Compression - Quench ?
03-29-2012, 08:55 PM
#1
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Compression - Quench ? I have just bought a 383 with dished -16cc srp pistons. They are in the hole .025 now. My heads are 55cc ported stockers.
If I deck the block to .005 deck height, use .029 gasket, on these dished -16cc pistons my quench would be .034, with compression at 11.03. (quench - .034, compress - 11.03)
If I get flattop piston at -5cc, deck height of .015, gasket of .026, my quench would be .041, and compression of 12.43. (quench-.041, compress-12.43)
The more I attempt to bring down the compression, thru gasket and deck height changes, the more I lose the quench. I really don't want to be over 12:1 cause I don't want to have to depend on a spot-on tune or else damage. I'd rather be a little safe on it as opposed to squeezing everything to the edge. 11.75 would be great. What is it I need to be more focused on? How do we get there? Deeper valve cut flattop?
If I deck the block to .005 deck height, use .029 gasket, on these dished -16cc pistons my quench would be .034, with compression at 11.03. (quench - .034, compress - 11.03)
If I get flattop piston at -5cc, deck height of .015, gasket of .026, my quench would be .041, and compression of 12.43. (quench-.041, compress-12.43)
The more I attempt to bring down the compression, thru gasket and deck height changes, the more I lose the quench. I really don't want to be over 12:1 cause I don't want to have to depend on a spot-on tune or else damage. I'd rather be a little safe on it as opposed to squeezing everything to the edge. 11.75 would be great. What is it I need to be more focused on? How do we get there? Deeper valve cut flattop?
03-31-2012, 04:11 PM
#2
If you've checked every hole and your MINIMUM current deck clearance is .025", I think you have room to tighten the quench down further. However this depends on the ptw clearance of that engine build (piston rock at
TDC). My buddy Harris is running .029 quench (tightest cylinder) with .004-.005 ptw, 383 ci, revving to 7100, and not tagging the heads.
Also, you may be able to mill the heads to smaller cc. AI cut my 200cc heads down to 52 cc chambers.
TDC). My buddy Harris is running .029 quench (tightest cylinder) with .004-.005 ptw, 383 ci, revving to 7100, and not tagging the heads.
Also, you may be able to mill the heads to smaller cc. AI cut my 200cc heads down to 52 cc chambers.
