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.

Well, it was a good day.

My machinist got the first case half set up yesterday, and we located then drilled the studs to 1/4". Heated each one for about 5 minutes the used a #4 extractor and a lot of torque to twist the first 3 studs out. Ran out of gas on the 4th, so I'll get back on it tomorrow, finish the first case half.

Gonna have to get one of these for the house some day.

http://forums.pelicanparts.com/uploads/mill pic.JPG

lookin' good john.. keep it up, you might be the first of any of the NC pelicanheads to get back on the road.

If so, do I get the award for highest Visa balance also?

Not sure either you'd be the winner or a close second behind dave. :D

Not to be negative or anything, but that's not the way I would have done it. I don't think registering the case off of the bottom studs is a good idea. I don't know of anyone who does any work without first removing the inside studs. This is so you can then lay the case surface flat against the Bridgeport table, and get good registration. If any of the studs are off a little bit, the hole you drill will be crooked. Unless, of course, you used a dial gauge to reference the top surface of the case...

-Wayne

I could be wrong here, but it looks as if the case is bolted down on some sort of raised block by means of the bearing webs in the two farthest cylinders.
And those two rear studs aren't touching (bad pic angle)

If that's the case, the machinist probably did this to make a perfectly straight hole by adjusting the tilt of the base that the case is bolted to.

my $0.02

Wayne,

My tool room buddy set the case up on precision blocks on the material of the main bearings, keeping things off the outside perimeter, and up high enough that the studs were off the table.

Then he used a dial indicator to locate the centers of the bores to get the block square on the x/y, then used the dial to get the coordinates of the broken studs.

This is when he handed it to me and walked me through spot facing the tops of the broken studs, center drilling, then progressivly used larger carbide tipped bits to drill up to 1/4".


I'm officially without studs now, pulled the last one out at lunch today. One thing I did learn was that a screw extractor is good for about 2 studs, throw it out afterword.

I don't know what EDMing a stud costs around here, but I got these done for a few hours of my time, $12 worth of screw extractors, and a case of beer for my buddy.

This weekends project is to clean the heck out of the case and measure everything, then make another order to Wayne's.

Okay, I see. From the photo, it certainly looks like the case is sitting on the studs!

:)

-Wayne

Maybe this is better:
http://forums.pelicanparts.com/uploads/blocks.jpg

Ding dong the studs are dead, the studs are dead, the studs are dead, ding dong the wicked studs are dead!

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

LOL! lookin' good john.

I wish each of us had a buddy like yours, John. Nice job on the case :)

Good topic with great pictures.

Certainly gives one an idea how much of a hassle broken head studs can be.

Can't wait to do mine someday................ :rolleyes: :D

Send me the case, we'll do it for you. :)

Wayne,

Since your are in the business, and are devoting your life to Porsche, really I mean this, you need to go to the furthest steps possible, personally, so you REALLY obtain the deepest possible understanding of everything Porsche. My old Judo teacher once said, unless you devote your LIFE to it you will not truly understand it. He was correct. My life was to short to inlcude Porsche, only a narrow portion of the microwave electronics field. But I have taken the last couple of years to devote 100 percent of my time and whole life to learn what I can. If you think this kind of talk is nonsense then you do NOT UNDERSTAND, if you are the best at your chosen profession, you almost certainly do understand.

Anyway enough pontificating.

Wayne, go out and find a place where you can get some hands on, including all the machining operations involved in engine rebuilding. It will help you understand what truly can be done and what cannot. It will, in the end make you more money than you invested in learning. I know there aren't many opportunities in this country to get this type of experience. In the worst case come to Orange county, CA for 9 months and take both the engine rebuilding, and engine blueprinting class at Saddleback College. A genuine hotrodder is the department head, and Professor. I have taken it 4 times now and am signed up again next year (slow learner).

The experience takes a lot of the mystery and crap out of doing the machining operations. You will get to do them all, yourself. YOu will not become a true expert like Walt but the experience will help make things so clear that you will have an entirely new viewpoint. It is difficult to transfer the info to people who have not invested the same time in learning the stuff to much reversion to the mystique of whatever. But transfering more info is in everyones interest, as well as yours, as it will help you develop and sell new and better stuff. This is even more true in the higher tech world of post 1980 engines. Those Honda guys are real techie nerds of sorts and the hot rodders of tomorrow, they are soaking up everything we knew and going the next step. Gotta run to keep up.

