extracting a broken off camshaft sprocket bolt!?!?

2.bp.blogspot.com/-zrp377V3J3k/TiSfAOCrO.../CIMG0442-748161.jpg any suggestions? The camshaft sprocket bolt broke off, my click-stop torque wrench didn't click...and broke off the head

Get some PB Blaster,Kroil, or other good penetrating oil & soak the broken piece for a few days. While doing so, get some left handed drill bits(the kind that cuts turning backwards from a regular bit) & drill out the broken piece. Just the action of drilling will sometimes remove the broken bolt.

Most machine shop supply stores should have what you'll need.

Here's some Sears Craftsman removal kits:

Craftsman 10-Piece Drill-Out, Micro Standard Drill-Out and
Screw-Out Set With Case
#009-52158

Craftsman Screw-Out 3-Piece Damaged Screw Remover
# 009-52154

Yup, good advise.

hlaf and half, atf and acetone is the best penetrant in the world.

Heat the part and pour some on, it will suck right in to it

Good luck.

A bolt, broken off in a through hole, that's threaded all the way through, I think left handed drill bits would be a waste of money

Try a regular right handed drill bit on the front to see if it will screw the bolt on out the back, if that don't work try the drill on the back side to see if you can unscrew the bolt.
If that fails, try a small punch and a hammer to try and rotate the broken bolt so it either goes on through or backs out.

If it's close enough to the surface you could use a small cutting wheel on a Dremel to cut a slot in the end and unscrew it with a screwdriver.

Bolts that break because of over tightening generally screw right out, no need for the chemical gymnastics

I agree with Steell, use a drill bit smaller then the threads (check one of the holes without a broken bolt)
Center punch just right ,start to drill until its cutting then lean on it and just drive it out the other end.
PS , PLEASE don't forget to use a vice to hold it AND tape off the cam where you chuck in it in.