Rocker arm bolts
 

OK so I was putting the engine back together this weekend...finally...and the very first rocker arm I put on stripped out. So, I need to helicoil it. What are the specs on the rocker arm bolts / what kit do I need? I think I read that it was 8mm, but not sure about the threads. Anybody have this info handy?

Unless you have a drill press I advise taking this into a machine shop.

Ive put some helicoils in during my shop days. Hand held drills wont cut it, or they are weak and wobble.

Depending on the year of your heads, either 8mm or 10mm.

haha dealer replaced both of my heads because rocker arm studs stripped out of head happend like 4 times junk aluminum heads.

maybe i was lucky, but i did the same thing and stripped the first one out. i just used a hand drill and got the angle right.

It can be done. What Im getting at.. While your drilling, your hand will move a bit. When that happens the drill bit moves and makes the hole egg shaped or however it happens. When you tap for the heli-coil theres less thread in that area, which allows the end bolt more room to move/wobble.

If you have the heli-coils a smaller shop with some manual machines would probably get one in there properly for ya, around $50 or less. Money well spend considering if you DO mess it up at that point you will be in for an expensive repair or a new head.

Rocker arm boss fixed. No drilling necessary. The threads stripped out completely and cleanly so I was able to just tap the hole and thread in the helicoil. Only problem being that the tap wasn't a bottoming tap, it was tapered, so the new threads tapered in near the bottom of the hold. Had to make a bottoming tap by cutting off the tap above the taper point, then run it in again to thread all the way into the hole, then it worked like a champ.

Ya another bad thing with them... lol

The Helicoil tapsa re special to. So your tap wont work again.