Exhaust studs on head, Need to remove and replace some really rusty one's Options

[Zimms]

I have a '73 1.7L that I just got and figured I should tune it up first so I know what i have. I set the spacing between the valve adn the adjusting screw based on the instructions on the bird. My only problem was that there was no way I was going to get the job done with the heat exchangers done. So I took them off, but they are a mess. 5 of the 8 times the exhaust stud came with the nut. one sheared in half. I don't thing there were gastets between the head and the heat exchangers either. SImilar to Jay in another thread.

Does anyone have a part number? I couldn't find anything at the bird or Mr'. Raby's site. I'd like to get this thing running, and still have the spark plugs and CHT gauge for DD to install this weekend.

Any advice on removing the studs that the nut came off of only, as well as the sheared one? I tried an easy out, and PB blast with no real success on the sheared one.


Thanks,

Mark

[HAM Inc]

1.7's used M8 ex. studs. They are usually extremely (if not impossible) to remove if they have busted. They usually break because they are permantly frozen in place. (Never-Seaze people! For spark plugs and ex stud nuts) I remove hundreds of T4 ex. studs from heads each year and I long ago gave up wrestling with the ones that bust. I now mill the stud out and weld in a new boss.
Laying under the car trying to deal with this is very tough (make sure you wear safety glasses!) and can lead to some pretty serious side effects. You said you tried an easy out so I assume you managed to drill a hole down the stud. Don't waste any more time with the easy out. It's more likely to break in the stud than it is to dislodge it. You can try a 1/4" left handed drill bit. Sometimes the bit will grab when it hits the end of the stud and becasue the stud is now cored it will back out. If that doesn't work then just finish drilling out the stud and you may have to jump up to an oversize step stud. Drill a 11/32 hole and tap the boss for a 10 x 1.5 thread and buy a new stud. Raby sells them.

BTW the drilling of the stud can lead to some pretty serious issues if the drill walks. I have had heads sent to me after folks tried to do this and the bit walked into the combustion chamber and hit the cylinder. I've seen this more than once. Watch your depth when drilling. Don't go deeper than it takes to reach the bottom of the old stud.
Good luck!

[Zimms]

Thanks Len! I was trying a female easy outthat felt like it bite into the remainder of the stud, but felt like if I fought it, it was only going to snap again.

Mark

[HAM Inc]

Ah yes... the old female easy out. I didn't consider that. Hope you can get it put back together without a lot of hassle.