Topic: Exhaust leak causing backfire flame? [Update: fixed]

[Chachi]

I pulled my pipes today to remove my DIY BBQ paint job. I also had the 'flare' cut off the end of pipe. Pipes are from the 70s (I think) and they turned out after the baffle. I did not cut into the baffle area as you can see in the pics. I just removed the last few inches that turned out so the pipes are 'straight' at the end. I also removed old copper gaskets and installed new OEM copper gaskets. I remounted everything and I'm getting some backfiring and flame from 3-4/right pipe.

-See pic attached: a small section of the header pipe lip from #3 came off during removal, just fell off. Is that enough to cause this?
-If that is not enough, maybe I just need to remount and try again?
-Did I possibly disturb spark wires?
-Just trying to determine what to chase, this was not happening before.

[Chachi]

It's a 4-into-2 set up by the way...

[KJ790]

Yes, if you have an exhaust leak where the header meets the cylinder head then that can cause the pop you are experiencing. It doesn't take much of a leak to cause this problem either.

[Chachi]

Think that header lip piece can be welded back on?

[trueblue]

Probably be better off building it up then grinding it to shape.

[Chachi]

I'm going to take it back up to the metal shop that cut my flares and see what they can do.

[Chachi]

My metal shop hooked me up. Took the pipe back up there with the header lip section that came off and they were able to cleanly weld it back on. They also hit a few pinholes on the underside I had too.

[lucky]

My metal shop hooked me up. Took the pipe back up there with the header lip section that came off and they were able to cleanly weld it back on. They also hit a few pinholes on the underside I had too.

It sounds like you are going to need some new pipes.
Welders should be telling you that instead of chasing pin holes around.
IF you do not have the money I understand, but the welding repairs cost money that could go into some new pipes.

You probably already know this.

[Chachi]

Hey lucky, I totally agree about throwing $ at bad pipes vs. buying new. My metal shop took care of me though. I went to them for a purely cosmetic change (cut the flares off) and they charged me $50, their minimum. In the process of pipe removal, a section of the lip from header #3 fell off and that was what causing my leak and backfire. I took the pipe back to them and they fixed the header lip and went ahead and hit a few small pinholes I had too - without charging me anything additional. The shop does great work and with the pin holes taken care of, I think the pipes should still have plenty of life left. So for $50, I'm good.