Quote: I have read many, many threads and posts but haven't seen this topic clearly defined. Maybe it is a gray area and hard to determine? Lets say you have a closed chambered Small block head with pistons .020 in the hole with a .039 head gasket. You have a .059 distance between the piston and the head. How effective is the quench? From what I have read, the sweet spot of quench is between .035-.045. What if this engine has a spark knock issue due in part to the high compression ratio. If the .059 gap results in limited quench, would it be safe to assume that a thicker head gasket could be used to drop compression a 1/2 point without a penalty? Jeff I have read that lowering compression via thicker head gaskets can result in more spark knock because of lost quench. My question is: If the engine is already out of the quench zone, would the thicker gasket help matters?
Address the quench first. There is no magic #. Tighter is better. .035' - .040" is safer. Address the detonation with fuel, ignition timing, cam timing, water.
