Manifold to downpipe joint

[polo2k]

Hey there all. Little bit of a hot topic really but a slightly different angle this time.

I have a 63 4 door with a 1098 engine. Im having some real headaches getting the manifold to downpipe joint to seal properly. The exaust is a 2 piece stainless however i have been working on mona for 9 years on and off and I cannot quite remember if I put a mini carb/manifold on. Is there any way of checking the manifold type?

I have redressed the flange with a hammer and dolly and as far as I can tell there is negligble stretching on the mating face. It there a trick to getting these to fit?

Soon I plan to split the 2 halves and fit the front first, then the rear onto that.

The clamp that im trying to use is 2 moon shapes with groves down there profile and 2 bolts coming through, with a washer and then another washer on the other side and then a nut. I found this very hard to fit and fount that tack welding the head of the bolt, and the spacer plate to the half moon helped.

So, how do I het the perfect seal on my joint?

-Ta-

[alex_holden]

Have you tried a new clamp? They seem to distort the first time you use them.

[mrbenn]

Are you using any exhaust putty on the join? I just had to re-do mine using some such stuff. Sorted it right out though

[Peetee]

The manifold from the mini 1000 is designed to take a 1.5inch carb and has the carb mounting bolts diagonally spaced. The Minor exhaust has the bolts vertically spaced.
Both these manifolds are designed to take a Minor-sized exhaust at the same angle and spacing from the head/engine/whatever so you should not have issues with swapping one for the other.
If exhaust putty has ever been used on any of these componants then you will probably need to take the manifold off and clean back to bare casting on the mounting face. after 7 exhaust chages of different types I have never managed to get a seal without using putty. Once this has been on a manifold for some time It's difficult to differentiate it from the manifold casting or see it if it's on the side facing the engine.

[bmcecosse]

The exhaust manifold end may be damaged or erroded - check it carefully. Best way is to hold the exhaust flange tight up to the manifold at the right angle with a small jack - then a smear of paste and fit the clamp with new bolts and brass nuts.

[rayofleamington]

The exhaust manifold end may be damaged or erroded

If the mating face on the manifold isn't exactly right, the joint can be a complete pig. On the flip side, if both faces are spot on, you can make the joint secure and leak free without paste (that's rare in my experience)!

If/when it leaks, this can erode the sealing face. If the exhaust comes loose the movem,ent will wear the sealing face.
I had one Minor where I always struggled to get a good seal. With hindsight I really wished I'd replaced the manifold.

[mike.perry]

This is probably obvious, however have you tried supporting the bottom of the downpipe with a scissor jack and then raising the exhaust into position and checking the flange alignment before fitting the clamp?

[polo2k]

thats the next step