Another crankshaft question!

With all the engine components apart (yes, I'm still working on that 22-36) and a warm day out I started cleaning up and thought I'd see how the crank mic'ed.

.003 out of round. Does anyone have tolerances for this? With .002 shims [looks like using about 6 {factory 11 from parts book} is about right] and (I think) .003 clearance specs, .003 oval seems rather high to me.

After a little polishing on one journal, it definitely had a few pits that won't come out - even if I have it ground .002, but few enough I doubt it's worth worry (let me know if I'm wrong though! ) . The rod [not originals but looked to be wore pretty similar] definitely got tight (so quick I didn't dare push it farther) about 45degrees from the loosest spot [after tightening it on 6 shims]; both the rod and shell behaved the same way on the shaft individually too.

This thing need a date with the shop, or are there options I'm overlooking?

Thanks again!

Spiffy,unless your a prefectionst that crank will be fine,adjust your shims and forget it

jimmy

For sure don't have it ground unless you find bearings first. But i've never worked on one that wasn't out of round. It should be fine. Those motors turn slow.

i agree, it will be ok. you will need some green plastique on hand. thats the one commonly used for engine brg. clearances. if your clearances are greater than the green allows, it comes in blue and red to check your max. clearance.you may need to torque and remove caps several times till your satisfied. i used 3 pieces , one in centre and then 45 degress on each side. for my own curiosity of crank out of round. you spend a lot of time doing this. when your confident you got it, the crank should roll over freely and no hang ups.

How much running is it going to do? It was running OK the last time it was used. If you remove shims and it still turns free, it will run for many years as a parade tractor.

Thanks everyone; you may have me convinced I'm yet again just paranoid considering the expected use of this machine.

I know replies get confusing with some of us in modern and some classic view: so I'll go backward order in modern view.

Teddy, I think the others know the history of this tractor from other threads, but I'll gladly bore them for a second to bring this thread into perspective, my understanding is:

this tractor was used for all the plowing and heavy work on [rough guess] a couple hundred acres until the 70s; then until the early 80's used on the silo blower and misc, when the governor broke. It ran wide open for a minute or so until they shut it down. Didn't seize, but despite pulling the covers off never got around to fixing the governor. Turned it over maybe once a year (outside catching some rain in the selector plate, also the manifold was rather attractive to mice) for a couple years keeping it loose but sticking nearly all the valves open. After a few years (and somewhere in that time frame rusted the cylinders stuck), it was pulled into a lean-to type shed and sat until this fall when they asked if I could fix it.

Rod bearings on #2 & #3 scored enough that chunks of babbit were ripped out. Alderson had a set quite a bit cheaper than the babbit work (even without figuring another $100 or so for new wrist pin bushings) to redo them all (I could have perhaps melted babbit into the rips and hand scraped them, but that's an art I've never tried) at a local babbit shop, so I went with Alderson's set.

The expected use of this tractor will be "parade" in hours, but much of that will be on a thresh machine, plow, ect. So niether the intense short durations of tractor pulls, nor all day of constant work; however not absent some heavy loads either. Right before ordering a complete overhaul kit, I found it'd be more like a couple threshing shows, and a little Sunday driving, rather than every show in the state originally bounced around. I still found a pretty good deal instead on 3 NOS sleeves/pistons, so am taking the best one of the old ones (less than .015 wear on the sleeve) and tossing new rings on that.

Never used the Plastique brand, so I'm not sure how they compare. In the Plastigage brand, I tried green .001 to .003 once (quite a few years back last I did one of these though!) along with red .002 to .006 but really drove myself nuts, so I only bought red this time. Maybe, I should grab some green when I'm in town again - if for no other reason than so I don't wish I had!

I like your idea of using the 3 pieces at the same time! Do you add the two side #'s together and trig the horizontal backward from that and the bottom or just use it to direct a gut feel? No doubt still time consuming, but like I noted, I remember really driving myself nuts with a piece in the bottom, then in the side, then feel how it cranks (with the others loose and spark plugs out), then adjust shims..... and again..... and again! :lol:

(quoted from post at 09:07:37 01/18/09) For sure don't have it ground unless you find bearings first. But i've never worked on one that wasn't out of round. It should be fine. Those motors turn slow.

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I've had to slap myself up a few times already, and say out loud "It only turns 1050RPM, It only turns 1050RPM...." :lol:

On the other hand, judging from the rod going tight, I already have the bearing fit if I had .001 to .0015 taken from the high sides (.002 to .003 diametral) and none from the lowest points; I can buff it with some fine crocus if it needs to be blended. Oh, oh, "it only turns 1050...." :?

(quoted from post at 08:44:25 01/18/09) Spiffy,unless your a prefectionst that crank will be fine,adjust your shims and forget it

jimmy

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Well, my replies in this thread are probably indicative enough, but I'm a bit bipolar on perfectionism! :lol: I've got away with things that would make both the shade tree mechanic and most detailed machinist cringe, and, on other things, fretted over issues that no-one would even consider an issue.

On this one, I am bit more paranoid though, because, after break in, I'll hear it run maybe once a year, so won't be able to "catch something before it's too late."

Thanks again everyone! Sounds like I may be a bit over cautious on this one, but I'm all ears either way.

A slight tangent too, I haven't been able to get crocus in coarse or medium.

With the crank on the bench, I'm not worried about getting emery dust in the engine, but am I risking embedding it in the shaft if I use emery cloth on the spots that need a bit more agressive attention than the fine crocus?

just wondering if you got it? if you have any where from .0015 to .003 clearance it is good to go, yes it only turns 1050 rpm so i would say it will out run you. it is not real critical to have these specs. right on. i bet there is some of these tractors out there running with maybe .010-.015 clearance. its if you put him to work you want things on the tighter side with hot thin oil. you could also go with straight #40 oil.

Hey that was timing rustred! I had just went out to take another look at it, upon return checked in here and saw your reply.

On the one I mentioned before driving me nuts with green Plastigage, that was just a matter of being a perfectionist.

On this one, the "new" used rods are only wore about half as much as the originals (only a couple of the thin [.002] shims left in those vs. 6 on these where it feels right) and bind 1/4 of the way around without even putting the cap on & vice versa.

I tried it again, and both halves individually [only gravity forcing it to the crank; the other half and bolts still on the bench] bind hard before even getting to the highest point while feeling about perfect at the lowest (actually perpendicular) while bolted tight.

Now I'm back to thinking it does need to be ground. I'd sure like to hear I'm wrong, but binding that hard and not even to the highest spot yet, even shimm'ed .010 wide I'm just not sure if it'd wear in without damage first.

Either way; thanks again for keeping me from getting too paranoid over this!

if you say its tight then add more shims till it feels good. then you can torque it down with plastigage and look at your clearances.this is why i was talking about useing 3 pieces.when you take the cap off you should see the tight and loose spots.without haveing the crank turned you are working with a "flat crank "as the saying goes.this is kind of a nightmare because you are using diff. used rods and brgs. i understand. it can be gotten close but it is very time consuming. you say the crank is .003 out of round.so you will have about.006 clearance at the flat spot if you go with .003 regular clearance.your not working with new machined surfaces here so you need to find a happy medium.you can e-mail me.