I have a tube of Permatex® Ultra Copper® that I am using and it is better than the other products I have used but is there something even better that could be used, for example, to seal headers? The Permatex® Ultra Copper® says it is good for intermittent use to 700 degrees F. Is there any thing that is rated higher?
No. It's not meant for that. Get your exhaust flanges smooth & flat and use good quality gaskets. You shouldn't have any need for goop to seal it.
Ran it all the time on late model stock car. no gasket just hi temp copper RTV.Put a small bead on the header flangesthe night before installing ,next day bolt them on and no worry stayed sealed until they were removed. just make sure they are clean before aplacation
If your flanges are smooth and flat, you don't really need any gasket (and I've run like that too in a pinch), but RTV is not meant for that. RTV is the most over- & mis-used automotive chemical out there... I used to like the white 'asbestos' exhaust gaskets the best - I'd soak them in water overnight before installing. They filled minor imperfections in the flange surfaces better.
I use this stuff on my OT drag car. It's made for wood stoves, works great and is far cheaper than the Permatex stuff. http://www.rutland.com/productinfo/600-rtv-silicone-sealant---red.html
on my last 2 cars i have chucked the header gaskets in the trash and just used the high temp red rtv , looks cleaner than a gasket hanging out and no leaks to report !
Huh I would have never recomended RTV on headers but I've never tried it! I have tried copper gaskets with mixed results. Usually best results with the paper gaskets just el cheapos from Mr.Gasket and making sure the headers stay torqued, the posi lock header bolts seem to make a huge difference!
You should never need any kind of "sealant" for headers or manifolds. Something is wrong and needs to be fixed. God I hate that sealant ****. I used to charge extra to get all that **** off of the joint so that I could fix it properly.
Had a friend who swore by pure 100% silicone. Let it dry completely first. Makes sense, silicone is by nature quite heat tolerant. Me? I prefer flat clean surfaces and no goo.
Well, many of you will apparently be quite surprised to find that Many Professional Drag Racers use Hi Temp RTV to seal the headers on race cars. I know lots of guys who do it and have seen it many times in the pits. Personally I would Never do it on a street car, just because it looks so messy.
I've been doing the same for a while now. Works great. Surfaces still should be as flat as possible. It's possible to wipe the part that goops out with a rag or if dry a razor blade. TP
Thanks for the replies.... I am currently using the Ultra copper on a vintage race car (1966 but it an English O.T. car) on the recommendation of the header fabricator. The header fabricator claims that if the headers are well built there is no need (on a race car) to use a header gasket. In fact, he claims that most of the header leaks (on at least race cars) is due to over torquing the headers on cars using header gaskets. A lot of Formula race cars, apparently, don't use header gaskets according to the header fabricator. So far I have not encountered any leaks during the last half of the last racing season but I also had to remove the head for other issues so it wasn't a valid long term test. I wouldn't recommend this procedure for street cars where the headers are likely built to a price and the exhaust is seldom removed. But so far it is working for me although I am still curious if there is any RTV that is rated higher than the 700 degree/intermittently that is claimed by the Ultra Copper?
This statement in on the Sanderson Header web site I have used this technique and have never had a failure............ We offer the only patented leak-free flange on the market. Our design is so unique that no gaskets are required! We start with a 3/8" thick steel plate, which has been precision laser cut to exacting specifications using our own template designs. After ***embly, a weld bead is built up around each exhaust port and all bolt holes. This bead is ground to uniform thickness with such accuracy that instead of a gasket, all that is required to seal the header to the engine is a bead of Permatex® Ultra Black® gasket maker silicone. Just keep the bolts snug and your experience with warped flanges and blown gaskets are over for good!
I've used regular silicone on header gaskets. A thin layer on each side, let dry, then a thin layer on one side to attach to the flange. Use wooden clothes pegs as clamps. No leaks, gaskets live longer.
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