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!

[saigon71]

Thanks for all the advice and suggestions – I greatly appreciate it. I REALLY didn’t want to drop the engine. After giving it some thought, I decided to try to tackle it with the engine in the car. My thought being: If I get lucky, I won’t have to drop it.

I center punched the hell out of the old stud, leaving a good mark. My key concern was drilling straight and true, so I decided to make some fixtures up out of scrap steel.

Took a measurement off a heat exchanger flange so I know how long they needed to be. Made a template of the exchanger flange so I could contour the jig to fit into the tight space. Welded two pieces of flat stock together:









Scribed a center line on the jig. Using a center-to-center distance of 2.340, I centered the dial caliper and center punched the mounting hole. I don’t have a drill press, so I improvised, holding part of a combination square in place while step drilling the mount hole with a hand drill. Finished with a letter “N” bit:





I still needed to know exactly where to center punch the other side, so put a dab of plumbers putty on the jig, sprayed the broken head boss with PB Blaster (so the putty wouldn’t stick) centered the fixture and tightened it up. Ended up with a nice A cup (IMG:style_emoticons/default/biggrin.gif) impression and was able to center punch through the putty: