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Master X
01-13-2011, 10:42 PM
Alright I have a 363 with -5cc flat tops and a block that has not been decked. What cc of combustion chamber/head gasket combo do i need to achieve 9.5:1? ALL help is appreciated!

fast_crew
01-14-2011, 10:49 AM
need bore and stroke to figure the compression ratio.

Master X
01-14-2011, 02:06 PM
Whoops its a 4.030 bore and 3.562 stroke.i know the deck is at stock height and I'm not sure on head gasket thickness....could I use a 64cc head with thick head gaskets?

fast_crew
01-14-2011, 04:43 PM
With .025 deck height .041" gskt (common ) you need a 69 cc chamber (about .050" off 76cc heads)9.48

.025 deck/ felpro 1094 .015" shim (common) you need a 75cc (about .006" )chamber for 9.43

Big piston to head clearance makes for a poor running, ineffecient, detonation prone engine. You should always try to keep the quench less then .050" but no less then about .035"

Measure the amount the pistons are in the bore for more accurate answers.

dirty white boy
01-15-2011, 01:48 AM
how bout stock deck height,4.30 bore,3.48 stroke,with 041 heads surfaced bout.20,+13.5 dome top pistons with thinnest head gasket possible???

fast_crew
01-15-2011, 07:12 AM
Assuming they are a 10cc dome, piston .025 in the hole, .015 shim gskt=13.25

dirty white boy
01-16-2011, 12:56 AM
Assuming they are a 10cc dome, piston .025 in the hole, .015 shim gskt=13.25

one more question??? what would it be with a 0 deck height???

fast_crew
01-16-2011, 09:28 AM
About the same Tom as you would run a .035-.041 gasket with zero deck.
.035=13.47 .041=13.21