Oliver 1550 overhaul

I haven't posted on this yet, right or wrong, here's where I'm at on it. The old tach has over 5000 hours on it and the new one that was on it when I got it has 125 hours( in 2 years). It used quite a bit of oil and had lots of blow by, so I figured it needed rings, bearings and a valve job. A few warm days in February and I got the motor out on the stand and started tear down. The head is off, you can wiggle the valve springs, so the guides probably need replaced. I took the head to a place I trust to check it out. There is NO ring groove in the sleeves, smooth as a baby's butt where the pistons stop travel, but there is a vertical scratch on 4 sleeves. I got the pistons out and those 4 had the top ring broke in 2 pieces, so I figure the scratch is where the broken ends rubbed the cylinder wall. I took the rod caps off and all of them have a brown spot on one side of the bearing, some bigger than others. I took the 2 center main bearings out and they are the same way, the thrust bearing appears to have a spot worn clear thru the bearing itself. I'm thinking that I need to have the block line bored and the rods checked. I'm trying to do this cheaply as possible. It only does tractor rides, shows, a couple plow days and piddle around home some, I can't see spending lots of unnecessary dollars on it for no more than it does. If it was a working tractor then I could see it. I have a wood project for my granddaughters birthday next weekend that I have to finish before I get back on the motor. Chris

And that is why I dont post much anymore, the 2 pictures in my original post took over 20 minutes to upload. Heres a couple more, see if my phone is faster.





Wow!! Three pictures in less then a minute

Ouch, the thrust face is pretty scored. The brown spots are were the babbit has worn through to the bronze backing. What does the crank look like? I'd bet all the mains look like that. Check the crank for wear and straightness.

What it looks like is pretty much a complete rebuild. The scoring in the cylinders is bad enough to replace them. The crank has been spinning on borrowed time, and I can't imagine it being within spec. I would do it right so the tractor is not a fence row queen in 10 years. Jim

I forgot to add that the rod bearings are.030. Im guessing that the crankshaft has been turned sometime in its life. I plastiguaged all of the rods and the 2mains and they all were.003

Well IMHO here and i have done loads of engine work over the years i personally do not think it needs line bored , Now for the rods yea i would have both ends done and Sleeves and pistons YES , Your not going to Hone those deep scratches out , if you take that much out then you more then likely will have piston slap . I pesonally have the crank turned . And with the block i would be worried about the lower counter bore area as i have seen some pretty nasty looking counter bores in Oliver engines that we have worked on . I mainly work on I H tractors but i also did contract work for and old Oliver dealer from time to time when they got swamped . Ya can tell that tractor did a lot of running where it got a lot of clutch use at higher RPMS by how the thrust side of the main looked like when baling and held down for long periods of time . or someone rode the clutch pedal . . Look at the thrust side of that crank well as it may not be usable . Now had the mains looked more woren off center then a line bore would be required. Tons of hours , poor quality oil not changing oil when one should , Ring breakage could be caused by use of EITHER or timing being off or low quality fuel.

The cylinder scrapes are pretty bad, and I suspect the ring lands are just as bad, so a set or pistons and liners will be in order.

I doubt it needs line boring unless a bearing spun, or the caps are mixed or came from another block. Line boring is expensive. Looks like it may have been put together dirty or not enough clearance. I don't know how many more under sizes are available on the bearings, some only go to .030. The machine shop should know before they turn the crank. But it may be ok just polishing it if it was too tight before.

The worn thrust bearing is pretty common. The thrust surface on the crank may need attention.

Thrust face on the crankshaft will need to be looked at and measured and reground and/or built up as needed, or, if too worn and building up is not an option the crank will need to be replaced.

i see even that thrust brg. is cracked. looks like that on rod is not straight. so them rods should be resized. probably need a crank, as that already has .030 of meat gone. ya them broken rings will scratch the bore. they will not come out. so to do it properly there is quite a bit to do. doing a patch job as you say just to run around on rides probably get away with them sleeves but u need to deglaze them first to tell. hardly think it needs a line bore. then check your piston lands also. but like this if a working field tractor it needs a major, if you running around its a patch up. u can pick . its not like your selling it to your neighbor after.

I'm thinking it will not need a line bore as well. It would be nice to find a crank not taken down so far. I'm wondering if it would be cheaper to find a complete running engine? But then you might risk being back to where you are currently.

