Im putting together my new motor a couple of nights ago, and while torquing down the bolts(head stud kit) the stud started lifting out of the block pulling the threads out.

Ive got a ton of money in this motor and machine work, over 8 grand. It really pissed me off because Ive done everything right to get this close to having it done and something like this to happen.

Im guessing I need a helicoil, but my buddy that owns a fab shop, builds alot of drag cars said something about a time cert. Something like a solid helicoil.


Just looking for some advice on how to fix this problem and any ideas as to why it might have started pulling the threads out.

We were torquing the studs to 85 ft lb btw.

Thanks,
James

 

Yeah - in that situation I would recomend a time-sert over a helicoil. How many threads did you have contact with the studs?

Time sert kits are expensive, so find a machine shop that will just charge you to install them.

 

2 possibilities for the failure.

1. Block was cleaned in an abrasive cabinet, or a tap was used incorrectly to chase the threads.

2. Studs were not installed properly in the block. Why studs anyways?

suggestions:
1. repair with time-sert or bearclaw. Forget about using a heli-coil. If this is a high HP install, index bolt centers off of crank centerline.

2. Replace studs with a decent bolt.

 

Were the heads angle milled and the bolt holes and face not corrected for the angle?

 

Why bolts over studs?

1racerdude, no, I had them checked but they didnt mill them any.

 

We forgot what heli-coils are since we got time certs. If the block was blasted could the threads have not been chased? I've seen that eat threads. If you want a time sert installed and are in my area let me know.

 

Why bolts anyways?

Your torque wrench could also have been broken.

 

Why not do it at home the easy way. Just drill and tap that one hole to the very next stud size? you can take a much larger drill bit and use it to make a little counter sink so the threads don't come right to the top of the block, just make sure you drill the tap hole straight.