Snapped a head stud during removal

[rich]

I will post the repair method used to extract the stud. It broke off at the threads. I am going to call the machine shop in the morning.

One thing I can tell you is you don't have to be afraid of heating the block at the base of the stud. I used a oxy/acetalene outfit with a zero gas welding tip. It took a long time to get the lock tite to release. The block soaks up the heat and cools fast.

[rhjames]

hate it when that happens-----

[928s]

I'm feeling for you, I bought an engine that when I went to torque up the studs they were like chewing gum. Getting them out was scary, I used the oxy to heat the block and I got lucky. Best of luck.

[Danglerb]

Are the shiny strips the places where the tool attached?

What kind of torque did you put on it?

[rich]

Originally Posted by Danglerb

Are the shiny strips the places where the tool attached?

What kind of torque did you put on it?

Yes, the stud threaded section is 1 1/4" long. The hole the stud slides into is 3 1/2" deep. I stayed above the block deck about 1/4" as not to scuff the deck if the cam tool I was using slipped.

BTW: The cam tool I purchased from Sears is a piece for crap. Good thing it's a Craftsman so I can bring it back.

So, I did some deep thinking about this yesterday. Unfortunately, I didn't have the light bulb moment until most places closed for the day.

Here's how I'm going to fix this. If it works I'll post pics.

I located left hand drill bits on http://www.mcmaster.com/

They also have left hand taps and bolts!

I'm going to machine a drill bushing that doubles as a chuck for a (short) left hand drill bit. Sometimes during the drilling the threads will back out. If it doesn't,,,,,

I am going to use the left hand tap to cut threads in the pilot hole.

This sometimes will cause the threaded section to back out. If it doesn't,,,,

I am going to thread in a left hand grade 8 bolt. This will repair the broken bolt and give me a positive bite on the threaded section. If the bolt breaks I can just drill it again.

If I used an extractor and it breaks, I toss the block in the scrap pile.

Extractors = bad.... bolt = good...

[Danglerb]

Don't you have a machine shop that specializes in bolt removal? One of those zapper things?

You can get left hand drills that are self centering, they also make them with the guide thing built in, but you are kinda screwed if one of the hardened things breaks off.

[rich]

Originally Posted by Danglerb

Don't you have a machine shop that specializes in bolt removal? One of those zapper things?

You can get left hand drills that are self centering, they also make them with the guide thing built in, but you are kinda screwed if one of the hardened things breaks off.

I contacted the EDM guy. He didn't think he could work 3 1/2" down inside a 5/8" diameter hole.

The drill bits that are available are too short. (jobber length) So My custom bushing will double as a drill bit extension.

[Danglerb]

Any kind of goop you can pour down the hole to dissolve the locktite?

I think I would be beating the bushes to find a cheap local 85/86 short block. My only problem finding one was that I ended up with a complete running low mileage motor I am reluctant to take apart just for the short block. Somebody must have one cheap in your neck of the woods.

[rich]

I think this will work. The left hand drills are extractor bits designed to drill hardened fasteners. What have I got to loose?

My reason for not just purchasing a 85-86 engine is I want a new bore. So I want to have a 4.7 bored out. That way I can start with a fresh engine.

[rich]

I thought I posted this. I put it in the wrong thread. The tools showed up today. Now I just need itme to try to drill it.

Nitro Carborized Left hand drill bit

High speed left hand bottoming tap

Alloy Steel left hand socket head cap screw

If the cap head snaps I can still drill it out at least on more time.

[rich]

Up date, I managed to tap the hole on the broken section of bolt and thread in the cap head bolt, but Still no joy. I could get enough torque on the bolt to turn the broken section. I thought I could get more torque out of the left hand tap but the tap snapped off. I tried to arch weld a tube to the broken section but only managed to crystalize the top section of the tap.

I may bring this to a machine shop some day but for now I pulled and dis-assembled my "S" I managed to get all the studs out of the block and it's off to the machine shop this week.