10 of 12 update
 

Here's the latest on my broken head stud saga.

Pulled the 12 steel studs off the top, no issues, got the 2 non broken dilivars off and the 2 dilivar remnants I could get vice grips on. That leaves 8 to be drilled. Here is what I've done today"

Stuffed all the openings and wrapped the rod ends

http://forums.pelicanparts.com/uploads/DSCN0125-2.JPG

Ground the ends of the broken studs off flat

http://forums.pelicanparts.com/uploads/DSCN0127.JPG

Mounted my handy dandy custom make drill guide to the engine (let me know if you are interested in one of these, works pretty good so far)

http://forums.pelicanparts.com/uploads/DSCN0129.JPG http://forums.pelicanparts.com/uploads/DSCN0130.JPG

Drilled a 5/32 hole into the broken stud. Started with a left hand bit, but got dull very quickly. Changed to a right hand carbide bit and drilled about 3/4" into the stud.

http://forums.pelicanparts.com/uploads/DSCN0131.JPG

Screwed a #3 screw extractor into the hold, tapped it a few times with a hammer to make sure it was set. Put on a tap handle and tried to turn the stud out.

http://forums.pelicanparts.com/uploads/DSCN0133.JPG

The extractor stripped out of the stud before it would pull it out. Tried heating with a torch, but I guess not long enough. Next step I guess is to step up to the #4 size extractor and try again. Drill guide gave me a great pilot hole to drill into.

ok, why arent you doing a full rebuild? split the case...

heck its easy and you have come so far

Spliting the case isn't out of the question yet, just that the motor looks like it only had a few k in miles before it got parked for a few years. If I don't have any luck getting the studs out this week, I'll tear it down the rest of the way and take the case to the milling machine.

Heating it up enough can be very scary. You need red, or almost red hot bolts to break the locktite bond. An acytelene or mapp gas torch is required, propane will NOT work.

You *don't* heat the bolts!
You heat the area around the bolts, the inner part of the spigot is where it works the best. It's not scary either, as the case is a very good heat sink. That's why Oxy-Ace is preferred for this job.

IT dosen't matter which you heat up, you are breaking the locktite bond. If you let it cool off completely the bolts still come out easily.

I say scary, because the bolts will at least turn red before melting, the case will not.

That's your opinion.
You always come on here like an expert.
Most of what you say flies in the face of what the professionals on this board really do know.

snowman, if you want to come on like an expert, search the archives on the subject first, then you can repost the old info and everyone will think it was your idea.

I also had to go to a #4 - the #3 started bending. I only had to do one (thank God). You've got your work cut out for you.

I had a friend putting MAPP-torch heat on the barrel area where the cylinder slides in, and could barely get the stud piece to turn out. Don't heat the stud itself. It's been pretty well established that that is the wrong way to do it.
Good luck.
http://forums.pelicanparts.com/uploads/stud2.jpg

Just to play devil's advocate for a moment. I haven't had the joy of removing broken studs from any part of the engine .... yet.
However, I recall numerous threads (no pun intended) on removing various broken studs. They go something like this:

a. If it's an exhaust stud, heat the stud red hot, then remove.

b. If it's a flywheel bolt, heat the stud red hot, then remove.

However.....
c. If it's a head stud, heat the .... crankcase, then remove.

Can someone explain the disparity in methods? Perhaps past experience has shown these methods to work best. What dire consequences await if one heats up a Dilavar stud (and allow it to cool) instead of the crankcase? I thought the process of heating was to melt any Loctite bonding the parts together.

Just wondering,
Sherwood Lee
http://members.rennlist.org/911pcars

exhaust nut, heat the nut, not the stud. nut comes right off.
flywheel bolt, use the proper tool, and/or hit the top of the bolt hard with a big ballpeen to loosen the grip. no heat required.
head studs, heat the case to expand the hole and melt the loctite. the loctite, and/or threaded hole will recapture the stud as it cools and the loctite sets again and/or the threaded hole closes up. keeping the case hot and the stud cooler allows easy removal. there have been plenty of times where a stud got tight as it was being unscrewed, and you had to reheat the case to get it moving again. what would heating the stud have done for that situation? this works on most applications, not just head studs.
no dire consequences, just doesn't work as often.

