At least, if you don't bolt the bare case halves together and measure the bore, do yourself a favor - when you assemble the lower end the crank should; (1) turn easily (almost glide) on its bearings, and (2) you should not have to break the crank loose to initiate rotation. If force is required to turn the crank, take the bottom end back apart and have it line bored.

All I am saying is 1 sert yes doing all 24 thats a chore and a good chance to get a porcupine good luck full steam ahead and let us know how you do.

You would need a fairly large drill press with a large table to hold the case square. How big is the press you're using?

Drilling the holes may not be the real problem, tapping 14mm threads on a drill press is.
On a Milling Machine, I believe that just a single tap can be used but on a drill press that may not work. Even at the lowest speed, a drill press is too fast for 14mm, IMHO.

You don't want to break the normally single tap, so, I assume you're using a set of 3 taps: Starter #1, then #2 and last the bottom tap.

If you're absolutely set on doing it, I suggest that you use the #1 tap to get an aligned start on the press, then use #2 and #3 by hand with a tap handle and lots of lube and frequent cleaning out the chips.

Standard procedure would be to go about one turn cw, then reverse a little to break the chip, then continue until you bottom out.
That way no taps are broken.

It would take time but wouldn't screw up anything.

But how would you align the case to do the holes for the I-shaft?

Lots of good advise given about using a Milling Machine etc.

another thing with drill bits as opposed to mill bits, the drill bit really can't accurately center over the hole you want to drill out. it relys on it's leading taper to center and combined with it's natural tendency to wobble somewhat until it gets down a bit and the wobble that most drill presses have, your holes will most likely all be different distances from the cylinder spigot. a mill bit, in a stiff milling machine, can be dead nuts every time. believe me, there isn't much of a sealing edge left next to the stud on a 2.7 after installing inserts.

I am using a 1/2 hp floor mounted drill press with 12 speeds. I am unsure about the 3 taps you speak of. The tap only has to go in deap enough for the case saver. I didnt think I had to go all the way to the bottom of the hole. I have a very helpful person that is lending me a milling tool and guidence. I can drill the death bolt by fipping the case over without the studs installed and it will lay flat and drilling it should work hopefully

My .02... When I decided to install my SSI's... I called my P-Car Mechanic.. He was $400 in labor... So I decided to do it myself... By the time I bought the gas, tools, specialized jig, bits, extraction tools to fix 4 broken exhaust studs... i had spent at least $400.. if not more... It was a good experience.. and I learned from it... and I enjoy working on my car... and im more confident now about tackling other projects on the car... but i had no P car for a month, and I really saved no money... So you have to decide whether worst case scenario is really worth it... Id bet on the fact that your drill press and all the other tools and supplies youll end up using to do this job will cost about the same as just having the job done. DIY'ers usually spend the money one way or another... Good luck...

You know, despite your asking questions, you are really set on doing it yourself. So, just go for it. It is your car and you can do what you want. If you succeed, great job well done. If it does not turn out so well, then at least you have no one else to blame.

Go for it.

I am in the automotive field. So far I had to invest in a 90 dollar drill press. You state that the 400 labor was to install the exhaust, but what you dont factor in is the final bill after that P-Car mechanic would have to charge you after drilling your 4 broken studs. In my opinion I'd rather spend 400 on tools and know how than sitting on the couch waiting for someone to do it for me. I commend you to be handy and get the job done, with help from others on this board a well I'm sure.

I bought a drill press, after its all said and done, I will have he drill press for the same cost as 2 (just 2) casesavers from the machine shop that was recommended. You do the math. This is a DIU community, maybe I'm crazy, but if thats the case we might as well tell everyone who is contemplating rebuilding their 911 to just go to the local dealer.

You are right. I asked questions, and expected some people to say it is impossible. But I posed questions for help and support by those who have done it successfully,or others that tried, and made a mistake. I have one person in particular willing to give me a helping hand, and critisizm to most who have never even tried themselves. I would never blame myself for trying. It cost me many dollars to go to school, and I have had to pay alot in 32 years of learning life itself. A butchered case would sadden me, but like everything else, there is price from learning one way or another. I have another helpful person willing to send me a junk case so I can try on any stud. Thats where I am smart enough to do research. Try on a junk case and if successful then great. If not, then plan B. If I had the money, then 900 would be no big deal. I dont have 900, so not to many options.

