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MG Midget and Sprite Technical - Exhaust: RC40, Maniflow or MGB ?


No "duck note" from the exhaust this time, but something more metallic... I can put my fingers through the (cold) exhaust (resonator or silencer? The one under the number plate) so I think it is time for a new one :)

I do have a no-name LCB, and then a 1 1/2 exhaust pipe (in good condition!) going through resonator and silencer (or opposite...).

Not too sure what I want to install... My car is fairly standard mk3 1275cc, with the intention to make it "fast road" day :) If it can be not restrictive for the flow of gas and of good quality, I will be sold :) I am not really after "dbA", as I am listening to the tappets and the wind anyway :P

Reading a bit in the archive, I saw often maniflow, RC40 and even the MGB being mentionned.... Would you maintain this in 2021? :) Should I update to 1 5/8 if I update for a nice LCB "in the future"?

CH Hamon

The std MGB silencer post was probably mine, we use these on quite a few 1275 midgets, simple installation and right sound. We fit them on cars with LCB manifold, slip a 1-3/4 pipe over the LCB outlet and fits directly into the silencer.
Not the only solution of course, but does work well.
Paul Walbran

If the engine is standard then changing the exhaust to improve flow will add a bit to performance, although to achieve best results its a good idea to tune it on a rolling road.
Maniflow offer a range of systems and are helpful on the phone. Personally I would fit a complete new system as second hand components unless you know their history, can fail adding frustration!
Bob Beaumont

I second Bob's comment about a Maniflow system improving the flow but that's just my subjective view and not based on any actual data such as rolling road figures.

If you go for a 'straight' system to replace your transverse system be prepared to spend some very frustrating hours trying to line things up so that the silencer stays clear of the tank and rear suspension!
C Mee

When my exhaust decided to play tunes one day on the M40's surface dressing I took the car to john Ashley Exhausts to have one of his systems grafted onto the Ashley manifold I put on the car a few years ago.

Having the fully 'designed for each other' system seems to help the engine tickover more easily, sound very nice on the road and seems to still be good for the power Peter Burgess released from the carburettor.

I advise following Bob's advice.

A joined up solution works for me.
Bill sdgpM

Just one little comment: your 'no-name LCB' might be a really good one, not for the scrapheap.
Nick and Cherry Scoop

My first Maniflow, bought around 23 years ago, was unbranded. The replacement for that one when it eventually gave out, had a Maniflow stamped plate spot-welded to it.

A vote for the Manifow LCB and RC40 - Kim at Magic Midget is a good person to deal with.
The bass note is IMO just right, not too loud but with enough depth, especially at start up, tick over and about 3,000 rpm. Enjoy it every time!
Jeremy MkIII

Thanks for your feedbacks :)

I have to admit that a full system is making its way inside my brain, despite the price: let's get it right first time, instead of making a puzzle that might gives fitting issues...

- Regarding diameters, should I move from 1 1/2 to 1 5/8 ? What are you running on your (fast) road cars ?

- For replacing the "transverse" system by the "straight" one and having fitting issue, that's one of my worry...I don't want to keep the car of the road too much (pretty busy with the flat at the moment :p). Do they all give issue ? I read mix feedbacks on the archives...

- What are the pros and cons on "straight" vs "transverse" ? I see a lot of Spridget on "straight"... Surprisingly to me, it looks like Maniflow offers the two options :

Thanks :)
CH Hamon

Another vote for the straight Maniflow exhaust along with their LCB manifold. As I may be one of the less mechanically minded on here I found it very surprisingly straightforward to fit, I did have a bit of tweaking to sort the positioning, but was well worthwhile.

I noticed an improvement in performance straight away and would guess it added an extra 5% to 10% power, a full system is not cheap but good value.
Tim Lynam

I have a fast road engine but use the 1.5" pipe as it feeds into a custom made rear silencer to retain the Frogeye look. Given your engine is standard I would have thought the 1.5" is fine. The LCB Maniflow supplied is their LMO31 11 but runs into a 1.5" collector. I would suggest you discuss it with Maniflow.

I also had the manifold ceramic coated to improve cooling and stop corrosion.
Bob Beaumont


I have a Maniflow system but have gone for the 'across the back' silencer however I don't have the additional resonator box along side the springs.

