[mtnbktrek]

first off i have been searching past threads,that being said it seems like using a gasket maker (ie hi temp red) or the blue fel-pros seem to be most common so what should i use?
i have:
400 w/#16 heads and the hooker comp headers w/mr gasket fibre gasket w steel mesh in middle

i hate changing these and the mr.g blew out again like 100 miles on them.
i was reading about NOT using a gasket and only the high temp it seems like it would be a mess b/c of the tight areas how much sealer do u put on? 1/4'' bead?
also, i was told to cut the header flange after the first hole and before the last to ease some pressure on the flanges. does this work/help?

[ugpkgb]

I have been doing a fiber gasket with high temp rtv on both sides to stop the leaks. Just smear it on the gasket first then put it in place. It works very well and wish I knew about it sooner. As for cutting the header flange. Don't it is a PITA to put the headers back on after a few heat cycles. Also just let it set up for awhile before running your engine.

[mtnbktrek]

i was going to do that but i was worried if it didnt work it be a bigger PITA to get the red rtv off

[Sirrotica]

Couple of things come to mind on header sealing.

1 Are the flanges flat or does the gasket sealing surface have a low spot? You need to have a flat surface with little to no warpage for them to seal. I have had to weld additional material and file a flat surface on some headers that were either warped from weak thin flanges of just had poor workmanship on the sealing surfaces. Any flange less than 1/4 inch thick isn't going to seal, 5/16 or 3/8 is preferred here.

2 Tightening the header bolts up after a few run cycles. You need to retorque them after 2 or 3 heat cycles as the gasket will compress with the expansion of the flanges with heat. Not retorquing them after this takes place is a sure fire recipe for failure.

3 Red RTV is your friend in this instance, it will keep the gaskets stuck on both sides to the head and the flange and seal irregularities without letting the exhaust start a path between the sealing surfaces which eventually erodes the gasket. Removing it is easily accomplished with a razor blade or a good sharp putty knife. Smear the gasket on both sides with enough to cover the sealing surface on the flange side and after tightening the headers leave it set up for 24 hours.

I have a set of Hookers on a 76 T/A that have been on there trouble free for over 20 years, same gasket that came with the headers and red RTV on both sides. Flat flanges and tight bolts and red RTV are the keys to longevity of header gasket sealing. You probably will have to modify some 7/16 inch wrenches to make sure you can get to all the bolts and get them tight, I have probably at least 4 modified wrenches I use only to tighten Pontiac headers up. 7/16 swivel sockets and long extensions can also be helpful on some of the bolts. Pontiac headers are one of the worst to install and get sealed, but if all the things I have outlined are done you will be rewarded with leak free headers.

[ugpkgb]

It is a pita to get it off but thats the point

[steve25]

A long lasting good seal with a street exh system hanging from the headers also depends on how good your motor mounts are!

[amcmike]

Brad covered it pretty well. You can also use special locking header bolts (you'll still need to retighten after heat cycles).

And if you really want to remove stress from the system, flex pipes can help.
http://www.summitracing.com/search/P...st-Flex-Pipes/

I've also heard of people running a solid engine mount on the driver's side and rubber on the passenger. It's supposed to limit overall engine rotation under high loads, while still damping vibrations to the chassis. By limiting overall engine movement, I would think this would reduce stress on the exhaust system between the headers and pipes.

[t/a 79]

I like using studs to mount headers are easy to tighten and dont back off as much as bolts

[mtnbktrek]

i was thinking about the studs but wasnt sure if i can fit a nut some of the clearances are tight to the tubes and i didnt know if theyd clear.

[t/a 79]

I have triy headers studs worked on all but 2(had to use bolts in those two holes)

[AGTO8U]

I have some Hooker competition headers. The flanges were not flat, so I cut sections out of the flanges between the ports and cut gaskets to match. Glued the gaskets to the header flanges using RTV and let them set out in the sun for a couple hours with the bolts in the holes for proper alignment. Then applied a bead of RTV to the engine side of the gasket and let it sit overnight. That was 2years ago and no leaks.

[beertracker]

I too am looking for header leak solutions. Have you ever heard of using two header gaskets per head and not using sealer? Wondering if this works or not. Some one mentioned it to me. My setup is a Pontiac 400, 6x heads and Summit headers that came with felt gaskets.

BT

[Sirrotica]

No need for 2 gaskets if the flanges are flat, the thicker the gasket plus being stacked one on top of another the more likely it is to blow through. The RTV not only seals the imperfections, it also glues the gasket to the head and the header to keep it in place. It works so well I don't have any idea why anyone wouldn't want to use this type of sealing procedure.

I first heard of a mechanic using red RTV to repair a cracked turbo housing on an OTR truck as a field fix, so I decided to try it on my header gaskets. One of my cars is 20 years with the original gaskets and red RTV on my Hooker headers in my street driven 76 T/A, not one problem. I had tried numerous fixes before this on Pontiac header gaskets without much success, and believe me I have installed more than a few sets on customer cars as well as my own cars in the last 35 years. I now use RTV on any exhaust sealing area that I think might be questionable. Retighten after a few heat, cool cycles and make sure the flanges are flat and true and you won't have header gasket problems.

A few weeks ago I installed a new crossover pipe on my turbo diesel K3500, the left exhaust doughnut was in pretty bad shape and I was doing it at night and wanted to finish it up so I coated it with red RTV let it set up a little bit and put it together, not even a hint of leakage. The other end I didn't coat with RTV because the doughnut was in much better condition, but I did have a little trouble getting that end sealed after starting it up. In retrospect I should have probably coated both with RTV.

[p4msi1]

You, know all those steel shim exhaust gaskets that come in overhaul gasket sets, that we all throw away. Well I saved mine just for a backup. I have a pro-Charged 1980 firebird with a 455 and 4x heads. For proper exhaust sealing the surface has to be Flat as mentioned earlier. Header manufacturers wrongly leave a raised bead around the header port and when you tighten the bolts that are situated outside of the bead it then bends the flange and will not uniformly load the gasket. Plate sand the header flat and make sure the weld has not been sanded through. I always plate sand and then tig weld again to penetrate further. Sand one more time to asure flatness.
Getting back to steel shim gaskets. I ran out of felpro gaskets and all I had was a handfull of steel shim gaskets and decided to stack 3 at a time, you know, just like a cometic gasket. All header leaks solved. I put 15 lbs. boost, and with 4 mufflers to keep it quiet, create a little backpressure and was hard on header gaskets. I will never use another type of gasket. There is really nothing to blow out. Oh, the motor put out about 700 HP.

Steve

[mtnbktrek]

Hey did anyone try the Percy xx carbon gaskets it like a carbon felt on steel core?I picked them up like $25 .... Also before i installed the gaskets I put a straight edge on the header side flange and had grind marks that would cause a leak so I filed them till flat... Pontiac header install PITA!!! I hope these work

[ponchjoe]

I've always had good luck with NAPA 95038SG myself. It is a carbon over steel core.