Ok so Im trying mount some headers and I cant get the two center tubes on My passenger side to seal properly on the underside of the flange, so my question is, Would using two gaskets help seal it up and has anyone tried this approach. Im thinking that some how they have become a little warped or something and I figure I can take up the small amout of slack with another gasket.

 

Percy header gaskets

These gaskets are Aluminum and thicker then most gaskets. They are suppose to be one of the best header gaskets on the market.

 

First use a straight edge and check if you have a problem. Use Mr. Gasket thick paper gasket and soak them in water over night. Install and start engine to operating temperature and retighten hot. Keep checking for tightness after installing for the first week or two. I check mine once a year,they are now six
years old and never leaked.

 

I'm sure you probably tried tightened the bolts from the center outward to try to take up any binding. If they are binding on the outer bolts, maybe grinding the end holes larger would allow for more space for them to lay flat.

Just a thought.

 

so no one has ever tried to use two gaskets before?

I dont realy think that its a binding problem, all the bolts went on nice and easy till they actualy began to hit the flange so I think thats out of the question.

 

Two gaskets will eventually just burn through. With the poor flatness from end to end now, it will only get worse over time by using multiple gaskets. Bolt torque will be a big issue also, you'll constantly have to tighten the bolts. If there are any left by the time you get back to tighten them, usually once the gasket looses load the bolts vibrate out. You need to remove the header and fix the out of flat issue, which is easier said then done. Cheaper headers use thinner flanges which makes this even more difficult. Switching to a different material header gasket will work but you need to address the flatness issue first.

Try not to machine the flange perfectly flat as this will make the flange thinner in spots and cause more flatness issues and leaks later. Use a straight edge, 2' level works, across the flange and measure the gaps. Split the difference, if it's .020" in the middle, then file the two end to get the reading to .010" in the middle. Now .020" isn't much but yours is probably around ..060-.125" off in the middle and that much filling on a thin header flange is asking for trouble.

You may need to look at your tuning when you done, a lean condition will be pumping to much heat into those headers and causing them to warp. On the dyno we use to have to ream the 3/8" holes to 1/2"+ just to get the threads to start. But this was after a hundred hour testing with the headers glowing bright red - too cool! Still, it all depends on your setup, but bottom line - stay away from stacking gaskets to seal a mechanical problem.

Good luck,
Later.