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MG Midget and Sprite Technical - Maniflow LCB - Att: Onno

There was a thread elsewhere in which people discussed installing a Maniflow LCB, which I have done when the OEM cast iron manifold broke. However, I slipped the original '67 1275 1.5" exhaust pipe inside of the collector, waiting for the extra cash to do what I believe Onno did--use new pipe running aft to an RC40 oval box.

So, Onno (or anyone who knows), in the attached picture, did you use 1.75" exhaust pipe between the LCB and your RC40? I assume the Maniflow's collector is designed to fit inside the 1.75" pipe, which I assume is 16 ga., yielding something like a 1.625" I.D., but am not sure. Can't quite make it out in this photo due to the clamps.

Don't want to buy the wrong size pipe from the local muffler shop, which is cheap but can't be returned once they cut it.

Please confirm, and thank you.

Joel.

JM Young

Hi Joel

You could try asking Maniflow themselves, saying 'I have recently fitted a Maniflow LCB and want to connect it to a Competition Silencers RC40, what size pipe do I need please?'

They might be helpful, although they sell their own exhaust systems. Maniflow LCB and RC40 is a common combination for Midgets and 1275 cc Minis (so Mini Spares Centre and Mini Mania may be able to advise too)

Maniflow Ltd
Mitchell Road
Churchfields Ind Est
Salisbury
SP2 7PY

Tel: 01722 335378
Fax: 01722 320834
Email: maniflow@lineone.net
http://www.maniflow.co.uk/?view=page&page=47

Magic Midget may also be able to advise, as well as a place to buy your RC40 from: http://www.magicmidget.co.uk

Cheer
Mike
M Wood

Joel

Also if you look at exhaust info on Magic Midget website, the RC40 can come as a single or twin box system, i.e. Includes the pipe from the exhaust header (manifold) to the muffler (silencer) box.

Cheers
Mike
M Wood

that is an old manifold (rusted through)
I now have a std maniflow manifold with a 45mm pipe (needs a kink or 2) going over the collector to the back box (rc40)

Though next time I might try an MGB silencer as they have the same diameter pipe but are round so might be a better fit between spring and tank.
Easy to work in an MG garage so I can pull one of the shelf to test fit ;)
Onno K

I have fitted a Maniflow LCB and a RC40 single box system to my Frogeye (1275 cc) without any problems. It just fitted ok.
J.W. Vlaanderen

J.W. Vlaanderen, how did you connect the RC40 to the underside of the car. I had to have a special bracket made (by Alan Anstead) which connects to the rear overider bracket.
G Lazarus

For my rc40 I just tried different combinations of brackets and old exhaust m mounts until i had a combination that hung it in the correct place. There are plenty of available bolts / captive nuts in the boot floor to give multiple options.
Dean Smith ('73 RWA)

Not on a Frogeye Dean, there's just the one hole which holds the original bobbin. This is nowhere near where the mounting is on the RC40. Perhaps they have a Spridget specific one these days, as mine was made for a central exit on a Mini.
G Lazarus

No spridget specific rc40 available
You need to make an angled bracket to the original hole and get an late MGB rear mount.
Combine thos an you'll be able to bodge up a nice solution
Onno K

@ Lazarus, see attached picture. It squeezes just in between the rear axle and the petrol tank. see picture attached.

J.W. Vlaanderen

I fitted the twin box system to my frogeye with some creative pipework between the 2 boxes. The rear most box ran behind the petrol tank and the other in a similar position to JWVs but maybe angled up a bit more with a tightish fabricated bend between the 2. Provided fairly civilised silencing. Mounting via existing holes and bracket welded or clamped to the exhaust system as appropriate. I'm sure I've posted a pic of the system before but can't find one on the computer at the moment.
David Billington

Onno,

I have to confess that I'm a little jealous. I wish I worked in an MG shop.

I am really intrigued with finishing off an LCB 1.75" (45mm) exhaust system with the MGB silencer. I assume it's straight-through, just like the Midget's? Would you mind terribly pulling an MGB silencer and posting the external measurements?

Gentlemen,

I have long been contemplating an RC40 system and now know how to configure it if I go that route--thank you for the suggestions and photos. However, I hadn't considered Onno's MGB option. Since that silencer evidently has the same inlet and outlet size as the RC40, and may offer a tad more clearance laterally, I'm thinking it might be a neat option.

I will post pictures if Onno is able to send dimensions and it's a viable option.

Joel.
JM Young

So, after further reflection, I think the cat's meow for my mostly stock 1275 is the following system: Maniflow LCB; 1.75" (45mm) pipe straight back ($3.00 a foot at the local muffler shop); and a Magnaflow 11123 Stainless Steel (not polished) Oval Muffler ($85.00 on Amazon et al.).

As for clearance, mounting the 7x3.5" oval vertically, like this guy did http://www.mgexp.com/phorum/read.php?3,1758630, but a little closer to the boot floor pan, would yield almost identical clearance to the stock round can. The offset configuration would place the mid-pipe just as close to the floor pan as stock, and the local muffler shop will mirror the stock pipe's slight jog to clear the axle for next to nothing.

I first worried that the offset configuration required a traditional, baffled muffler, whereas I want a straight-through design. But the Magnaflow 11123 is straight through, as the attached image of the interior I found on the web reveals.

I think the only downside is that the Magnaflow *appears* to have actual size 1.75" inlet and outlet pipes, which in my case means paying the shop to also weld on the muffler and tail pipe. I really do need to get a small welder and learn how to use it one of these days...

JM Young

This thread was discussed between 14/09/2014 and 25/09/2014

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