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?
Answer is NO, the thicker head gasket won't help until you get the piston at least .120 away from the head. Quench range is .045 or less, or make sure the piston is .120 away or more. This is much more important with compression in the 10:1 range and less important below 10:1. Brian
