Need help deciding on method for reducing CR

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Jan 19, 2004 | 11:11 AM

Shinobi'sZ

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From: Forced Induction Heaven

Need help deciding on method for reducing CR

I need some help deciding whether or not to pull my heads off and sell them and buy some AFR 76cc heads or remove some more material and make my existing 72cc LS6 Heads, 75cc and O ring them for use with Cometic Gaskets.

My CR is 9.67:1 right now and I would like to lower it. The motor already has -2cc Forged Diamond Pistons and Lunati Pro Billet Forged Rods. ARP Head Studs too.

I would like some opinions about either modifying my existing heads or selling them outright and buying the new AFR Heads.

If I keep my heads and hog them out some more (least expensive), I plan on O ringing them and using a Cometic Gasket.

My deck height is .014 so what thickness Cometic Gasket should I use? I would like to go as thick as possible without screwing up the quench.

I have calculated my CR to be 9:1 if I hog my existing heads out to 75ccs and use a .060 crushed head gasket.

Thanks
Kevin

Jan 19, 2004 | 11:19 AM

blackz93

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From: nc

i guess that would give you .046 quench which is ok i guess. assuming that its .014 out of the hole.

Jan 19, 2004 | 11:37 AM

smokinHawk

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From: Columbus, ohio

you cant use a MLS gasket with a o-ring. people either use copper or a graphite gasket.

Jan 20, 2004 | 05:14 AM

SS00Blue

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Quote:

Originally Posted by blackz93

i guess that would give you .046 quench which is ok i guess. assuming that its .014 out of the hole.

.014 OUT of the hole?!? I HOPE he meant in the hole!

SC-

Jan 20, 2004 | 05:31 AM

y2khawk

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From: Olmsted Falls, OH

what's wrong with .014 out? production is .006 out.

Can you even get AFR's yet?

Jan 20, 2004 | 10:22 AM

blackz93

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From: nc

Quote:

Originally Posted by y2khawk

what's wrong with .014 out? production is .006 out.

Can you even get AFR's yet?

exactly...

Jan 20, 2004 | 12:05 PM

Shinobi'sZ

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From: Forced Induction Heaven

Quote:

Originally Posted by blackz93

exactly...

It depends I have seen it vary (deck height) between .006-.009 from the factory. Also it depends on your Rod and Piston Combo. My 6.125" rods for a 3.622 stroke and Diamond 3.905 Pistons along with a .004 resurface of the block left my deck height at .014 out of the hole! So I should be able to use a thicker head gasket.