Right!
I remember when I was removing the Dilavar studs from my 3.0, I had to stop work on one stud I was heating. It was moving pretty good when I stopped. When I got back to the stud, it would have broken off rather than come out easily. Some more heat around the cylinder spigot and it finally came out.

John,

You are 100% WRONG about the loctiite setting again, IMPOSSIBLE. Once the loctite is heated beyond a certain point it is HISTORY!!! As to heating only the case, which is in intimate contact with the stud, it is simply impossible to heat the case more than the stud. With intimate contact the heat flow is so quick, and complete that there is almost NO chance of any temperature differential between the two. Ever done a heat flow analysis?, It shows that you have NOT or you wouldn't support such a perposterous idea. The time constants are in the sub second range, the temperature differentials in the hundreths of a degree C. I have done hundereds of such analysis for electronics devices for space applications and KNOW, from experience, analysis, and direct measurements with bocou dollars of equipment what this answer is. I have instrumented exactly this type of thing as we have had to take apart very very expensive equipment that had been bolted togather and epoxyed or loctited bolts had to be removed without destroying the equipment.

The discription stating that the heat helps but when removed hurts, simply means that you haven't heated it hot enough to destroy the bond. More heat is the answer.

PS when attempting to run spell check all I get is the following

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after working on cars for 40 years, porsches for nearly 30 of that, you find out what works and what doesn't.

Yet again, I agree with JW. From my experience (and the experience of people who helped me with the book), adding heat to the engine case helps the removal. I'm not sure if you can get the case hot enough to break the Loctite bond, but heating it up helps expand it around the stud. Also, dropping some liquid nitrogen (see the Engine Book for a tip on this) on the stud while heating the case has worked for me as well.

Snowman, you need to stop talking so emphatically.

-Wayne

Listen up JW you might even learn something. (an aside, do you know how unprofessional it is to begin any discussion with things like "you are wrong" and other personal attacks that are unrelated to the discussion? Didn't your mother teach you any manners? reflect on my last answer to you for a bit..see what I mean? .. and I know I did it again in the beginning of this post but it is to make a point. anyway back to the discussion) I have been talking about BREAKING the loctite bond. When the bolt is heated to some high temp, but not enough to break the bond, it does soften up the epoxy or loctite a bit which helps a little. In fact if the bond isn't broken and the bolt is allowed to cool the loctite may become even harder to bust than it was in the first place even when reheated to the same temperature. But if you heat it up to the point where the BOND is broken the bolt will come out very very easily in comparison to heating and not breaking the bond. How hot is this, I do not remember the number but I usually heat the bolt till it is visibly red in the daylight, thats HOT, it may even be overkill but its simple. Let it cool and then remove the bolt. I do not heat aluminum or mag directly because like I said earlier they do not change color before they melt, and you DO NOT WANT TO MELT YOUR CASE or even worse light off a Mag case.

THe process is fairly safe on flywheel bolts and anything not in contact with Aluminum directly, like I said earlier its a little scary on the case but still works ok if you are carefull.

didn't you just say i was 100% wrong? and now you're giving me crap about it? you're pretty much coming around to what i said previously, in a backpedalling sort of way. if you can't dazzle "em with brilliance, then baffle "em with bull *****, eh?

"John,

You are 100% WRONG about the loctiite setting again, IMPOSSIBLE. Once the loctite is heated beyond a certain point it is HISTORY!!!....out destroying the equipment.

The discription stating that the heat helps but when removed hurts, simply means that you haven't heated it hot enough to destroy the bond. More heat is the answer."

Did you read the second paragraph, quoted above? how is this back pedaling?

jhelgesen:

I hope you got the studs out, thats whats important here anyway. I'm considering doing a full engine rebuild, as I've read Wayne's book twice now and each time I read it I wanted to try it more and more.

Thanks for all the words of wisdom Wayne, I know I appreciate it.

Mike

Thanks Mike,

I'm taking the case in Wed to start the machining process, we'll see how it goes, I'll take pictures.