Question regarding head gaskets & comp ratio
Racer
Joined: Apr 2003
Posts: 286
Likes: 2
From: Suffolk VA
Re: Question regarding head gaskets & comp ratio (71coupe)
You need to figure out what your head gasket bore is and how many cc's those valve recesses are as well...generally the head gasket bore is larger than the cylinder bore..(even a few hundereds of bore can add up to a significant amount of area).... most times I've found the gaskets to be 4.166" bore dia.
Generally what I've used as a thumb rule in the past was .010" gasket thickness is about 1/10th of compression....that being said you should be around 10.6:1 with that super thin head gasket....but like I said it's just a rule of thumb and I would need more info to be 100% positive. :cool:
[Modified by KyRP2NITe Corvette, 10:11 AM 5/6/2004]
Generally what I've used as a thumb rule in the past was .010" gasket thickness is about 1/10th of compression....that being said you should be around 10.6:1 with that super thin head gasket....but like I said it's just a rule of thumb and I would need more info to be 100% positive. :cool:
[Modified by KyRP2NITe Corvette, 10:11 AM 5/6/2004]
Melting Slicks
Joined: Dec 2000
Posts: 2,041
Likes: 0
From: Wichita, KS
Re: Question regarding head gaskets & comp ratio (KyRP2NITe Corvette)
If you are at zero deck height you may need to use a thicker gasket to insure that you have clerance between the piston and cylinder head. .030 is generaly the minimum clearance that you want to account for piston rocking in the bore and rod strech.
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
Re: Question regarding head gaskets & comp ratio (1979toy)
Then use this: http://smokemup.com/auto_math/index.php
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: (71coupe)
On one of my old 355 ci motors i ran the .015 steel shim head gasket because the pistons were the stock .025 piston to deck height. That got it down to a perfect .040 quench.
Presently I have surfaced decks and the pistons came in at .020 down in the hole so the closest gasket I felt good about was a .021 silicone coated copper gasket from FlatOut Racing.
I also used .030 solid copper for two years in my last 383 with a .038 or so quench
Presently I have surfaced decks and the pistons came in at .020 down in the hole so the closest gasket I felt good about was a .021 silicone coated copper gasket from FlatOut Racing.
I also used .030 solid copper for two years in my last 383 with a .038 or so quench
