pushrods * Strong ignition * Upgraded cooling system* Headers and free-flowing exhaust system
For maximum boost and horsepower applications (11 psi or more)* High-quality forged or billet crankshaft * Four-bolt main caps w/quality bolts or studs * Steel harmonic balancer or crank hub * High-quality steel rods (H- or I-beam) * Forged blower pistons * Severe-duty stainless steel valves * Solid or roller cam designed for high boost * Roller rockers * High-output ignition-management system or magneto * Blueprinted carburetors or fuel injection * High-octane race fuel (112-plus rating) * Minimum of a 3-inch-diameter dual exhaust with free-flowing street/race mufflers and large-tube headers.