Ficking leaking cometic head gaskets...
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TECH Enthusiast
Joined: Dec 2001
Posts: 548
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From: Dublin, CA
Ficking leaking cometic head gaskets... Found why my head gasket was leaking...
The Cometic LS1 head gasket is a set of metal stampings riveted together in three spots. The core sheet has a separate 'double figure 8' which appears something like siamesed o-rings. This fits snugly within the outer core. If this center core sheet shifts, you have overlap between the core sheets. Then as far as sealing goes, you're shift out of luck.
Easy to tell by the carbon soot left in places it shouldn't be on the gasket.
On to fixing the oil pump o-ring.
The Cometic LS1 head gasket is a set of metal stampings riveted together in three spots. The core sheet has a separate 'double figure 8' which appears something like siamesed o-rings. This fits snugly within the outer core. If this center core sheet shifts, you have overlap between the core sheets. Then as far as sealing goes, you're shift out of luck.
Easy to tell by the carbon soot left in places it shouldn't be on the gasket.
On to fixing the oil pump o-ring.
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Joined: Nov 2001
Posts: 1,975
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From: SW Florida
Re: Ficking leaking cometic head gaskets... Well, I am no expert, but I have said all along that the best head gaskets for these engines are the stock GM graphite type.
In fact, the Turbo Buick camp will tell you that they still like the stock GM graphite gaskets best and thats with up to 20 psi boost. Thats all I ever used on my modified 89 TTA.
There is absolutly nothing wrong with the stock GM graphite gaskets.
In fact, the Turbo Buick camp will tell you that they still like the stock GM graphite gaskets best and thats with up to 20 psi boost. Thats all I ever used on my modified 89 TTA.
There is absolutly nothing wrong with the stock GM graphite gaskets.
Launching!
Joined: Jul 2002
Posts: 257
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From: South Jersey
Re: Ficking leaking cometic head gaskets... When first building my 422 ci I used cometic head gaskets and i went through two sets becuase they kept leaking, Just in my opinion i won't be using them again.
Re: Ficking leaking cometic head gaskets... My buddy and I both have the cometics on our buildups. We were both scared to use them after hearing all the horror stories. He used copper gasket spray and his and I used a blue(forget the name) spray gasket sealer. I also used a bottle or bars stop leak just to be safe. So far neither of our has leaked. I've also heard that cometics is all that lingenfelter will use on his motors.
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Re: Ficking leaking cometic head gaskets... when I build my 4.125" bore motor, what gaskets should/must I go with?
I don't think the stock GM gaskets have a big enough bore hole for what I'm doing. What did GM use on the C5R 4.125" bore?
I don't think the stock GM gaskets have a big enough bore hole for what I'm doing. What did GM use on the C5R 4.125" bore?
Re: Ficking leaking cometic head gaskets... FelPro makes a gasket for the 4.125 bore that is .052" thick. I am going to use another cometic set since felpro doesn't make a gasket for my bore size.
