| Author |
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Crashcourse411
| | Posted on Thursday, July 28, 2011 - 09:53 pm: | 
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dremel brand makes diamond bits that work well, better than the burr style. Just cut right along the flutes. Then go up one size on the stud with the extra long heli coil, not the short ones, that the hardware store has, they usually have 3mm-5mm more threads.
Also lots of MagicTap, keep that trap from wobbling out the hole. Stud should go in snug, and not have any end play.
EDM is the other option, but that means taking off the head. Some machine shops can do this.
I'd be curious if Harley used, a roll tap to form the threads, the are much stronger in aluminum heads. |
Reepicheep
| | Posted on Thursday, July 28, 2011 - 10:18 pm: |
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The dremel diamond bits wouldn't do much more than make divots before they were toast. The tungsten carbide was what I needed to get through. |
Aesquire
| | Posted on Thursday, July 28, 2011 - 10:23 pm: |
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The timesert looks good, I've done a lot of helicoils, ( Nortons...brit butter aluminum ) and the Timesert looks better for drain plugs and other fluid tight applications.
yes, get the long helicoil. All the advice above that sounds good, is. ( shmart bunch of guys here )
Manual tapping is an arcane art. Modern machines torque limit the taps, or they'd shatter all the time. Taps are Very hard & brittle material. ( as you know all too well )
Depending on tap and material, I use maximum zen, gentle power, reverse often to break the chips, focus on straight. |
Reepicheep
| | Posted on Friday, July 29, 2011 - 08:08 am: |
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+1 Aesquire. The slower I go trying to tap a hole, the faster the job ends up finishing. Anything other than absurdly slow and I end up with a 4 to 8 hour detour of tap-ectomy headaches. |
Etennuly
| | Posted on Friday, July 29, 2011 - 08:15 am: |
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Re-reading the title of this thread, I would suggest that you not put a broken tap into a hole. |
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