drill bit is out!

[chris401]

I don't think the ball bearing trick will work because there is a 90 degree turn they would have to go around. Unfortunately when the bit broke it was because it bit in too aggressively so I am thinking it either needs to be rotated in revers which I have been unsuccessfull in doing, or driven out. I will try to reverse rotate it some more to get it loose but I am not confident that will work. If it means the block is junk anyway, I may try drilling a hole just above the drill bit tip and try and drive it out. I would then tap the new hole for a pipe plug. I would then have to re drill the passage carefully past where the pipe plug intrudes.

It may not. I don't have a block out in front of me but what I had in mind was once the front galley fills and you see the top of a ball bearing you could tap a large Philips screw driver in the valley side galley and jar the bit loose.

[Heo]

I don't know if you have them in USA but here we have...
whatever the name but the pieces you change on the gaswelder
we have (AGA) those that are made of thin copper tubing that
you cold bend and shape when you weld hard to reach places
 they are straight from the factory
about 6 inches long if you could get one of those in to the hole
and anneal the drill bit

[RJP]

EDM'ed?  EDM...Electron Discharge Machining

[Heo]

And for the lefthand twisted drill that long. You can regrind a Concrete drill
with carbidetip to cut the other direction the spiral will still be the wrong way
but thats just to transport out the chips. But lets hope the whole drill will came out

[Jim Comet]

Thanks all, I will give it the gentleman's try tonight or tomorrow. If I had a stick welder I wonder if I could slide a piece of copper tubing down the hole and insert a couple of welding rods and hit the welding power just enough to get the welding rods to stick to the broken drill bit. then I could use my slide hammer to hopefully bump it out. Any thoughts?

[Heo]

There is carbonrods for stick welders  that you could melt
the drill with the arc but big risk the arc go from the stick
to the block. There is equipment for spotwelders and mig
welders to weld nail for dentpullers but i think 5 inch is
to deep but I'm not sure

[turbohunter]

I just looked up Electron Discgarge Machining.
You guys are to smart.
https://en.m.wikipedia.org/wiki/Electrical_discharge_machining

[Heo]

EDM is not exatcly DIY friendly

[babybolt]

You might try putting the remaining broken drill bit back in the hole and using an impact hammer set in reverse. 

[cammerfe]

I, too, suggest you look into EDM. May depend on where you're located. Here in Detroit, things like that are available.

KS

[babybolt]

I've had a shop EDM a bunch of carburetors with broken off idle screws, etc.  It does work well, even leaves the original threads in good condtion.  But finding a shop with a tank big enough to hold a block sitting a about 30 degree angle will be tough.

[RJP]

It was not a problem for the shop that EDMed a broken bolt below the surface in a 460 block. My cost was $100.00 mainly because they had to break down the fixture that the machine was set up for production runs. If the machine was not set up the cost would have been considerably less.

[Jim Comet]

Well my copper tube and stick welder deal didn't work. I could get the rod to stick to the drill bit but it was not strong enough. when stroked the slide hammer, it broke away each time. I just couldn't get a decent puddle built down the blind hole. Does anyone know of a shop in the twin cities metro area that does EDM bolt removal. Not much came up on google. I would prefer to not drill into the oil passage below the tip to drive it backwards if I didn't have to. If I did that I would then end up putting a pipe plug in and drilling through it to get the passage size back to what I want. Thanks, Jim

[Jim Comet]

Well I drilled a hole just above the drill bit tip and was able to drive the drill bit out by inserting ball bearings (thank you Chris for the idea) and prying them down toward the drill bit. Now I just have an extra oil galley plug. Thanks for all your suggestions. Jim

[machoneman]

That's a pretty good trick. Congrats!