Broken Exhaust Stud

[RD911T]

While I was waiting for paint to dry and parts/tools to arrive, I decided to work on my exhaust studs. I bought SSI's for this project and the 81 3.0L motor I picked up had one broken head stud (thanks for mentioning that Joe, NOT) and about half of the studs were too short for the thick flange SSI's. Weird combo of long studs on one bank and short ones on the other bank. I've got the motor on a stand, so access is easy.

I had done a bunch of reading and decided that this was the thread I would follow:

Exhaust Stud Removal (Intact) In 1hr With Simple Tools - Pics!

I bought the set of Irwin stud extractors a while back and had been periodically soaking the studs with Kroil. I last hit them about a week ago. They've probably been soaked 10 times in the 10 months I've had the motor. The motor is exhaust side up on the stand, so the Kroil could soak in.

I went after the broken stud first. New tank of Mapp gas and heated the cylinder around the stud for a couple minutes. Pounded on the the stud extractor, hit it with the air impact and out she came!


I moved to the other side of the motor and went after one of the short studs the same way. The extractor is a little tough to get on real straight, it wants to cock to the side. I hit it with the impact and it twisted off the stud about half way down! Crap! Ok, don't panic, there's still enough stud to get the extractor on, start over with the heat and pound the extractor on there again, try to get it a little straighter this time. Hit it with the impact and


Double Crap!! Looks like I'll be buying one of the Stomski Racing kits to drill that puppy out! Not sure what I did wrong? I'm trying to decide if I go try to get some of the others off tonight or not. I'm going to leave the one opposite this broken one so I have something to mount the Stomski tool on. Is there a better or cheaper method than the Stomski Racing tool? I don't mind spending the money (much), but I'm open to suggestions. One of the threads I read had a video of placing a washer with a inside diameter slightly smaller than the stud on top of it and the welding the washer to the stud, a nut to they washer and then turning it right out. I don't own a welder, but could probably find one to borrow. Of course then I'd have to figure out how to use it.

I contacted Christian (A Quiet Boom) here on the forum and he still makes his jigs for drilling out the exhaust stud. I ordered one from him this morning. It's almost half the price of the Stomski jig. It also has the blessing of some very respected guys here on the forum.

Looking back, I think my biggest mistake was not lowering the torque on the impact initially. It has four settings and I had it on the highest. I had already tried my 3/8" cordless impact and it had no effect at all. If I started at 1 and progressed through the settings maybe it hammers the stud loose instead of breaking it. Live and learn.

I'm looking for feedback on my stud removal technique as I have at least 5 more to go if I only replace the short ones.
__________________

[aston@ultrasw.c]

bummer

sounds like you took every precaution!!!

[Bob Kontak]

Originally Posted by RD911T

Not sure what I did wrong?

I am no expert as I still ended up with one like that. Did you provide heat and shock to the studs before/during the kroil application(s)? That may be a helpful hint even if you heat and bang on the remaining ones tonight then Kroil and wait a day.

I got way to frisky with my broken stud and drilled it by hand. It worked with an easy out but I absolutely lucked out and drilled (only) a sliver amount of the interface between the stud and threads out that allowed the Kroil to do the job fast.

Don't do this. :-)

Let us know how the tool works.

[RD911T]

Originally Posted by Bob Kontak

I am no expert as I still ended up with one like that. Did you provide heat and shock to the studs before/during the kroil application(s)? That may be a helpful hint even if you heat and bang on the remaining ones tonight then Kroil and wait a day.

I got way to frisky with my broken stud and drilled it by hand. It worked with an easy out but I absolutely lucked out and drilled (only) a sliver amount of the interface between the stud and threads out that allowed the Kroil to do the job fast.

Don't do this. :-)

Let us know how the tool works.

Bob, I didn't heat or bang the studs while hitting them with Kroil. Would I heat the stud or the surrounding area of the head? Heat, Kroil, shock? Is that the right order?

[Flojo]

I drilled mine out with regular hardenend drills.
first I grind the rest of the stud down flat, then pre-drill small, then larger and then in 3rd step drilled it to near oem width.
re-cut the wind in the hole, inserted the new stud with some loctite and off I went.

fine since 5/2012!

[gjmascoli]

I'm with FloJo, I'm. In process of drilling out 6 by hand drill. Too late now to tell me this is NFG, I already have 4 drilled and tapped.

[RD911T]

I'm stumped. I came home tonight and hit the studs again with Kroil and beat on them with a hammer. I waited a bit, then heated the surrounding cylinder with mapp gas and then pounded on the stud extractor. I set my impact at 1 (of 4) and then 2, 3 and then she broke. I stayed on 2 the second time. The compressor was set a 80psi, pretty low. Well, now two additional studs have chunks off them. Two off of 1 of them and a single chunk off the other. I didn't take them down flush, trying to decide if I should go ahead and do that to see if one of them comes out. I'm leaving the opposite stud alone so I can use it to locate the tool that A Quiet Boom is making me.

