drill bit is out!

[Jim Comet]

Does anyone know of a EDM bolt removal service in Minnesota. All my other attempts have failed. Thanks, Jim

So I decide to do some of the oil mods on my std. bore really nice mirror 105 block tonight. Ive done a few before with no problem. This time I change things up and lube my drill bit with Deep Creep and when I am about 10 inches into the from oil passage that goes from the filter mount to the center oil passages. I've never used Deep Creep before to lube a drill bit but it was close by so I gave it a spray and boy did it bite hard and snap. 5 inches down the passage is 5-6 inches of wedged drill bit. I think the block may be junk. I used a grade 8 bolt and make a fork on the end tapped it in and tried to reverse the rotation. No luck. Any miracle help out there? It is a blind hole so I cannot tap it back out. Jim

[chris401]

Can you drop a dozen or so ball bearings down the top side of the hole and use them as a wedge? Same principal as grease to pop out a pilot bearing.

[jayb]

Jim, that is a tough problem.  Can you look into the main bearing hole of #1 and see the drill bit?  Any chance you can get a pick or something in there to pry on it?

[Jim Comet]

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.

[blykins]

Make sure you blow lots of air down the hole to remove all chips.  Some penetrating oil will also reduce friction to help twist it.  I think you're on the right track, just twist it  back and forth. 

[BattlestarGalactic]

Maybe a little quick heat on the block right where it is stuck might help open the passage a bit and loosen the grip it has?  Too much heat it will soak into the bit and expand it also.

[babybolt]

Reverse rotation drill bit.

Heat up a long thin rod to cherry red and carefully insert it into hole and heat the end of broken bit.  Maybe you can anneal it enough to get a bite into it, or repeated heating might loosen the bit.

[RJP]

Have it EDM-ed out. Not cheap but it may save your block and all the headaches associated with DYI methods.

[turbohunter]

EDM'ed?

[cjshaker]

Reverse rotation drill bit.

That's what I was going to suggest. If it's bit into the metal, you just need to get it un-bit (for lack of a legitimate word), then you should be able to get it backed out....with a lot of patience. I'd think just lightly nibbling at it with a reverse drill bit should eventually get it backed off enough.

[Jim Comet]

The hard part about a reverse rotation drill bit is it has to be 8 inches long to reach it by the time you chuck it in the drill. I will see if there is anything available.

[turbohunter]

Be a bitch to get any bit to bite on a hardened broken bit. Would think you'd have to create a level area first. Would take a hell of a lot of nips.

[fekbmax]

Knock a piece of solid rod about 1" long in behind the bit the same size as the bit y9u used to drill. Start with a long 1/4" bit and drill through the solid rod and on into the bit. The slug of solid rod will help keep your bit centered and supported so you can drill into the broken bit.
Now you can drill the slug out and try a 1/4" easy out or if it's going well just drill on through with the 1/4" bit, then step up to a 5/16" then a 3/8"  and finally a 7/16". This may not be necessary if you get a good 1/4" hole started in the bit and can get a good bite with an easy out.
I have used this technique several times before for retrieving broken bolts and bits down inside a passage.
Just my 2 cents..

[cjshaker]

Be a bitch to get any bit to bite on a hardened broken bit. Would think you'd have to create a level area first. Would take a hell of a lot of nips.

That's where the patience comes in. I've done it a few times in aluminum, where you have to be real careful so you don't get to drilling off into the aluminum. But all you're trying to do is just wiggle it backwards enough to loosen the bite, then you can use several things to try and get it out of the hole. But I agree with Jim, finding a reverse bit that long would be difficult. I have a local machine shop ran by a friend that can usually help me out with oddball requests. Worse case, I've welded drill bits to longer shafts before, but you have to make sure they're fairly straight.

[turbohunter]

Yeah a bitch all the way around. I think Keith's idea of giving the rescue bit a pilot to support it is brilliant. Being 5 inches in just sucks.
Hope you get it Jim, good luck.

[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!

[wowens]

WOOHOO ! Great outcome, congratulations.

[gdaddy01]

glad you got it out , I lot know that is a big relief . thanks for sharing , a lot to be learn from your post .   

[chris401]

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

Glad it worked out.