jeffrobb

I am back dating to SSI heat exchangers on a 1978 911SC with 1983 Euro 3.0 engine.This was a european car for a good percentage of it's life,saw salt, and so the cylinder head exhaust studs have corrosion. I broke one of them off despite heat and PB-Blaster spray.I have removed the engine ,welded a stand to mount the engine upside down , and have successfully drilled out the broken stud and replaced it. I would like to remove and replace the other studs as they are '' moth eaten'' and thin but I don't want to break any more of them. Question----Whats the best way to successfully attempt removal of these studs from the aluminum cylinder head without tearing the engine down? Or should I just put the exhaust on as gently as possible and hope for the best? I'd like to hear all suggestions no matter how far fetched . I'm really at a loss. Thanks in advance

bbh03

Snap On tool called a collet tool. It will grasp the threads of the studs to allow relatively easy removal.

Peter Zimmermann

Jeff: I've encountered your problem many times, and there is no easy answer. If you've checked for broken head studs, and you don't have any, then there is no reason to pull the heads if oil consumption, etc., are satisfactory. I have used a varity of tools for stud removal, none are the answer. The selection available from SnapOn are the best. The struggle is to get one stud out of each flange, so if the other one breaks you can make a drill guide using the good hole on that flange. If the problem proves too daunting, and you do remove the heads, I know a wonderful SoCal machine shop who will do a perfect job for you. Of course, you can always bolt on the SSIs, tighten those nuts and keep your fingers crossed that the studs don't break. I strongly advise against putting the nuts on at anything less than tight, you don't want exhaust leaks!
Pete

fixnprsh

EMD is a good option since the motor is out, you would have to take it to a hole shop the specialize in it though and it wont be cheap, the snap on stud remover might work, but will be alot of work, and then install stainless studs............

r911

C-4 ... be done with it...

jeffrobb

Thanks guys for your help. I will buy a collet tool from snap on . Then I guess I will heat the aluminum head around the vicinity of the stud and try to remove them.

g-50cab

heat around the stud. I have also dremeled a broken stud into a square pattern and put a pair of vice grips on it to get it out. Here though - heat is your friend.

DGaunt

BTDT. Then the stud breaks flush. It is a battle of wills. It is hard to heat the head as the aluminum moves the heat away so fast, which is its job after all.

Afterr that, you have Peter's course or EDM.

When installing new studs, I suggest you never-sieze them into the head, and use copper nuts on them. If the copper ever refuses to come out, it is easy to defeat without breaking the stud.

jeffrobb

Do you guys heat the head around the stud or heat the stud itself ? I was thinking of spraying the stud immediately after heating with penetrant with the possibility that some would be wicked down the aluminum/stud interface and help loosen it. Iwas told that each time you heat the stud it shrinks slightly when cooled. I thought I would try a few cycles of this. The shrinking theory doesn't make great sense though since the heating cooling cyle happens every time you run the engine and based on that all the studs should eventually fall out and leave your exhaust system on the ground.

theiceman

old mechanics trick -- heat is your friend -

heat JUST THE STUD until red, as soon as the red fades crack it loose with what ever tool you prefer. I have done this sucessfully with brake bleed niples.

A Quiet Boom

I sell a tool used to drill these studs out. It all started with a thread on Pelican Parts http://forums.pelicanparts.com/showt...8&goto=newpost

-Christian