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MG Midget and Sprite Technical - Maniflow exhaust with resonator

My new Maniflow exhaust with resonator arrived this morning and it's raining!!!!!

To save time grovelling about under the Frog on a damp concrete drive a bit of advice is sought.

1/ I assume the bent pipe would normally attach to the main silencer?
2/ I further assume that I will need to cut this pipe to shorten it to fit the resonator between the heel board and axle?
3/ To do this I will have to fit the exhaust with just the main box in order to work out how much to cut out of this pipe?
4/ I will need to salvage a bit of cut off pipe to join the resonator to the main box?
5/ I will need to obtain a few exhaust clamps for all the joints? (though why Maniflow couldn't supply them I don't know)
Rob



MG Moneypit

So they still finish them with a thin coat of green Hammerite? It lasts about a month, then the whole lot goes rusty very rapidly. I have welded the silencer 3 times. I even got it powder coated at one stage and still it rusted.

Anyway, to be helpful, I have the same system but without the resonator. Yes the bent pipe goes behind the straight one. It looks as if it will be difficult to fit the resonator in the rear (bent) pipe, but if in the front pipe it will reduce ground clearance. Without the resonator, there is very little clearance to get the rear box and pipe lined up correctly, but it is possible. Maniflow supplied stainless fittings, which I would recommend.

How useful is the resonator? They didn't offer it when I got my system about 8 years ago.

Les
L B Rose

A very uneven coat of Green Hammerite. I'll add some to my shopping list.
Not sure about resonator but I'm hoping it will make it quieter. I think Flip? fitted one. I was reading the archives about it.
The current exhaust is a 10 year old single box 1275 straight through that I suspect has ejected all the sound deadening material over the years. It was REALLY load when I had a cast iron manifold and when I fitted the LCB it was worse.
If it lasts 10 years it will probably outlast me!!
Rob
MG Moneypit

Bu**er, sh*t*.
After 7 or so hours trying to get the bent pipe and main box to fit I have decided I must have ordered the exhaust for a Mk3 midget instead of a Mk1 Sprite. I must have ordered it for a 1275 engine forgetting it was going into a Frogeye.
AAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGGGHHHHHHHHHHHHHHH
Rob
MG Moneypit

Thats odd Rob. I thought the underpans of all the A series engined cars would be the same. I have had some slight difficulty getting the two maniflow pipes down through the hole beside the main chassis rail, but that was easily sorted by bending the flange of the rail back a bit.

Why else would a 1275 system not fit a Frigeye?
GuyW

My Maniflow didn’t fit either - and that was the right system for the car!
John Payne

It's the 1/4 elliptical suspension that is the problem. The suspension attachment points are different on 1/4 elliptical rear suspension cars. You can see the difference by the link from the shock absorber to the axle. On a 1/2 elliptic its like a Z but on the 1/4 it is like a U. The bracket on the 1/4 elliptic axle is further away from the spring so is closer to the exhaust pipe so there is less room. The pipe that joins to the box has 2 bends in it but no matter how I rotate it I can't seem to get the position right. I either have the box touching the tank or the pipe touching the bracket, there's no in between.
Maniflow list 2 exhaust systems LS030 and LS031 for Sprites. I'm pretty sure I ordered LS031 which they describe as Sprite Mk3/4 and should have ordered LS030 which they describe as for Sprite 1/2/3. Both systems are described as the same in terms of pipe bores etc. but instead of describing LS030 is for 1/4 and LS031 is for 1/2 elliptical they just give the MKs and engine sizes.
I'm not sure 100% what I ordered, the confirmation email didn't list the order, it just said thanks and we'll be in touch when it ships.
I'm going to phone them tomorrow. Hopefully, the difference is down to a different shaped bent pipe.
Rob
MG Moneypit

I ordered a 1098 system ( 1/2 eliptic cars) for my MK1 Sprite as I have fitted a 1098 engine. It fitted straight on without any problems. But its a standard system, not a Maniflow one so there may be some other variation.
GuyW

The pipe for the 1/4 elliptical cars does have a different bend as the exhaust pipe from the silencer exits just to left of the bumperette in standard form. If the larger 1098/1275 pipe is fitted it can foul the tank/spring and will exit to the right of the bumperette. When I had one made in stainless, I got the manufacturer to bend it so it would clear the axle /spring/tank and exit to the left of the bumperette as per original
Bob Beaumont

My thought was a good local exhaust place would be able to cut and bend the exhaust and add brackets if you could get the car and exhaust to them.

Or the places that make up the exhausts for modern modified cars seen to be skilled and not expensive judging by the exhaust systems they make and fit at the prices they do, this would be an easy, different and perhaps interest change for them.
Nigel Atkins

Interesting Bob, I had never noticed that. I had to go and check. Sure enough, on my Frog + 1098 the pipe exits just to the right of the bumperette. It looks as if tank and spring clearance is ample but as its not yet been on the road that's a problem to look forward to!
GuyW

I have the medium bore Maniflow system on my 998 car. The tailpipe is to the right of the bumperette, which is correct. I have telescopic dampers, which leave even less clearance because the mounting eye on the damper is thicker, but it just about works. I also have a Panhard rod, so avoiding all this lot from clashing was quite a challenge. The rear box is much bigger than standard and it only just clears the tank. Actually when I changed to stainless pipes I could not get it to fit, so I ran the car over to Maniflow (only 10 minutes from home) and they put the car on the ramp and corrected the fit. They said it was because when they make the bend in stainless it's more springy than mild steel so tends to go straight again.

