Best way to get out broken exhaust studs?

[89325iturbo]

Broke a few studs taking my manifolds off.

[der affe]

stud extractor, if it is not flush to the head.

weld a nut to the stump and twist?

[Naplm00]

If its sticking out, i use these

http://www.amazon.com/Lisle-19250-Stuck-Bolt-Remover/dp/B000P0TZZG

[gone002]

you sould

buy these from me...

[b*saint]

The best way is to put the manifold back on. use the manifold as a bit guide and drill it out.

[quickervicar]

Are they flush or protruding?

Protruding: Lots of penetrating oil (PB Blaster/CRC/etc.) over several hours/days. Then use a torch to heat the stud a few times (letting it cool COMPLETELY) to try to break down the corrosion. Use a Vise-Grip to get a solid grip on the stud & try to work it back & forth. You could also weld a nut to the stud. Again, let it cool COMPLETELY after the heating before you try to wrench it free.

Flush/Recessed: Two methods can be used: weld or drill. If you plan to weld it, first dish a washer and place it over the stud. Tack the washer to the stud, then weld a nut to the washer. (more heat cycles, better contact with the stud) If this doesn't work, then you're going to have to drill it. I center-punched mine, then drilled them out with a very small bit, being very careful not to over-stress the bit. Once you have it drilled, step up a size. Then do it again. Then I carefully ground out the remains with a carbide bit in a Dremel. Eventually, I was left with a thin "shell" that I could punch in and collapse on itself to remove it. Chase the threads with the proper tap. Use copper-based anti-seize on the new studs.

If the welding & the drilling didn't work, you're going to have to drill it over-sized and either Heli-Coil it or use these: http://www.mcmaster.com/#threaded-inserts/=78ql5l

I had 6 of them snap off on me on my M30 head. The front "bank" of them all came out rather easily, but the back manifold (the one with the leak) all snapped off. The reason was that the PO tried to seal the leaking manifold with the orange form-a-gasket. The only thing that did was seal the threads on the studs from allowing any penetrating oil to get in & work. It was a grueling 10-day process to get it fixed and I don't wish it on anyone.

[b*saint]

You would use a torch to remove bolts from a head?