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MG MGA - Header and exhaust system

Hello,

If I fit an exhaust header as offered by Moss, what is involved in fitting to the exhaust system? It would appear that it would not bolt up. How much fabrication is involved?

As this is a piece by piece restoration, I need to get the exhaust system too. Is the factory style the best approach with the header?

Thanks,

JMG
John Greenlee

I just purchased one to the Moss (Maniflow) units and it collects into a 2" pipe, so the stock tailpipe won't fit. If your going to shell $$$ out for the header, then go ahead and spend another 100 or two on a 2" tailpipe and muffler.

Good Luck
j
JohnB

Hello John,

Can you explain a bit? What size is the stock system?

JMG
John Greenlee

I'm not sure off the top of my head what size the orig is. Maybe 1.5 or 1.75. If you want to use the stock tail pipe you would have to neck down the pipe after the collector causing restriction to the header design and then what would be the point of the header in the first place?

If your orig manifold is cracked you can pick one up cheap on ebay and stick with the orig tailpipe/muffler.

If you are looking to enhance performance, then do the header and tailpipe/muffler. Any muffler shop should be able to help you with the tailpipe and muffler.

For my project, I'm going to buy a Thrush Turbo muffler (about $20) and a 6' section of 2" tailpipe (about $20) and weld it up myself.

Good luck,
j
JohnB

I faced the same situation on my MKII. I eventually purchased a twin cam system as it is two inches OD. Fits great and offers a stock look
J.H. Hall

I am interested in the Maniflow header and exhaust system. I believe the standard Maniflow is the one offered by Moss. They also offer a big bore race system.

Does anyone have any experience with their products? I have a 1960 1600 I intend to use as a street and road (non raced) car. Does their header and exhaust system make for a bolt together solution?

Safety fast!

JMG
John Greenlee

John,

The system that is offered through moss is the maniflow. I received mine about 3 weeks ago and it had maniflow stickers all over it. Though I have yet to make the final installation on my mk2, I have test fit it onto the head on my bench and it fits very well. I have heard some complaints that the 2 outermost flanges need to be spread to fit. I have not had this problem. I am very impressed with the workmanship. Since I have not installed the header let alone the engine in my car I cannot yet comment on performance.

As per my earlier posts mentioning welding up the system. I belive that you can use exhaust clams and clamp the whole system together. The header itself is 4 pieces. The two outerpipes are welded together, the center pipe is clamped to these with a collecter, and then a 4th piece is clamped to the collector that has a bend in it to make a straight exit. I believe that you should be able to buy the items necessary to run the tail pipe from Pepboys or any of the other auto parts stores, save the tail pipe itself which you should be able to buy from a muffler shop and then hack into the necessary lengths.

I've emailed you a picure of the non big bore maniflow product.

j
JohnB

The Moss supplied header is expensive (a result of small production compared to MGB, I expect) but I have nothing but good things to say about it.

It fits (mirabile dictu) aside form any possible 'set' a particular header may take when it cools, which shouldn't matter anyway as it can be spread or compressed to line up and once clamped, can't go anywhere (I'm not saying they DO take a 'set' but any rumours of such would be accounted for by the things metal does when it heats and cools - not manufacturing defects).


As for the system behind it, bear in mind that if you clamp a pipe on the way it needs to be clamped in order to retain it and make it gas tight, the metal will be deformed and it will be a right bugger to disassemble. I prefer slip fits with two flat bits welded one onto each pipe with a bolt through both to hold them together, but that admittedly does not make for as tight a fit. Nice thing is that you can at least get it apart again!

You NEED a header like this if you want to get even the stock horsepower out of an MGB engien swap, as using the MGA exhaust will reduce power significantly.

A 1 7/8" system is adequate, but a 2" is probably better. More is unproductive. The nice thing about buying the rest of the Moss system (I didn't) is that you get stock tailpipe appearance.
Bill Spohn

The Moss supplied header is expensive (a result of small production compared to MGB, I expect) but I have nothing but good things to say about it.

It fits (mirabile dictu) aside from any possible 'set' a particular header may take when it cools, which shouldn't matter anyway as it can be spread or compressed to line up and once clamped, can't go anywhere (I'm not saying they DO take a 'set' but any rumours of such would be accounted for by the things metal does when it heats and cools - not manufacturing defects).


As for the system behind it, bear in mind that if you clamp a pipe on the way it needs to be clamped in order to retain it and make it gas tight, the metal will be deformed and it will be a right bugger to disassemble. I prefer slip fits with two flat bits welded one onto each pipe with a bolt through both to hold them together, but that admittedly does not make for as tight a fit. Nice thing is that you can at least get it apart again!

You NEED a header like this if you want to get even the stock horsepower out of an MGB engien swap, as using the MGA exhaust will reduce power significantly.

A 1 7/8" system is adequate, but a 2" is probably better. More is unproductive. The nice thing about buying the rest of the Moss system (I didn't) is that you get stock tailpipe appearance.
Bill Spohn

This thread was discussed between 03/03/2006 and 10/03/2006

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