need help on broken stud
 

spent an hour on the search function, too time consuming. while fixing a head gasket leak on my 82 3.0 motor, i decided to upgrade a few things, one was replacing the lower studs with steel ones. None were broken, or even rusted, just thought it would be a good thing to do. all came out easy but two. applied heat, double nutted, finally a pipe wrench twisted them about 360 degrees before they snapped. ground one down, went to homo depot for bits, (good ones i thought, carbide) got a nice center punch made but the bits wont cut. is there a special bit i need to find, what other options before tearing down for machine shop? thanks, don

I used titanium tips when drilling my exhaust studs use lots of cutting fluid, Slow and steady with a lot of pressure use your shoulder. Someone recommended using leverage. I also used a jig but if you can keep it going straight you will be allright.

Don are you talking about the head studs or the exhaust studs?

Man I feel your pain.

Aircooled 911s dont have head gaskets, are you refering to intake, exhaust or cylinders?

Drilling Dilavar head studs with a hand drill is a major PITA. I found a drill with concave section opposite the drill chuck so I could use a cheater bar to apply more pressue. I still went through several drill bits. Did they snap off right at the case?

john, the 3.0 sc engine does indeed have a head gasket. both head studs snappen a few inchs above the case, but i have cut one down even so i could start drilling. I guess i need to find the best bit to buy, but which ones? any advice from anyone? this is getting to be a real pain. wish i would have left them alone now. thanks, don

Don,

This very tricky and potentially costly; procede very carefully.
It is virtually impossible to drill straight with a hand-held motor into the broken head studs without the danger of wandering off into the softer Alu material of the case.
Carbide tip drills are for concrete, etc. but don't have the right cutting angle for metal.
You'll need very high quality bits, cutting oil, a precise, deep center mark in the stump and 2 people:
One to hold the drill motor straight and control power and the other one to apply some pressure with a rigged 2x4. Rope-sling on one end, motor in the middle and the 2nd person pushes/pulls down on the 2x4 gently but firmly.
Issues to consider: Keep the motor straight, don't let the drill bit wander off, easy pressure from the 2nd person.

Done it many times on machinery in the field but with Millwrights or Machinist who know how.
Grinding the right angle on the drill bit is important.
Can you find someone with Machinist background to help you?
Do you have an angle-drill?
Or just a regular 3/8" drill motor?

John,

I believe that he is talking about the ring that sits in the groove on top of the cylinder.

There is a copper gasket between the cylinder and the case too - maybe you are thinking of that.

Don,

Best luck man! Hope it works out. Curse that Dilivar.

Solid carbide drill bits are available in any size at all machine shop tool suppliers. They are also sold by McMASTER-CARR on line. You can buy various lengths and drill point angles. All the info you need is there on their web site.
A drill press or even better, a mill, is the best way to keep that drill going straight.

Don

Solid carbide is too brittle to use in a hand drill, you need a real machining center to take advantage of that.

See if you can find a TI coated 135 degree split point drill in a screw machine length (shorter much less flex)
Since you are buying stuff any way get or borrow a solid lathe type center drill much easier to get the hole started (also very short) in the right place then switch drills.

You may try the above split point in a lefthanded twist (not hard to find) as you drill and generate heat vibration and pressure sometimes it will break loose and screw out. I keep a few sizes in the tool box just for jobs like this, even if it does not start to un screw you are no worse off, it may break loose after drilling a bit of depth and allowing the "shell" of the screw to relax.

Try msc.com for drills if you dont have a real machinist type supply store around.

The 135 deg point is wider and helps center also the point is thinned to a very narrow tip web to aid starting and self centering when drilling, lots of oil, low drill rpm and HIGH PRESSURE

Good luck, take your time and do this properly or the slippery slope will catch up FAST

Regards

I built a jig for drilling these, let me know if you want to use it:

http://forums.pelicanparts.com/uploa...1247683640.jpg

here is where im at right now. my brother jeff ( a machinist in the navy) rigged up a drill press bolted sqaure to the block, trying a cobalt bit, its cutting but very slowly, will need about 10 bits im sure. will let you know how it works out. wish me luck and pray for me tonight, thanks , donhttp://forums.pelicanparts.com/uploa...1247693971.jpg
http://forums.pelicanparts.com/uploa...1247694025.jpg

Looks like the good old college try, well plotted out, cobolt is an excelent choice.
Best of luck, remember "if" you try and break off an easy out you will think that stud was soft.

