[cutlass72]

Hello all,
I was replacing the heads on a friends 4.9L and when I was torquing them to spec one of the inboard head bolts stripped out. :banghead:

What brand insert should be used? I use the search and found permacoil, helicoil, and time serts said a lot but no definite this is the one you should use for the head bolt on a 4.9. I do know timeserts are the ones used for the N*s.

Any help would be greatly appreciated.
Thanks in advanced,
Michael

 

[daedalus__]

they are just brands. in the aircraft machining industry helicoil inserts are most common. they have specifications for each application. you just have to figure out if the insert you are buying is strong enough for the application. they have hi-torque and other nifty kinds. there is a brochure on the helicoil website.

you should call a machine shop and see what it would cost to have them do it or borrow the tools. otherwise you are going to be buying a nice expensive STI tap with the corresponding drill size. plus you get to tap it by hand which is also fun. get some tap-magic or other tapping fluid

 

[steelybill]

I believe my FSM for the HT4100 shows GM part numbers for those. I'm real leary about taking bolts out of the aluminum block, since I haven't done it yet. Being an aircraft tech, I've done the spark plug Heli-coils, and on landing gear struts etc, but not on a Caddy yet. Too bad GM didn't use them in these engines when they built them.

 

[cutlass72]

Thanks!
The taps and drill aren't the problem I have ready access to them luckily

 

[Ranger]

Factory repair on the Northstar is Timesert http://www.timesert.com. Helicoils WILL fail. Not sure about the 4.9., but I'd go with the timesert.

 

[Submariner409]

If the block is aluminum, DO NOT use Helicoils for cylinder block head bolt hole repair. Use either TimeSerts or BigSerts. Time Fastener Corp.