I'm struggling to find an exhaust manifold for the right money. The only ones I can find are the type that go through the chassis rails rather than over the top. As none of the exhausts I'm looking at were actually designed for the Haynes roadster, they tend to collide with the chassis diagonals between the top and bottom rails. Given that my chassis is now powder coated, how much of a ball ache is it going to be to cut the offending rail out, fit a manifold, then weld in another diagonal wherever it will fit? Do you reckon the chassis strength will be too compromised, or will putting whatever diagonal I can get in there be ok?

Opinions please!

Cheers

Adrian

Welding a powdercoated rail will ruin the powerder coating on the heat affected areas. Someone has done it on mine in the past and its all flaking off and rusting!!

I would look at buying a system that fits best and modifying it rather than the car.

What engine? I would think that if this was a problem someone else will have sorted it out. Have you posted on the Haynes forum?

had the same problem...ended up chopping upou the diagonal and re bracing....

you would be best making your own manifold...

what engine is it for?

It's a zetec engine.

Its not just a simply case of chopping out either, if you remove a diagonal you need to keep the box made of triangles so would replace with a Y, as below so will burn in three places.
Rescued attachment Drawing1.jpg

hence why i siad re bracing.....

I've had to chop out and move a few bits on mine and destroyed the powdercoat. If it's black you could try black enamel paint, I used that on mine and is a pretty good match.

Hi Adrian,
Sorry to hear you're having troble with finding a manifold to suit. MK do an over the top Manifold I thought as do Fisher - have you tried these?
Anyway, i modified the diagonal to enable my manifold to fit. 1st pic shows exhaust fitted and you can just see where I cut the diagonal off on lhs of pic. Second pic shows new diagonal(s) welded in place. Wasn't too much hassle.
Hope this helps.
Matt
Rescued attachment IMG_5660.JPG

Pic no. 2.......also welded some extra braces in on top rail and earth stud which can be seen in this pic too.
Rescued attachment IMG_5784.JPG

Nice looking exhaust that Matt, where did you get it?!!

Glad it worked out ok for you

Cheers

Adrian

Yep it's worked out great....couldn't understand why you didn't go this route yourself but I hope seeing what i've done helps. Still think you can get a decent "over the top" manifold though.....check out the pic in Big_Wasa's photo archive under Engine for his Fisher exhaust.
My chassis is powder coated too and yes it does bubble up and flake off local to any new welds but I cleaned it up and repainted with hammerite smooth and primer and to be honest it's hard spot the difference.
All the best,
Cheers,
Matt

I had my exhaust made by martin keanan of mk enginering , mine goes over the top rail,
Rescued attachment Exhaust 4.jpg

pic 2
Rescued attachment Exhaust 2.jpg

pic 3
Rescued attachment Exhaust 3.jpg

we modified the the whole interior of the car and just repainted where we had to weld.
Its just a thing you sometimes have to do.
You can limit the damage to the powdercoating by using a product called cold front.
Its a putty that stops the heat in the affected tube /area
http://www.frost.co.uk/item_Detail.asp?productID=8822&frostProductName=Cold%20Front%20%28414ml%29&catID=33&frostCat=Welding&frostSubCa t=&subCatID=

Hope that helps.

I got a nice over the top manifold from 907 on here, bloody beautiful lump of steel.