I'm 71, kinda doubt I'll be around in 10 years. If I am, pretty sure I won't be able to get on a tractor let alone drive it.

bet cam bearings look nasty too.
as for plastiguage i question it on mains. put pastiguage on bottom of main cap n torqu it. if bearings are worn the weight will be supported via pastiguage. but thats my theory.
line boring isnt needed but crank needs checked,sleeves pistons rods reconditioned head redone and cam bearings too. you do all the other work n old cam bearings decide to turn cutting oil flow off to mains and rod is not good either

I've got tractors that just go to shows and drives too, so I know where you're at. You're even older than I am. I'll tell you the truth, if I was in your shoes, I'd hone it, put rings and bearings in it and put it back together. Tell your wife to be honest with the next owner if she's the one who ends up selling it sometime down the road. Sometimes you just have to be realistic. A $4000 overhaul won't make it worth $4000 more.

2 X

Goals:
I'm trying to do this cheaply as possible. It only does tractor rides, shows, a couple plow days and piddle around home some, I can't see spending lots of unnecessary dollars on it for no more than it does.

At only 65 hours of use per year it won't take much to make it last a long long time. RRLund's suggestions would make it easily last for several more decades.

For peace of mind, while the engine is apart you could also check: the cam bearings; oil pump; crankshaft journals; and cam shaft lobes and then decide if any further repairs are justified. The distributor, carburetor and even the cylinder head are more accessible so they could easily be rebuilt anytime in the future if ever needed.

It would not hurt to do a compression test and a leak down test before tearing it down. They might give you even more peace of mind.

It ran and worked before you tore it down. Burned oil, but did what you needed it to do. And that was with broken rings. You could get a simple ball hone and clean up the bores and stick In new rings and bearings. And it would do what it did before, presumably with less oil consumption. Or you could spend the bucks to do a major on it and have something that will surpass what you had before and do it for many years. It's the cost to benefit ratio. What cost are you comfortable to pay and what return or benefit do you expect from it?

Best advice so far.

I second that, assuming it's a gasser. Rings, bearings, new valve seals and maybe snug up the valve guides a tad, clean up the valve faces, and you should get years of what you do out of it. I'd probably touch up the crank with some really fine emery tape if it seemed to ask for it. Yeah, there are guys that wouldn't be happy with anything less than chroming, balancing, and blueprinting every engine they touch. More cash than logic,,,,,, gm

Yea i know that . Have you ever welded up a crank and reground it ????? , BTDT along with line boring of engines and bore them with a potable bar and also on my friends fancy high tech stationary boring and milling center , and the time the only one like it this side the big creek located in and out of the way back road machine shop . loved that machine ya could set it up and once set up and operation plumbed in ya pushed the big green button and walked away and went an did something else , when it was done it would let you know . take a d 361 or 407 and do the line bore first then set the block up on the boring center and set up off the main bearings and bore her out .010 for the ten over sleeves and you would see how much core shift ya had . when done it was perfect. If he took the crank in then where ever he took it they would tell him if it was salvageable or NOT . A way to slow down thrust ware is to add in a oil passage into the thrust side and give it a pressure lube by drilling at and angle thru the side of the thrust into the main galley just a small drill home and cut in and oil grove into the thrust

(quoted from post at 11:13:31 02/12/23) Yea i know that . Have you ever welded up a crank and reground it ????? , BTDT along with line boring of engines and bore them with a potable bar and also on my friends fancy high tech stationary boring and milling center , and the time the only one like it this side the big creek located in and out of the way back road machine shop . loved that machine ya could set it up and once set up and operation plumbed in ya pushed the big green button and walked away and went an did something else , when it was done it would let you know . take a d 361 or 407 and do the line bore first then set the block up on the boring center and set up off the main bearings and bore her out .010 for the ten over sleeves and you would see how much core shift ya had . when done it was perfect. If he took the crank in then where ever he took it they would tell him if it was salvageable or NOT . A way to slow down thrust ware is to add in a oil passage into the thrust side and give it a pressure lube by drilling at and angle thru the side of the thrust into the main galley just a small drill home and cut in and oil grove into the thrust

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T.V., my comment was directed at the O.P., NOT you.

But who could tell with the obsolete software here?

I sure hope the new software orders the replies below/with the post they are in reply to!

Nice to finally see a few guys that think like me. It was running before I took it apart and probably would have ran a while yet. If it weren't for the broken rings, I'd be tempted to leave the rings alone and just do the head and bearings. That will probably make some heads explode!! I do think I'll have the crank checked, replace the rings, bearings and have the head done and call it good. I'll bet anyone a shiny new nickel that it will run and do what I need to do. Thanks