1850 Oil Pressure and other questions

I am bringing my 1850 into the garage to change out a very weak Hydraulic pump. I have also noticed that the oil pressure is slowly dropping. It used to come right up to 40-45psi on the gauge and stay right around 40 all day long. Over the past year it has gotten lower and now drops from 35-40 after start up and then runs about 25-30 once its warmed up. Seems to me like bearings are getting a bit worn although it does not knock any worse than it ever has. I was thinking I might drop the pan and have a look at the bearings once its in the shop. I have had tractor for 20 years and only God knows how many hours are on the engine. I have no idea if anyone else touched the engine since 1967 when it left the factory.

Question 1 is: If the crank has been ground at some point will the bearings be stamped as oversized?
Question 2: Do the rod bearings or the main bearings make the oil pressure or is it both?
Question 3: Can you drop a piston out the bottom with the crank in place? No 1 cylinder always smokes bad. I changed the head gasket in the summer and the valves looked fine so I am thinking the rings are a bit worn on that cylinder. I changed fuel pumps and put a new injector in and nothing changed. An old English mechanic told me you can give these old Perkins sleeves a quick hone and slam new rings back in. I know I should have done this when I had the head off but only had a short rain delay between hay fields.

Yes, the bearings will be marked as over sized. We have the same tractor at the farm. Early on we found a weak spring in the oil pump. That brought the oil pressure up some for a few years. It was totally rebuilt this past winter. You are describing a well worn engine. Just putting new rings in an old engine with sleeves that are probably out of round is a bad idea.

you have camshaft brgs to deal with also. plus the crank brgs would be undersize not oversize, if the crank has been turned. how do you know #1 cyl. is the one smoking? you do a compression test? it could be a bad injector also. when u want to check oil pressure you put a master guage on it and check the pressure. pistons come out the top. valves must be removed from the head to inspect the valve and seat wear.

I had taken the exhaust manifold off to change the gasket and ran the engine. Most of the smoke was coming out of the forward cylinder. The tractor has always smoked heavy when cool or under light load. When working hard the smoke turns from white to dark. When I had the head off this summer I checked the valve seats and they looked pretty good. For that matter when I rolled the engine over the cylinders looked decent as well but the forward cylinder did seem to be a bit more glazed then the other 5. The tractor uses little oil, still makes good power and starts easy.

Sounds like I better just get it over with and order a couple of rebuild kits. I have been limping the beasts for too long. It?s feels daunting to do a big engine when I have only done little 4 cylinder Suzuki engines up till now.

I can remember reading about some old engines that you could drop a piston out the bottom. I even remember a description of this being done in the ?Grapes of Wrath? but maybe Steinbeck wrote that part as fiction along with the rest of the book? Haha

I pulled a Ford V8 apart a few years ago and found that just one of the pistons would come out the bottom. But it does no good because you still have to deal with the ridge that forms on the top of the cylinder. UNLESS you use "ridge dodger rings" but that's another story we won't go into.

Pistons won't come out the bottom of that engine. I bought a one owner 1850 20+ years ago. Sharp tractor,but the owner must have over done the ether or something,it had broken rings in two cylinders. After having that one torn down twice,and having oil pressure issues,I threw in the towel and put a low hour engine out of a White 8700 combine in it.

I guess it must depend on the length of the piston skirts whether the piston will drop out. I will limp it until spring now. I have a complete engine sitting on my shop floor that a old fellow had started to tear down but ran out time. He had rebuilt the head but when he put it all back together the bottom end failed after a short time. I will try to get to May and swap the motor, maybe do the clutch at the same time. I had a similar failure years ago after putting new injectors and fuel pump on an 1850 I bought from my neighbor. It ran for about a day really nicely before the head gasket failed and broke a piece off the top of one of the sleeves. Its now a parts tractor. It seems when you repair one part it just goes to the next weakest link in the chain.

The Perkins in the 1850 has the single bolt at the front to support the engine. Did the engine from the white combine have the same configuration? I can still find the occasional White or Massey 510 combine up here that have the Perkins engines in them. I passed on a couple last year because the combines were in such good shape I just could not imagine scrapping them just to use the engine. They went cheap enough. I would consider doing this if I could get one home for less than the cost of a rebuild.

A 510 engine will work. It doesn't matter which combine you get one out of,Super99 used one out of a 750. You have to strip the combine engine down to the block and head for the most part. You use the parts off the tractor engine to remake it to fit. The oil filter and cooler base has to be moved to the other side and the plumbing for the oil pump had to be changed to take the oil to the other side. You put a pipe plug and soft plug in where you take the combine filter base off. You use the tractor front engine cover,oil pan,water pump,front pulley,tappet cover,rear side cover,even the injector lines since the combine uses a cable and the tractor uses a rod. The combine lines aren't bent and spaced right for the rod to run down through them. The plate on the side of the injector pump has to be changed to hook the rod to vs the one for the cable.

Don't over think it,it's not a huge deal,you just have to swap things over until the combine engine looks like the tractor engine. I just don't know if it's worth the cost of overhauling a 354. You can buy a low hour combine engine for way less than it costs to overhaul one. Even better if you can buy the whole combine and sell it for scrap after you take the engine out.

I am keeping my eyes open for a 510 or Old White combine now. I think I will still rebuild the engine that I have had sitting on my shop floor as the head only has a few hours on it. It really needs to get out of the way. I have a hydraulic pump to change out this week and then its on to the engine.

I am keeping my eyes open for a 510 or Old White combine now. I think I will still rebuild the engine that I have had sitting on my shop floor as the head only has a few hours on it. It really needs to get out of the way. I have a hydraulic pump to change out this week and then its on to the engine.