I'm having real issue with header gasket failure. Felpro and Mr Gs that match my ported heads/Headers keep blowing apart, Tried using copper coat and RTV, and they still fail. I installed Perce metal gaskets and lost ET and MPH, so I tried opening they up but had to cut so much material away that I can't get a good seal!

Anyone using copper gasket or have a part number of something else I could try?

The flanges are straight, nothing is tweeked. Most times the gaskets fail on the ends where the material is very thin. I keep rechecking the bolts are tight, and they were, but the gaskets keep failing and changing them ever couple weeks is getting old quickly!

John

 

The biggest mistake I have made with header gasket is not tightening them down enough.

With my Kooks headers, the exhaust flange is very thick. Couple that with your stock header bolts and I might be able to get 1/4" of thread past the flange.

I switched to longer ARP header bolts with a 3/8" 12 point end so I can get a wrench on everyone of my bolts and tighten the **** out of them.

The standard 7/16" 6 point header bolts simply put are not up to snuff imo once you start getting big heads.

 

Sorry, should have stated I'm using ARP bolts, not the locking type. I do get them very tight, even after the gasket fails the bolts are still tight. That is what is driving me nuts! I could understand them failing if the bolts were loose. The Mr Gs. I installed last weekend, installed, 5 mnute heat cycle, tighten, another 5 min/tighten. Test drive, within 5 miles the pass side near the alt. leaking and the bolt was still tight.

 

Try a some silicon on gaskets.

 

You to have a bent flange or head that is not straight. I've never had any problems getting Felpros to seal. As long as the bolts are tight, they should not leak. Have you put a straight edge on the header flange to make sure it is flat.

 

screw the copper, there's a new gasket out now that's 6 layers of aluminum. it's a thick gasket but it won't leak.

also, check out breslin's split-loc header bolts. i had them and they didnt back out a bit...since day one.

 

SPlit the header flange into 3 pieces, with the center 2 tubes being one piece, will cure your problem. you have a warped flange.


David