Big Inch and high compression engines can sometimes be difficult to start. Better batteries, and high torque starters can cure the problem, but starting big inch motors can still be troublesome. The time has come for a reliable solution that actually eliminates high compression starting problems. The S&S compression release kit is that solution. S&S compression releases are designed to be used in S&S Twin Cam style cylinder heads, which have been machined to accept them. The compression release consists of a small valve that opens during starting and allows a portion of the cylinder pressure to escape into the exhaust port of the cylinder head. The reduced cylinder pressure makes it easier for the starter to turn the engine. When the engine starts, the valve closes and the engine runs normally, with full compression. There are two versions of this system available: an electrically operated kit, and a manually operated kit. The electric version opens the valve automatically when the starter button is pressed, and closes automatically when the starter is released. The electric compression releases require the use of S&S die-cast rocker covers or Zodiac billet or die cast covers (ZPN037020 & 037023) with a central hole. These central holes in the rocker covers are required to provide clearance for the solenoids that operate the compression releases. A cable similar to a choke control activates the manual compression releases. Before starting, the handle is pulled, which opens the compression releases. When the engine fires the increased cylinder pressure automatically closes the compression releases. The manual compression releases can be used with any style rocker covers. A special billet accessory cable knob for the manual release cable is available. The compression releases can be installed while the engine is in the frame with the handy 2 piece compression release socket kit.
•All S&S 89 CC Twin Cam style cylinder heads are machined for the S&S compression releases.
•Compression release machining is optional on S&S 79 CC Twin Cam style heads.
•Stock cylinder heads can not be machined for S&S compression releases because there is not enough material in critical areas.
•If cylinder heads are machined for S&S compression releases, but you don't want to install the compression releases, the compression release hole plug can be installed to seal the hole.
•S&S electric compression releases can only be used in conjunction with S&S die-cast rocker covers or a similar rocker cover with a center hole or chimney. The chimney provides clearance for the solenoid which activates the compression release.
•S&S manual compression release valves can be installed with OEM and most aftermarket rocker covers.