Engine Seized after rebuild

This post is a continuation of the struggles I've had rebuilding my 1010RS. As a catch up: tractor started running really rich with no warning last summer--in my foolishness I thought the enigne was giving out because it already had low oil pressure and started a rebuild of the mains, rods, and cam bearings (lower half of the engine. Did not touch the head or cylinders as I'm ok w/ where compression is right now). That was completed around thanksgiving but I spent the next months (until now) battling the flooding problem and poor spark. I'm a college student so I only go home on some weekends. Well I'm happy to say that I think I finally figured out the fuel and spark problem, but my engine has seized. I haven't run the tractor more than 10 mins since the rebuild but have cranked it a lot trying to figure out the fuel problem. I'm preparing to tear it back down, but wanted peoples thoughts/ideas on here of what I did wrong. I have checked the main and rod bearings, and I can see oil dripping down from the caps, and I removed the no 1 main cap and the no 1 and no2 rod caps, all of which had a film of oil, and my pressure guage showed 60 PSI the few times it ran. At one point I got the tractor to run for ~5 minutes, albiet poorly, but it screeched to a halt and it sounded like it came from the front of the motor. I'm suspecting its in the cam. As I've been looking into this, I've also discovered that the front and rear crankshaft seals (which I replaced) are both leaking, so I've got to fix that as well. I am attaching pictures of the rear seal, as well as an image that shows the no 3 cam bearing with oil pooled at the bottom, which makes me think it was getting oil. I don't suspect a valve problem because I didn't have one before the tear-down and none of my pushrods are bent in the slightest. Anybody have any ideas or suggestions on what I can check or what I may have done wrong? I won't be home again to work on it until Friday, but plan on putting the engine on a stand and removing the cam to see whats going on.

Also, completely unrelated, but the service manual calls for a special "clutch disk centering tool" to be used when reinstalling the clutch. Do I really need to be concerned about that or can I just use the shaft that connects the flywheel to the powershaft to center it when I put it back together? Thanks!

Is the cam seized? It shouldn't be unless you replaced the bearings.

I did replace the cam bearings, that's why i'm thinking its the cam.

(quoted from post at 20:26:07 05/26/19)
I did replace the cam bearings, that's why i'm thinking its the cam.

Click to expand...

Were the bearings installed with the holes in the bearings matching up with the appropriate oil holes in the bearing bores in the block?

As best as I could tell, yes. I had to take one of them back out twice in order to get the holes lined up. However, its entirely possible that I screwed that process up, and I do think that one bearing was covering about half of the oil hole but I thought it'd be all right.

Assuming that it is a cam bearing that has seized, is this something where i can just remove and correctly reinstall the bearing, apply abundant amounts of oil to the cam, and reinstall, or am I looking at a bigger job here?

I'd also double check the ring gap.

I didn't touch the rings during the work I did. Pistons were never removed from the sleeves.

Replace cam bearings. Was there any rust in bore?
Be sure they are clean. Only install bearings once.
You probably disfigured the one you removed. The
cam is probably galled.

So I need to replace all the cam bearings? What does it mean if the cam is galled? Is it no good at that point?

It could be anything.

Why do you think it is cam bearings?

If the cam is gallded material from the
bearing will be stuck to it. Polish it
off. And yes they are a one shot deal
unless you have a reamer.

Bumping this back up to re-ask, any suggestions on fixing the leaking front and rear crank seals?

Thanks

On lip type seals I grease the rubber
good before installing. I install and
then take a thin feeler gauge and slip in
at an angle. Work it back and forth a bit
as you go all the way around. This will
ensure the lip didn't roll over on you. If it has rolled you will feel the difference. Just go slow and it will seat properly.

Allright, so I got the engine out on a stand and started taking stuff apart. It wasn t the cam, and the problem became obvious when I pulled off the rod caps. Two of my rod bearings seem to be disintegrating. I m attaching pictures of the bearings and the crankshaft. So, what are my options here and what do you guys think caused this? Since it s a show tractor and gets few hours I m wondering if I ll be ok just cleaning up the mess and putting in new bearings, but not knowing what caused it I m afraid it might happen again.

A reminder that this was just ground and polished to .020 over.

Thanks again

Did you check any of the clearances with Plastigauge?
Sounds like things were a little too tight. I would guess the clearance should be around .002-.0035". Green Plastigauge.
Always check your mains and rods with Plastigauge when assembling. And always pre-lube the bearings with at least oil; I use Lubriplate 105 assembly grease.