drill bit ?'s

[doctorgonzo]

The only reason a machine shop could not extract a broken GS head exhaust stud is because they suck, and are lazy.

The reason the 25 year old studs are difficult to drill is because the studs are "seasoned" or another term is "tempered" from thousands of "heat cycles" . Yes they are hard, but totally machinable with a standard Bridgeport milling machine (and a patient operator).

I know, I need to find a better one. It's the OLD school racing machine shop in town, but they discouraged me when I asked about it. I needed a top end rebuild anyway.

[bwringer]

Cobalt bits, start small, re-tap.


I don't think I've ever seen an extractor actually work -- they usually break off (BIG problem) or simply fail to do what they're intended to do.

[briyenkieth]

just wanted to thank all of you for the advise and help. Went with cobalt bits and tackeled it today. Just need to heli-coil and install new studs and gaskets. Again thanks!

[doctorgonzo]

Cobalt bits, start small, re-tap.


I don't think I've ever seen an extractor actually work -- they usually break off (BIG problem) or simply fail to do what they're intended to do.

Yep, extractor broke when I tried to use one, result, new head.