How to get out a broken tap?

[76zimmer]

I have a broken tap in one of the timing chain cover bolt holes....I think its 1/4 inch. I've tried a cobalt drill bit, carbide cutter, acetylene torch, a punch, and a small pointed chisel. This is broke off about 1/4" below the surface of the block, so I don't think a welded on nut or something of the nature would work. I have used that before, but feel the 1/4" hole, and hardened tap would be a challenge for me to get to work without welding to the block too. I'm not sure how long this thing has been in there, I thought it was a broken bolt to begin with, but after cleaning the hole out, I can see the shape of a tap in there.

Any other ideas?

 

[nvrenuf]

If it's nots cross threaded then you might hunt for a tool like the one I borrowed - http://coloradok5.com/forums/showthread.php?t=257626 It's not a common toll though so it'll probably be tough to find.

 

[thorguy57]

Here are the tap extractors.
http://www1.mscdirect.com/CGI/GSDRVSM?PACACHE=000000114282592
I would heat up the metal around it, melt some wax it it and then hurry up and use one of these on there before it cools to much. Won't get much that will touch a tap. I carbide bit should have cut into it but you have to go slow and keep it cool. I would try to extractor plan first.

 

[MTBLAZER89]

Takes a while but I used a dremel with a cutting bit to get a broken EZ out..out.

These are diamond bits.
http://www.mytoolstore.com/dremel/dmdbits.html

This is the exact one I have used.
http://www.amazon.com/Dremel-9902-Tungsten-Carbide-Cutter/dp/B00004UDJK

 

[josh86k10]

I second the Dremel with cutting bit/ tiny rotary file technique. Has worked for me previously, with both taps and easy-outs.

 

[ssyork]

Walton tap extractors. They work pretty good. I used to sell them quite a bit.
The fingers are sold seperatley if you bend them up. They have proved to be pretty tough thou. Just get them in there as far as you can. http://www.waltontools.com/prod.htm

 

[76zimmer]

Thanks guys, I will take the block to my machinist tomorrow, and see what he thinks. If he can do it on the cheap, I'll let him, if not I WILL be persuing these thoughts.

 

[4X4HIGH]

Pray, and lots of it.