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426 Hemi exh manifold to headpipe ball flange question?

Posted By: Finoke

426 Hemi exh manifold to headpipe ball flange question? - 11/17/11 08:46 PM

I'm getting ready to install the OEM exhaust system in my 70 Challenger and have a question about the connection between the exhaust manifolds and the head pipes.

Should the ball flange have a gasket on the inside diameter of the exhaust manifolds?

I bought the manifolds as a used repo set and they have a round composite ring type gasket stuffed in both exhaust manifold outlets. Should I be using them?

Its been so long that I'm missing one. But maybe I don't need them?

Attached picture 6923983-CIMG0519.jpg
Posted By: HPMike

Re: 426 Hemi exh manifold to headpipe ball flange question? - 11/17/11 08:55 PM

Quote:

I'm getting ready to install the OEM exhaust system in my 70 Challenger and have a question about the connection between the exhaust manifolds and the head pipes.

Should the ball flange have a gasket on the inside diameter of the exhaust manifolds?

I bought the manifolds as a used repo set and they have a round composite ring type gasket stuffed in both exhaust manifold outlets. Should I be using them?

Its been so long that I'm missing one. But maybe I don't need them?



Nope..

The pipe has a taper which mates with the rounded outlet end of the manifold.. Which headpipes are yo using?

MB
Posted By: Finoke

Re: 426 Hemi exh manifold to headpipe ball flange question? - 11/17/11 09:49 PM

Thanks Mike, that's what I thought. I'm using the accurate exhaust system.
Tom
Posted By: Finoke

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/13/12 03:46 PM

My exhaust manifold to head pipe flanges continue to leak a little. I was gonna go back in and insert the round gasket that was on the exhaust manifolds when I got them.

The only thing is, I can only find the one. Does anybody make a ring gasket for the ball and socket type exhaust flanges.

I know your not supposed to need a gasket, but my connection seems to leak no matter how much I tighten.
Posted By: JohnRR

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/13/12 04:17 PM

I've never seen a gasket on a ball and socket flange . Take what you have to the auto parts store and see what they can come up with that looks similar . I have a repop set of hemi manifolds and I don't remember seeing a gasket with them.

Have you tried sealing the joint with hi temp red rtv ?
Posted By: gtx6970

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/13/12 05:25 PM

Due to the design of how the pipe seals ( it has to flex there ) to the manifold , a gasket is not going to last long.

Posted By: ogopogo

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/13/12 05:56 PM

I had to spend some time on my manifold flanges grinding casting irregularities off or they would have never sealed,did you inspect yours before install?
Posted By: Finoke

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/13/12 06:36 PM

Good replies, I'll try to post a picture later of the gasket that came with the manifolds.

I havn't thought to try high heat RTV. I also never thought to inspect for irregularity or burrs.

Nows the time since I pulled the heads due to a sticking valve.

I'll post later with what I find.
Posted By: sawdust

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/14/12 12:47 AM

The tapered flange of the cast iron manifold for the original and reproduction manifolds seals with the bell mouth of the H-Pipe (no gaskets), unless someone ground the taper off your manifolds. Another key thing is the reproduction manifolds have to be dressed up as the flange area was not machined to remove the casting lines. If your manifolds were not "Modified" and still have the tapered flange you need to dress the taper to remove the casting lines.
Just some experience talking with repro parts, see casting line in picture, it leaked, of course.
My 2¢

Attached picture 7249282-flangecastingline.jpg
Posted By: 68jim

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/14/12 02:34 PM

I had a buddy with the exact same issue using the repro manifolds. He found an aerosol can cap that was the same size and used it as a template along with a file to knock down the high spots and casting flash. No more leaks. He said the file work probably took longer than a die grinder but he had more control and less chance of making a mistake.

Good luck!
Posted By: Finoke

Re: 426 Hemi exh manifold to headpipe ball flange question? - 06/16/12 04:50 PM

Quote:

The tapered flange of the cast iron manifold for the original and reproduction manifolds seals with the bell mouth of the H-Pipe (no gaskets), unless someone ground the taper off your manifolds. Another key thing is the reproduction manifolds have to be dressed up as the flange area was not machined to remove the casting lines. If your manifolds were not "Modified" and still have the tapered flange you need to dress the taper to remove the casting lines.
Just some experience talking with repro parts, see casting line in picture, it leaked, of course.
My 2¢



Yes, this is the case. Looks like I will be breaking out the die grinder.
Thanks
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