2 bolt exhaust flange gaskets, that dont suck.

My issue is that rotaries love higher heat temps and I am constantly popping exhaust gaskets at the flange. It is never at the bolt hole ends, it is always the top of the bottom where they are too thin. IE vibrant performance once.

tooooo thin here (highlighted area) always pops.

Can anyone recommend me one of this style (2.5" ID) that does not have as thin areas, a little more robust. I am open to material (except for paper, because those cant stand the heat)

Why not switch to v-band?

Or use thicker flanges on the pipes. 3/8" should kill any deformation at the thin area and keep the clamp load on the gasket more consistent.

I had problems from this same spot on the Miata (between header and cat). A healthy smear of some red gasket maker goop seems to have solved the problem.

Remflex.

Or mill them bitches flat and run no gasket. The best gasket is no gasket.

EvanB wrote: Why not switch to v-band?

not a BAND idea! (better verbal pun)

but then I need to recruit my welder friend again...

also, the flanges are 3/8"

You could also try making a gasket out of pure copper. A piece of 16 gauge should hold up. The melting point of copper is nearly 2000 deg and it's soft so it will seal.

Boom:

http://www.mandrel-bends.com/catalog/2-50-slotted-2-bolt-universal-exhaust-gasket-0-043-copper-2519.html

Great company and they're local to me, so I like to support them.

turboswede wrote: Boom: http://www.mandrel-bends.com/catalog/2-50-slotted-2-bolt-universal-exhaust-gasket-0-043-copper-2519.html Great company and they're local to me, so I like to support them.

I love you.

just ordered it. Gonna give it a shot!

Swank Force One wrote: Remflex.

+1. I use these on my rotary.

Many times those flanges are no longer flat. That inherently leaves the unbolted segments loose. Check and hammer then back flat if necessary.

Many times those flange bolts are over-torqued, flexing the flanges and leaving the unbolted segments loose. Don't go nuts with the wrenches.

Hmmm, I've had a similar problem so may try a copper gasket. Otherwise I was thinking of lopping then off and replacing them with 3 bolt flanges which would also do a good job

I have had good luck cutting the ears off the gaskets so that they are just round circles and then putting them in. For badly warped ones cut one into a circle and double stack it with a regular one.

And for the really bad leakers some muffler shops still have on hand the gaskets for the old Dodge manifold to pipe, which is about 1/2" thick, like a donut, and kind of flexible.

Remflex is awesome on rotary exhausts

Draw a big file over the flange, perpendicular to the line between the bolt holes, this will tell you if it's reasonably flat, and flatten it for you. Don't overtighten the bolts and warp it again. Depending where in the system it is, try either a copper gasket, or assembling it with just a little permatex ultra copper RTV. You can generally get away with the rtv trick on the header flange, where the block soaks up a lot of the heat, and past the first cat/resonator. Though I've heard of it working all the way up to turbo flanges. Stuff is good for 700*f IIRC, and flanges are a lot cooler than the pipes they connect.

File them flat (be patient) and then use high temp silicone, no gasket.

Works for me.

Actually I use Right Stuff, and it doesn't work 100% because I have the true dual exhaust system and I'm mating one species of header to a Racing Beat mid section and the bolt patterns are different, so I only have five bolts holding them together (can't redrill for the 6th) and there is a maybe 1-1.5mm gap at the top where the header flange got warped after I spent too much time converting a different-brand 12A header to 13B, so I glob on a bunch of Right Stuff and bolt it together and it lasts about three or four months before it starts leaking again. High temp silicone lasts longer, but I never have a tube of that in good shape while I always have the huge caulking gun of Right Stuff.

Right Stuff is also good on ham on rye, and as a mixer for scrambled eggs.

I had an older Saab once that had a slight exhaust leak where the manifold met the front pipe. I took the stock gasket and coated it in silicone based furnace cement, tightened it up and it didn't leak. The downside was the cement was a little on the messy side, but it cleaned up with water.

One other option would be to go to your local parts store and ask to look through the exhaust book for a gasket that is the same specs as the one you need, but with a thicker ring.

i always use copper on my header gaskets. back in the day when i was too young, poor, and cheap to know any better i blew out header gaskets made out of that material OP's gasket pic is of constantly. switched to copper exclusively on headers about 8 years ago and have never had an issue.

Used to have the same issue with the sidepipe collectors on the Cobras until I did away the gasket altogether and started using this instead:

Jeff