Stripped head bolt hole !!!

[RonSerling]

Good afternoon all !!!! I have a 4.0 engine block that one of the cylinder head bolt holes is stripped out !! I have never run into this problem here at the shop but here it is and my buddy wants to know if it can be repaired. I know I have a M12x1.75 set of helicoils but I am not sure if I can repair it on a engine block. So the question here is can that hole be helicoiled SAFELY ??? Let me know as I have never done it in this situation before, thanks

 

[gaz]

No way you should consider a helicoil repair to a 85 ft/lb torque head bolt. You can weld fill it, then drill and tap...just like new.

 

[RonD]

Time-sert would work but much more expensive.......but cheaper than a new block swap

Helicoil would be a roll of the dice in this application

 

[RonSerling]

Time-sert would work but much more expensive.......but cheaper than a new block swap

Helicoil would be a roll of the dice in this application

Ron,
I have seen a lot of your replies, a lot of really good opinions, and I am curious as to why the TimeSert would be a more feasible repair in comparison to the helicoil method. I am probably going to go with the TimeSert, not that expensive on Ebay, but I am curious as to why you like them better.

Thanks

 

[RonD]

Time-sert is more substantial and insert is locked into place better in my opinion

Helicoil is great for other applications for stripped block or head holes, i.e. for brackets or manifolds, not sure I would trust it for head bolt, especially TTY(torque to yield), which you have in a 4.0l regardless of year

That 80-90deg final torque is based on the threads in the block not moving, lol, to stretch the TTY bolt so it holds better
Not sure I would trust helicoil not to move
If final torque was a "number" like 85ft/lb then it is what it is even if the helicoil moved a bit

 

[Curious Hound]

I agree with Ron. A solid type of thread repair insert should be fine. I would not trust a helicoil for this. Ez Lock or Timesert. I think these come in different lengths. Get the longest one that will fit the depth of the hole. That way you have the most thread engagement.

 

[RonSerling]

Time-sert is more substantial and insert is locked into place better in my opinion

Helicoil is great for other applications for stripped block or head holes, i.e. for brackets or manifolds, not sure I would trust it for head bolt, especially TTY(torque to yield), which you have in a 4.0l regardless of year

That 80-90deg final torque is based on the threads in the block not moving, lol, to stretch the TTY bolt so it holds better
Not sure I would trust helicoil not to move
If final torque was a "number" like 85ft/lb then it is what it is even if the helicoil moved a bit

Just wanted to say thanks Ron !!! it was well worth the $110.00 I spent on the Time Serts. It worked like a champ and I am back finishing the 4.0 today !! Thanks again for the Great words of advice

 

[RonD]

Good work, not an easy job

Thanks for the update and comments

 

[RonSerling]

Good work, not an easy job

Thanks for the update and comments

Actually it was quite easy once I got the correct drill motor. The torque my small 1/2" drill puts out caused the bit to grab and spin me in circles, LOL. Once I put my Milwaukee HoleHawg on the job with it's extended torque absorbing handles it was a breeze from there !!!

 

[Josh B]

My uncle worked on airplanes and gave me a small helicoil to use on a small motorbike.
It worked for a while but not that long, thankfully I was already buying a $35 62 Chevy Biscayne by then, which we loaded up and headed to Austin for a concert at gatlin creek.
I left it with my brother when I headed to Walton Beach with an aunt at the request of an uncle who was stationed there.
Sounded great to me cause it was coldern hek in Dallas that winter, but lo and behold we got and saw their first snow in 40 years :/
When I got back to Dallas learned my brother had left the car in some wet cement on a new freeway