Maniflow offer this option - it has a heavy duty single box and is not noisy - just a nice sound.

I'm not a great fan of the exhaust between the springs/tank as there is little room to spare, although I used to have thay arrangement on my earlier cars 'in the day'

Check diameters with Maniflow as if your existing is in good condtion it would save a lot of bother not fitting a new manifold - especially for a chap with a house to restore and very big job's list!! !!

Pic of mine when it was first fitted many years ago.

richard b

Neat solution Richard, just having the single rear silencer.
Image shows straight, single silencer. Wasn't too bad to fit and adjustment was helped by the pipe being in two pieces.

Jeremy MkIII

I had to replace the silencer box on my Mk2 Sprite and found the RC40 the cheapest and as it turned out, the best option. A previous owner cobbled together a system which ended in a silencer box from a Reliant Scimitar. It took me a while to identify it and almost bought a replacement but they only had a box in stainless steel and it was 90+vat. I hunted around and bought an RC40 in mild steel meant for a Mini and it fitted perfectly after fabricating a rear bracket from my parts bin. Think I bought it from Minispares or Minisport, I can't remember which, anyway it cost just over 45 including post. It looks just like the one shown in Jeremy's post.
I had difficulty getting a mild steel one. They seem to be going to SS exclusively.
MG Moneypit

Apart from possibly the reported slightly different resonance from SS I cannot see why anyone WOULD NOT want a SS system. The one I fitted to my 1275 has been on it since 1996, over 100k miles. The only part which gave out was the Maniflow manifold which was in mild steel. That lasted about 18 years, so that was good value.

I do seem to remember replacing standard OEM mild steel exhaust systems on standard British cars every 2 or 3 years at one time!

Having had a couple or more s/s exhaust systems I do know they have 'cons' as well as 'pros'.

The sound is different, much more sibilant (if that's the correct word), not as nice sounding as standard to my ears.

S/S seems to expand and contract more as I've found I've had to nip up U-bolts (I gave up on the clamps) a few times.

They don't seem to soot up as much as mild steel, again perhaps because of the expansion and contraction so slight blows at the joints don't seem to soot themselves up.

Biggest problem is that after a good number of years the baffles in the s/s silencers seem to 'go' a bit making them noisy, they still work by not as silently, I've had this and I've heard others.

Then of course as with mild steel exhausts some are made better and with better materials than others. If I was having a s/s system now I would go to one of the places that does modding of more modern cars that custom make and fit exhaust systems, if they have pipes small enough, as the quality of materials and work is often high at very reasonable prices and it'll be a tailor fit.

I once got an offcut of stainless steel from one of those places (for free) and the weight and thickness really showed up my MG supplier system.
Nigel Atkins

Thanks all for your comments and feedback, as always :) Did help me to make up my mind :) On order at Kim @ Madgic Midget :)

Kim said that my LCB might be a "Peco" one. The exit is 42mm, so I will mount a 1 5/8 on it instead of the current 1 1/2 set-up. Do you put exhaust paste on each "connection"? Can heat of a blowtorch help to dissasemble old rusty connections? :P

Richard, it looks nice! And the green match and suits your car perfectly :) But not sure on my "mustard"... Thanks for the pic, I didn't really realised that before :)

Nigel, did I do something wrong? I was expecting your feedback much earlier... I remember you telling me a lot about exhaust choices when I saw your car, but sadly I couldn't remember the conclusion as I was still a young Midget owner at that time :)

CH Hamon

Good decision Cedric,
To answer your questions - yes use exhaust paste in the joints and yes a blow torch will help loosed rusted nuts/bolts. Be careful if you're using it anywhere near your petrol tank though.
Jeremy MkIII

no nothing wrong, I just can't remember exhaust sizes and what fits over or under what. I can't remember discussing exhaust only the urgent need for you to sort the tyres so you were not having to go below 50 mph on the A14 and still be wavering all over the lane, not so much ditchfinders as wanders

You definitely done right by going to Kim.

Personally I would angle the U-bolt so that the nuts are accessible from the side of the car by lying on hard ground and reaching under a dirty car on dirty ground with a 13mm ring spanner or socket should they need nipping up in the future. Also it takes the sticking out part of the fixing away from the bottom of the car and from hanging down to catch on raised parts in our roads.

Your u-bolt is already at a Jean-Luc angle, even I can see that with my wonky eyes.

