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Exhaust Flange Gaskets

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Bob_Spidell

Bob_Spidell

Yoda
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Anyone have a source for exhaust flange (manifold-to-downpipe) gaskets? The ones I've bought the last few years keep blowing out; the filler--whatever it is--turns to a white powder and is blown out. My flanges are flat and smooth, and I keep the nuts torqued up properly. The gaskets I've been getting from Moss and others just don't last (would love to get my hands some NOS asbestos-filled jobbies).
 
Try BSC and use fresh brass nuts. I've not had a problem since I switched to theirs. And some times they look like they are flush together but not exactly lined up.
TH
 
I am having the same problem with my exhaust flange gaskets. I have a BN4 Longbridge. What is the website for BSC. I'd like to order from them.
Humdog
 
I think tahoe_healey meant BCS (short for British Car Specialists--https://www.britishcarspecialists.com)

I bought some 'Mr. Gasket' header gasket material and cut two gaskets to shape. I blasted this material--which looks like thick poster paper--and a new, 'stock' gasket with a propane torch. The stock gasket warped and blew out, just like in the car, but the header gasket material just turned black but otherwise held up. I've installed them but haven't run them.
 
I have owned 2 exhaust shops and done a lot of fabricating over the last 25 years. If the flanges are truely flat and smooth then this is your first step. I would build an insert that goes into the exhaust head pipe, much like what the 1980's Toyota head pipes were like. The Exhaust gaskets are round asbestos and have metal rings to withstand excessive heat. The inserts can be made from a slightly smaller thin tubing and then pressed into the pipes. Make sure these will slip into the exhaust manifolds also. You can press them in with a block of wood and hammer. The exhaust gaskets will be available any Napa Auto store. The same gaskets can also be found around the catalytic converters on the same ( 1980 to 1990 ) Toyota but in different sizes. I would also install studs in the exhaust manifolds and use brass nuts on the studs to secure the pipe to manifold. Brass wont rust or come loose. The studs in the manifolds wont wear out the manifolds, but unscrewing and screwing bolts in them will and the bolts can break. Also "VERY" important is using a solid hanger off of the bell housing. They do this on a lot of imports because when the engines torque it will create a stress point at the hanger and not at the manifold to head pipe connection. Good luck !

Willy
 
Thanks, Willy. I was going to weld an insert in the manifold but the diameter of the manifold exit is significantly smaller than the downpipe ID, and I couldn't find any sort of reduction tubing to fit. I was having trouble getting good torque on a couple of the studs and ended up stripping one--lots of fun. I finally welded a nut on the stud and was able to screw it out, and repeated this on another stud.

I looked all over the Net and couldn't find gaskets of the correct ID--all the new stuff is a lot larger (3" plus). I finally put in new stainless studs and made gaskets out of Mr. Gasket header gasket material. I put jamb nuts on all the nuts--I used steel with lots of anti-seize on the threads--and I think I got everything sealed up good. Next step will be a bracket I can bolt to the block (like they use on 100s).
 
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