Stuck Cam Cap bolt

Anyone with a fix for this? Cam cap bolt will not tighten or back out, only spin. Not able to get anything under it to apply upward pressure.

Use vice grips to pull up and rotate?
Cut the head off/ cut a slot enough to fit a screwdriver underneath it?

Yeah. Vice grips should do it. Weak aluminum threads. Have a helicoil ready when you get it out.

Vice grips NFG with out the grinder first. Found previous heli-coil repair had failed. Looks like I'lll be going up size wise on the bolt 8mm x1.25 and doubling up on the heli-coil lengthwise . I'm contemplating skipping over the red Locktight and going straight to a bit a JB weld to hold the repair coils from spinning again....

I suggest you use Time-Sert rather than Heli-Coil. Ed

www.timesert.com/

I suggest you use Time-Sert rather than Heli-Coil. Ed

Normally I'm 100% with you Ed. The TIME-SERT is a much more professional repair IMO. But upon further inspection I found the bolt hole behind this one has a failing TIME-SERT repair that won't hold torque for more than a few minutes. So In this case I'm wanting to double up the repair insert depth for added bolt thread grip. The shallow TIME-SERT has a widened lip at the top to set its depth so not possible to double them in the hole. I can do that with the less desirable Heli-coil..
So plan is for now, Purchase 8.mm x 1.25 Heli-coil repair kit ( $42.00 vs $83.00 TIME-SERT kit), prior to insertion put a dab of JB weld in to hold the two repair coils. Wait 24 hours for it to set and put it back together.

I'd be interested to hear from anyone who has successful first hand experience repairing these stripped cam cap bolt holes. One more thread repair failure and the hole mess goes way up in the order of fix it magnitude so alternatives idea's are welcome.

Just my $.02. How can you “double” up any insert. How can you guarantee the thread timing would be consistent. Can’t a longer insert be purchased. Be mindful of the alignment dowel when doing any ID size changes.

It´s possible but difficult to do a double insert. The Heli-Coil inserts are guided by the thread you had cut before so the thread timing must be consistent.

It´s possible but difficult to do a double insert. The Heli-Coil inserts are guided by the thread you had cut before so the thread timing must be consistent.

Correct. Heli-coils are essentially wire so they can be stacked. Haven't seen a longer heli-coil but worth looking into.

You can buy time serts in various lengths.

The main reason the bolts are stripped in the head is overtorquing the bolts. Two reasons for this are the service manuals sometimes were in error advising too much torque, but even if you use common sense and use about 60 in/lb on a 6mm camshaft cap bolt they will strip because the the 60 in/lb is dry torque value for a 6mm bolt. Reduce torque by 40% for oiled threads, so spec is more along the line of 36 in/lb. You won't strip threads at 36 in/lb and trust me, the bolts will still be there all happy and tight til next time every time. If someone stripped helicoil repair they must have been used both the in error spec in the service manual plus failed to compensate for the oiled threads. I've repaired too many stripped 6mm camcap bolts to even remember off hand, but helicoil repair worked fine every time. Don't overtorque and minimize agony.

RonKZ650's reply is spot on about some manuals specifying the wrong torque by far. The point on wet torque is legit too, as well as the torque ranges mentioned.

Another reason many threads strip in the holes with dowels is that fewer threads are engaged while at the same time expecting the bolt to depress the nearby valve springs with the cam.

Our process is to cover the cam closest to the cap being tightened with a clean folded shop towel for cushioning, then use the heel of a palm to press down hard on the cam while at the same time tightening the cam cap bolts. That removes much of the load from the threads. Two people make that part of the job easier; one to press, the other to run the ratchet. Once snug, tighten to spec.

Some people use longer cam cap bolts in the holes with dowels for the initial cam cap draw-down for more engaged threads, then replace them with the correct bolts for final tightening.

Good Ridin'
slmjim & Z1BEBE