Rocker Arm Bolt Hole Stripped - Need Advice
 

The thread on one of my rocker arm bolt holes is stripped out. I tried a helle coil repair kit which included a bit, tap, and correctly sized metric 8mm helle insert. I'm running a TT with 10 psi and 9:1 compression and it keeps backing out and breaking my rocker arm guide plate. I even tried drilling and installing a larger 3/8" helle coil and that pulled out to.

What options do I have at this point to repair the existing head? Should I get it welded up and redrilled and tapped to factor spec? Can I use JB Weld and try to weld in another helle coil?

Your advice is greatly appreciated as I'm running out of patience. Please email me at joey.wheeler@wellsfargo.com or call my cell at (972) 898-0101.

Thanks.

:smash:

Is it only one rocker? The heli-coil should have worked. What is the rest of your setup (cam, springs, installed height, etc.)?

You may need to pull the head at this point to fix this problem correctly, or pick up another head used.

For the love of sweet Jesus, do not use WB Weld!!! The head is toast if you have tried two different helle coil repairs on it

Keith

Unless you have new heads in your plans/budget, you probably need the services of a good welder and machine shop.

Hey, Ive JB Welded a spark plug back into the head after it blew out and took the threads with it. It held for about a day and a half.

:eek: AND then what did you do?

He used the JB again. :D

The head is going to need to be welded and heat treated.

I would suspect something is not right w/your valve train geometry. Properly done both should have held...I suspect spring bind? A thread-cert may work, but that is your last option w/out having to get it welded up.:cheers:

:iagree: :iagree:

That's also what I was wondering and why I asked about his setup. Original poster hasn't responded though.

It was on a police interceptor that was given to the public services departments to drive around so it was wore out after being driven by LEOs for 90k miles. It wasnt worth it to replace the head or do anything else, so that meant it was going off to auction anyway. Thats why we decided to see how long JB weld would last.

Yes it is only one rocker, #4 cylinder intake port, cam is turbo cam .224 and .600 lift, dual springs, not sure on spring height. What is a thread-cert? If I get it welded, do I need to pull it off first? The heads are 317 castings that have been CNC'd so if I replace the head with another unported 317, I guess I need to replace both to have a matched set?

Contact Gunnar at Patriot. He has done some amazing head repair. Get his input on what to do. I think you need to pull the head in any event to properly correct this. Since the heads have been ported, it is likely less risk with that approach as well.

We use keenserts where I work if the hole is too big for a helicoil.
http://www.barnhillbolt.com/index.ph...=1145&catid=-1

I notied at the bottom of this page a vender called time-sert. They look like something inbetween a helicoil and a keensert.
http://www.timesert.com/

Whatever you do I would suggest using thread lock next time.

:iagree:

A thread-cert is the same thing. Very strong, but are the last resort. You still need to determine if the installed spring height is correct & that there is no spring bind.:thumbs:

Other issue with Keenserts, they don't have a lot of thread engagement.