Finally preparing to install a new turbo kit on my 86 BJ70. The upper rear exhaust manifold stud was laying on top of the manifold when I removed the heat shield. Never leaked a bit. Bad news it broke off a couple threads inside the head. I dont think easy out will be an option for an exhaust stud. I was thinking of possible drilling and tapping for a new bolt. Any help will be so appreciated.
3B broke exhaust stud help
- Thread starter dukecharmary
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Its a common issue, and commonly solved by using a helicoil (thread insert) or similar. A good skill to master and an exhaust stud is the ideal place to learn.
Check if there's enough clearance from the firewall to get a drill aligned to drill it out for the thread insert - if there isnt - you may need to pop the engine of its mounts and bring it forward a little.
Check if there's enough clearance from the firewall to get a drill aligned to drill it out for the thread insert - if there isnt - you may need to pop the engine of its mounts and bring it forward a little.
Last edited:
- Thread starter
- #3
Forgot about those, haven't used them in a few decades. So they are secure in high temp area?
- Thread starter
- #4
Any concerns of hitting a coolant passage?
No.. just mark your drill bit (with a bit of tape) by checking the depth of one of the other stud holes. And from a temp perspective there's zero issues with being used in a cylinder head.
- Thread starter
- #6
Perfect, I feel better. Certainly appreciate the assistance.
These issues always suck. Easy out generally never work. I know it;s alot of work, but, if you remove the head, you can get it on the work bench where you can accuratily deal with it. There're a few tricks. if you have a tig welder you can build uo the broken stud proud of the head and with all the heat they almost always twist right out. or you can precisionally center punch the stud and begin step drilling one size after the other until you just reach the threads, then the out male threads can be peeled out. If you have access to a milling machine, then a left-handed drill may twist it right out.
These three princples have been employed by machinist for ever and are very successful. I would not helicoil a head. Very worst case scenerio if(AND ONLY IF) the attempt to remove went sideways and you buggered up the hole, then you could drill and tap to the very next size up (either imperial or metric).
Side benfit of removing the head is you'll get a opportunity to inspect it. Do to high egt's and overfueling from pump tamperings have the consequence of cracked precups. This inspection wil allow you to verify it's proper or if not, repair prior to your turbocharger. Which will certainly give you peace of mind and allow for the upgraded horsepower and performance.
Thanks again for perchasing our Turbo kit. Feel free to contact me if you have any other questions.
Keith 530-227-3745pst
These three princples have been employed by machinist for ever and are very successful. I would not helicoil a head. Very worst case scenerio if(AND ONLY IF) the attempt to remove went sideways and you buggered up the hole, then you could drill and tap to the very next size up (either imperial or metric).
Side benfit of removing the head is you'll get a opportunity to inspect it. Do to high egt's and overfueling from pump tamperings have the consequence of cracked precups. This inspection wil allow you to verify it's proper or if not, repair prior to your turbocharger. Which will certainly give you peace of mind and allow for the upgraded horsepower and performance.
Thanks again for perchasing our Turbo kit. Feel free to contact me if you have any other questions.
Keith 530-227-3745pst
- Thread starter
- #8
Great advice, surely appreciated. Just too tight for any accurate drilling, I was able to protect the threads with a tiny piece of copper tubing and mig it very carefully until I got it proud. Then welded old nut on. Came out slick as a whistle and with a celebration.
Thanks again Keith for great assistance
Thanks again Keith for great assistance
Hey, that's a great solution. Been doing this for decades and you just taught me another new trick!!!!!!
Keep me posted on the progress and give me a shout once it's running and we'll dail up the tune.
Excellent work
Keep me posted on the progress and give me a shout once it's running and we'll dail up the tune.
Excellent work
