SSI installation - broken exhaust headstud

pbeezy · 04-03-2016, 08:04 PM

Hey everyone. I was removing the stock heat exchanger on my 79 SC as part of an SSI installation and 1 of the head studs broke at the level of the heat exchanger foot - it sheered off when I turned the nut.

I'm really disappointed that it broke as I was hoping for the best when I started the job. I guess the fact that it didn't break at the level of the head is a plus but still a little uncertain as to how to proceed.

What are the best options to remove the stud? Vice grips? As I do have a fear of breaking the stud off at the level of the head, maybe I should install the SSI and drive the car to my mechanic who may have more tools and options at his disposal. Thoughts?

Alan L · Alan L's Garage

You got plenty of room - vise grips, but first, plenty of heat around the stud. Let the heat do the work, keep testing the stud with the grips til it wants to move moderately easily.
Alan

billybek · billybek's Garage

Can you thread on a nut?

If so, I would try to double nut it (sounds painful) and back it out. If not enough room for two nuts, thread one on and plug weld it to the stud. The heat from welding might get it loose from the head.

Or borrow a stud collet the correct size.

Lots of options with that much stud sticking out from the head.

Start soaking it with your favorite penetrant before trying anything...

jason2guy · 04-05-2016, 09:38 PM

its not going to unscrew, save yourself the aggravation. be patient and acquire the drill jig/guide that is made for this purpose. youll have to dremel the stud as flush as you can get to the case then install the jig and drill. when its done the bad threads come out as a wound wire.

sebastianroher · 04-05-2016, 09:44 PM

+1 on Vise Grips!

Spray some PB Blaster on it, let it sit for a bit and have at it with the vise grips.

Hope you can get it off!

timmy2 · timmy2's Garage

MAPP gas is your friend. Get it red hot before using vice grips or double nutting or whatever. Cherry red....
Or mig a nut on it.

afterburn 549 · 04-05-2016, 10:13 PM

Listen to the HEAT advise.
And straight propane is not near enough.

faverymi · 04-06-2016, 02:23 AM

prschmn · 04-06-2016, 02:57 AM

Gee that's a lot of heat.

afterburn 549 · 04-06-2016, 05:46 AM

That will do it , if a person is not all that savvy with a torch, you can improvise a heat shield with some scrap sheet metal .
Heat the stud, , soak it, do it again. Somewhere in there it will jump out (almost ).

theiceman · 04-06-2016, 08:27 AM

forget the pb blaster comments, it snapped because it is bonded in there good . get one of those map/oxygen kits from lows, it has a pencil tip point with it. heat the stud until it is cherry red and get the vice grips on it . this will be relatively easy as the heat will ll go down in the stud and there is no exhaust to sap away the heat .

the other option I would consider is screw on a nut and tig weld it on the top . the heat alone will probably do it but then you have a "bolt" to work with .

pbeezy · 04-06-2016, 08:50 AM

Thanks everyone. I tried the double nut technique but was unsuccesful. It's a tight spot to get both wrenches. I think the heat application is a little outside of my comfort zone. I lack the equipment and my car is on a ramp, not on a lift. I'm gonna take the car to my mechanic for this one thing.

I do want to thank everyone for all of their advice. This forum is an awesome place.

atcjorg · atcjorg's Garage

maybe have it towed on a flatbed to your mechs faster and easier

911pcars · 04-07-2016, 11:25 AM

I would heat the surrounding metal around the stud rather than the stud itself. You want to accomplish two things:
- Melt any locking compound on the stud threads
- Expand the aluminum to create space for liquid thread penetrant (suggest Kroil)

Applying torque to a heated fastener may cause it to distort. Wait until it cools a bit before applying loosening torque. Then repeat the above several times. You want to avoid breaking the stud flush with the head if at all possible.

Double nuts (or a weld-on nut) provide a more secure grabbing area than locking pliers in that confined working space.

Sherwood

fred cook · fred cook's Garage

What 911Pcars said. Don't heat the stud, heat the head. The best place to heat is inside the port right next to where the stud is threaded into the head. I replaced all of the exhaust studs when I rebuilt my SC engine using this method. Everyone came out easily. I used one of the Mapp gas type torches and a stud remover tool. You will want to heat the head, try turning the stud. If it doesn't move, repeat the process. All that heating the stud will do is to weaken the stud, causing it to break again at the surface of the head. Then you will have to do the drilling process!

al lkosmal · 08:58 AM

I rebuild engines and have to deal with this all of the time....so I use stud extractors...and heat.

this

3 8" Drive Dr Universal Broken Thread Stud Extractor Tool Remover Removal Socket | eBay

and this......

http://www.ebay.com/itm/New-4pc-Socket-Stud-Screw-Extractor-Remover-Installer-/330607842282?hash=item4cf9c353ea:m:mM7v-WsP5_BK3Ja-G1FNU9w&item=330607842282&vxp=mtr

and this.........

1982 Porsche 911 SC Coupe - Engine Rebuild Wizard - Page 6

These allow you to get into a tight spot, like the exhaust stud that you are showing in your pic and they work very well, if combined with heat.

Note: the cheapies from ebay are surprisingly good quality for the low cost.

regards,
al

Amstaff · Amstaff's Garage

Weld a nut on it and while it is red hot crank it out.

porterdog · 04-10-2016, 03:51 PM

I've never been faced with this particular treat, but every "use heat" comment aimed at *head* studs recommend heating the surrounding metal, not the stud. Dunno why this would be any different.

Making the stud OD larger doesn't seem like what you'd be looking to accomplish...

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by pbeezy

Hey everyone. I was removing the stock heat exchanger on my 79 SC as part of an SSI installation and 1 of the head studs broke at the level of the heat exchanger foot - it sheered off when I turned the nut.

I'm really disappointed that it broke as I was hoping for the best when I started the job. I guess the fact that it didn't break at the level of the head is a plus but still a little uncertain as to how to proceed.

What are the best options to remove the stud? Vice grips? As I do have a fear of breaking the stud off at the level of the head, maybe I should install the SSI and drive the car to my mechanic who may have more tools and options at his disposal. Thoughts?

PB,

Are your adjustable return oil line tubes correctly installed? The larger diameter end of an adjustable return oil line should be on the crankcase side and by looking at the picture you posted they seem otherwise. In other words, they look like they were installed backwards. Keep us posted. Thanks.

Tony

pbeezy · 04-10-2016, 05:40 PM

Hi everyone. Thanks for all of the advice. This proved to be a bigger job than I anticipated. With the exception of the broken headstud, however, things went really well. I removed the air pump system, swapped out the oil lines, installed the SSIs and installed the new muffler. So with 5 of the 6 nuts in place in the passenger side, I'm gonna drive it to my mechanic, have him take off that SSI and fix that stud. I'm comfortable with my limitations and it shouldn't cost that much for him to do it.

Anyone want to tell me a horror story that makes me tow it in rather than drive it in? I've been around the block and it runs great.

Tony, I'll ask him about those oil line tubes. It's possible the previous owner put them on incorrectly. You are right about the orientation.

Thanks again for everyone's advice and support.

PB