Exhaust stud woes, What's the next step? Options

[saigon71]

Nothing is ever easy on these cars...

My heat exhangers got some oil in them from the bad oil cooler seals, so I decided to pull them for a good cleaning. One exhaust nut was really difficult to remove. Once I finally got it off, I saw that the threads were galled.

Ordered some new exhaust studs.

Went to work removing the old one after researching 914 world.

Heated stud boss with MAP torch & sprayed a bunch of PB blaster.

Welded a nut on the end...nut kept breaking loose without budging the stud, removing small portions off the top of the stud during the six attempts.

Then welded a bar to the remainder of the stud and used an adjustable wrench for leverage. Heat & PB Blaster, working it a little at a time, back & forth. It finally broke free. Reheat & apply more PB. On about the 5th cycle, the stud broke off below the level of the head.

Engine is in the car & I'd like to keep it that way. What are my best options for getting this thing out now...and installing a new stud?

I've had horrible luck with EZ-outs on other applications.

Thanks!

[Mark Henry]

Really hard to do in car.

What you did there is sort of like what I do with the head off, but I heat and quench it several times. Tad hard to do in car.

Now you have to drill it out. Hard part in car is getting it centered and straight. You also have to be careful not too drill to far, as you can drill right into the combustion chamber.
Then I step up the drill size till I take out everything but the threads. I get the rest of the thread out with a dental pick and small chisels. Sometimes you get real lucky and that's done.

Often not so lucky, so I go with the 9mm/8mm step stud or a timesert.
You still have to get every bit of steel out first before you go oversize, so you still have do all the above steps.
If you don't get ever speck of steel out, when you drill your new hole it will drift and not be centered proper. I see this mistake often.

Also there are jigs and stud guides but they don't work every time.
https://www.google.ca/search?q=stud+drillin...mp;ved=0CDcQsAQ

If you have a bigger budget you can get it removed with a MDM machine, about $100-$120 per stud, still have to remove the head. This shows you how it's done.

https://www.youtube.com/watch?v=YbeKxFBZrF8