[IMG][/IMG]

[IMG][/IMG]

The third piece is on the floor somewhere after I punched it out of the extractor.

[JJ 911SC]

The Pics are not showing up...

QUOTE=RD911T;7978506]I'm stumped. I came home tonight and hit the studs again with Kroil and beat on them with a hammer. I waited a bit, then heated the surrounding cylinder with mapp gas and then pounded on the stud extractor. I set my impact at 1 (of 4) and then 2, 3 and then she broke. I stayed on 2 the second time. The compressor was set a 80psi, pretty low. Well, now two additional studs have chunks off them. Two off of 1 of them and a single chunk off the other. I didn't take them down flush, trying to decide if I should go ahead and do that to see if one of them comes out. I'm leaving the opposite stud alone so I can use it to locate the tool that A Quiet Boom is making me.[IMG][/IMG]
[IMG][/IMG]

The third piece is on the floor somewhere after I punched it out of the extractor.[/QUOTE]

[timmy2]

Heat the studs to red hot, hit them with kroil then remove them.


Sent from my iPhone using Tapatalk

[RD911T]

Originally Posted by timmy2

Heat the studs to red hot, hit them with kroil then remove them.


Sent from my iPhone using Tapatalk

Thanks for the suggestion. I heated the stud with mapp gas for about 10 min. I couldn't get it to glow red, but it was pretty hot. I hit it with the kroil, extractor, snap!
[IMG][/IMG]

Now I have 2 broken off flush. Maybe I need to get an oxy-acetylene torch to get them hot enough?

JJ, can you see the pics now? I can see them.

[zippy_gg]

With now 2 flush broken studs the Stomski tool starts to make sense. You can always turn around and rent or sell it when you are done.

[JJ 911SC]

Originally Posted by RD911T

JJ, can you see the pics now? I can see them.

Yes they are showing now.

For the flush one, as per zippy_gg suggestion

For the one sticking out, as per timmy2 suggestion

If all fail, as per my suggestion Time-Serts to the rescue

[RD911T]

With now 2 flush broken studs the Stomski tool starts to make sense. You can always turn around and rent or sell it when you are done.

I already committed to buying A Quiet Boom's tool. John Walker is on record that it's superior to the Stomski tool, good enough for me. I might need to order another carbide bit if I keep snapping studs.

[slow&rusty]

I am pleased that my thread was some assistance to you, but sorry to read that you had a few stubborn studs that snapped, it is the most heart sinking feeling. I would have continued to heat the general area with the MAP gas until the stud was glowing. You should not need oxy acetylene, you don't want to melt the heads! Another integral part of this procedure is a quick hammer action of the Impact, not too low.

Good luck to you,
Yasin

[fred cook]

I changed out the exhaust studs in a set of Carrera heads recently. I used a hand held propane torch to heat the head inside the exhaust port next to the stud. All of the studs came out ok although some took more than one heating.

[fred cook]

Originally Posted by slow&rusty

I am pleased that my thread was some assistance to you, but sorry to read that you had a few stubborn studs that snapped, it is the most heart sinking feeling. I would have continued to heat the general area with the MAP gas until the stud was glowing. You should not need oxy acetylene, you don't want to melt the heads! Another integral part of this procedure is a quick hammer action of the Impact, not too low.

Good luck to you,
Yasin

Don't heat the stud, heat the head around the stud. Heating the stud just makes it weaker and tighter in the threads.

[RD911T]

Here is the mapp gas torch I'm using:
[IMG][/IMG]

Is the the wrong type of tip? I can't seem to get the cylinder or the stud all that hot with it.

[safe]

If they aren't broken..... leave them alone.

[slow&rusty]

Originally Posted by fred cook

Don't heat the stud, heat the head around the stud. Heating the stud just makes it weaker and tighter in the threads.

That's what I was suggesting, maybe I should have been more clear.

RD911T - That's the same torch and tip I used.

Two (2) of the studs broke flush with my head before I decided to use the Irwin tool and the Impact gun procedure. I purchased the Stomski Racing tool to drill it out the installed Time-Serts which worked well but still a nerve racking process and several weekends of work. If you need any pictures, please let me know and I will post them.

[RD911T]

I changed out the exhaust studs in a set of Carrera heads recently. I used a hand held propane torch to heat the head inside the exhaust port next to the stud. All of the studs came out ok although some took more than one heating.

Hmm, heat inside the exhaust port, I've been heating the surface around the stud. The short studs on this side of the block look pretty rough. The longer studs on the other side look more recent, at least to my untrained eye. I'll see how easy the drilling out is with the jig before I think about touching the other side.