Broken head stud removal

[Hymodyne]

I started tearing down the engine I took out of our Triton and replaced with frankenfour. things went allright, until I tried to turn the engine over on my engine stand and the stand tipped over. Early model engine, I cracked the lid to the oil fill, broke two head studs right at the top of the block, and bent another. Suggestions as to how to get the two broken ends out would be appreciated.

My plan was to drill the stud remnants with drill bits, increasing in size until I get a hole large enough to put an extractor in. Then i would heat the area and try to back the stud pieces out.
I have also heard of welding a rod to the broken bit; the heat of the mig and a good weld can work.
James

[BunnyPlanet169]

Sorry to hear that!

Drilling successively larger is a good strategy. Go to McMaster Carr and buy left handed drill bits. Seriously. They drill counter-clockwise. You'll often end up removing the thing you're drilling on the end of the bit.

Personally, I don't like easy-outs. If you ever break one off in the hole you're in serious hurt because they're hardened. YMMV

Good luck!

[Al Schober]

I'll second the vote for left hand drill bits. Go to McMaster.com and buy an assortment - they'll do you well in the future. As I recall, they even have cobalt ones! Take your parts drawer that says 'EZ Outs' and empty it into the trash - re-label it 'LH Drill Bits'. IMHO, your best option for saving the existing female threads.
If that fails, look up Heli-Coil.

[MN John]

the welding technique

You can weld a nut on the broken stud if enough of it is left sticking out. Even if it is broken off close to flush, you can build up some weld on the bolt until it is long enough to slide a nut on to be welded. I have done it with mig successfully, but you would have a greater success rate with tig welding, much more control with the heat, penetration, build up. Since the material of the stud and block are compatible you could accidentally weld the two together if your not careful. Also cast iron likes a slow pre-heat and slow cool down, so you have to be cautious pouring all that weld heat into a cold block, especially with a machined surface. Welding is one of my first choices but thats only cause I would already be at the welding bench with the tig torch right on hand. The left handed bits are probably a better option if you dont do alot of welding, but dont break any bits!
Here is a video of the technique(i think i know how to add a shortcut?)

https://www.youtube.com/watch?v=J8NdQHqKxIU

If that doesnt work, youtube keith fenner put a head on your thread.
check out his other videos if you like machining, metal fabrication, he does alot of marine work.

I would consider using a dye penetrant to check for cracks near broken studs, not trying to scare you, but why not for peace of mind.
Pretty easy to use and should be available at a welding supply store (if you got to welding in the area and there was a hairline crack it would open up like the grand canyon)