Does anybody have any ideas on how I can keep the header gasket leaking at the head to header interface? I thought I had a tired gasket, replaced it once and almost immediately it was leaking again. Took the header off, examined both surfaces which appear to be OK, zipped it back up and still, I get a leak between the 4 and 6 ports.I verified I'm not bottoming out with the fasteners. I haven't tried doubling up, yet was wondering if anyone has other ideas/experience. They are Mr. gasket 1 piece gaskets.

The problem may be with the gaskets you are buying. I have used Felpro header gaskets for a long time and have never had a problem with leakage. They are more expensive though. This is definitely an area where more money = better part.

I usually double up the gaskets. I use 1 pair of Mr. Gasket Ultra Seal and the other set doesn't matter. I even go through the trouble of soaking them overnight before installing. I know that's an old school method and probably doesn't apply with the new gasket material, but I can tell you its been a looooong time since I had a header leak using that method.

Just get the fel pros. I've never had to replace a set due to them failing. They cost about 25 bucks.

Never use gaskets. Have always used Permatex High Temp Red RTV silicone, never had a leak, it's all we use at work also.

It's a good idea to go through at least 2 or 3 retorques after you get them warmed up. In other words, torque the bolts when you install them. Run the engine to get them good and hot. Torque them again. Heat them up again and torque a third time. After the third retorque is when you'd install the bolt keepers if you're using them.

-dnult

The exhaust manifold gaskets work well in many cases. They're so cheap, not too much reason why NOT to try 'em.

a leak at 4 and 6 isn't surprising, but you should be able to seal 'em. first i think i would check the header surface w/ a straight edge, and make sure its relatively flat. then buy a good gasket. i'm currently running an earls pressure master gasket set, and i have never seen another gasket that even comes close to the quality. they are the first gasket that when i checked the bolts to re-torque them they didn't need it, and still after months of use have not yet. yes they are a bit pricey, but well worth only having to do it once. hope that helps, good luck

I've never had to retorque the Felpro gaskets.

This time around I used Fel Pro 1406 gaskets and tightened the bolts from back to front and no problems so far. I always used cheap gaskets and tightened the bolts from the center out. Not sure which change cured my problem. Maybe both?

[ 04-24-2003, 02:45 PM: Message edited by: Fuji ]

I had mentioned this in a previous post.
The most common mistake made when buying header gaskets is buying them to match the port on the head. Look at the size and shape of the tubes welded to the flange. I have headers with round welded tubes. I went through 3 sets of square port gaskets before I got smart and bought a set of round port gaskets.
Haven't had a problem since. graemlins/thumbsup.gif

This so called "Split-lock fasteners" seem to be a good alternative to loose header bolts. Does any of you have used them? Any idea on price for them? http://www.go-breslin.com/Splitlock.html

[ 04-26-2003, 07:35 AM: Message edited by: ORENCH ]

EARLS! unique design: aluminum w/ raised hard silicone inserts over the port/interface. Expensive though.

I second Silver69's graemlins/thumbsup.gif suggestion on the stock exhaust gaskets with the foil backing, same as those included with FelPro's complete gasket sets. Ran them last year without a leak and they look great too because you don't have all of the ugly extra gasket material covering your pretty cylinder heads! The only think different I plan on doing is to match the opening tio the ID of the header tubes this time as they are a little smaller. :D

OK , OK, I put the Felpro 1406's on and they were worth the extra $$. No problems, didn't need to re-tighten either and I've been through several thermal cycles. One more felpro believer graemlins/thumbsup.gif