legacycentral bbs

I cleaned up the exhaust headers, cross-pipe, & up-pipe yesterday.

I noticed on the passenger side exhuast manifold where it loops around and goes into the up-pipe that a small area was removed. It looks like a gasket failed some time, and the owner never replaced it, so the exhaust gas ate away at the header, since the cast iron wasn't as hard.

Do you think some high temp silicone sealant with the stock gasket will provide enough sealing?

Short of replacing that one side of the manifold, I don't think a gasket alone will seal things.

Here's pics
http://www.main.experiencetherave.com:8 ... s/ej22t/26

http://www.main.experiencetherave.com:8 ... P_5232.JPG
http://www.main.experiencetherave.com:8 ... P_5233.JPG
http://www.main.experiencetherave.com:8 ... P_5234.JPG

Depending on the thickness of the flange, I would either belt sand till the spot is gone, or weld and then belt sand down flush. When I had a badly warped flange on a Mitsu 2.6 turbo exhaust manifold, the machine shop belt sanded it back flat. 50K+ miles later, no problems. They problably removed about 1/8 of an inch at the most warped spot.

I don't think I would trust any kind of sealant. Maybe a high temp metal replacement epoxy I might try if I could not find somebody to repair the manifold at a reasonable price.

Jess

I'd say the flange is probably thick enough. Welding cast iron can get tricky.

I've got a borla header I may be using, or at least testing out. So I think for the time being, I'll try the sealant, and just keep an eye on it. If I can find some epoxy, I'll try that instead.

The gasket will completely cover that area. I'd just glob some Mega Copper High-Temp Silicon Gasket Sealer in there and you'll probably be fine.

Yeah....that's all I really want to bother with right now. The gasket sealing point goes right over that area..

I've got some hi temp copper permatex silicone. Is this Mega Copper silicon sealer a specific brand name, or were you just generalizing?

Hmm, I'm not sure. VersaChem is the manufacturer of the stuff I have. As long as it's high-temp copper silicone it should be ok though. The stuff I have is just listed specifically as an exhaust gasket sealer. I don't really know if there is a difference or not.

Thanks Matt.

I'll see if I can find some info about it on the net.

Why not just JB-Weld the spot, simply for filler, and then glob on the gasket stuff.

I'm a big fan of the Copper Spray-a-Gasket. I remember Vikash telling me that people would use that stuff when replacing head gaskets without even milling the head flat again! It's cool stuff, and I've used it in place of a real gasket.

I often use the red High-Temp Silicone RTV IN PLACE of a gasket on the exhaust (for the test-pipe). It's been good and hasn't leaked for quite some time, though I don't think I'd trust that stuff for what you are looking to do.

I'm with the gasket sealer fans too. Cast iron is NOT easy to weld. Can be done, i have done it alot in my job, but for the problem you have its the gasket goo is probably more suitable.

"so the exhaust gas ate away at the header, since the cast iron wasn't as hard."

Cast iron is hard, an exhaust leak just creates a passage for it to shoot through at high velocity causing this errosion.
anyone whoes tried to hacksaw through cast iron can tell you its harder than mild steel.

I took off the up-pipe. You could see on the gasket where it didn't seal.
http://www.main.experiencetherave.com:8 ... P_5248.JPG

I put the gasket back in with the high temp silicone gasket maker on.

I'll keep an eye on things for leaks once I get it running.

Matt, the versachem stuff looks to have the same temp range as the permatex I have.

Cool, I think it should be fine then.