Top End Rebuild - can it be done in time?

[disfin]

here is the clean tranny

[EarlyPorsche]

Looking great! I disagree with the naysayers, you may not have replaced every single little thing but you will have an engine that will last you for as long as you own that vehicle. I'm sure the bottom end was tight enough if you didn't touch it. Good job, you will really enjoy your 911 now.

[disfin]

Thanks, that is the plan! I was hoping that this thread would inspire more people that are in the situation I was in.

[dfink]

I will say it now just so it was said...

Don't forget to put the ring gear on the flywheel.

[Superman]

Originally posted by rusnak
Superman, what is the reason for very little oil during assembly?

The new rings need to "get acquainted" with the cylinders. Too much lube and they might not. Honing is done primarily for this purpose. If the rings don't seat properly, they will pass oil which the combustion chamber will burn. If they do seat, they will do so in the first ten minutes. Perhaps in the first ten seconds. Some builders like to install dry. The danger of that is a broken ring. When I freshened my engine, I reused the pistons and cylinders which were Alusil. Bruce Anderson specifically told me not to be nice to the rings. Start it up and drive it hard. Compression helps press the rings out against the cylinders, by virtue of the rings shapes. They are beveled, for the purpose of using compression to press them outward. Clean the piss out of the cylinders. Hone lightly. Very thin film of oil during assembly. There are differing opinions here, and this is mine.

[Superman]

Originally posted by Gunter
For an engine that has never been apart:
Instead of using new rocker shafts, I turned them exactly 180 deg.
One can actually see the slight wear pattern from having pressure on the same area. Centering the shafts is critical to get the right torque and prevent leaks.
I recommend doing the rods professionally.
The shop will shave a few thou off the shoulder, then mount the lower half with the OLD bolts and bore out for the large bearings.
The small bushings are replaced and the rods are peened.
Give them the rods with the new wrist pin and the old bolts.
If the crank, after polishing, is standard, the new bearings can be standard.
I like ARP bolts.

I still think doing an engine in a hurry is asking for trouble.
Doing things right takes a certain amount of time.
Watch the clips for the wrist pins; they want to zoom off into the void. (Or disappear into the case)
Hope it works out without disappointments.

This is all really good advice. I turned my rocker shafts 90 degrees, not knowing if having the wear pattern turned 180 degrees might still cause trouble.

[Superman]

You are an inspiration. We virtually never see a project this disciplined, which is why we didn't expect you would be successful.

[disfin]

Thanks. To be honest, if we weren't up against such a tight deadline we'd be moving a bit slower. But since we don't have the luxury of time we are working 5 or more hours a day on it - after working our jobs during the day and while making sure Donnie is on track with his packing and loading. We spent our fourth of july turning wrenches while everyone else was BBQing. But I don't regret one second of it - Donnie might though, hahaha.

But please trust me when I say that just because we are doing this in a compressed timeframe doesn't mean there is any lack of planning or care.

[rusnak]

disfin, can you post a writeup when all is done and finished? I'm interested in what parts were replaced, and those parts that were re-used, what was done to recondition them? On inspection, what did you see and were risks taken?

[DaddyGlenn]

Originally posted by rusnak
disfin, can you post a writeup when all is done and finished? I'm interested in what parts were replaced, and those parts that were re-used, what was done to recondition them? On inspection, what did you see and were risks taken?

I second the motion. A detailed write up would be very valuable.

[ischmitz]

man you guys are tough - I am surprised he found the time to snap any pictures and post them given his tight schedule. When I am knee-deep into a project I ususally forget to do so. On top of that it is a royal PITA to take off your gloves every time so that the camera doesn't get as dirty as my hands. It interupts the flow......

[disfin]

engine is fully assembled minus the tranny. too tired to deal with pictures, so they'll have to wait.

Tonight was finish cam timing, install remaining rockers, chain box covers, tin, exhaust, alternator, clutch, intakes, plugs, wires, and all the little things that go along with it.

Just think, after we get done with the car tomorrow we get to load a 24 foot trailer with furniture. SWEET!

[dweymer]

get out of bed and get over here lazy a$$!

[DaddyGlenn]

Well???? We are waiting!

[disfin]

Well, the engine and tranny were reinstalled yesterday. It fired up on the first try, but proceeded to run rough. Rough enough that we decided to shut it down to avoid damage and evaluate before running further. Unfortunately that was at 8pm and donnie was due up in NC by the early morning so we were unable to diagnose any further. It was a very long hard day (12 hours of loading a trailer and working on the car in the FL heat) and was a major disappointment as we were certain we had dotted all our I's and crossed our t's throughout the whole process, but especially the reinstall.

The good news (for me and the car) is that donnie's buyers were unable to get their loan paperwork back in time to make closing so we have another week with access to his garage so we didn't have to tow the car home. He'll be back in FL sometime next week and we'll be scrambling to diagnose. I really don't want to put it on a trailer!!

Seems that its running rich, it doesn't hold idle very long (idling high and hunting for idle), and doens't gain power hesitatating to go above 3k rpm. There is a laundry list of items that could be the culprit, intake leak, speed sensor, vacuum leak, ground wires, and I'm sure several more. Since the car is motronic we are ititially ruling out ignition timing. We'll focus our efforts on items that can be checked without removing the engine again. We put in new intake gaskets, and double checked the intake nuts, so a leak in there is unlikely. The ground wires were double checked and cleaned. The speed sensor worked just fine before the engine removal so it is unlikely to have failed. There was one tiny little vacuum hose that was loose in the engine compartment when I bought the car, but since it ran fine I never thought much about it, just figured it was an emissions control or something. Anyway, I didn't put it back in cause I don't know where it goes.

So after two exhausting weeks I failed to meet my deadline of having the engine complete and running properly. I love a challenge and I especially love being able to do something I'm told is impossible, so typing this post has been tough. My only consolation was being able to sleep in today. I hadn't slept past noon since college. I really am tired. I'm sure donnie is even more so after towing a trailer up to NC last night.

John Meyers

[EarlyPorsche]

Don't worry, if the hard parts are good then the rest is easy. Sounds like cam timing possibility to me, but I could be wrong.

[dfink]

+1 on cam timing. I had one side 180* out but caught it when the intakes for 1 and 5 were opening at the same time.

[dweymer]

It seemed to get worse as it warmed up, I double checked the cam timing, twice. Easy enough to pull the intake covers and look. I will be working on a list of things to check:

So far:
CHT sensor
oxygen sensor
idle sensor
speed sensor
cam timing via observation through upper valve covers

It sucks to not meet a deadline; although we had contingent plans, one never likes to have to use them. I apparently do not have enough experience with DME to quickly diagnose like CIS. Sorry we missed it this time, we'll get it this weekend. The good thing is I know all the good places to stop on 95 now!

[disfin]

Agreed, it did seem to get worse as it warmed up. Glad to see you made it up there alive.

[alniki]

John,

Wish you correct the issue very soon and enjoy the car again.

Also, did you get a conclusion of what caused the high oil consumption? Is it the valve guide, valve seal, or piston ring?
I'm interested to learn about that, thanks!