8N Saga - Phase 2

NCmau

Member
I am moving to phase 2 after my initial post. I decided to remove the engine vs just the oil pan mainly because I wanted to inspect the clutch department. I am glad I did because there is oil everywhere and it will require attention, (but that will be phase 3).
So here I am proud to say that I lost my virginity in tractor internal medicine. The only internal medicine experience I had was a 2-cylinder lawnmower engine, same concept but much more grunt and knowledge intensive, not to mention new creation of choice words.
What happened originally I bought this late 52 8N, drove a short time to check it out, small indication of oil pressure, then I heard a scraping noise from inside the engine, zero oil pressure, and drove to the shop. Tried to start it again… no go… locked up. Head off, poured PB blaster in cylinders after trying to rotate it for a few days, I was able to free it. Drained the oil, the screen and the oil pickup assembly were like a tortilla and was just everywhere. I guess It got stuck in the crank and locked up the engine.

I like to mention that this tractor is not a family heirloom. I bought it for a winter project in the summer and I intend to keep it just to have it for light work. I used to have an 8N years ago and I always liked the elegance and simplicity of the N tractors, not to mention the parts availability. But, I wanted a loader and everyone knows that N tractors are not loader tractors unless you just want to go straight. So I ended up with a Massey 40 HP class tractor which is a great machine except for the parts. When ordering a part sometimes, you never know get the right part. (So many models, made in so many different countries).

Now I have the N engine on a stand and here are the measurements I have taken to the best of my ability. I used a micrometer and a telescopic T gauge for cylinders.

Rod Journals……2.082 to 2.090……………..Manual Specs 2.094………0009 - .0025

Main Journals……2.240 to 2.245……………Manual Specs 2.2485……..0005 - 0025

Sleeves ID………3.190 Across……………...Manual Specs 3.1875 - 3.1885

My intentions are not to spend a fortune for this tractor. I like to have it running in a decent manner but not necessarily with the same specs that it came out from the assembly line in 1952. Before the oil pickup tube mishap, the tractor actually sounded really good, no smoke, no skipping, idle speed and all. The only problem was that I had to run it with the choke all out, no vacuum leaks, probably carb issue… anyway, minor problem.

At this point I need guidance.
1. With the readings above, can I get by installing just new bearings and maybe shims? I know I am not exactly in specs, but this is not a racing engine. I am just hoping. I refinished journals in steps to 1000 grit and they are smooth, no ridges, finger nail test.

2. The cylinder sleeves and pistons look pretty good, they are very close to tolerance and I would like just to replace the standard rings.

I will greatly appreciate all your collective opinions regardless how different they maybe.
 
(quoted from post at 14:13:32 05/31/18) Crank needs to be ground to .020. It is past .010 already.

Yea, I expected that. So going to the machine shop, I give them the manual specs and they determine the amount to ground for a .020 bearing? I just like to know I have never been in that situation before.
 
(quoted from post at 15:05:59 05/31/18)
(quoted from post at 14:13:32 05/31/18) Crank needs to be ground to .020. It is past .010 already.

Yea, I expected that. So going to the machine shop, I give them the manual specs and they determine the amount to ground for a .020 bearing? I just like to know I have never been in that situation before.

NCmau, I think you're doing great. I know you are reluctant to put a lot of money into it, You are already this far, bearings aren't all that expensive, just the machine work might be. After you put in new gaskets and rear seal, you probably will have taken care of phase 3. Keep us posted.
 
NCmau, I think you're doing great. I know you are reluctant to put a lot of money into it, You are already this far, bearings aren't all that expensive, just the machine work might be. After you put in new gaskets and rear seal, you probably will have taken care of phase 3. Keep us posted.

Thanks. I am going to the machine shop tomorrow. So as asked previously, I give them the manual specs and they determine the amount to ground for a .020 bearing? I know this is second nature for these guys, but I need to know what info I have to provide beside my credit card number.
 
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In two day I should get the crank back. Actually it was cheaper than I expected ($80+tax). I ordered the one-piece front seal.
Question: this seal has one solid side and the other side is hollow, like a channel. I would think the solid side would be placed towards the block. Just want to be sure.
 

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