If you insist on using a drill press, I would strongly suggest finding one of these:

http://forums.pelicanparts.com/uploa...1235619689.jpg

It is a reversing tapping head, and I think it would be almost required unless your drill press has a reversing motor (most don't). If you can't get a hold of a tapping head, I'd recommend using the drill press for alignment purposes only, and turning the tap by hand. (you should be able to turn either the chuck or the top pulley.) This way you'll really get a feel for how the tap is cutting the case. Use lots of tapping fluid (not motor oil; there is a difference), go slow, reverse often and use compressed air to clear the chips, and be careful.

I'd also suggest using a spiral fluted tap that draws the chips out the top of the hole:
http://forums.pelicanparts.com/uploa...1235620256.jpg

Like others have said, it's your motor, so all I can do at this point is give you some pointers and wish you the best. If you have any more questions, don't hesitate to ask.

Jim

Excuse me for my nieveness, but is everyone against me doing it because of my drilling or the tapping portion of the task at hand. I guess I have been worried and wrapped up in enlarging the existing hole since it is so close to the edge of the hole the jug sits in. The tapping is the least of my worries. I might have a jig handy, or at the very least will fabricate something. You dont all honestly think i would just jab a tap and turn it by hand without making sure I am going in totally straight. I a worried about enlarging the hole that close to the edge where there is no material. Thats a great flute tap, thanks for the pic. Very good advice. I'll have to look into finding one

OK, prices. My guys (Engine Machine Service in Los Angeles) will do your case savers for $200 complete (studs removed, case separated & empty). Add $25 for a Heli-coil for the long case stud, and $80 to check the line bore and you have no mysteries. If you decide to ship the case pm me for details.

Wow! Even with shipping this will be less that half what the OP was quoted locally and the shop comes with a recomendation from one of the top Porsche experts around. If my1st911 can satisfy his DIY urges with taking the engine apart and putting it back together this sounds like a winning option. My 2¢.

That sounds like a very good deal.
Having done a lot of work on my 911 including rebuilding a couple engines, and having quite a bit of technical experience including machining, I'd go with that offer.

I'd also add a very friendly advise that an old 911 is not a vehicle to run with minimum Dollars; they're no fun to drive unless set up properly.

Anyone expecting to maintain one on the cheap, is in for a disappointment. SmileWavy

Thank you for the nice words! I think that, even today, a bare case-half with the head studs removed can be shipped for well under a hundred dollars, so you're probably correct about the total investment.

Another thing that EMS frequently does is line-bore a mag case back to standard, thus avoiding a possible lengthy search for, and the horrific price of plus-size line bore bearings.

In my view those two machine operations are critical for long-life, and when they're done right make for a very rewarding engine.

Thank you very much for the offer. I have a junk case that I will try on first, as I picked up my drill press today. I expected to pay around 350 dollars for all this, but when I was quoted 900 I quickly went with plan B. Now that this thread has turned from me asking for help from people who have done it, to everyone betting against me, I have a hard time accepting your offer without at least trying. I asked simple questions, which very few have even hinted at an answer. With the case flat and true, drilling the hole a bit larger with a drill press in my mind would be doable. I understand your concern for me tapping straight but with a jig I dont think it would be impossible. Is this what your concern is? I posed the question before, adn noone has told me where they believe I will fail at this task

I never said that I would cut corners, I did ask for a bit of help on a DIU job. I dont expect to maintain this car on the cheap, but I know where things need to be done, and where I think alot of people go overboard. I am jealous of everyone that can just say "while I am in there" attitude. I cant. Some people have to understand that I am not a doctor, or a lawyer, and some things just cant happen. I dont know the financial records of the people on this board, but just to give you a glimps, my property taxes are 12,000 a year. Thats not mortgage heat electric etc. All on just my salary as a tech at a local garage. I'm not made of money. Like I said, this is my first 911, one of the least sought after, so a prudent person would say to get her up and running, but to not treat it as a show winner, or a car that I cant recoupe my money on when this chapter is all over. If I want to dump a ton of money, I'll pick up a 993 and just cruise. I got this car for $2000, and plan on making her leak free and reliable. I appreciate all of you who are trying to look out for me, but I am very technical, and a perfectionist. If I cant get it on the junk case, then the case will be shipped

No worries, case is apart and cleaned. It will be put back as well with the original bearings.

I don't have concerns, I'm just pointing you in a direction that I know will lead to you getting the job done right, the first time. Your simple questions have been answered, people have told you about Tapmatics, fluted mill bits, the importance of drilling and tapping perpendicular to the case, etc.

For the record, my "offer" is only a referral. I'm not affiliated in any way with Engine Machine Service, nor do I get kickbacks for jobs that find their way to them.

With a lot of luck your engine will turn out fine, good luck with the project.

Pete is that a special offer or every day prices?