Hi,

Wondered if any of you chaps would know the best way (or know someone) to remove a broken rear engine stud-bolt from an engine block.

I've Recently acquired this June 1949 25 hp engine which I am building up for the hopeful day of fitting it to my car and have this very dilemma.

Please see pic below - it's been broken almost flush with the casing next to the flywheel.

Thanks in advance for any help.
Leon.

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option 1, Use a welder to weld directly to the broken stud. Either a mig or a arc welder will work. If using a arc then use the best looking rod that you have. You will be trying to create a ball of weld at the end of the stud. The ball of weld will get stronger if you tap it with a hammer as it cools. Then go with the welder again trying to increase the length and potential grip area on the ball. Eventually you will have enough to grip with vice grips and the heat of the welder will also help loosen the thread. Only move the ball/ stud a very small amount and use loads of wd40 or similar lubricant to take the pressure off the weld and move the grips in a left right gentle motion continuing to spray with wd40. the wd40 will then get to lube the tread as you wind the stud gently in and out and it will free up and come out. Use plenty as the weld may break if you put it under pressure and you will have to start welding a new ball to be able to grip it again. Dont try and wind it out in one go as it will break the ball off. Small left to right movements are best and you will be able to remove it with you hand/ pliers. This is my favourite method of the two.

option 2 Hit the centre with a pointy punch drill out with a small bit and increase the bit size until most of the stud is gone then use a stud extractor to remove the remainder of the stud or tap a new thread in the case using a tap and die set. I think its m8 x 1.25 but check first on another stud.

I've used option 1 a few times on other broken studs or sheared bolts, once you get a bit of a ball on the end you can sometimes weld a nut to it which helps a lot.

But I've always been too scared to weld near a magnesium case, I've heard a lot of scare stories about what happens when it catches fire (you can't put it out).

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Thank you for the options - All I need to do is find someone who can do it as I can't weld and in the past when using the stud extractor method I have been a bit careless and made a right mess! Don't want to ruin the overall nice engine.

A chap I was talking to mentioned about magnesium cases being prone to catching fire! But I believe, unlike the transmission I have, that this is an Aluminium case due to it's age and shininess 🙂 - I will carry out the vinegar test to make sure before carrying out the above options.

Thanks again for the help,
Leon

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Yeah, I did think that it might be an ally case but I wasn't sure what year they changed.

:thumbup:

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option 1 Point it in the middle and dril it out is the best option .
I did it several times no problem
option 2 You can make a hole in it and make a left thread in put a left screw in and turn it out
For sure i wil never weld near by a engine case not for the fire but for the cracks you get.