Exhaust Temperatures

[spdpug98]

After a bit of advice regarding exhaust temperatures, not the gases but the actual headers.

I am running an R1 bike engine in my MNR kit and am having nothing but trouble with sealing the headers with the 4-2-1 collector. I have tried everything I can think of from Fire Gum to repair putty, but every time it just blows it all out. So my next thought is possibly using a high temperature silicone, but I don’t have any idea what temperature the headers will get to. (Wurth high temp silicone is OK up to 285 deg C)

Or anyone have any other ideas on how to seal them

[450Nick]

I just use boggo ordinary black silicone on my blown 4.6 Rover V8. I tried all sorts as you did to seal the rear section of mine until a garage recommended I try ordinary black silicone. It's worked a treat for about 2 years now! Having said that, mine is a little way from the headers so maybe something like blue hylomar would be better that close to the exhaust ports as I expect there's a bit more heat to deal with...

[jr6yam]

Try GEOCEL fire block seal. Rated to 1500c
It's available from hardware stores and only 3 quid

John

[rev-erend]

Sorry but I don't think you need sealant. That gap in the middle is huge. You need to get it TIG welded..

[spdpug98]

rev-erend said:

Sorry but I don't think you need sealant. That gap in the middle is huge. You need to get it TIG welded..

The problem I have is if I get them welded up (which I have thought about) then I won't be able to ever get them off again, the headers go through a small hole in the body and I don't really want to put a big oblong hole in the side of the car

[Bollah]

spdpug98 said:

rev-erend said:

Sorry but I don't think you need sealant. That gap in the middle is huge. You need to get it TIG welded..

The problem I have is if I get them welded up (which I have thought about) then I won't be able to ever get them off again, the headers go through a small hole in the body and I don't really want to put a big oblong hole in the side of the car

Can you not get something like this done?

[spdpug98]

jr6yam said:

Try GEOCEL fire block seal. Rated to 1500c
It's available from hardware stores and only 3 quid

John

One tube of Geocel bought and exhaust re-done, fingers crossed it works this time

[stevieturbo]

get better collectors made.

And add proper clamping. No not springs. IMO springs arent very good. Its easy to weld a couple of tabs on and use a bolt to pull the collectors together.

[rev-erend]

Take a look at the manifolds I just made for my car .. to give you an idea for the clamps :

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

Edited by rev-erend on Monday 17th May 22:42

[spdpug98]

rev-erend said:

Take a look at the manifolds I just made for my car .. to give you an idea for the clamps :

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

Edited by rev-erend on Monday 17th May 22:42

They are awesome, since you posted yesterday I have been thinking of getting them welded if the Geocel doesn't work. I guess you can Tig weld, if they did get welded up and ever needed taking out I would either have to cut the hole in the body bigger, or pull the engine out and pull it through the existing hole

If you ever fancy a bit more Tig practice let me know

[rev-erend]

Dave,

I only tack welded them with mig and then took then to a mate down the road
who tig'ed them up for me. My mig welding was giving porus welds - they looked ok but had minor pin pricks which leaked gas when I pressure tested them.

[stevieturbo]

Mig welding will do fine, but TIG is prettier.

Although proper collectors, and proper fixing of the collector to the manifold will not leak.