Frogman

My downpipe gasket keeps leaking no mater how tight I crank. The gasket I had leaked very little but finally blew out a week ago. I bought another fell pro band gasket which is a bit thicker and this one leaks as well.
Any tips ?
Some one recommended a remflex gasket but the materials run 50$.

Toruki

I has the same issue and couldn't find a "thick" gasket. I bought a sheet of gasket material and cut my own, $13 at amazon

Frogman

How thick is it ? The new felpro one i bought was a bit thicker and still leaks.

Toruki

Maybe mine was not as bad as yours. The amazon linked stuff is 0.75", slightly bigger than a 16th.

Found this cheaper remflex on ebay, 6.5x11" sheet

https://www.ebay.com/itm/20292470671...Bk9SR5y1uJeWYQ

Toruki

Is it bad form to double up on gasket material? Never tried it but I don't see why it wouldn't work, despite being a bit of a kludge.

Frogman

No idea , might sound clever in theory but two weak materials rubbing up may make it worse . Kind of like how you shouldn't double up on condoms.

mazdaverx713b

iTrader: (91)

You can double up tue gaskets if need be. The reason that the flanges aren't sealing is that they are likely warped. They would need to be belt sanded flat again. Some machine shops do this, or if you prefer you can do it at home with a belt sander. You must remove the studs and that can sometimes be next to impossible unfortunately.

Frogman

My studs fell out haha .Would that copper ultra temp rtv work ? Its 700deg, i highly doubt it gets that hot there.
Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube https://a.co/d/2U0omTz

Frogman

Ok so it turns out the gasket recommended here is the WRONG one . I got the one recommended by Autozone and it is the same hole size but the bolts for the bolts are about a quarter inch closer. Hopefully, this solves it. IF not copper RTV + gasket , if that fails I'm buying that 30$ remflex stuff !

mazdaverx713b

iTrader: (91)

The exhaust leaves the engine at up to 1500-1700 degrees on a rotary engine. The copper gasket sealer will melt out fairly quickly. I tried using it on one of my TII's years back snd it didn't work. You can try it but if your studs have fallen out, I'd recommend belt sanding the flanges and using a quality gasket.

KansasCityREPU

iTrader: (9)

There was a discussion about this gasket availability and fit last year.

https://www.rx7club.com/1st-generati...asket-1152307/

Frogman

I have a 1985 exhaust system on my 12A with the cat's.

KansasCityREPU

iTrader: (9)

Do you have you have the factory part number?

Frogman

Yes . 1480 31 621 or so says partsoq.

KansasCityREPU

iTrader: (9)

This is the after-market one.

FEL-PRO Exhaust Flange Gasket 60933

https://www.autozone.com/gaskets/exh...933/225413_0_0

Frogman

I bought that one yesterday. Probably the last one in my area as its NLA on every website and autozone says i bought the last one in a 100 mile range . Fingers crossed. Mazda sells it aswell with a A behind it .

Frogman

So I found the correct stud and the gasket above sealed like a champ, I removed the bolt I ran through and discovered that with enough torque they bend and don't allow the parts to sit flush . For any one looking the correct bolt size and thread pitch is a 10 x 1.50 , it bolts right unto the header flange.

BUT now that it's quiet i can hear a very distinct tik tik tik coming from the manifold but can't seem to feel the leak, that sound is exactly what a cracked header sounds like Sigh..
The good news is the car is pretty quiet now and driving it the sound is smooth as dr pepper 😂.