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Engine stud removal

Posted: Sat Sep 10, 2011 10:44 pm
by oliver-morrisminor
With the fitment of the extractors and twin carbies the manifold studs
on the sidevalve are not quite long enough and there is not much room
for a spanner anyway.

So I was wanting to remove them and use socket head bolts to screw into
the stud holes left in the engine block.

THE ENGINE HAS NOT BEEN REMOVED. (YET)

How ever they have not been playing the game. I have used:
WD40 ( libberal doses )
Penetrine ( libberal doses & additional over almost a week )
Cold freezing spray I have.
Double nut removal and shocking ( hammer hit ) the stud with the nuts on.
( the tread is metric fine and I can't seem to get the nus locked tight enough without fear of stripping the thread)

Nothing!

The only other thing I can think of is appling heat?

Has anybody got any ideas?

Re: Engine stud removal

Posted: Sat Sep 10, 2011 11:21 pm
by mike.perry
I think that whatever you do you are going to snap the studs. The block is harder and the studs have probably been there for 60 years.
Have you got the long hexagonal manifold nuts? You should be able to tighten the manifold with a 1/4 Whit. ring spanner.
My engine builder replaced the manifold studs with larger diameter studs, guess he must have drilled the old ones out and retapped the block.

Re: Engine stud removal

Posted: Sun Sep 11, 2011 7:30 am
by kennatt
(The only other thing I can think of is appling heat?) thats the first thing I would have tried,why are you hesitant about it :-?

Re: Engine stud removal

Posted: Sun Sep 11, 2011 9:46 am
by ian.mcdougall
If you dont want to reuse the studs then use a stud extracting tool, they normally come in sets and slip over the stud, but can damage the thread, use with heat and hope, if at first it doesnt move leave and come back to it later. thats what I did with my spare engine. good luck


stud extractors like these, I dont know where you would get them from where you live but I would think a car tool shop would have these [frame]Image[/frame]

Re: Engine stud removal

Posted: Sun Sep 11, 2011 9:47 am
by TvdWerf
To use heating, is not a problem, but think about one rule:
When you have heated nut and bolt, and you use a cold spanner on the nut, the nut is crimping, so this gives more problems.
Inside thread should never be warmer as the outside thread, when you will take this out.
25 degrees difference could give problems, also when you use a new bolt and nut.

When you heat a bolt and nut, you have you heat primary the bolt, so the nut or outside thread, is being warmed by the bolt.
On that moment the bolt is a little bit crimping, and it gives a big force on the rust between inside and outside thread.
Because rust is a little bit an isolator, this will help to give a bigger temperature difference between outside and inside thread.

This temperature difference will help you to remove the studs.
Cool down the outside first with WD40, or the cold freezing spray.
Think about fire with WD40, and use a good fitting spanner.

Re: Engine stud removal

Posted: Mon Sep 26, 2011 11:29 pm
by bmcecosse
I would use LOTS of HEAT - get the studs red hot - then let them cool before trying to remove, obviously.......

Re: Engine stud removal

Posted: Fri Oct 14, 2011 10:05 am
by oliver-morrisminor
Sorry to be so long in replying, but I ended up getting a profesional to remove them.

At first he used all the tricks but to no avail.

He actually removed one but it was very rusty.

And the other three broke on trying.

So they where drilled out and rethreaded, which for your information is an 8mm Metric fine thread.

Re: Engine stud removal

Posted: Tue Oct 18, 2011 1:45 pm
by rayofleamington
drilling out & retapping broken atuds can be a problematic experience (expensive?)

Since working out how to do extraction of broken studs using a MIG welder in the process, I've always had success. The thermal shock usually cracks them 'free' before torque is applied. I've only had a few that needed significant torque after the end of the stud was welded (to the middle of an oversize nut). For the tight ones, sometimes the nut will come unstuck, but that does at least give you access to repeat the process - trying to get a more solid weld to the nut on second attempt of course)