Anyone ever break a head stud?, Looking for ideas, tools success stories, horror stories, what cha got Options

[rick 918-S]

Have you called 928 international??? Maybe they have a cure for this???
Or Pevec (SP) the guy who hot rods these motors???

I am sure someone has dealt with this in the 928 community before.

Rich

I posted this problem over on the list where the 928 Int guys hang out, and the bird. The consenses seems to be if the stud breaks in the block it's junk. Granted, the guys in the know on the list seem to be luke warm when anyone asked a real question.... The guys on the bird are much more helpful but there are fewer of them. Not like this place.

[Bartlett 914]

What is the size and pitch? How hard is it? You can see how hard it is by filing or grinding. Drill and tap on the section you have in hand to see how hard it will be to drill and tap.

[rick 918-S]

What is the size and pitch? How hard is it? You can see how hard it is by filing or grinding. Drill and tap on the section you have in hand to see how hard it will be to drill and tap.

I plan to chuck one of the studs up in a lathe and run the drill bit in the end of it as a test. It's a head stud. It's designed to hold tension and resist torsion during torque.

The left hand bits are extraction bits designed to drill hardened steel bolts and studs.

Cross your fingers for me. I wish you were closer. I'd bring it over to your shop and we could tag team it. (IMG:style_emoticons/default/beerchug.gif)

[Bartlett 914]

I plan to chuck one of the studs up in a lathe and run the drill bit in the end of it as a test. It's a head stud. It's designed to hold tension and resist torsion during torque.

The left hand bits are extraction bits designed to drill hardened steel bolts and studs.

Cross your fingers for me. I wish you were closer. I'd bring it over to your shop and we could tag team it. (IMG:style_emoticons/default/beerchug.gif)

With any luck the bolt will be a little softer in the middle. I am a little concerned about your getting the drill to start in the center. What would help the most is to use an end mill to machine the top of the broken stud. This would require another bushing for the end Mill. Long ones are expensive and a little hard to find (although I have a long .5" carbide one). After the stud is milled flat, center drilling would help. again the length would be a problem and that I don't have.

Yes its too bad you are not closer. I was thinking the same thing. (IMG:style_emoticons/default/beerchug.gif)

Lots of luck

[rick 918-S]

The tools arrived today. All left hand or left twist. Now I just need some time to try the extraction...

[GWN7]

To center the drill, find a piece of pipe with the OD the size of the hole and the ID of the drill bit. It should act as a guide and allow you to drill exactly in the center.

[rick 918-S]

To center the drill, find a piece of pipe with the OD the size of the hole and the ID of the drill bit. It should act as a guide and allow you to drill exactly in the center.

I have a friend with a lathe. I'm going to turn a an extension that will double as a guide for the O.D.

[Richard Casto]

I hope this works out for you.

(IMG:style_emoticons/default/popcorn[1].gif)

[Bartlett 914]

To center the drill, find a piece of pipe with the OD the size of the hole and the ID of the drill bit. It should act as a guide and allow you to drill exactly in the center.

I have a friend with a lathe. I'm going to turn a an extension that will double as a guide for the O.D.

(IMG:style_emoticons/default/agree.gif)
And have a second one made for the tap. The tap looks a little short. You can also get longer taps. They are called pulley taps (Maybe not in left hand). How deep will you be able to tap the stud.

[rick 918-S]

To center the drill, find a piece of pipe with the OD the size of the hole and the ID of the drill bit. It should act as a guide and allow you to drill exactly in the center.

I have a friend with a lathe. I'm going to turn a an extension that will double as a guide for the O.D.

(IMG:style_emoticons/default/agree.gif)
And have a second one made for the tap. The tap looks a little short. You can also get longer taps. They are called pulley taps (Maybe not in left hand). How deep will you be able to tap the stud.

That's the problem, Left hand, I felt very lucky to find the one I did. The broken section is all thread. Based on the other studs, it measures 1 1/4" long. I figured I would build in a drill stop on the extension that won't allow me to pass 1". I don't want to drill and tap through the stud and into the block. That would suck! (IMG:style_emoticons/default/headbang.gif)

[rick 918-S]

I ran a test tonight on the broken stud. The left hand Drill bit I purchased worked very well. It cut into the stud like butter.



