Re: Tell me about "quench"
"Don't get overly concerned about it. "
NO, get seriously overly concerned about it, doing it wrong can break an engine.
Quench (squish) is the distance from the flat deck of the piston top to the flat deck of the combustion chamber, measured in thousandths of an inch. Good quench distances are between .039 to .045, measured with the piston at TDC.
If quench distance is too large, mixture will migrate out of the quench area, letting that area go lean, heat past reasoable levels, and cause detonation.
If quench distance is too small, mixture will be pushed out of the quench area, leaing the chamber out, and causiong heat, detonation.
Correct quench distance holds mixture in the quench area, letting the piston cool form mixture, and cool down the side of the piston to the top ring. .
Example of bad quench, too large, piston down in the bore .025, .055 compressed head gasket, add .025 and .055, distance would be .080, way too large. too small, piston at zero deck, flat with the top of the block, .020 steel shim head gasket, distance too small, .020.
Correct quench examples, piston down in the bore .022, .020 head gasket, distance is .042, just right. Piston at zero deck, .044 thick head gasket, .044 quench distance. Perfect.
YES, be very overly concerned about quench, it makes a BIG difference in any engine. I have seen engines done extremely well, should have been just a terror, but they are dogs, quench is way off.
I had a Ford 289 engine that had been professionally built before I got it, always had tuning/performance/overheating issues. A friend explained quench, and we measured mine, .095. We pulled it apart, engine had a .050 thick pack type head gasket, and Silv-O-Lite "destroked" pistons in it, down in the hole the stock .025, PLUS the destroked piston compression height distance of .020. Quench was .050 + .025 + .020 = .095. I had the block decked .045, made the pistons zero deck, used a .042 head gasket, quench went to .042, NO OTHER changes except new gasket set, engine stopped overheating, stopped being a slug. Proper quench is vital.