stripped threads on intake manifold

[xnoahx]

Well, I managed to strip one of the bolt holes for the carb on my edelbrock intake and now I'm wondering what the best way to fix it would be, I'm thinking either JB weld drilled and tapped out or maybe a heli-coil. Ive never done one of those heli-coils before, are they easy?

 

[big83chevy4x4]

yep they are preaty easy, buy the kit, comes with a drill bit, tap and the thread inserts and installer. you drill it out, tap it, thread the insert on the installer and thread it in the hole. /forums/images/graemlins/waytogo.gif

 

[dyeager535]

How much material around the hole? I did an AL intake that had a bad thermostat housing bolt, no problem.

Threadserts are 10 times better than helicoils, and cheaper to boot.

Only negative is that the threads on the outside require you to tap the existing hole two thread sizes larger. (Common thread sizes, not like 27/64) But intake manifolds usually will accept this no problem. So if I've got my sizes right, a 7/16" bolt would require a 9/16" tap to repair. Or something along those lines.

Threadserts run about $2-4 each from what I've seen, drive in with a flat blade screwdriver, and take a standard tap. Helicoils can't touch that. In a blind hole with enough meat around it, threadserts are where it's at.

 

[beater_k20]

the point of helicoils, or threadserts, whichever you prefer, is to restore the threads to their original size, why would i matter what size the OD of the insert? you'll be going back to the original thread size anyways.

 

[dyeager535]

Because helicoils are so thin, you could use them on something that is a "boss". Only example off the top of my head would be a rocker arm stud. If the threads are screwed up on one of those, could you drill and tap that hole out two sizes larger than original without affecting strength of the casting? No. It would fail in short order because you removed too much metal.

A helicoil in the same location wouldn't require you to remove as much metal from the casting, thus strength of the casting would change less.

Another place I thought of is the water pump threads, for the newer ones that use a threaded hole for the PS pump. There is simply not enough meat in the water pump at that location to drill/tap that 7/16" hole to 9/16". There would be no casting left.