Jump to content
Ultimate Subaru Message Board

Stripped head bolt threads!!! Resize or helicoli?


Recommended Posts

Hey guys,

So I'm in the middle of a re-ring on my 97 2.2L, I was getting ready to reinstall the heads and a couple of my threads spun. I mounted the heads and went through the first step of tightening, which was 22 ft-lbs. When I started the second step of 51 ft-lbs, I barely started on the number one bolt and it spun. This happened on both side same #1 bolt. I was wonder which is a better repair, heli coli, or rethread to a bigger size like M12x1.25. I've searched around and can't really find the M11x1.25 thread repair kit besides pricey ones. 

Edited by ClassySoob
Link to comment
Share on other sites

You can't change the thread size. There are not oversized head bolts available nor would the torque values of the sequence allow for this.... usually if the block is weak in this way and the threads are crumbling then you either need to do them all or replace the block. If you do a thread repair you either need 33mm (3x diameter) long inserts, or you need to stack three 11mm inserts (1x diameter) to get proper thread engagement. Also you need custom made tooling to create the threads at the proper depth and install the inserts. Standard screw thread insert taps, and install tools are not long enough to reach the depth required. I charge $200 for the first hole, and $100 for each additional. It's a pain in the neck. 

GD

Edited by GeneralDisorder
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...