25 replies to this topic

[tomtic]

Rebuilt my carb, while the carb was off we took off the cast iron manifold, changed all the gaskets and cleaned up the bracket and joint (there was signs that it had already been blowing, lots of thick black soot everywhere). Changed the fuel pump while we were at it, it's all been rebuilt and put back together and now it's blowing more than ever, just seem to have made it worse

I was wondering, are you supposed to use a sealant on the exhaust flange to manifold? If so, which sealant do you recommend, could do with nipping up to halfords and grabbing one to get this sorted.

[1984mini25]

Remove both the exhaust strap that’s bolted to the gearbox and the clamp on the manifold,
Cover both mating surfaces of the joint between the down pipe and manifold with exhaust sealant available from halfords,
then using a jack and block of wood under the down pipe, jack till the flanges are a nice tight fit and smear on some more sealant,
With the jack still under, refit the strap on the gearbox (might have to bend slightly) and the clamp onto the manifold.

That’s the way I’ve done mine and have had no probs so far

It’s also worth checking / changing the engine steadies bushes as the movement of the engine can cause the joint to leak.

[tomtic]

Ok, will try that tomorrow, I've recently changed the engine steady bushes.

Does it matter what sealant I get?

[THedooBZ]

holts gungum is good, this is available from halfords.
they also do a bandage thing which u soak in water the put on the join with some paste and it sets rock solid once warmed up.

[Dan]

I've never found the need to use sealant on the manifold, especially the cast iron one. Did you use a good quality gasket or a cheap Halfords one? Try the latest Rover steel laminated manifold gasket, it seals well. New studs and brass tube-nuts help a lot and make sure all the spacers and washers are properly in place. Do it up tight and re-tighten it after getting it up to temperature once and letting it cool.

[Bungle]

i dont think its the manifold to head leaking dan

its manifold to exhaust leaking

[Dan]

Oh where the funky standard clamp is? First thing to do is check that neither part has a chunk missing in that setup, and use a new clamp as they bend over time and stop holding properly.

[tomtic]

Yeah, exhaust to the manifold is leaking, but we didn't get it up to temperature and then re tighten it, so good thinking, cheers.

[Clubby1275GT]

oh mini exhausts are fun ent they! a speed bump ripped mine clean off from the Y-piece as the bump caught a nut on the u clamp!! so when u do urs try and arrange the u clamp bolts n nuts away from the ground!!

[tomtic]

Oh aye, heh. I've bought some gungum and a new cast steel clamp. Is the gungum the right stuff to use though? I was told at minimine that it's too coarse and I should buy some of their 'sealant'?

Hmm...

[Steve Rowe]

Oh aye, heh. I've bought some gungum and a new cast steel clamp. Is the gungum the right stuff to use though? I was told at minimine that it's too coarse and I should buy some of their 'sealant'?

Hmm...

ill do the same job mate

[tomtic]

Sealed it up with gungum, just in process of running engine and retightening. Hope it's fixed it! Can't hear or feel it blowing atm

[tomtic]

Been out for a drive in it, accelerator pedal seems to do nothing anymore, it will only drive off the choke :\ Nice cruise control though!

As I accelerate it just makes it cough and splutter and try to cut out, have to whip out the choke a little bit to get it to move. I think I've solved the exhaust blowing issue though, didn't really get that noise much.

Just now it's messed up and will only drive off the choke.

[THedooBZ]

Oh aye, heh. I've bought some gungum and a new cast steel clamp. Is the gungum the right stuff to use though? I was told at minimine that it's too coarse and I should buy some of their 'sealant'?

Hmm...

i would say that they are just trying to get your custom thats all, think about it there not going to brab about other products they dont sell.

gungum should be fine its what i always use, the only downside is that after a long time it does crack and crumble and so can eventually fall off but you would notice instantly anyway.

[Dan]

You've very likely upset the carb while messing around underneath it. Make sure there's nothing snagging the cables or linkages and give it a tune.