Exhaust Header Blowing

[Gusty]

Hi,

 

As per the title slight blow from the headers. I've fitted qualityVictor Reinz gaskets but slight blow.

I have some Loctite copper silicone , good for up to 350 deg. Will this be ok? Also do I apply to both sides of gasket? Do I leave it to set before running?

 

Cheers

[IanS]

Is the mounting tight?

When I fitted my original Exhaust manifold it blew between the head and the manifold face.

A bit of head scratching and I realised that the new fabricated manifold was thinner than the cast iron original and the nuts were bottoming out on the studs just before everything was tight.

Some washers under the nuts sorted this.

[Gusty]

Yes it's tight. I replaced the studs with stainless ones. I think the header may be twisted.

 

Thanks

[kevin the chicken]

You would be best to see if it is flat before you try anything else. Get a straight edge on it. I think they can be ground flato if you have a machine shop near you. It might save a lot of messing about in the long run.

[Guest mcramsay]

The manifold tends to bow like a banana when it's welded (I am assuming custom 4 branch and not a cast manifold) I had similar on my zetec manifold. I used a straight edge to and a file to get it back to being close to flat. And did not have any further issues. Of course machining is the proper way to do it but not always practical.

[Gusty]

Yes you are correct 4 branch . It's only blowing on one, I'll get the angle grinder on it and glue it!

 

Cheers

Edited April 14, 2016 by Gusty

[Guest mcramsay]

No angle grinders! Honestly you will make it worse! use a straight edge to identify the high points and then file away until it's flat. Honestly I could not advise more against using an angle grinder, the manifold will end up looking like the Scottish highlands

[Gusty]

I was joking:) a little fettle and exhaust sealant then back on.

 

Thanks for your help

[cb750]

Never needed to use sealant on mine. Just filed it flat as suggested then used standard gaskets and pulled nuts down evenly.

[Gusty]

I'll try it first without the gunk.

 

Cheers

[Bob Tucker]

Maybe use 2 gaskets to take up a bit of misalignment?

[Gusty]

Yes, I would rather try that first than sealant. Good idea. Thanks

[Guest mcramsay]

Two gaskets or one the manifold will still not be flat, so you will just be moving the problem further back, the manifold will only go on as far as hitting the high points. So you will end up with less compression on the joint face where the manifold is bowed, and then a leak path between the two gaskets. A gasket on top of a gasket is also a No no. The only way you could make the above suggestion to work is to use a single gasket but thicker and of a more compressible material, this would allow the higher points on the manifold to sink in as tightened and allow the non sealing surface to come closer and compress the gasket.

 

I might be being a bit too over dramatic for a exhaust manifold on a kit car but hey ho!

[Gusty]

No, it's all good thanks . I like your logic. I'm off to work for four days now but i will get the file out on my return and report back.

 

Cheers

[Gusty]

Exhaust header sorted. Little bit of weld protruding. Filed back and refitted . Thanks for all the info.

 

Cheers Andy