The real test is going to be the tap. I managed to cut threads into the bolt but it was scary. I feel somewhat confident in that the tap, being left hand thread may have enough cutting resistance to actually catch and back the bolt out without having to screw the left hand cap head screw into the bolt.

[Wilhelm]

I've had luck getting a stud out of a deep hole by slipping a tube down the hole with its bore roughly the same size of the stud. Then I feed down a 7014 rod and then arc weld the tube to the bolt letting it all cool. Fill the hole around the pipe with diesel for a few days so it can penetrate the thread. Heat the block in the area where the threads are locked and now try to wind out this mess.
Good luck!!!

[rick 918-S]

I've had luck getting a stud out of a deep hole by slipping a tube down the hole with its bore roughly the same size of the stud. Then I feed down a 7014 rod and then arc weld the tube to the bolt letting it all cool. Fill the hole around the pipe with diesel for a few days so it can penetrate the thread. Heat the block in the area where the threads are locked and now try to wind out this mess.
Good luck!!!

That's a great suggestion! (IMG:style_emoticons/default/aktion035.gif) That's the first doable idea I've heard for a stud in a deep hole. I've welded washers to flush broken bolts before, then welded a nut to the washer and backed out the bolt, but I've never seen a broken stud in a deep hole before. I may need to try this one.

[Joe Bob]

That's sounds like the best DIY idea. Other than that I second the EDM.

[Dr Evil]

Well?

[rick 918-S]

Well?

I can't get a break! I drilled the broken bolt perfect, I tapped the threads perfect, I threaded the cap head in perfect but the allen stripped. I pounded in a metric size allen wrench and removed the cap head bolt. I tried a second bolt but even with super heating the block I couldn't apply enough torque to the cap head to move the stud. Size does matter. I probably needed to move up to the next size drill and tap. I could literally twist the allen 1/8 turn without phasing the broken bolt. I tried to use the tap as an extractor as it was less likely to loose power in the flex the allen wrench was showing. But as luck would have it, just as I thought I felt the bolt move, SNAP! the tap shattered!

I'm going to try that welding idea now. I've got nothing to loose. (IMG:style_emoticons/default/headbang.gif)

[Wilhelm]

Well?

I can't get a break! I drilled the broken bolt perfect, I tapped the threads perfect, I threaded the cap head in perfect but the allen stripped. I pounded in a metric size allen wrench and removed the cap head bolt. I tried a second bolt but even with super heating the block I couldn't apply enough torque to the cap head to move the stud. Size does matter. I probably needed to move up to the next size drill and tap. I could literally twist the allen 1/8 turn without phasing the broken bolt. I tried to use the tap as an extractor as it was less likely to loose power in the flex the allen wrench was showing. But as luck would have it, just as I thought I felt the bolt move, SNAP! the tap shattered!

I'm going to try that welding idea now. I've got nothing to loose. (IMG:style_emoticons/default/headbang.gif)

If the weld ing idea doesn't work, or as an alternative, can the stud be addressed from the bottom? If there is more access to drill it out from the bottom, or oversize drill it out, maybe the block can be tig welded to seal up the hole that is made. Have you let a machinist take a look at the block? Some are actually purty sharp and can devise alternative methods to get these studs out. Also if hour drill hole is "perfect" you might want to keep drilling it till it is t the base of the threads, then pick the threads out. Though I suspect this would be awful tricky deep down a hole.

[rick 918-S]

No access from the bottom. It comes out through part of the main bearing saddle.

I probably could have drilled the bolt out all except the threads but now with the tap snapped off (IMG:style_emoticons/default/confused24.gif) We'll see how the welding idea works. I like that one.

[rick 918-S]

I tried welding a piece of square tube to the bolt about 10 times. I managed to crystalize the top of the tap section but couldn't get the weld to stick to the bolt. The slag from the rod blocked the edge of the tube leaving a poor weld connection. So, some day I may bring this engine to the machine shop to see what they can do with it. But until then it's scrap.