Lagavulin

How many cylinders had scratches? Did you happen to do a compression and leak-down test prior to tearing down the engine? If so, what were the results, and what were the results with the scratched cylinders?

BC

I'm osrry Lag, but I was not able to get a leakdownb test done before disassembly. It doesn't say much, but my mechanic/friend here in SD saw the scratches and said they would probably contribute to a 5-10% leakdown on those cylinders, as they resided at the very top across both compression rings.

It was TWO cylinders that had these scratches. Those were also the same ones in which the pistons were just a tad off from the very good condition the rest of the pistons were.

The main bearing was shiny in a large swath, and some of the rod bearings were not what I would call pristine.

This is a 75k engine with all records since 10k.

BTW - that white sealent that tony has shown us was ALL OVER my engine on the inside. It was inbetween the cams, in the oil galleys, and stuck to the oil pickup. Very scary. Someone was a bit too liberal with that stuff when they assembled the engine.

Oh - and the ball cup bushing is easy to get to when the engine is out, FWIW.

Tony

Well, the driver side cams are off as well as the head. Piece of cake actually. Ive had the video camera on a tripod filming stuff for reference. When i get the time and know how ill try and post a vid of the cams being pulled as well as the heads.

The driver side has some issues i think. The head gasket looks like it has failed...but not around the metal retaining ring. A pic will be worth a 1000 words so i will let it speak when its posted. I appreciate any input. ill try and bring some of the parts to Sharktoberfest for those that which to have a look see. The issue lies in the head its self i think. The area where the head meets the failed part of the gasket looks as if it has corroasion or has been "eaten away" slightly. I guess there is no such thing as slighly on a SMOOTH flush fitting head! Again i hope a picture will better describe it. To me it seems obvious that a new gasket wouldnt sit flush up agaisnt this area. So, that is my first "now what??"

Clyinder and Combustion chambers look ok, all the black stuff just flakes away with my finger nail and is very soft. There sure is alot of it though and is clinging to the fire ring around the head gasket int he combustion chamber. More and more im thinking this motor did suck in some smoke and that sooty residue from burning rubber..plastic. etc etc.

Im in the process of uploading pics MANY MANY of them. I should have them up in a bit. Ill add what ever notes i can..but i wll go back and updated it more at later time.

OK..is it after noon yet?

Yup....

BC

I had some of the same stuff on my head gasket. The coolant seems to have eroded the gasket in some places. Thehead can be decked, and even welded in those damaged areas. These heads are too pricey to not try and work with them.

I have the same carbon on my combustion chambers. It comes right off with a wire-wheel. The issue is that it could get in the rings if you are cleaning them. This made me take mine out. And now I am sleeving.

Slippery slope.

atb

Sorry to be a late poster to this topic. Looks like Tony is really taking off on his tear down. Hopefully I'll be able to do some catching up this weekend.

Here is where I'm at now:



'87 engine with 148K miles. It was a smoker, but I think the source was found. Thurston Pritchard, a fellow 928 owner that actually come up with the suggestion of flip flopping the engine stand mounts to use shorter bolts noticed one of the cam plugs had ejected and was sitting in a melted and crumpled ball down by the #4 exhaust valves.

Looking forward to getting it into pieces soon.

BC

For the engine removal issues, here is what I remember:

Four bolts holding the engine to the engine mount hats.
Remove all accessories. (i'd like to put it back in with them on - any ideas?)
Remove clutch assembly.
Remove four bolts holding upper bell housing to TT
Remove/unplug looms
Fuel/Coolant lines
Throttle assembly, lay back.
Oil Lines

thats all I remember

Oh, and don't chintz on the engine stand. Mine sags and its a 1k one.

Jay Wellwood

Excellent tip Brendan that all who ever plan to pull their motor should remeber - 2K# engine stand.

Thanks-

BC

That black one that Adam has looks pretty sturdy. You'll see in my pics that I just always have cinder blocks under the block. When I assemble the engine before reinstallation, I may have to rethink my 20 dollar purchase at the local swap meet. It was not so sturdy initially, and that was without the intake on - intake was removed before engine removal.

slate blue

What pistons are you guys going to use? That includes all three of you.

Jay Wellwood

I am using 968 pistons.

Tony

I have a set of 951 pistons, used..in OK shape. Im really not the one to judge the condition of a piston, ill probably leave that to the pros. They do need a clean up and insepctin,, i know that , some little nicks on them. I recieved a nice email from Chris Carrol at PowerHaus. He said he can inspect them and prep them and even ceramic coat the tops if need be.
May even send the block..parts to them to build up a short block..not sure yet.

All avenues are still open..just the billfodld isnt!!

In the meantime, for those that want to follow my autopsy i just uploaded a BUNCH of pics. Im at 120ish i think? May be painful for dial up. I plan on getting a more organized page up eventually. I just need to get this stuff on the computer for my own reference so i can go back and view it if need be. In the meantime, you can all follow along!

Some intersting and scary stuff! All in all its a lot of fun and pretty straight forward!

All input appreciated!

http://members.rennlist.com/v1uhoh/engineproj.htm

BC

I will be using JE for the pistons. The 106mm bore will be chromemoly, and the pistons will probably be the 4032 material that they use. Hopefully I will have enough room with the sotkc rods and stroke to have a nice low compression ring placement (needed for boost) and enough dish area with that lower rod placement for 9:1. JE is right here in SoCal, so I have a few contacts. I have already contacted the gentleman for this, but he wants the bores done first. Pistons, pins, and rings will be sourced with him.

There is an "ultimate headgasket" that is making its rounds in the 951 world, and I will be using one of those.

Ed Taylor

I see Tony has been busy. Hey, it's always after lunch somewhere!


Don't know about the area on the gasket? Haven't seen that on anything I've taken down personally.
Thanks for the update.

BC

Tony - My 81 gasket was exactly like that. I just think its water that gets up in that weave of the gasket and boils right at the barrier to the head. It then pushes on the gasket down into the coolant area. Bad, obviously, but unsure why it happens.

Jay Wellwood

Excellent documentation Tony.

If memory serves, to use the 951 pistons, the side skirts will require a bit of trimming.

The evidence of corrosion between the heads and block are a curious thing...wonder what kind of coolant was used - hopefully it was a non-phosphate type, but who knows???

That black/brown crap in there on top of the pistons - probably left over plastic/hose bits along with the dry chemical as they were sucked into the engine and have been left for who knows how long sitting until you took it all apart.

Looks really good though. Be sure to keep a good record of what cam bracket goes in which position as they are all matched sets.