Most of the time leaks like you're experiencing occur because the header flange isn't completely flat/true. Many headers (even new out of the box) have warped flanges. Some try to close up the gap with different types of gaskets, and by cranking down on header bolts -- but often with the result being continuing leaks, header bolts that back out and have to be retightened or stripped threads.
I'd pull the headers out and get a straight edge on the flange to see if it's flat/true. If not, a few bucks at your local machine shop can get you a mill job that will make the header seal like it should.
I tried the copper gaskets, for the life of me I couldnt get them tight enough to stop leaking so I went back to the regular ones. As soon as I did, I didnt have any more leaks...
Honestly I think they are a waste of money, just my .02
is there a trick to sealing them tight? i'm pretty sure the raised seal(for lack of a better term) is supposed to be facing the header, is this right? should i use some kind of gasket sealant?
Yea I'm pretty sure the seal faces out and just tighten them up real well. I do have some problems with the bolts backing out over time but I dont have to worry about blown gaskets and plus I've re-used them almost 6 times now.
What type of headers are you using? It's possible the face is not perfectly flat like others have mentioned.
I think graphite gaskets are cheap anyways so test them out and see if it works.
Yea I'm pretty sure the seal faces out and just tighten them up real well. I do have some problems with the bolts backing out over time but I dont have to worry about blown gaskets and plus I've re-used them almost 6 times now.
What type of headers are you using? It's possible the face is not perfectly flat like others have mentioned.
I think graphite gaskets are cheap anyways so test them out and see if it works.
i'm using MAC 1 5/8 unequal length shorties, individual flanges and each looked good and flat. can i get the graphites at autoparts store? soak them in water, use copper rtv, or both?
thanks for your help
I bought the copper gaskets for my Nova and they leaked like a sieve. I pulled them off a couple of times, cleaned everything up and still they leaked. The heads are Dart and the headers are super comp hooker. I finally got them to stop by buying "Byson" exhaust gaskets. they are about 1/8" thick and guaranteed flameproof. I haven't had a leak on this car since I used the Byson gaskets. Byson is the trade name for the gaskets. There also used to be extra thick gasket made by a company called "honest george gaskets", but I think they may be out of business now. They were in San Bernadino CA.