: Removing Heli-coils



mechanix
01-21-05, 03:54 PM
Does anyone know a time saving method of removing heli-coils from a 4.6L Northstar block? Timesert cautions against drilling them out with a cobalt drill bit because of the risk of damaging the block and/or embedding coil chips that could tear up the timesert drill bit. I can get the top heli-coil out by hand, but the other two that are deep in the hole...? :confused: I have all twenty holes to do! Thanks! -Victor

dkozloski
01-21-05, 04:56 PM
There is a genuine Heli-coil removing tool but it probably won't do you much good. I would take a very large flat bladed screwdriver and modify it by grinding it to where it will go down through where you already removed the Heli-coils but still wide enough to engage the remaining coils. Grind the sides at an angle so it has as long a taper as possible and has edges that will cut into the coil. If you insert the tool until it is in the coil and give it a light tap, the end of the coil will be bent out from the aluminum to where it will no longer dig in and you should be able to screw the Heli-coils right on out. If you have any trouble understanding just PM me and we'll arrange a phone call.

BeelzeBob
01-21-05, 05:08 PM
You can also try cleaning up the old head bolts and screwing them into the helicoils with a light coating of some stud grade/permanent strength loctite. Let them set up for several days and unscrew them. I have seen a number of thread inserts removed like that. The permanent strength loctite will really grip the thread insert. If you want to get them off the head bolt after they come out then just heat the inserts gently with a propane torch and the loctite will loose it's strength and they will unscrew easily.

eldorado1
01-21-05, 05:43 PM
That's a great trick! I'll have to remember that! http://cadillacforums.com/forums/images/smilies/ego.gif

mechanix
01-21-05, 06:24 PM
Alright! This website is the bomb! *lol* Thank you very much gentlemen, for your input. I'll try those methods and see what happens. I did manage to get all 3 coils out of one hole and installed the first Bigsert. It went in pretty slick...no problems. I will keep y'all posted. Thanks again! -Victor

dkozloski
01-21-05, 10:28 PM
I'd be very careful how much Loctite I used because I wouldn't want to be gluing the Heli-coils to the aluminum. Loctite will wick in behind the inserts if you use too much.

BeelzeBob
01-21-05, 10:57 PM
I'd be very careful how much Loctite I used because I wouldn't want to be gluing the Heli-coils to the aluminum. Loctite will wick in behind the inserts if you use too much.

True...that is why I mentioned a "light coat" of loctite and to use the permanent grade stuff that is much more viscous...not the wicking grade that seeps in everywhere. But you are right...don't overdo the locktite or it can cause problems.