Exhaust woes

OK here's the story so far. At the mini50 show I ordered myself a Maniflow system comprising LCB and a sigle box side exit system. It arrived today and I started taking the old exhaust off. It's toast with plenty of little holes and a few big ones.

So I unpacked the LCB to discover (and I can't say I've seen this ANYWHERE on the internet) that if you are fitting a LCB you need a new inlet manifold. Nice of the guy's at Maniflow to tell me this and why the hell isn't it mentioned on other sites (minispares, Minisport, Huddersfield minispares to name a few)

So, more internet searching and I discover there are inlet manifolds available. Slight problem as ALL appear to have 4 bolt fixings and my carb has only 2. So how can I fix this as I am now without a car until I get sorted? Do I now need a new inlet manifold AND a new carb?

Sorry for the rant but this is annoying as I could have sorted what I needed at the show.

you can carefully cut the cast manifold in half - go in from the exhaust side so you don't cut into the inlet manifold. Fit the LCB first and then keep checking the inlet for clearance - you need about a .5 mm gap. Lots of hacking with the grinder required. You may also have to thin down the nut/washer face so it is the same thickness as the exhaust manifold face.

If you are stuck I did have one cut down somewhere in the recesses of the sheds

As a quick bodge if you need the car on the road use the front section of the old exhuast so that the new system will slide over it by about 6 inches and wrap a slit tin can around it and tighten a couple of jubilee clips on. Would do the job for a short period of time.

Never thought to ask on sunday if you had the manifold as well, just presumed you had got the full system (you might need a new gasket as well)

I understand why you're miffed. I have LCBs on two of my cars, but they came to me that way. I suppose if you are used to dismantling the engines you would know that the standard inlet & exhaust manifolds come as a unit, but it might be useful for the companies to point this out; an exhaust is something that might reasonably be attempted by someone who doesn't normally do bigger jobs like removing manifolds.

I have an inlet manifold in my shed with twin HS2s which will be interesting to experiment with sometime; there's another manifold there somewhere but I can't remember which carb it's for.

Anyway, I've just checked the car in the garage and I can assure you that the two-hole HS4 carb does fit the 4-hole inlet manifold (in this case the GMC3000 from Minisport). I know the other LCB car has a HIF 44 fitted anyway. HTH.

Oh, just had a thought. Many manifolds come with a vacuum take-off for later servo-equipped cars, so you might also need a blanking plug for that.

Thanks for the advice. My carb is a hs2 and had a weird spacer that restricted the size of the inlet. Would that have been standard on a 850 mini?

I fitted a Maniflow three branch a few weeks ago and also had to fit a new inlet manifold which are available from Maniflow themselves.

Your existing carb will fit ok with only two studs as they match two of the holes.

You will however find that when you install the manifold there will probably not be enough space to put on your original air filter as the new manifold is deeper than the original and sits nearer the bulkhead.

I contacted Maniflow about this problem and they said that this was the only inlet manifold available in the UK ( seems it is a Chinese Import and is the same sold by Mini Spares etc) and said I had two choices.

1. Cut down the existing manifold ( which they said was hard work ) and use the existing air filter or

2. Buy the new manifold and fit a pancake filter..

I chose the second option as it was an easier solution.

I bought a K&N filter (56-9128) for my HS4 carb (but there is also one available for the HS2 , but make sure it is offset) from Mini Spares which just fitted and no more but the cone shaped filter might be a better buy.

The vacumn hole on the new type manifold is plugged so does not cause a problem.

Hope this helps and please contact me if you need any further info.

Sorry Zef, I thought I said in my previous message that Maniflow told me at Castle Combe last year that I may need a new inlet manifold, but I declined because I knew I had an a-series Metro one kicking about in the shed... needed a new gasket too, and had to weld a little bit for the spring to locate properly.

The only thing was that when I went to put the bonnet back on the original air filter pan sat proud and the bonnet wouldn't fit so after a bit of jiggery and much pokery, I made the filter to fit on an angle. Added a breather filter to one of the openings on the metro manifold (this stopped the coughing and spluttering) and it worked perfectly! I reckon I gained a couple of bhp too, because I could never get up Birdlip Hill in 4th before, but now he flies up it!

Hopefully you can see what I mean about the sngle from these pics...





Jase

"I could never get up Birdlip Hill in 4th before, but now he flies up it!" Quote

I'm pleased to say Birdlip did not give me any problem in fourth gear on my way to Beaulieu and I only have the standard exhaust and no mods whatsoever! I even had to brake hard to stop at the roundabout at the top

TONYELF wrote:"I could never get up Birdlip Hill in 4th before, but now he flies up it!" Quote

I'm pleased to say Birdlip did not give me any problem in fourth gear on my way to Beaulieu and I only have the standard exhaust and no mods whatsoever! I even had to brake hard to stop at the roundabout at the top

You must have approached it from the shallow end!

discoman41 wrote: I reckon I gained a couple of bhp too, because I could never get up Birdlip Hill in 4th before, but now he flies up it!

That's what LCB manifolds do! (and why the insurers look for it as a mod). There's a Keith Calver article about it on the Minispares site; you've probably gained 15-20%. You have, in effect, a "stage 1 kit" fitted.

Well it's finally on, sounds lovely. It was a bit of a git to fit but I managed in the end.

Mr angle grinder did for the manifold and then it required a small amount of welding where a hole developed. I then heated the centre pipe of the lcb and hammered it so it would fit. Job done, or so I thought.

The test drive showed another problem as the centre pipe (again) was fouling the uj. More hammering after loosening the clamps had it fitting great. The tail pipe finishes just below the rear bumper.