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freeing seized studs

Posted: Sun Jun 30, 2019 7:06 pm
by ian.mcdougall
Hi all
HELP!!!!
Does anyone have a surefire way to remove seized studs from the block .I am fed up snapping studs in the block and having to drill and try to remove studs or heli-coil some studs in my block. Heat? .Hammer on end of stud?. Hammer on side of stud?. Releasing fluid?. Any ideas.
I am trying to removing exhaust studs at the moment. Its so frustrating.
Any suggestions welcome
Ian

Re: freeing seized studs

Posted: Sun Jun 30, 2019 7:35 pm
by philthehill
Block studs:-

Heat the stud and let it cool down before attempting to remove. Replace the stud(s) after heating.

Do not hit on the end of the stud as you could damage the top of the block.

Do not hit on the side of the stud as you could damage the top of the block.

The problem with the block studs is that some of the holes are not blind and they screw down into the water jacket. Clean up the threads which are 3/8"UNC with a bottom/parallel tap, coat the bottom threads of the new stud(s) threads in copper ease or use Loctite Loc & Seal.

Cylinder head exhaust studs:-

Heat the stud 5/16" UNF and let it cool down before attempting to remove.

Release fluid can be used on both of the above but if the stud is well seized release fluid may not be enough.

Re: freeing seized studs

Posted: Sun Jun 30, 2019 10:47 pm
by ian.mcdougall
Hi Phil
Cylinder head studs all done, one broke, one loose, one had been a problem in the past and someone had a step stud made and the block was bored and tapped to a larger size but not tapped straight and then stud bent so the head could be fitted, so i had to find a bolt the right thread (not tapped metric size as is the case for side valve engine), fitted it in hole and leveled with block face and then had to drill for correct size metric tap, I used head as drill guide to get it straight.
Mine is the side valve engine so tap sizes will be different and exhaust studs in block.
Did try heat on one of the exhaust studs let it cool put on release fluid but still snapped, so will put more release fluid on and leave and try later , or may leave studs in

Re: freeing seized studs

Posted: Mon Jul 01, 2019 7:19 am
by philthehill
Thank you for the update. It sounds as if you did not have the easiest of jobs.

Phil

Re: freeing seized studs

Posted: Mon Jul 01, 2019 7:49 am
by RobThomas
Not all blocks used metric for the exhaust. I have 2 here with (IIRC) 5/16 bsf which I only discovered when I removed them. At first I thought my thread gauge was wrong. Had lots of fun making new brass manifold nuts.
Same issue with some of the gearboxes using non-metric bits.

Re: freeing seized studs

Posted: Mon Jul 01, 2019 4:41 pm
by DAVIDMCCULLOUGH
I have used Plus Gas with good effect several times. Not easy to get these days, I found it on the Euro Carparts website. Also on Amazon, but they wont post it outside of mainland UK, so couldnt come to me in NI.

I also bought a stud extractor that you use with a socket, studs are beyond re use after it has bitten into them but seems to work quite well.

Good luck!

Re: freeing seized studs

Posted: Mon Jul 01, 2019 8:30 pm
by ian.mcdougall
Used stud extractor set that you use with a socket and it snapped the exhaust stud and as you say studs are ruined but have new set. Having a night off tonight back at it tomorrow, oh got the drain plugs from Moss, a bit dear, but thems the breaks. Using wurth penetrating oil for a long time found it to be a good product.
I was looking at the exhaust studs and i think they may be BSF as well .Will know when i get to them.Have to drill and tap at least one. Got new nuts at the same time as studs