broken valve cover bolt

[audiomick]

55 minutes ago, Pressureangle said:

Looks like you might still have a bit sticking above the gasket surface. 

Do you think so? I'm doubtful. I think we need a photo with the cover off. 

[docc]

1 minute ago, audiomick said:

Do you think so? I'm doubtful. I think we need a photo with the cover off. 

Yes, indeed . . .

[gstallons]

I have these punches ($napOn) that fit in the bore of the hole to locate the center and a punch tip to hit in the center of what you want to drill. They locate the center and drill away , left handed naturally and it will snag the broken bolt and spin it out.

[mikev]

it happened during tightening the bolt

[audiomick]

11 minutes ago, mikev said:

it happened during tightening the bolt

So you've got an even chance of getting it out if there is enough stub sticking out to get a good grip on. 

If there's not enough sticking out, something like this might work (not a specific reccomendation. It's just the first hit of that sort of tool in English that I found...)

https://www.totaltools.com.au/6816-sutton-no-1-no-6-screw-extractor-set-easy-out-6pc-m603s15a?srsltid=AfmBOoqSWrh6TBcPMQ6vByl5TZUMmxOQ-fljbiVTOx3-DmxGtBl0fJk-

[gstallons]

You are almost there. I went out to look for the SnapOn bag they are in and found pin punches and everything else instead. I was gonna post the part # but can't find it. Any GOOD tool store can hook you up with these. They go into the bore of the hole and you can center the punch prick.

 That is why you will use the L.H. drill bit. It will snag the broken part and spin it out. Remember this when you do this for someone else. You can get paid for your skills. Remember , the family stays in the waiting room while you are operating. No need to bother them with how difficult it was/wasn't to do.

Edited September 14 by gstallons
more info

[Speedfrog]

3 hours ago, gstallons said:

I have these punches ($napOn) that fit in the bore of the hole to locate the center and a punch tip to hit in the center of what you want to drill.

Transfer punches ==> HFT

 

[gstallons]

These are the bees knees . As long as you can find them ! Every workshop needs them along with roll pin punches. Which is what I thought was in that particular drawer !

[FreyZI]

@mikev I'd be inclined to try the extraction.  My motto is give it a shot and be willing to call in the experts if I screw it up beyond my abilities.  Fortunately, I've never had to call in the experts, and so have become (if not adept) capable at many endeavors.  Also, I'm cheap.  Also, the beer will taste much better as you look upon your success.

I recently sheared the small kickstand bolt that goes into the sump.  A little scary, but took it slow and got it out.  Agree with advice previously given in this thread (extractor), but FWIW, I got my sheared bolt out by drilling several small holes along the diameter of the shank to make a slot, then a flat-head screwdriver did the trick.

Good luck!