scular

Thanks. I was considering making a threaded plug as a last resort. I actually came up with a similar method to remove the broken stud and I have it most of the way complete, I just need to get an extra long tap.
For the records if anyone else gets in to the predicament:
I took a 3/4"x4" bolt, turned it down on my lathe to make it snugly fit into that horrible recess. I then used the lathe to drill a center hole through the bolt... this turned the bolt into a bushing/guide for the dirll bit. I simply then pressed my bushing into the block and drilled the broken off stud out. So now, I am searching MSC for a long enough tap with the proper thread. For anyone that does not have a lathe and needs help with this, send me an email, and I will be happy to send my bushing to you.
Cheers all,
SCular

Wormhole

I'm glad it's working out for you, I know what a pain it was. Keep in mind those studs go straight through on some blocks, you don't want to get any shavings in the crank.
Good luck

BoyRacer951

Is there any chance you’d sell the bushing, and tap you used? I’m in the same unfortunate situation you guys were once in.. two broken studs at the start of the threads in the block.

Nowanker

Wow that situation sucks. Scular's bushing idea is great. If he doesn't respond, a local machine shop might be able to help you.
I might add a step to the process:
After you have the bushing, use a center cutting end mill with it first, to flatten the broken stub. Even with the guide, drilling against the uneven edge might still walk the drill bit off center. Or worse, break it.
If you need to have the bushings made, maybe make 2. A small one to get started, and a bigger one to get closer to the edge.
Good luck!
For anyone else replacing the studs...
Some info from removing them on my 951 long ago:
Mine went all the way through into the crankcase, and were sealed with some deadly kind of Loctite.
SOB to remove because of that, not because they were so tight. Heating the stud releases the Loctite, and don't worry that the studs might expand and make them tighter.
By now, corrosion may be compounding the problems. Heat is your friend for either.

And from 40+ years of removing broken bolts...
If you can snap a bolt off removing it, your odds of success removing it with a relatively small EZ Out are minute. A snapped EZ Out is an even bigger can of worms.
Drilling it all the way through will help, Drilling it as big as possible will help.
If you can keep it drilled dead center (good luck!), you can take it all the way to the edge and clean the remains out with a tap after the EZ Out fails.
Heat is also your friend, if you have room to use it. No room deep inside an engine block...

T&T Racing

I agree with heating is you friend. The heat input needs to modify the chemical bonding characteristics of the red loctite.

This is the link to explain the red loctite
https://next.henkel-adhesives.com/us/en/articles/how-to-remove-red-threadlocker.html

Maybe the broken stud can be prepped for induction heating after being prepped for an extractor.

Good luck