Fixing Crankshaft Threads

[DuckRyder]

Coming back to this, anyone know the tread diameter and pitch, looking at options.

The ARP bolt is pretty long already.

[blykins]

The crank balancer bolt is 5/8" fine thread, 5/8-18.

[My427stang]

They make helicoil kits, 41/64 drill and a tap for the thread insert. I have never done one on a crank, but should be doable

[DuckRyder]

Yup, got it in my cart... longest insert seems to be .98, wondering if i can/should stack inserts... guess .98 is 1.5 times bolt diameter so it theoretically should be plenty.

Bigger issue seems to be that i cant seem to find a 41/64 drill guide or 5/8 tap guide. moderately concerned about getting it straight...

[pbf777]

............wondering if i can/should stack inserts...

      All I could say is good luck with that!   

      Aka...........no, don't try it!   

      Scott.

     

[Tunnelwedge]

............wondering if i can/should stack inserts...

      All I could say is good luck with that!   

      Aka...........no, don't try it!   

      Scott.

He could make a thread insert as long as he needs.
But he would need a lathe to fix it properly.

[blykins]

I've built some SBFs with Callies cranks that had a stud and nut for the balancer.  Is that an option for you or are all the threads gone?

[DuckRyder]

............wondering if i can/should stack inserts...

      All I could say is good luck with that!   

      Aka...........no, don't try it!   

      Scott.

   

Noted, wont try that.

I've built some SBFs with Callies cranks that had a stud and nut for the balancer.  Is that an option for you or are all the threads gone?

It might be an option, i will see...

[pbf777]

........ guess .98 is 1.5 times bolt diameter so it theoretically should be plenty.

      Yes, it'll be fine.   

      Just stop and think of what the standard torquing spec. might be on a 5/8 X 18t fastener vs. what you might be actually torquing this fastener to in your instance?   

      Scott.