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MG MG Y Type - Exhaust Fitting

Chaps,

Sorry for the generic subject matter.
I have finally gotten around to buying a new exhaust for my YT after years of patching or ignoring the blows in my old one.
I had intended to take it somewhere to get it fitted by someone who's got a clue, but to be honest it doesn't look like it's going to be particularly tricky to fit (famous last words).

Would I need to use any sort of sealant or gunk when I am clamping the different sections together or do I just push the bits in and clamp them tight?

Similarly should I use any sort of sealant on the flange gasket, and if yes should it be special (high-temp) stuff for use on exhausts or any old (red) gasket sealant?

And is there anything else a complete novice should bear in mind?

Thanks in advance.

Cheers,
Saul.
Saul

Your biggest pain will be getting the old nits off the exhaust manifold nuts. If they dont come easy, then for safety remove the carbs and heat them with a propoane torch until the studs are nice and red. This will save you breaking them off and then having to remove the manifld and risk breaking off studs in the head. The rest of the system you can be fairly brutal with as yours is a non/std system anyway.

I would suggest gunking up the front pipe to the baffle box, and the baffle box to mid-rear (I believe NTG now cut the rear pipe into 2 for shipping) and the mid to tail section. No need to do the header pipe to manifold - the gasket will take that up.

If you are suceesful in getting the old nuts off - toss them and buy a nice new set from Moss. For the money I would also buy new studs too. Again you dont want them snapping off when you sug the system all up.

Dry run the assembly before you gunk it up to that you know which way round and approximately which angles the pipes join at to get over the back axle cleanly etc.

When using the paste - be liberal with it. You can always clean off the excess later. Put it on the pipe first, insert the pipe into the join, clamp it down then wet your fingers first and smooth the stuff that squashes out back into the joins so that you get a nice tight seal when it dries/bakes off.

Finally check which way round the baffle box goes. I think NTG put their sticker on the front end of the box. Dont worry about taking it off - it will wear off.

Paul
Paul Barrow

As an addendum to the above Saul, start at the front and build the system on the car only loosely assembling the joints to begin with. This will save you having to constantly go back and loosen them off to jiggle everything into position.

An assistant is useful too at some points in the process as unless you have a very long arm span it is difficult to keep everything together! I have just finished fitting one to a YT this evening and it was a stretch at times!!

Before I put the header pipe on I liberally smeared both sides with exhaust goo. This was so that it didnt have too much chance to harden as I messed with the rest of the system getting it aligned. When I was done and snugged the header pipe onto the manifold I wiped the excess off and made sure that the gasket was sealed all the way round too. That way if there is a small miss-alignment of the front pipe on the manifold the goo will compensate.

Paul

PS It was much easier with a 2 post lift!
Paul Barrow

Thanks Paul.
You are definitely right about the most troublsome bit being releasing the old nuts and studs where the current front pipe is connected to the manifold.
I think once I've done that I'm home and dry.

I had a quick look at it last night and to be honest I can't see that there's going to be enough space for me to get a wrench or spanner in there anyway.
Any advice? Don't tell me I need to take the steering column out...

And if by some miracle I do manage to get the three nuts off then how am I best to get the studs out of the manifold? Do I lock a couple of nuts on them and use a wrench or spanner, or do I go at them with some mole grips or something?

Cheers,
Saul.
Saul

It's probably a lot easier to cut the od exhaust pipe and remove the manifold from the engine and then replace studs and nuts on the bench. Cheers, Dave
DM Gibson

I remember "not speaking French" when I replaced the manifold / exhaustflange gasket.
I did succeed in loosening the nuts and used all the extensions on my ratchet to reach one or two nuts from under the car.
I thought it prudent not to tighten the nuts too tight because I was afraid to bend the flange.

To remove the studs, tlock two nuts and TIGHTEN first before you try to loosen the studs.

When we were dismantling a scrap Magnette engine a few weeks ago, I learned this trick to my son. He was amazed that he could loosen studs that didn't come loose just by loosening, and did release after tightening (but at 9 years old he is still easily impressed).
Willem van der Veer

You will need:
* A deep socket (5/8AF inch from memory??)
* A knuckle joint
* 2 long 8 - 10 inch socket extension bars, and
* A ratchet drive

When snugging up the header pipe tighten it until it is tight - you will feel the resistance. Do not over tighten or you will strip the threads and have to start over.

As mentioned in the first post though - removal of old studs ... take the carbs & float chambers off first and then apply direct heat from a propane torch to loosen them. Take it till the studs glow a dull red and then they should crack off nicely. Get the old studs out using a stud extacting tool on your socket wrench. If you dont have one, now is a good time to buy one. Since I bought mine it has saved me 1000s of times!

Paul
Paul Barrow

I would disagree with DM Gibson - leave the manifold well alone. If you dont, you will also need an exhaust manifold gasket, and you can sometimes create more problems if you snap a stud off in the head and their is insufficient length on it to get a stud extractor on it.

Willem - re the flange - you would either have to tighten it considerably to bend the flange (you would strip the new brass nuts first) or you have a very poor quality steel in the pipe!

PAul
Paul Barrow

I would disagree with DM Gibson - leave the manifold well alone. If you dont, you will also need an exhaust manifold gasket, and you can sometimes create more problems if you snap a stud off in the head and their is insufficient length on it to get a stud extractor on it.

Willem - re the flange - you would either have to tighten it considerably to bend the flange (you would strip the new brass nuts first) or you have a very poor quality steel in the pipe!

PAul
Paul Barrow

Saul: I tend to agree with Paul about leaving the manifold in place unless all else fails. It's best to work from under the car using all the half-inch square drive socket extensions you can muster to turn the nuts off the studs - it gets the best grip on them without risking your knuckles or the stud threads too badly.

And use NTG's brass exhaust flange nuts when you reassemble: I recently did have to remove my manifold (it had distorted slightly around no 4 exhaust port and needed machining flat) and the three nuts I last tightened 18000 miles and about 12 years ago came off beautifully. That was a good moment...
Tim Griggs

Well, I recently installed a new stainless exhaust system on a TC that should have been a two hour job-but wasn't. The flange on the new pipe was not as thick as the old one and when running-up the new brass nuts, they stripped when they got to the rusty part of the studs which the old nuts never engaged.
Scott Barrow

This thread was discussed between 20/05/2008 and 16/06/2008

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