RESOLVED - Stripped out the cylinder head bolt hole while replacing valve cover, what now?

[tom3]

I've had some luck over the years with using a stud instead of a bolt. Bottom out the stud in whatever threads are left, then put a nut on it. A stud is a whole lot better as it is not turning while being torqued.

 

[bdbull]

Got my truck back yesterday. Cost me $300 for them to do the heli coil kit and an oil change bc they got metal shavings in it when drilling it out. I'll probably run it for a few hundred miles and then change the oil again just to be safe and get it back to what I like to run on it.

I probably could have done it myself, but whatever, it's done. As my dad used to say, "it's just money, i'll make more tomorrow."

 

[drakon543]

most helicoil kits are designed to have a bite after they are actually inserted. there's a few different versions from a typical spring style look to a full thread insert. i have never used any type of loctite on a helicoil as the normal type has a chance of the loctite getting on the inside and causing you an issue reinstalling the bolt. the thread insert style has tabs you use thier special tool or a hammer and a punch to push into the metal to lock them in place. drilling in a sensitive area as inside the head like that should be drilled slow with a second person with a shopvac sucking the drillings up as the come off. you can also use a clear cup of some kind and drill through cup into the piece to contain the shavings if your by yourself. if your drilling steel in a sensitive spot i use the same thing with magnets glued inside the plastic cup. working facyory maintenance for a while now myself and you have to be the shop and come up with some nifty home made accessories.

 

[donjetman]

Put wheel bearing grease around the tip of the drill bit to catch the shavings.

 

[thompsoj22]

I think that's why I was so damn mad. I was using the torque wrench and sat there thinking, "good grief, is this every gonna torque down?" Then I realized something was wrong.

I kinda wish I would have at least attempted the heli coil, but having to drill out the hole just scared the hell out of me. Hopefully they'll be able to get it done without too much trouble, otherwise I will be giving it a go.

quite likely the mech before you? they knew the next guy was hosed and your up! helicoil is simple, youll be driving for less than a Benjamin!

 

[Just Fishing]

You guys who have done multiple helicoils -- are you in the habit of using (red?) loctite on them when you install them, or something else, or leave them dry? I did one on a lawn mower exhaust bolt thread, so not a helicoil virgin, but not an expert...

I took a crash course with helicoils in my vette.
I suppose the rear ends cover either had never been off before, or the last time it was off the threads were damaged.

Either way, no matter how hard and how careful i was, the threads would not allow me to torque to the proper spec, and i had never ending leaks.

Compounded by the fact that the diff cover is a structural part of the suspension.
It also serves as the transmission mount... lol

I ended up having to go with helicoils to fix it.

The helicoils have a little part at the rear that bites into the aluminum once fully installed.

But i did use red loctite for the install.
Careful to not get that red loctite on the inside of the coils.
I did not want any chance of those coils backing out for any reason.

After 24hrs, i installed the rear cover with blue loctite.

They are not too hard, but doing it again i would suggest to do it on a test piece first.
After two of them, the install made more sense to me.

 

[petethepug]

Nope, you did the right thing. Once you get the damage done and you’ve got that feeling of “can’t undo this”, it’s a good idea to call in a pro. What if you really did run into someone else’s f up timed to go off when you touched it. Handing it off to a pro made have saved you from an advanced level fix beyond the norm.

I had to rebuild the same motor three times because my pop overlooked the cylinder taper wear. He lost $400 on new pistons. Next we got a reman block that had a stripped head bolt discovered AFTER the block was installed.

After doing it again we got another reman block that had a camouflaged repair on the same head bolt. The company broke the corner of the block off and used brazing rod to build it back up and some how tap threads to spec. The corner of the block fell off when torquing it down. The piece that broke off was all brazing half the size of a slice of bread.

My pop was cheap but with good intentions. People often pulled the wool over his eyes. He wasn’t upset I had done the job three times at 17 years of age, he was embarrassed and angry he got swindled. The Reman company installed the 3rd motor at no charge.

My pop lost weeks of time, I paid time to gain experience. If you haven’t done a job that requires a fix to an overhaul job gone sideways, team up w/ a pro or let the job out. Kudos to you for doing the smart thing. Who knows what else the shop ran into on the repair. If it fails again this year, guess who’s NOT doing it over again.

 

[donjetman]

sadly our best lessons are learned from mistakes.

Today we have utube.
Watch some utube vids then get after it.

 

[petethepug]

Mod can update title to resolved now.

 

[bdbull]

Doing some more work and one of the other bolt holes stripped out so I guess I'll get my chance to learn now to do it. I've been doing some research and people seem to like Timeserts or Keenserts more than Helicoils.