williemon

I just helicoiled 2 studs on my 22re. I asked about this a few weeks ago. heres what I did. Went to napa to get the kit. It was 60 some odd dollars. Too pricy for what you get, but I needed the right size and thats where I found it. I think they called it a 1.5 by 10 I think. Kit came with the proper size coils, tap, and a crappy install tool. I wound up using the tool from a 19.00 autozone kit that I had got but the coils and tap were the wrong size. I also got an exhause manifold gasket from auto zone. I removed the air tube from the manifold and then removed the manifold. It may be best to remove the down pipe from the manifold first also. Once it was all out of the way, I had to buy a drill set that had a 13/64 (or was it 13/32) drill size. I marked the bit so I would not drill in too far. It was tough getting the drill and bit in there to drill. I wanted it to be as straight and true as I could get, although I was not perfect. I took it slow and drilled the hole out. I then got a small rubber tube, inserted it most of the way into the hole, and blew through it to blow shavings out of it. Then I tapped it with the tap. I just happened to have a tap set that gave me an adapter so I could use my ratchet. I then blew the shavings out again. I used the crappy tool from napa to insert the coil. Once in, I installed the stud untill tight. I then removed carbon and sanded smooth the mating surface of the manifold and the head with 300 or 500 or so grit sand paper. I coated the exhaust gasket with copper seal(used this on jetski exhaust)and installed everything. Be sure to torque from the inside most studs and work your way out. I torqued in 2 increments to 33 ft lbs I think. During this process, one more stud started pulling out from the same area as the first. I just let it pull out, then pulled it all the way out with vice grips on the nut. I left the manifold on and drilled slowly into the head with the drill, retapped it and cleaned out the shavings, put the coil in, ( it was hard to tell when it was in all the way, but use the tool as a depth guage)reinserted that stud and used 2 back to back nuts to get it snugged without tightening it against the manifold, removed the nuts and reinstalled the proper nut and torqued it down against the manifold. reinstalled the air tube (reuseing the gaskets from it) and reconnected the pipes. Tested and all was well.

toysoldier

I think the thread pitch is 1.25

T

williemon

I cant remember what it was now, but the kit I got from napa seemed to do the job, and Im happy to report that it is still holding well so far. This is a daily driver and gets much abuse.

Toyo22R-E

It is a 1.25 thread pitch for those exhaust studs. I hope you had the manifold machined or at least straightedged it. If the manifold is warped, it will pull those studs loose again. I know this because it happened to me (before I did the Heli-coil fix). The rear bolts (the hardest ones to get to) were loose when I got my rig, and I tightened them up; quieted it right down. About a week later I noticed the noise coming back and tried to tighten them again. Too late, the threads in the cylinder head were stripped in the back two holes (upper and lower). I did the exact fix you describe, and had the manifold machined. I've been driving it for 20K miles now and it's been fine.