You should put exhaust paste on the connections which need to be clean, but if the connections are a tight fit most of the paste can be pushed out and you then rely on soot build up, based on your carbs previously you should have no worries there. 😄

No, you do not need heat, are you just saying this to get me going, wire brush clean u-bolt threads, nuts and pipes, then apply PlusGas in the procedure often mentioned.

I took me a long time to discover I needed two different sizes of u-bolts to get a good fit, IIRC 41mm and 42mm (think I tried 43mm too), I can't remember which and where but definitely by 1mm and it made all the difference. Of course your system may be different to mine especially as mine has a custom made centre pipe.
Nigel Atkins

I have used one of these stainless steel, heavy-duty Norma clamps. They are lower-profile than traditional U-bolts (and less likely to catch on speed humps) and I like to think they exert a more even pressure on the pipe, so are less likely to cause distortion and problems next time you come to disassemble.

See for example


Jonathan Severn

Much rubbish is spouted about the power release potential of exhausts. As long as you are not restricting the engine, then pretty much anything will suffice. I too have a straight flow Maniflow system fitted to the 2.0. It's fine enough, but the finish isn't great. The paint on the silencer is very thin, as is the steel used. I echo Guy's comment about using SS. Had one on the mk3 - no issues at all.

I tried those sort of hose clamps on my exhaust but they were just off the correct size 40-43mm or 43-47mm, neither would tighten well and remain tight on my s/s exhaust, but even the u-bolts need nipping up now and again.

I favour the Norma as they have the folds through the slots rather than the welds of the Mikalor which I was told can break but a mate has the Mikalor on his exhaust and they've been fine.

If you get lower front road springs fitted than you asked for then even those bands might not be low enough profile, see the second photo of a gouged Mikalor (43-47mm) clamp previously on the front end of the exhaust on my car.

Nigel Atkins

I understood Cedric to mean using heat to separate the two pipes, rather than the clamps.

One thing to bear in mind when using standard exhaust clamps, is not to over tighten them, as that can result in distorting the pipes, making than very difficult to separate.
Dave O'Neill 2

49 years old birthday gift :)

That will make the 50 next year challenging :P

CH Hamon

' And the green match and suits your car perfectly :) But not sure on my "mustard".'

Green on a Mustard car - what next !!!
Risk being 'black balled at the club' LOL

Hope the fitting goes well and not too many new tools required !

richard b

49! I never realised you were that age Cedic! You look good for that age.

BTW I also meant use GT85 or PlusGas on the pipes too, then elbow-grease and strongarm.

Can't you use black exhaust paint and risk being white-balled out of the club.

I'm at a loss how that L-bracket on the big ring-clamp fixes to hold the silencer.
Nigel Atkins

Richard, I suspect the last fixation holding the tail pipe will need to be cut as the nut is turning. An angle grinder would make it an easy job :) But if only I could find a need for it for the flat refurbishment first, then it could be paid by the joint account :D

Nigel, I am even older than that: I still have in my mind that a Jag saloon would be a nice car to travel in, adding two more people than the Midget can carry, if the need shows up one day :P
CH Hamon

I can't think of starting a flat refurb without one !

The diamond blades from Lidl's when they have them in stock are really great and last as well as the expensive ones I find.
richard b

a Jag saloon can be a nice car to travel in particularly if it belongs to someone else and they're paying for the petrol and its upkeep and having the troubles from a British car, particularly very old ones.

The "classic" Jag saloons often don't have a lot of leg or headroom, my head would touch the roof lining.

I think you need not only decades on to your age to suit one but also to get the experience and wealth to keep one going.

Many years back I used to be in the local Jag club as they meet at a good pub and the local chairman wasn't the usual type of Jag owner and had driving events, when asked what Jaguar I owned my reply always was "None, I'm not old enough" and that remains so.

My wife used to drive the four us back from far flung pubs in the 1990s Jag saloon my mate owned before he got probably the first XK V8 4.2 drop-top (not XK8) in the county, nasty rear seats in that. Another mate had a slightly earlier Daimler (Jag) with the earlier engine and floorplan that was nicer than my mate's Jag saloon. I didn't like driving either they were far to big and long - and automatics.
Nigel Atkins

This thread was discussed between 28/07/2021 and 11/08/2021

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