Practically Classics Forum

Hi folks looking for a product that will seal the exhaust downpipe to the exh manifold on my mini. Problem is, exhaust is rigid but the engine moves. Tried the usual paste but it breaks up.Need something flexible that can take the high temperature, hopefully before I go deaf, regards jtk

Hmm, yes, the exhaust is rigid but jacking the bell end against the manifold while the paste sets is the usual way with minis and I can only remember having this to see to when they came in with broken top stays, so the bushes at the ends of that would be the first place I'd look. I also remember people fitting extra or alternative top stays that were in fact either less effective or that - if used in place of the factory one - would allow the engine to shuffle around far too much thanks to bigger bushes.

If you already checked or changed that, my apologies for stating the bleeding obvious and in that case, assuming that the engine/gearbox can only move very slightly and then not radially to any great extent; try applying the paste, hold that end with the pad of the jack, then, before you take the jack out, attach the other mounts starting with the rigid one that ties the front pipe to the remote extension (assuming it's not a magic wand car).
It really shouldn't be difficult to get a lasting seal that way, but check the bell end before offering it up, they do occasionally split and chunks can break out if too much paste has been used in the car's past.

I can still hear the mechanic's voice ringing in my ears when I told him that the downpipe didn't seal well on my Wolseley Hornet - "Never use cement on Minis as the pipe needs to be able to move slightly on the manifold" (a few words have been omitted ...). That would be over forty years ago - and we had three or four Minis (and variants, 1100s, Maxis etc) after that. , I never used cement after that bollocking and never had problems - so long as the steady bar bushes are sound (as John says) and the exhaust flange isn't broken or bent!

To really hack me off - the mechanic died about eight or nine years ago (he didn't reach 60) and he was still teaching me until a week or so before he died.

I always had a short flexable section between the manifold and the exhaust itself to stop it breaking. There are only so many times you can re-seal it before it gets boring.

TerryG wrote:I always had a short flexible section between the manifold and the exhaust itself to stop it breaking. There are only so many times you can re-seal it before it gets boring.

I don't really understand how anyone has this problem with mini exhaust sealing. If it's done properly (sorry chaps, but these things didn't come apart randomly when the cars were current and there's no real need for them to come apart randomly now) it'll last the life of the system unless a top stay bush is worn to the point where it's barely there or the stay has been replaced with one of those fancy ones with a big squishy bush that looks expensive but in reality only serves to make the mount under the clutch housing shear sooner and that could well cause the exhaust system to be under stress.

I didn't have a problem with it sealing so much as cracking, A flexible pipe sorted it. It may have had something to do with having a 1293 turbo rather than the 850 the car came with and me being a teenager with a very heavy right foot but I could be wrong

Gotta agree with the above - had Minis for several years, and had a couple of exhaust sealing problems, but only when the engine steady bar bushes were shot. New ones of those, perhaps a new exhaust clamp too, and all was well for many thousands of miles. I used to use a bit of copper grease, but not exhaust sealant.

with my dads mini, we put a sports exhaust on it had a free flow manifold? that cured the problem & it wasnt that much louder than normal. if i remember rightly we had to fit an inlet manifold from a metro..

rich. wrote:with my dads mini, we put a sports exhaust on it had a free flow manifold? that cured the problem & it wasnt that much louder than normal. if i remember rightly we had to fit an inlet manifold from a metro..

That's an expensive way around a sloppy engine stay but a good upgrade, only thing I'd say to the exhaust aspect of fitting Metro manifolds is that Metro front pipes have two of the same style of flange so potentially, could cause twice as much trouble!
Seriously, if the exhaust is properly clamped and the engine stay bushes in sound condition there's never a problem unless people miss the clamp by the remote extension housing on cars which have one, fail to support the pipe with a jack while the paste dries (I'm not talking about some sort of bodge there by the way, I mean the assembly paste and not the stuff for patching. In an ideal world and with a split new manifold then nothing would be needed to assist with the seal at that damned flange but aftermarket, original style manifolds are rarely right).

TerryG wrote:I didn't have a problem with it sealing so much as cracking, A flexible pipe sorted it. It may have had something to do with having a 1293 turbo rather than the 850 the car came with and me being a teenager with a very heavy right foot but I could be wrong

Oh Terry, you animal!

hope the link works.. have you tried one of these?
http://www.google.fr/imgres?imgurl=http ... Q&dur=1300

as for my dads mini we used to live up a track so i could re fit the standard exhaust daily if i wanted