Regards

Dang Don, that sucks. This car apparently does not like you. Maybe you should paint it a different color (Shane ducks for cover:eek:)

Hope it turns out your way. Any chance you are going to the PCA Sonic cruise in tomorrow night. www.pca-msr.org

I was going to try, but then found out I need to be in KY tomorrow for business. Have to see what time I get back.

succsess! after aprox 9 HOURS of drilling, got a hole big enough for a large extractor, and got one out. but, the new stud feels a little wobbly until about halfway in, and it worrys me. i know the 2.7 can be timecerted, can i do it to the 3.0sc engine too?

started on the second one, what a pain, i wish this on no one. If i didn't have the engine out and on the stand with my brother helping me, this could have turned into a disaster. before we ground the second down to drill, figured we would try and weld a nut on again, put a cool pack on the stud and a little heat to the case, came out about half an inch before it got tight, babied it as much as we could before it snapped, what a let down. time to mount the press back on the block and more drilling and bits. http://forums.pelicanparts.com/uploa...1247930136.jpg
http://forums.pelicanparts.com/uploa...1247930217.jpg
http://forums.pelicanparts.com/uploa...1247930274.jpg
thanks for the kind words Shane, did you make it to the pca meet at the sonic Thursday?

round twohttp://forums.pelicanparts.com/uploa...1247931837.jpg

"a little heat" may be the problem. I use oxy-acetylene and bee's wax. At the least, I'd use MAPP gas.

When ever I am trying to drill out a stud I use left handed bits.

Sometimes the heat and the pressure of drilling alone causes the stud to spin out of the threads.

You might want to try getting a set.

No did not make it. Got back later than I thought from KY. I just got back from meeting the MTFR group down at Casey Jones Village. Had a good turnout. Hope your day ghoes successfully with all of this. I am off to change the radiator in my Suburban. Probably not as much fun as you are having...

finally got all 12 lower studs in, ive fixed a lot of broken bolts and studs before, but nothing like this. Strange how all came out so easy but 2. Anyone thinking about replacing those 12 lower studs be prepared, this was no amature job.http://forums.pelicanparts.com/uploa...1250726193.jpg

Hey Don... gonna have it all back together for the last PCA Sonic Drive in this Thursday?!?!

You should come out anyway. I should finally be able to get out. Maybe Scott can drive?

wont be going anywhere in the pcar soon, mach. shop has had my heads for almost 2 months now, but will stop by the sonic, got some things that belong to you.

Look forward to cathing up. Been awhile.

Snap-On stud remover plus impact wrench........
 

Don,

I don't know how I missed this thread. I could have saved you from lots of aggravation. The first time I replaced the Dilavar head studs of my SC's engine in 1999, it took me a good day (8 hours). Intense and nerve wrecking experience.

However, I did an engine teardown 2 months ago and have to remove 2 broken head studs plus 10 good ones. Since I was doing a process (new to me) for removing these stubborn studs, I was skeptical about it. To my surprise, it took me just over half hour to completely remove all 12 studs without heat!!!! Actually it was about 35 minutes from first stud to the 12th lower stud. It was unbelievable!!!!! As long as there is enough stud left for the collet to grab, this is the way to go!!!!!!

Our good friend Tom Butler has shown me how it was done. So I would like to share this experience with other members who would do similar task in the future. HTH.

Tony

I used a lot of heat on the case at the base of the case. MAPP gas, let it burn for about 5 minutes, used a Snap On collet tool, and a big long bar. None snapped.

Good luck to you.

snapped extractor
 

I had the same problem.... To compound the situation the bolt extractor also snapped in the hole as well.

I sent it to an engineer - he used an electrode extract. Costs peanuts and gives you piece of mind. Also, not a bad idea to get the engineer to tap all the holes just to tidy them up!

I consulted with John Walker before I did mine, and I had no trouble. I put oxy/acetylene heat on the cylinder spigot surface adjacent to the stud I was working on. I let it get pretty darned hot. They all unscrewed smoothly. I kept the heat on the spigot until the stud was entirely out.

Tony I guess im not familier with that tool. Live and learn. It was character building anyway. Ended up using a time cert on one, it was just a little to wobbly Now if only the mach. shop will hurry up.

Missed you last night Don. Not much of a showing really, mostly Boxsters. But we did have mine, another SC with 24,xxx miles (Jay), Dave's (Blue Sky) beauty of an RS interpretation, and Chuck's 993. You and Scott up for a quick trip for breakfast in Counce tomorrow. Trying to get a group to meet up with David Bailey.

sorry i wasn't there Shane, Thur. is golf day and im usually done by 5, but because of the nice weather the course was packed and did finish till 7:30. Next time you are in town, give me a call and come on by.