dmiz0420

Ok take it easy on me guys...

My lifter guide/tray bolt started to strip so I backed it out and maybe 50 to 60% of the threads came out with it. I taped it out and used lots of red thread lock, but there were just too few threads remaining to be comfortable. My next step was to use some JB weld to fill the hole, let it cure for 2 days and tap it out.

My considerations to leave the JB weld fix in place are:

-the guide tray is plastic and carries no load: the pushrods and lifters handle that. So the threads on this don't bare any tension forces and it is used as a pined (shear) connection to keep the lifter tray centered on the cam lobes.

- it was better to use the stock bolt because the head was made to center the tray than tap it out and use an oversized bolt without centering head

-all materials used in the repair (JB Weld and Red thread lock) are good to 600*F and

-I felt the bolt was tight. I was able to verify with a torque wrench that it was at least 65 of the 106 required in/lbs spec without thread lock. The tray didn't budge at all side to side or when I was pulling out. In fact, I felt the plastic tray begin to flex and still no bolt or tray movement.

-I have had the heads off 4 times and am worried about fatigue of the cylinder head bolt hole threads in the block. If one of those strip out because they are aluminum, then this becomes a side note.

What didn't occur to me before I re-assembled the engine was that I could use a heli-coil thread insert, but I have herd of issues with those as well. I have since started and run the car a bit and had no issues, but nothing like the use it’s about to get on the dyno scheduled this friday and track (Road Racing).

Any thoughts or experiences with JB Weld similar usages?

(yes I’m doing searches too)

Thanks for any input

Tech

I've used JB Weld plenty of times... but not inside the engine. I don't think you did anything crazy. It'll be fine although a helicoil probably would have been a better solution.

lucky131969

Install ARP studs and rest easy.....

Using a heli coil would have been the best repair in this situation. I'm not sure what you have "heard" about heli coils, but they are extremely reliable(properly installed), and even have aviation grade units for cylinder head repair on aircraft.

I'm sure JB weld has a thousand uses, but I would never use it in an engine or tranny. My grandfather used to refer to JB weld as "duct tape in a tube"....

dmiz0420

thanks for the replys!

vettenuts

Well its in there so not much you can do now, if you remove the heads again fix it correctly. The one salvation is the bolt is captured by the head so it can't back out.

gleds

I have heard of it sealing cracked blocks before and the repair last until the person sold the vehicle (80's chevy truck w/350)

K RIPPER

LUCKY 131969,right on the money,helicoil are the prefered repair, would be hesitant to use JB inside eng. or tranny, but if you must use inside engine the only stuff I would use is "Marine Tex" available in places that service boats ,marina and such.If out on the water and stuck this stuff is pretty amazing,but you have to mix the entire package ,catalyst and epoxy must have exactly the prescribed amount of each.I've seen cracked blocks repaired,guy on the water repair head gasket,works under water too.But any of those epoxys are temp.fix's there are no miracles in a can you should take that "you can file it drill and tap it" with a grain of salt you can do that but in a very limited way