Jump to content
CaddyInfo Cadillac Forum

Northstar head bolts on a lathe

Recommended Posts

I was made in Dallas,68 year’s ago, I’ve been a mechanic all my life, and have a 2002 Deville w/4.6L Northstar engine, it has a compression leak in the coolant/ head gasket leaking. I’ve decided to stud the block 5/8”x11. I bought 7”long grade 8 CAT BOLTS and cut the hex heads off, then turned them down on a lathe, from the 5/8x11 threads to reduce the shoulder to a 1/2”. My question is: wii the heads bolt holes allow a 1/2” diameter stud, or do I need to keep on machining down to 7/16”. If you know I’ll be waiting for an answer, and very appreciative of your knowledge. Thanks 

Link to comment
Share on other sites

Hi Dave, Welcome to CaddyInfo.   Have you look at what Jake is doing at http://www.northstarperformance.com/sgstuds.php ?

The standard headbolts are either M11x1.5 or M11x2 depending on year, so the 'hole' is for an M11 bolt with either 1.5 or 2 pitch threads depending on year.  The M11 bolt is 11mm diameter, (0.433071"), or around 7/16 inches (0.4375").  Ref


2016 Cadillac ATS-V gray/black

Follow me on: Twitter Instagram Youtube

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.
Note: Your post will require moderator approval before it will be visible.

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.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...