Exhaust fitting trouble

[liammonty]

Hello, I'm wondering if anyone has any experience with the large bore exhaust system from the Birmingham MMC (not sure who manufactures it) with the single downpipe to mate to a Marina manifold. I've just spent hours unsuccessfully trying to fit mine- the downpipe is so poorly shaped that when it's clamped to the manifold, the end of the downpipe touches the torsion bar. If you align it so that the end is where it ought to be to attach to the middle section, it fouls the cut out through the bulkhead, and won't mate to the manifold properly due to the angle. Additionally, it seems that the middle box is likely going to foul the crossmember, and the back box barely clears the shock absorber! Basically, it will require quite a lot of modification (heat and bending) just to get it to fit, and even then I think it will be hard to prevent it knocking on the crossmember etc . Does anyone have any experience with fitting this system, or any top tips?!

[mike.perry]

I had trouble wih an LCB system. The rear section attaches to the centre section on the angle over the rear axle. With front the silencer properly aligned the back section would not fit over the axle and the only way I could make it fit was to twist the centre section around so that the front silencer was almost touching the underside of the floor. The obvious (to me) place to join the sections would be on the straight section between the silencer and the bend over the axle, then each section could be turned without affecting the other sections

[liammonty]

Hi Mike,
It sounds like I've got the same trouble as you have with those 2 sections, but I've got the additional trouble with the downpipe (as opposed to your LCB) which is actually impossible to fit at all due to it's shape...

[mike.perry]

The solution would be
A. Complain to Birmingham MMC enclosing photos
B. Cut the pipe and insert a joining section

[bmcecosse]

Send it back... [edited]

[smithskids]

I tried to fit one to my daughter's pickup and had to file open all the manifold stud holes and rebend the rear pipe, I have stayed with the minispares RC 40 system ever since, yes I know you have to cut and weld but they last 7 years and dont cost much.

[liammonty]

Thanks to all for the advice. In the end, BMMC compared the faulty downpipe to other stock, and it looked different. I was offered a complete refund or the chance to try another downpipe, which I did, and whilst not a perfect fit, it's much better than the previous one and I've managed to get the system connected with almost no knocks or rattles (some fine-tuning to the pipe positioning required). For general information, the system (twin box, inch and a half bore) is no louder than a standard system (bearing in mind this a 1030 ((ex 948)) running with a Marina manifold, not an LCB) and sounds very nice from outside the car. I guess it flows well too, as it's certainly perked the car up a bit.

[bmcecosse]

That's a good size for a 1 litre engine - it would be too small for a 1275 though which should be 1.75" internal.

[liammonty]

Yes- it certainly seems to have helped a lot, especially at the mid- high rev range (perhaps not surprising!). I was really pleased that it's not too noisy. I guess not having the LCB makes it lose a horse or two, but I can live with that as I've saved £150 not buying one.

[bmcecosse]

Not at all - the LCB is much over rated - it really only comes into it's own with a hairy camshaft - otherwise you are better with a 3 branch - but the Marina big bore cast manifold is 'ok' too for moderate power.

[liammonty]

I've got a 3 into 1 from a Vanden Plas 1100 (the same as the Mini Cooper one- I think you've got one fitted to your Minor BMC?) but I couldn't be bothered with the hassle of making it fit, so just went down the lazy route with the Marina manifold. Like you say, I don't think it makes so much difference (well, not at the revs that my wife drives the car at!).

[bmcecosse]

The VP manifold is slightly different to the Mini one - but yes - it does need some work to use on a Minor, Your big bore Marina manifold is fine for what you are doing with the car.