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MG MGB Technical - Manifold studs

I need to remove exhaust manifold to get at side cover plates to stop them leaking oil.It's the first the manifold has been off in 23 years. Studs are badly corroded and nuts seem to be plain steel rather than brass, so I expect I'll need to replace at least some of them afterwards. Is there any reason I shouldn't make up some studs in stainless steel and use them with SS nuts & washers?
Also which is better gasket, rubber or cork?
Cheers
Vic
V Todman

Vic-
Stainless steel studs should be fine. The later rubber gaskets are less vulnerable to the heat of the exhaust manifold than the earlier cork gaskets.
Steve S.

I've found that the cork gasket fits better on the front cover, and the rubber fits better on the back one on my 74B. Just something you may want to keep in the back of your mind when you're struggling to get them to fit properly...
Steve Orton

What I found out about 15 years ago, when we tried the stanless steel studs & nuts that thay will loosen up! Well I know that you need to keep a ck. on them for a while, BUT these would not stay tight. The stainless steel is to slippery & will NOT stay tight.
Glenn Towery

Vic - I would advise against putting stainless nuts on a stainless stud. similiar materials in both stud and nut have different degrees of tendencies to gall together with stainless to stainless being the worst. I have seen stainless nuts put on stainless bolts and atempted removal in just a mater of hours, only to find that they galled so badly that it was like they had been welded together. Cheers - Dave
David DuBois

Vic. I would use carbon steel studs and either brass or carbon steel nuts. Glenn Towery is well know for the excellence of his V-8 conversions. David DuBois is well known for the high quality of his SU fuel pump rebuilds. Neither bothers to post drivel. Hence, I tend to take both of them seriously when they do post. I am very familiar with the problem of galling on stainless steel. This is normally handled by using differential heat treatments amoung the various stainless parts. For some reason, when stainless steel parts of similar hardness are required to move together, such as the frame and slide in a pistol or the stud and nut on the exhaust manifold, the parts tend to gall and seize. I can remember trying to get some of the early stainless steel pistols to function reliably. The use of some of the exotic lubricants resulted in a great improvement--they became marginally reliable rather than totally unreliable. What finally resulted in full reliability was to heat treat the parts to different levels of hardness. This resulted in parts that moved across each other without galling. Thus, it might be possible to find a "grade five" nut to fit onto a "grade eight" stud and not have any problems. But, carbon steel studs and nuts have worked well for many years and are easy to find. A little anti-seize on the studs makes future removal easy. Les
Les Bengtson

Use zinc plated steel studs and the correct brass nuts, they don't corrode quickly and will stay done up!
Chris at Octarine Services

Thanks everyone. -Stainless seemed simple, but I've not seen it used, so I wondered if there might be some metallurical reason not to. This prompts the next question. Where can I buy zinc plated studs? Do you sell them Chris?

Vic
V Todman

Yes, complete kits, see the website parts shop
Chris at Octarine Services

Thanks
I'll be in touch
Vic
V Todman

Not all studs are created =. There are several thread variances used in studs and if the wrong type is used they will come loose. There are 'interference' studs that use a slighly oversized thread that will not come loose and they are available in various types of metals. I have been using stainless studs and nuts for many years w/no problems on an engine but I do use antiseize to prevent galling. I also use teflon tape when installing the studs into the head and sometimes Loctite. Not all stainless is created = either. There's cheap stainless (409) and expensive stainless (416L) which have very different characteristics. If you know of a large industrial supplier you can browse through their catalog and find all types of neat stuff. I like MSC in the US but I don't know anyone in GB.
Mike MaGee

Vic
If the mild steel studs have not been off for 23 years, what are you worrying about, next time you need to remove them it will be the year 2026.
Wayne
Wayne Evans

True but - pride of workmanship for one thing. Another is that I won't be either as strong or as patient when I'm 81! If this BBS is still going I'll let you know if Chris's zinc plated studs do the job.

Vic
V Todman

I look forward to the order then Vic!
Chris at Octarine Services

I placed it on your website last week.
Vic
V Todman

This thread was discussed between 29/09/2003 and 05/10/2003

MG MGB Technical index

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