78 3.0 engine rebuild 2/11

[Flat6pac]

I haven't posted a build for a while, I have 2 to do, been sitting in the garage all winter on stands so I could move them out of the way for other things.
The engine had a few defects that were purchased knowingly with the engine, just not knowing exactly the problems.
Bruce

[onboost]

That's right man.. time to get busy!

[boyt911sc]

Bruce,

I'm also starting my 3.0 liter SC engine rebuild which is long overdue. I have a problem about getting the old crankcase sealant residue off the mating surfaces the PO used. What method would you recommend or suggest to get this hard and brittle residue off the crankcase. I've been scraping and cleaning the crankcase for 2 days in a row and still not near to completion. Thanks.

Tony

[Cipotifoso]

One trick I learned to clean up a sealing/mating surface is to use a small rectangular knife-sharping stone lubricated with WD-40. You can remove the old residue and clean up the surface with this method. You'll need to remove the oil residue, of course, before the new sealants are applied.

Dave

[cgarr]

Getting everything clean is what about 80% of the time in a rebuild?

[Flat6pac]

Well, the topend has been apart.
There is 24 993 dilivars in place, too expensive not to use.
The top was not torqued properly, very loose
The PO had dropped a tensioner on the left and wore a rail trail to the rear of the chain box.
One of the heads was date stamped different but is a proper big port euro so its a match.
The #5 has blowby between the cyl top and the head Head gasket in picture 3 shows what is and what should have been.
This engine hasnt run much since the top end redo but you can tell the heads were loose from the deposits on the new oil return tubes.

Bruce

[Flat6pac]

I was quite suprised as to how clean the inside the engine was, good oil and not letting it coke. Bearings are beautiful and original. The case through bolts have white O rings on them, original factory from the time, this thing has never been opened.
Bruce

[Flat6pac]

I pumped up the oil cooler since Friday, 75# for 4 days, will be good to go.
The case is de greased, doesnt look as good as it did wet but some stains are there to stay seeing they been there for 32 years.[img]
Bruce

http://forums.pelicanparts.com/uploads18/DSC020551297735006.jpg[/img]

[Flat6pac]

The first picture of the cooler didnt take
Trying again
Bruce

[Flat6pac]

Ill be getting everything together, the mains had lots of original standard spec, Im resealing the center case now that I can tell someone what I have for sale all the way to the bottom.
New chain rails and properly lining the chains, intermediae shaft bearings, return tubes, etc, check the heads at the shop, let the machinist decide what is perfect.
Bruce

[Flat6pac]

After noon it warmed up enough to get in the garage, 75 yesterday, 55 today..
I put the 2 halves together, got everything torqued and turning. New chain rails installed. The Yamabond looks rough until it seasons then can be cleaned up. The sealant works very well but it has to be applied to both sides of the centerline.
I took the fan system apart so I can get fan, housing and shroud cleaned up and on the shelf.
The time things take
Bruce

PP doesnt want to take my uploads right now so I ll post the pictures later.

[cgarr]

Torco assembly lube?

[Flat6pac]

Just some super slick to keep things rolling..
Bruce

[boyt911sc]

Originally Posted by Flat6pac

Ill be getting everything together, the mains had lots of original standard spec, Im resealing the center case now that I can tell someone what I have for sale all the way to the bottom.
New chain rails and properly lining the chains, intermediae shaft bearings, return tubes, etc, check the heads at the shop, let the machinist decide what is perfect.
Bruce

Bruce,

Is there a specific orientation of the connecting rods when installed. I tried to document my engine teardown but I missed this one. Looking at the pictures of my motor, the connecting rods for #1, #2 & #3 cylinders show the stamped number (face down when installed). The question is how are the other bank's con rods are oriented? Would con rod's stamped numbers for #4, #5 & #6 be facing upward when installed? I don't have a good history of this motor but obviously it had been overhauled prior to my purchase.

How do you orient the connecting rods with respect to the crankshaft during installation. Thanks.

Tony

[Flat6pac]

Tony, I ve already sealed this engine up. I have another crank open for the next build, anoother 78, I ll look to see how the factory did it.
I ve read a snipit on the numbers but I dont remember the high lights. I know I build it with the numbers up, the 6 rods pointing at me so I know the numbers match. That would be 3 up and 3 down. I ve done well over 200 motors and there hasnt been a problem.
Bruce

[boyt911sc]

Originally Posted by Flat6pac

Tony, I ve already sealed this engine up. I have another crank open for the next build, anoother 78, I ll look to see how the factory did it.
I ve read a snipit on the numbers but I dont remember the high lights. I know I build it with the numbers up, the 6 rods pointing at me so I know the numbers match. That would be 3 up and 3 down. I ve done well over 200 motors and there hasnt been a problem.
Bruce

Bruce,

Thanks for the reply. I believe it was 3 down (for 1-2-3) and 3 up (for 4-5-6) but not certain. I've done a couple of top end rebuilds but this is my very first top/bottom project. Sharing your vast experience with us is priceless!!!!

Tony

[Flieger]

I would think that it would not make a difference since the rods are symmetrical.

[TibetanT]

Agree!

rods are symmetrical and the only stipulation is that the numbers match-up when putting them together; both Wayne's book and factory manual information.

Of course, I am no expert, but I will share my findings with respect to number placement on my '78 3.0L crank as soon as I can get into my garage from all the snow we got. I haven't taken them off of the crank yet, since everything looked very good inside on a 120K mile engine. That way we will have another "factory" look at how things were done back then.

[tom1394racing]

In this video, Nick Fulljames explains the preferred orientation of the rods on the crank

YouTube - 911 68 crankshaft assembly.wmv

[mycastle]

Bruce - been fun watching you do the rebuild. Glad to know there was a lot of good left in that engine.