stripped crank bolt

I stripped out the bolt on the crankshaft(holds pulley,damper,etc) can it be heli-coiled or suggestion for fix ,(its in 350sbc/T -roadster), J_B weld ???I am open to ANY safe ,permanent fix irv53

 

Drill and tap to 1/2 " thread and make sure to put a long enough bolt back in it >>>>.

 

drill tap///OK ,no problem ww/ hardness of crankshaft?? if not ,I appreciate the quick response ...IRV

 

IRV, get a helicoil kit...7/16 fine thread..use the proper size drill bit (marked on the kit ).
Fixed a bunch this way, no problem...
Why did it strip ?
Usually they strip when someone uses the wrong length bolt...
good luck
Dave

 

x2

 

Cast cranks are not hardened---Ha that's why it stripped out. A heli-coil is going to be a short depth repair as you need more depth on the threads so you don't strip it out again >>>>.

 

7/16" is the tapping size drill for 1/2"unf, clean out with 7/16" drill & tap 1/2'.

 

I have a sbc that got water in cylinder #2.
It was stuck and someone tried to see if it turned and strip the said bolt.
The cyl walls are great and im in the process of freeing the pistons,I put mystery oil on all cyl and most of them freed up.
Can I just stick a longer bolt in there??
Or do I have to tap it...
Thanks

 

i'm with pro five x on that, drill and tap to 1/2 standard thread,the hell with fine thread,ain't worth a damn

 

Heli-coil or larger bolt is the same work. You got to drill out the striped threads and re-tap the hole. Measure the depth before re-drilling to be sure you go deep enough. The crank will not be too hard to drill if cast, a little tougher if forged, still it can be done. Just use the correct size drill and DON'T step up from a smaller size. Also be sure you don't go sideways with the new hole. The drill should follow the original hole, but it can still drift. Be sure to tap FINE threads, they are stronger than course and that is what was already in there.

 

that why its striped(fine thread),its not stronger than standard thread

 

Sorry wrong answer. Fine threads have greater contact area, like fine splines on a tranny input shaft of axle shaft. The threads were wiped out because the bolt wasn't long enough, was the wrong pitch, or someone over-tightened the bolt.

 

if you want to keep the correct thread size then i would use a KEENSERT or KEYSERT or some otherb brand of keyed insert, tough and you can install and remove the bolt a thousand times without any trouble, http://www.noblefix.com/key-locking-threaded-inserts.htm

 

I'm with drill it and tap it 1/2-20. There is no downside to this. Just use a long enough bolt (at least grade 5) and drill the big fat-assed washer 1/2 inch.

 

^^^^^^^
Bad info and an opinion based on wrong or no facts.
http://www.engineersedge.com/thread_stress_area_b.htm
Much more holding power, higher torque ratio and loosening resistance with fine threads.

It stripped because someone tried to free a stuck motor with it and a very long pipe.

 

well, how come i here so many guys messing up threads on there cranks with 7/16 fine threads,then drill and tap 1/2 standard and shazaam!!!!just saying

 

A course thread will hold the crank pulley on, however the factory used fine threads in these cranks for a reason and I recommend following their recommendation of using fine threads. Plus it is easier to tap a fine thread as the threads are shallower.

 

283's and most 327's were never drilled for a bolt, they were just pressed on, and ran OK, i've launced a couple, but for the most part they are fine

 

Why are all lug nut studs fine thread?

 

Why is a 2 year old thread by a banned guy still going ?!?!?

 

Because someone who had a simple question knows how to use the search deal...