1968 S engine rebuild - seeking wisdom

[Gearby]

Me thinks the only gift I'll receive is to rectify the carnage. I worked for him in the 90's maintaining the drills and trucks for our foundation drilling company. Comically now, I was his mechanic then. When I asked him about plastiguage, he gave the deer in the headlights stare. Then he finally said "Well, we had some trouble figuring out......" I'm sure you can fill in the rest. He felt it was too much trouble to remove the pan and main caps. The engine was still on the stand.
Oh, just wait until....

Rich, keep us updated. I'm curious as to what you find.

[304065]

Something doesn't make sense. If the engine won't rotate because the bearing clearances are too tight, how did the assembler time the cams?

My money is on the fan belt being too tight or something hanging up with the clutch.

How much has the flywheel been lightened?

[Frank Beck]

Something doesn't make sense. If the engine won't rotate because the bearing clearances are too tight, how did the assembler time the cams?

My money is on the fan belt being too tight or something hanging up with the clutch.

Again, not to talk over Rich but it's not that it's "locked up" but simply "too tight."

It can't be the belt or clutch. Monkeys would fly from my butt before that could happen.
I suppose it could have been the flywheel dragging on the bell housing but even that would have "lathe cut" necessary clearances by now.

I'm betting someone didn't do their due diligence in properly assessing the case align bore. Although case looks like sand cast alu; would be very strange to have align bore issues.

[Richsmith901]

I went with this

https://www.design911.co.uk/mobile/#part;id=131114

Weighs 15lbs

[Gearby]

I'm with Frank, you couldn't tighten the belt enough to do that to a motor. Any problem with the clutch you would hear as its external to the motor. Assembly Lube is pretty slick stuff so maybe it's possible that the mains could be a little bit tight and the person assembling the motor might not have noticed but now that the assembly Lube is gone and it's just oil? Just trying to offer alternative possibilities.

[gled49]

I've seen main lines in Mag cases so crooked it took a 2 foot breaker bar to turn the motor over, but never Alu. Is it Alu? I've seen bearing sets with one .25 bearing 1/2 in the set. Not likely, but I always double check sets for matched bearing. Good luck and let us know what you find.

[Richsmith901]

Crank case is aluminium.

Attachment 450380

[Frank Beck]

Crank case is aluminium.

Attachment 450380

Is that a neoprene o-ring on the #8?

Haven't used one of those since the Carter Administration.


And not to dis your guy but silicone is a little antiquated too. Viton baby.


Please don't leave us hangin once you find the final problem. I'll recant on my first hunch... my new guess is tight rod bearings.

Good luck.

[edmayo]

You mean because those rods are standing straight up?

[Richsmith901]

Think they are sitting up for the picture

Attachment 450496

Attachment 450503

Attachment 450504