I also had problems with the LCB manifold, because it was made for a 1275 and was too tall. They cut and welded it and it has fitted perfectly ever since. I find they are a helpful company (but you have to phone, they don't read emails!).

Les
L B Rose

Had a phone call with Maniflow when i was told they only make 1 system and it fits all MKs. Well it doesn't fit my Frogeye!
So, I've been photographing the problem as they asked to see what the problem was.
Image 2 shows the pipe that feeds the silencer in it's correct orientation. As you will see it is underneath the bracket for the shock link attachment, instead of being to the right of it. On a 1/2 elliptic car that link is closer to the spring and in front of the axle so this exhaust would fit that type of Midget OK.
Image 3 shows the difference as measured from the back plate. Left mark is 1/2 elliptic, right is 1/4 elliptic, difference is 3 cm.
How they can say it will fit all Midgets and Sprites I don't know.
Rob






MG Moneypit

I spent some time modifying my old pipe to see if I could use it instead of their pipe.
One thing I noticed immediately was the pipe was straight, up to the point where an S bend joins it to the silencer box.
Image 6 shows the result. The S needs to be a bit bigger to raise the front of the silencer into a more horizontal position.
Image 7 shows a bit of a slope on the silencer.
If the S was bigger I might have gone with this but I will wait to see what Maniflow say in reply.
Also the end of the S part on my old pipe has a reduced diameter (to fit to the original box) and was not a good fit in the Maniflow box.
Rob






MG Moneypit

As I'm still waiting for a reply to my email to Maniflow (they did send an acknowledgement of receipt) I've been playing around.
I found, in my stock of items I'm sure to need eventually, a section of stainless steel exhaust pipe stretching from the S at the box almost to the LCB manifold. I believe this pipe was originally part of a Midget 1500 exhaust system.
I cut it so I could use it with the Maniflow straight section that runs from the LCB to just in front of the axle. This pipe had the same bend as the Maniflow pipe so would not fit so this didn't fit either. However, I decided to try and take the bend out.
I made tight wooden bungs for each end, filled it with sand and hammered the bungs in tightly. Then using a sleeper from the garden hammered the bejesus out of it until the bend was almost eliminated.
I fitted this modified pipe, attached the Maniflow box and half an hour later it was ready for a road test.
The exhaust note was very much quieter than the standard one, probably half the volume, and the exhaust rasp from 2.5K to 3.5K was mostly subdued.
Also, what really impressed me was the car idled so much better than it did before I put the LCB and exhaust on. When being driven there also seems to be more low down torque (the cam is a Kent 286) and a real increase in power can be felt while accelerating.
A downside to a quieter exhaust is I can now hear the noisy tappets and the whining gearbox !!!
It will be interesting to find out what Maniflow can do for me, maybe send me a straighter pipe section.
I'm still puzzled why they don't make a pipe section for 1/4 elliptic cars as my experience suggests it is impossible to have one exhaust system for all MKs of Spridgets.
Rob

MG Moneypit

I bought a stainles steel exhaust for my 78 XJ6 made by Bell.
Its was rubbish and took a very experienced mechanic a day to fit!
Had to re-bend several parts of the pipes and still the main pipe was 4cm to short so had to weld extra length to it...
How diffecult can it be to make a fitting system for a multi produced car like the midget or jaguar?


A de Best

Still waiting for Maniflow to get back to me.
Rob
MG Moneypit

Not much progress with this I'm afraid. I do realise the extraordinary circumstances we are in and I'm sure Maniflow are finding the situation exasperating as much as me.
Progress so far.

25th June. Received email saying David is out of office. He is the man in the know about these exhausts.

8th July. Sent email requesting help with this problem.

8th July. Received email. "We could make a new centre pipe but need measurements"

At last, some progress.

12th July. Send image showing dimensioned diagram.


30th July. Sent email requesting update.

Nothing so far.

12th August. Decided to phone only to go to answerphone with no option to talk to anyone. I didn't leave a message.

17th August. Phoned again asking to be phoned back about progress.

17th August. Maniflow phoned mid morning. A nice guy (probably David but not sure) said they were about to make some Midget exhausts so could probably do my pipe. I told him about the image I sent a while ago. He promised to get back to me later.

17th August. Maniflow phoned. David had found the diagram and had made up a pipe to my design.
Great I thought until....

18th August. Received email. "We've made your special pipe. It will cost £15 + vat plus carriage £10 + vat". DOH.

18th August. Sent email refusing to pay anything and pointing out the original exhaust did not fit so was not of Merchantable quality. As the new pipe was my design I offered it to them FOC for future business so they could offer it as an exhaust system for Midgets and Sprites that have quarter elliptical rear axles.

Not sure what is going to happen now. We shall see.

Rob

MG Moneypit

This thread was discussed between 19/06/2020 and 23/08/2020

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