Exhaust manifold nuts

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David Witham
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Exhaust manifold nuts

Post by David Witham » Tue Dec 08, 2020 4:58 pm

When taking the engine and gearbox out to change the speedo drive worm gear in the back of the overdrive, I found there was an exhaust manifold gasket leak. My car has a Tourist Trophy tubular stainless manifold and system.

I am careful not to tighten brass nuts too tight in case they strip and this may a have been a factor. The manifold nuts I bought new to fit the manifold last year were thicker than normal nuts but not as thick as I remember the brass manifold nuts being in he past. The number of threads in the nut will presumably have some bearing on the torque it will take before stripping.

Does anyone know of a good source of manifold nuts?

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Charles Farran
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Re: Exhaust manifold nuts

Post by Charles Farran » Tue Dec 08, 2020 8:08 pm

Hi David,
I have the original manifold which i removed 3 years ago to access the tappet covers. I obtained new brass nuts ref GHF261 from MGOC Spares & have had no problems with them.
Cheers,
Charles
1980 Roadster

David Witham
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Re: Exhaust manifold nuts

Post by David Witham » Wed Dec 09, 2020 10:51 am

Since my post yesterday I have found that Spalding Fasteners have just what I was looking for. Theirs are 3/4 inch thick.

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Charles Farran
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Re: Exhaust manifold nuts

Post by Charles Farran » Wed Dec 09, 2020 1:59 pm

Hi David,
I have used Spalding Fasteners quite a bit for replacement of a lot of nuts & bolts with Stainless Steel versions for the MGB where stress is not an issue.
Cheers
Charles
1980 Roadster

Vic Butler
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Re: Exhaust manifold nuts

Post by Vic Butler » Thu Dec 10, 2020 6:57 pm

I've got MGOC brass barrel nuts on the manifold to head on my BGT. They will fit the downpipe studs on the standard cast iron manifold and interestingly the manifold to downpipe studs on my 1975 Series 3 Land Rover. Being longer than the studs, they stop corrosion on the studs and I can remove the carburettors on the inlet manifold on my BGT too.
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine

ChargedAutoGT
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Re: Exhaust manifold nuts

Post by ChargedAutoGT » Tue Dec 22, 2020 10:27 pm

I too have the long MGOC brass ones. last time I put the manifold on I stripped two of them but they have been on and off a few times whilst designing supercharger. But it's a lesson learned - in future i would only reuse maybe a couple of times. When one went there was one heck of a ping that I thought the manifold flange had cracked, so was very happy when it was the nut that had failed.

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Bumpa
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Re: Exhaust manifold nuts

Post by Bumpa » Wed Dec 23, 2020 11:16 am

Slightly off topic David, but is your Tourist Trophy exhaust the one sold by Moss with flanged joints? https://www.moss-europe.co.uk/exhaust-s ... 9-075.html

If it is, how do you like it? Is it noisy? The flanged joints must be a good idea in preventing leaks.
Mike
1969 MGB GTV8 3.9 Conversion, 1977 Triumph Dolomite 1850HL, 1971 MGB roadster undergoing restoration.

David Witham
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Re: Exhaust manifold nuts

Post by David Witham » Thu Dec 31, 2020 9:13 am

It is the one sold by Moss but I have the one that comes with a matching tubular manifold.

I like the flange joints. They make taking it apart for other jobs very easy.

The system feels very strong and the modern style mountings are probably an improvement.

It was a bit noisier than I expected. However, when I removed it to take the engine and gearbox out I found I had a leak at one of the joints under the car and around 2 of the exhaust ports at the manifold to head gasket. Since putting it back together I have not had a chance to try it out properly.

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Bumpa
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Re: Exhaust manifold nuts

Post by Bumpa » Thu Dec 31, 2020 10:39 am

Thanks David. I'm rebuilding a '71 roadster at the moment (when the weather is not quite so bally cold!). One of those exhausts may go on my shopping list.
Mike
1969 MGB GTV8 3.9 Conversion, 1977 Triumph Dolomite 1850HL, 1971 MGB roadster undergoing restoration.

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