Technical Anyone used a Helicoil to fix a crank balancer bolt hole?

Bought a used 454, resealing it so pulled the balancer today. Only about 3/4" of threads left in the crank, rest of it is stripped out. Pretty sure someone used the bolt instead of the right tool to install the press fit balancer.

Saw a few posts online about using a Helicoil to repair the threads. Anyone done this and did it work? Believe the balancer bolt is 1/2-20 and the kit isn't too expensive.

 

Timeserts are a much better option. You don't need the expensive kit. Just get the timesert and the right tap. You can use a punch to drive in the locking pins.

Helicoils would probably work on a stock engine.

 

Yes I have used Helicoils . I do NOT use the balancer retaining bolt to pull the balancer into place . I have balancer installation tool that does not put as much stress on the crankshaft threads . Once it’s pressed home, the Helicoil has plenty of thread surface to hold it in place. It’s a press fit . Early Chebbies had no bolt to retain the balancer .

 

I think it would be better just to tap it to the next size up, and forget the heli-coil or insert

 

This summer my son had a SBC built for his hobby stock. After everything was balanced and ready for ***embly it was noticed that the threads were weak. My machinest/engine builder put it in the lathe and cut new threads for a helicoil. So far it's worked fine and that engine sees 6500+ rpm. I think it also would have been fine to just go to the next bolt size up.

 

I've done it once, and it worked fine.

 

Helicoils and the likes claim the repaired connection is stronger than the original.

Chris

 

9/16-18 tap drill size is .515.
If it is stripped that bad you might already be at .515.
Might be able to just tap 9/16 w/o drilling.
Otherwise would probably want to dream up a drill guide to drill to .515.
Slow and steady wins the race when only drilling out .015.

 

I did it once on a Chevy 350, back around 1988 for a customer's van. It worked.

 

The fun part of drilling to the next size is keeping the drill straight.

I have a variety of bushings/liners and holders that have saved me more than once.

 

Should be fine to do. Balancer is press fit; bolt acts as retainer.

 

Going with Helicoil. Found other things wrong with the motor so really the least of my worries right now.