Stripped headbolt

[KVH]

I want to hear more. Did you take the whole car in, just the engine block, or what?

What kind of drill/apparatus did they use? One big deep bit extension?

Why did they recommend helicoil?

Who did you use?

thx

 

[Roger]

Once you get it fixed (and I like helicoils, but each to their own taste) you may want to wonder why the thread in the block stripped and not the nut, as I seem to remember studs and nuts, not bolts, secure this head.
Female threads don't normally strip unless the male is turning, so had you bottomed out on the thread of the stud, or were you plain unlucky?

 

[TR3driver]

Female threads don't normally strip unless the male is turning, so had you bottomed out on the thread of the stud,

Most likely, IMO. Some sort of foreign object in the (blind) threads kept the stud from being screwed in all the way. Factory studs had a relief groove to at least let out any fluids in the hole, but I've seen aftermarket studs that lack the groove.

However, corrosion is also a possibility.

 

[HarryL]

It was a female thread that stripped on one of the deep studs.
Could've bottomed out as someone said. Switched from standard studs( they have a relief groove) to the ARP ones. Since this is a frame off; the engine was
on a stand for the rebuild so just took the block which was stripped back to zero. Motor Reco out of Houston did the job. Roger probably knows James.
We chose helicoil because they didn't have to machine much out of the block;
compared to a timezert(?). Can't tell you the whole proceedure since I wasn't
there; but took about an hour to set it up properly. Know they ran a deep
bit down to get it set up properly. Believe a bit of unluck was involved-
those that know me will understand !
Harry
PS- tomorrow comes the real test when the head goes on.
PSS- Roger- you need to see the super 7; best in the county !!!