Need a bit of input here, when I took the front head off my 89 evo for a leaking head gasket I see the exhaust stud that I helicoiled in last fall came loose again ( wasn't like that after doing the rebuild a couple weeks back) , the helicoil is stuck on the stud. What I'm wandering is rather than trying to rehelicoil again is it possible to run the helicoiled stud back in and lock tight it and have some one weld it in place permanently? I'm no welder so I don't know if the steel stud could be welded to the aluminum head and I want to do this right once and for all.

 

what if you took the head to the machine shop have them tap it and install a new helicoil.Ive had pretty good luck with helicoils myself.also you may need to change that stud someday down the road.

 

What exactly came loose? Did the helicoil come out or just the stud or what?

You can't weld steel to aluminum. Doesn't work.

 

the stud came out with the helicoil red loctited to it.

 

That is more than likely what will happen but sometimes if you don't know what your talking about and give them direction they will mess things right up.

 

Well, are the threads in the head that the helicoil goes into OK? Maybe the red loctite just locked the helicoil to the stud. You might be OK just threading in a new helicoil with some loctite on it and letting it sit a few days so it sets up good, then blow out the hole and install the stud.

The other choice would be to get the hole TIG'ed up, drill and tap to original spec.

 

Especially if the head is off, that's the correct and prefered repair.

But a helicoil should work fine if the threads in the head are still OK. On the other hand, if the helicoil came out, that's a sign the threads aren't as good as they need to be. Most, but not all studs have an interference thread on the "short" end and they will yank a helicoil as quickly as anything.

If I were going to go back as quick and cheap as possible, I'd use genuine Loctite Stud 'n Bearing Mount (high strength-high temp) glue the coil and stud in the head and use anti-seize on the fine threads and use a new nut.

 

Looks like welding drilling and rethreading will be the best way.

 

Just got back from the welder and job was completed in 20 minutes, he started by grinding a V shape gouge on the" head gasket side" bottom of where the stud would be then further used a pencil shape grinder to clear out the rest of the stock and welded it up closed, the redrilled the hole with hand air drill and made new threads, good as new.

 

Agree. That is what I did to my shovel (both heads) some years ago. After welding I had helicoil inserts fitted.

That's great. Hope it all holds up for you!