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Broken cylinder head stud

Posted: 11:57 pm May 12 2015
by Corey
Hey Folks,
Was removing the head studs from the cylinder to send it off for plating and one of the studs broke. Luckily about 3/4" of it still exposed with half of a thread exposed above the surface of the cylinder. It broke right were the threads stop that fasten the head nut. I have two more to do but I'm leary taking those out. Any suggestions on removing the broken stud and is there a preparation I could do to the two remaining that will make removal easier? Any suggestions would be appreciated.

Re: Broken cylinder head stud

Posted: 12:26 am May 13 2015
by newbbewb
Spray the stud where it goes into the hole with penetrating oil. Soak it really good. Really good again, and let it sit for like 12 hours. Don't be shy with the penetrating oil. Weld a nut onto the broken off portion of the stud. Let it cool. Soak stud with penetrating oil again. Put jug in vice, or secure it somehow. Get a breaker bar or long ratchet with appropriate socket that fits the nut you welded on to the broken stud. Now take a torch, MAPP gas will do, and heat the portion of the jug where the stud is stuck. MAPP gas is very hot, and will make the aluminum expand, therefore helping you to get the steel stud to roll out easier. I would start with 15-20 seconds of direct torch, then try to delicately unscrew stud. Good luck

Broken cylinder head stud

Posted: 11:59 am May 13 2015
by pumpguy
+1!

IME, the best penetrating oil is a 50/50 mixture of Acetone and Type F ATF.

Let it sit long enough for the Acetone to evaporate off before using the torch.

Good luck.

Re: Broken cylinder head stud

Posted: 10:35 pm May 13 2015
by KDXohio
Pair of vice grips and penetrating oil may work too usually i find when a stud breaks above the halfway point they typically thread out easily from the base

Re: Broken cylinder head stud

Posted: 12:02 am May 14 2015
by Corey
Thanks for your input. I will be giving it a try.