Head bolt hole in block stripped, can I heli-coil?

[Alabama65stang]

Puttiing the 200 back together today and as I was putting the final torque on the head bolt near the water pump, BANG! she lets go. Took the head back off and it appears the top 1/2" or so of the threads in the block are gone. There looks to be about another !/2"' or so of threads remaining in the bottom of the hole. Can I use a longer bolt? Can I heli-coil the whole thing? Are studs available? I had cleaned the threads all the way down but it appears the bolt was just catching the top 1/2" or so.

Thanks for any help you can give.

 

[Anonymous]

yes arp makes them i also believe mike at classic inlines makes them. summit carries them aswell. you can use a tap and die to clean the holes and threads.

 

[addo]

One of the guys here (Does 10s) has just upsized to ½" studs - so that I suppose is the physical limit. For a street driven car, a Helicoil type fix should do fine.

 

[Anonymous]

they also make a thingus called timesert does the same thing only better of course
poping a sparkplug out is one thing, but i would be concerned with a wire holding my head down its not a tin lizzie

they are self locking, cold rolled, symetrical(threads line up) bacically a thin cold rolled sleeve

 

[Stubby]

If you try to drill and tap for Heli Coil, be prepaired. The drill bit is so close to the hole size it will grab and put you in a bind real fast.

If you are going with 1/2 in bolt. The tap drill size for 1/2 x 13 threads is .421 and the stripped hole is .437 so you don't have to drill it except for the threads that are left. When you drill the remaining threads the drill will grab, so be prepaired.

Either way can work but you only have one good shot before you have a real problem. If you know someone who has a magnetic base drill get it. It is the easiest way to do it and drill it straight.

 

[Alabama65stang]

Follow-up to the original post-Did the heli-coil based on advice from NAPA dealer/machine shop. (He even let me borrow the heli-coil installation kit) Also bought the ARP head studs from Mike. The studs go all the way in down in the holes in the block and use all the threads, unlike the original bolts which only used about the top 1/2 inch. Put it together last night, re-torqued this morning and again this evening and everything is holding fine. Hope to get it all back together and up and running this weekend.