e3photo

If you want to borrow my circlip tool, shoot me a pm, and I can ship it to you. It made the job easier. I really enjoyed the rebuild process.


Emerald

dgmattingley

Cool tool, Ed. I'm jealous of your warm-looking garage. And keeping your magnetic numbers on the fridge is very trendy.

Mike,
I'm also going to be using a pro shop for those things, as well as cleaning/flusing the case since I don't have a parts cleaner. Did you have to have the rods machined? Do you know a good source for the ARP rod bolts/nuts? What head studs did you use? Do you have any tips on judging the condition of main bearings? Since I'm there I plan to replace them, but I'm just wondering if there is anything particular to be on the lookout for. The only thing I noticed is that some of them have some "glassy" looking spots, but they are smooth and appear otherwise in good shape. The intermediate shaft bearings have more visible wear, almost like scuffing, but I understand that it is normal for those to wear more quickly.

Yes, I do have everything in labeled baggies, and I've sharpied and/or inscribed all the P/Cs and heads. The only part I'm really worried about there is the intake and all the vacuum lines...I labeled and took pictures, but once it is totally apart it does seem like quite the jigsaw puzzle of rubber hoses.

I split the case because I just wanted to be sure everything was OK and because, by my calculations, it really didn't add that much more time and expense, relatively speaking. But yeah, I don't think it was really necessary.

dgmattingley

Here's a shot of the crankshaft after I removed all the connecting rods. It's mounted to the flywheel, which acts as a handy stand. The bearing surfaces looked and felt good.

dgmattingley

The one strange thing I noticed when opening the case was the condition of the #8 bearing. You can see in the picture below 2 of the 3 pits or divots in the bearing, of which the one on the right has some raised material and is very sharp when running your finger over it. I can only assume that some grit made it's way in there?

Ed Hughes

EBS is good for ARP bolts and such.

Mike J

I had the rods re-bushed with new wrist pin bushings (bought from Porsche), honed to fit the wrist pins, new ARP bolts, and rebalanced. Not I used a stretch gauge on the ARP bolts, not the torque technique - if you are going to spend this much money, I figured its best to do it right. The gauge was not that expensive anyways..

My head studs were in good shape, and there are very few issues with these on the 993, so I reused them.

I used EBS for most of my parts, including the wrightwood racing gaskets, rings, etc. I used Sunset for the Porsche specific parts.

The main bearings should have a consistent grey look - no shiny spots or different points of wear. You noticed the wear on the intermediate shaft - that is typical and I found that on my engine as well, the bearing I think is quite small for the shaft. I had all kinds of wear spots on my bearings (see picts below) but the crankshaft was in excellent shape.

Are you getting the crank checked, cleaned and polished? There are two schools of thought on the bearings - one is that its impossible to check using plastiguage, since torquing the case deforms the bearing shells, and you only want to do that once. The second is its OK to measure this way. I measured it, got about 2 thousands clearance, and went with that.

Your end bearing does look a bit weird. I had some scuffing on mine where the shaft wore though the surface of the bearing material (like the intermediate shaft) but not like yours (see first picture below). How is the case condition once the bearing halves were removed? How about the intermediate shaft bearings, etc?

I have about 600+ pictures of the rebuild, many not published because at the time its was VERY painful to upload to rennlist. Do you think those would be useful to you?

Cheers,

Mike

dgmattingley

Mike,

Any pictures you can share would be appreciated, particularly pics of the case, crank, bearings, rods, and P/Cs.

The case looked good overall and I specifically checked the area around the #8 bearing, which showed no marring or anything that looked problematic. I honestly haven't had the chance to go over it thoroughly yet.

For the crank, I'm having it cleaned, checked, and measured, and plan to have a pro install the rods with new bearings and wrist pin bushings.

I've heard that there can be issues with head stud breakage when re-torquing the head nuts on dilavar studs. My head studs look fine, and I hate to shell out the crazy money for new ones, but at the same time my plan is to renew as much as possible while I'm there.

I did plan to check the bearing clearances using plastiguage, I'm unaware of the differing schools of thought on this that you mention.

Mike J

BTW, have you visited the pelican parts engine rebuilding forum? LOTS of stuff over there... :-)

dgmattingley

When I removed the cam housings a week ago a little metal cap felll to the floor. It was in good shape but it didn't look familiar, and I at first surmised it was some type of plug for the oil galleys on the cam housings. Inspecting the housings, though, I couldn't find a place for it so I stuck it in a baggie labeled "cam housing ??"

Yesterday I was giving a friend a grand tour of my disassembled engine, and I noticed that the lifter end of the cyl. 1 exhaust rocker looked different than the others. Then is suddenly dawned on me (duh) that the mystery cap is a tip of a hydraulic valve lifter. The reason this mystery is only partially solved is that there's another part of the lifter still missing, the sleeve that holds the metal cap to the rocker. I checked the cam housing again and the #1 head but didn't find it. Wonder where it went? I'll post pictures later.

dgmattingley

I found a picture (from a post by Mark D) that illustrates what I'm talking about. The part on the left in the picture below is all that was left in my cyl 1 exhaust rocker. The spring and the "sleeve" are missing, but I found the little end cap that makes contact with the valve.

dgmattingley

OK, it's been awhile but I'm finally starting to put things back together. A few weeks back some local PCA friends helped me seal up the case, and this past week I installed the pistons and cylinders.

Sealing the case was a challenge but seemed to go smoothly. The tricky part is getting the oil seals on the through bolts and torquing everything up in the 45 mins you have after pushing the two halves together. It also took me several tries to drop the crank/rods correctly without catching the rods on the case.

Getting the pistons installed into the cylinders was not an easy task for this rookie engine builder. I had a few pop out AFTER install onto the case, and had to go back again and remove some others for access, etc. You have to be extremely careful in lining up the pistons so that the rings don't pop out but that you still have enough clearance to get the the wrist pin into the rod. VERY FRUSTRATING but I managed in the end to get them all in, and with all the extra practice my technique certainly improved by the end. The wrist pin clip injector was invaluable for this task.

The most satisfying task was painting the fan. Check out how it looks in the freshly powdercoated housing -- a nice bit of bling for the engine bay.

Mike J

Don, looks like you are doing GREAT!

Agree with the case half's, you have to be well prepared and have someone help to hold the through bolts still while you torque them down so you can motor through it.

I did not have too much trouble with the pistons slipping out of the barrels - did you end up making up a tool to put the wrist pin clips in?

The most nervous and best part ?- starting it up and it WORKS! :-)

Cheers,

Mike

dgmattingley

Yeah, I had some major issues with the pistons slipping out but I think I can chalk it all up to inexperience. The top ring with the spring also jumped out on two of the pistons but I didn't have much trouble getting it back in. My mechanic told me that the 993 pistons are the most difficult to work with of all 911s because of the short distance between the top ring and the wrist pin.

I borrowed the SIR tool from Emerald for the clips, who kindly offered his for loan. It took a few tries for me to get the technique down for that, but then it was really easy. I can't imagine doing it without a proper tool!

e3photo

Glad to see it is going well.

geolab

You did change bearing #8 ? looks like it took a scratch whilst you were trying
to remove the pulley.
late, but this is how I block my pulley.
https://rennlist.com/forums/993-foru...n-car-diy.html
best of luck, regards