Decompression kits for s&s cylinder heads

Solenoid operated, this system automatically opens and closes when the start button is pressed and released. Practical and simple, this is the best configuration for high-compression, large-displacement Evolution Big Twins and Twin Cams with S&S cylinder heads. • S&S 89CC Super Stock Twin Cam cylinder heads and all recent S&S Super Stock cylinder heads for Evolution Big Twins are machined for S&S compression versions. • Pressure relief machining is optional on S&S 79 CC Twin Cam style heads. • Stock cylinder heads cannot be machined for S&S compression versions because there is not enough material in critical areas. • If the cylinder heads are machined for S&S decompression systems, but you do not wish to install the decompression systems, the decompression hole plug can be installed to seal the hole. • S&S electric compression triggers can only be used with a rocker cover that has a center hole or chimney. The chimney provides clearance for the solenoid which activates the compression release. We suggest S&S die-cast rocker covers or ZPN 037025, 037026, 037017, 037018. • The S&S two-piece pressure relief bushing kit is highly recommended to protect the wiring and make installation easier.