While I'm sure that you mean well (I do have to keep saying that to myself), your remarks are condescending and presumptuous. I think that my BS and MS in manufacturing (with honors) from MIT (with a 4.7/5.0 GPA and TBP/PTS membership) speak for themselves. Heck the two books speak for themselves. It is not my desire to become Walt (Competition Engineering), and work on engine cases my entire life. I enjoy new things, and I am *not* devoted to Porsches either. The next book is on BMWs.

I enjoy doing and learning about new things (whether it be a Nissan truck, a communications satellite, a symphony I haven't heard before, or a Porsche engine. It is not my goal to be 'the best' (although ironically, I do end up there sometimes in certain areas), but to be the best that I can be. I'm not going to spend nine months in an engine class - heck I feel that you can learn way more outside of the classroom. I use almost none of the imperical knowledge of my college degrees in daily life (I do use the thought processes that I learned there though).

As for you, I would suggest that you take Jerry Wood's engine rebuilding class - I think you will learn a lot more via this venue than your class in Orange County...

-Wayne

P.S. I have about 500 hrs experience in machine shops with Bridgeports and CNC machines.

Then you have not learned enough.

PS, I really want to add to my statement, but I cannot. There is no way to add to this. IF you do not understand what I have said, and it is VERY DEEP philosophically (pardon the spelling) you will eventually. If you are making a living at something, its your DUTY to be the best. Not simply a good stab, but the best.

How do you know when you have arrived at this mystic level of competance?

Its when people will lay milliions of bucks on the line, all on your word. I hit this many years ago in my field, its like a fairy tale, but real. Thats the result of laying your life on the line for a field of study. I have had several MIT grads work for me, all outstanding in one way or another but here were some who were emotional cripples for one reason or another. they did eventually grow out of it but at age 40 or so. In other words the predigree is important, and significant, but you never know when you have really learned what there is to learn, untill that point where you can acknowledge it. You are NOT it the catagory I just mentioned, far above it, I think, but you have not arrived yet, either. This is demonstrated by your posts.

This anaylsis is not derogatory, by any means, in fact you are far above the average mortal, but the deep, and I really mean deep meanings have escaped you at this point. By the way this does not reflect on my own standing in most ways. It is always easire to criticise one, to analyze why one is not perfact, than to become the exhaulted one.

Wayne,
You are a guru of used and new Porsche parts. Like it or not, thats what you are at this time. Be Proud of what you are. You are signigicant in the world at this time due to Porsxhe parts!!! Many people would die to be the same as you are.
Wow, I did not mean to get off into this the way I did, but oh, well, age has its advantages. Tomorrow I will have forgotten it all togather.

Well, this whole thread has me bewildered. How on earth did this case ever get in such a predicament? Were all of the studs broken off flush w/ the case? (So that one could not grab w/ a stud extractor)? Which case is this? Aluminum or Mag?

I removed all 12 of my lower dilivar studs, including two broken ones, in approx. 15 minutes TOTAL, using the technique John Walker recommends, I learned it here on this BBS. I brought my case down to a muffler shop, (for their torch), showed the guy where to heat it, and twisted the studs out so fast it made my head spin. Maybe I got lucky, but my studs were installed in Stuttgart like all others. I used a borrowed snap-on extractor, spun 'em out.

At first the muffler guy didn't want to heat my case, (afraid he'd ruin it), but thanks to other's experience and knowledge here I confidently told him, "this is not an experiment. It is a proven technique for removing the studs". And sure enough, they spun out way before any excessive heating of the case occured.

That would be the difference between theory and application, JW is long on "application". :cool:

"Many people would die to be the same as you are." Highly doubtful.

Jack, I don't know what's going on in your head, and frankly, I don't really care. I'm quite happy with my own position here in life. I think that I have accomplished quite a lot. I am happy with my new wife and I'm excited about Pelican continuing to grow. I've managed to turn a hobby of mine into a thriving business. No, I have not reached the 'higher alter' of conciousness, nor at this time do I so desire to.

I'm going to start deleting your posts in the future if they continue to be wildly off topic. At the very least, I will move them to the OT forum, for they don't belong here.

-Wayne