Ryan wrote: > My question was meant to find the "minimum distance" necessary for piston to head clearance > in our air cooled engines and not for setting compression ratios.
Sorry I didn't answer your question, but then I'm not sure that's the question you asked either! Without digging through some stuff to check, I think miniumum safe piston to head/valve clearance is generally considered to be .060", but that depends on how brave you are, and stuff like what kind of RPM you plan on running. I've taken VW diesels apart that ran great but had imprints of the valves in the piston tops... Mark Langford, Huntsville, Alabama N56ML "at" hiwaay.net see KR2S project at http://home.hiwaay.net/~langford
