Oliver 1850 gas engine rebuild

[DaveNay]

I am thinking that my tired 1850 needs to have the engine rebuilt, and I am contemplating doing the job myself. I am asking for opinions on what the level of difficulty is for this task for a person with a good amount of mechanical experience but no engine rebuilding experience itself. I am quite familiar with tolerances, run-out, end play, backlash, torque, etc from having done mechanical design of industrial automation equipment but I have never torn apart an engine. I have replaced a couple, but that was a simple swap. Obviously if there was any machine work to be done, a shop would be involved, but what about replacing the cylinder sleeves? Can that be done in an average garage shop environment?

There seem to be two primary distinctions in the rebuild kits; in frame and not in frame. I am assuming that the single biggest difference is that I couldn"t do any work with the crank (or mains or rear seal) on the in frame method?

Finally, what would be the estimated time to complete this job? I have about 6 weeks until the next hay cutting, but I could probably borrow a tractor for that. I do work a regular 40 hrs, so this would be nights and weekends.

I"m sure I am only hitting the high points of my questions, but I want to make sure this is a task easily and reliably done by a regular ol" guy without specific training.

Thanks!
Dave

 

[Soundguy]

before I did anyting I'd do more than 'think' it needs a rebuild. I'd do some testing to see where I'm at.

IE.. dry then wet compresson test.. evaluate valves and rings/ cyl... give you some idea...

 

[flusher]

When the 25 hp 4-cyl Hercules gas engine on my 1951 Minneapolis Moline BF tractor needed rebuilding, I pulled it from the tractor and sent it to the engine shop. Cost $800 parts and $800 labor to rebuild it completely to the short block configuration. Fortunately, I could get all the parts (new old stock) that I needed for the engine rebuild from one supplier (Hercano Propulsion). The engine had zero compression on 3 cylinders and 30 psi on the fourth when I did a compression test prior to removing the engine. You need to have decent equipment to handle the heavy parts (engine hoist, gantry crane, engine stand, etc). My stuff comes from Harbor Freight and works fine.
Good luck.

 

[nwngunner]

I would do an out of frame if you need it. How many hours are on your engine, why do you feel you need a rebuild? I have over 9000 hours on my original 1650 oliver gasser. I thought i was going to need to do an engine rebuild my self then realized it was the clutch that was causing me to loose my pulling power. When i pulled the engine to replace the clutch i put a new front main in it.

The hardest part on the olivers in regards to working on the motor, is getting it out. The four bolts that connect it to the frame are a pain in the arse to get to. Also having a puller tall enough to pull the motor. A normal cherry picker is not big enough to pull the engine easily. You will be at weird angles and trying to work around the front tires to pull the motor. I would suggest get some one with a loader tractor or a over head gantry to pull the motor.

 

[flusher]

I would do an out of frame if you need it. How many hours are on your engine, why do you feel you need a rebuild? I have over 9000 hours on my original 1650 oliver gasser. I thought i was going to need to do an engine rebuild my self then realized it was the clutch that was causing me to loose my pulling power. When i pulled the engine to replace the clutch i put a new front main in it.

The hardest part on the olivers in regards to working on the motor, is getting it out. The four bolts that connect it to the frame are a pain in the arse to get to. Also having a puller tall enough to pull the motor. A normal cherry picker is not big enough to pull the engine easily. You will be at weird angles and trying to work around the front tires to pull the motor. I would suggest get some one with a loader tractor or a over head gantry to pull the motor.

Righto. I use a $500 gantry with 1 ton chain hoist from Harbor Freight to remove engines.



So far I've used it to pull the engine on my 1951 Minneapolis Moline BF and 1947 Farmall Cub. My 1945 Oliver 60 Row Crop is running fine so no need to pull that engine.

 

[DaveNay]

Well the rebuild has been put on hold for a while until I do some more evaluation.

My immediate problem (no power under load, missing, backfiring and stalling when engaging PTO with mower) has been solved by replacing the coil and points & condenser with a Pertronics electronic ignition and coil.

I have a compression gauge that I borrowed from a friend and hopefully I have time this weekend to use it.

Can the oil pan be removed with the engine still in the frame? That is the biggest leak I have.

 

[nwngunner]

No i dont think you can pull the pan, the hole in the frame is just to small. The pan is massive. How does it run now after electronic ignition upgrade? Now if you still dont have much power under load could be your power just isnt getting to the ground? At one point i thought i had a tired motor as well. Then the clutch went out on me one day planting. After doing a clutch replacement and upgrade the tractor takes and puts the power to the ground much better.

I would see if you can find a buddy with an inspection camera and look in the inspection plate on the bell housing and see how the clutch looks. When you pull the motor might as well get the flywheel turned and a new clutch put in even if it is still in ok shape. Save you from having the issue i did and loose it in the field.

I put the clutch in for about 350 bucks, that was including front main seal. I would suggest going to the upgraded clutch that is 6 pucks. Thing will lock up and almost throw you off the tractor.

 

[DaveNay]

How does it run now after electronic ignition upgrade?

It runs nice. Better than it has in a couple years actually. I still don't have full power because I think the governor is either worn or needs adjusting. When mowing with a huge 9' cut/ditioner in tall grass/alfalfa, it only maintains about 1800 rpm. Even with no PTO load, it will only go to about 2100. Full PTO speed is 2400, so it should go to at least 2500 with no load, but it just doesn't go that high. There is no surging from the governor, just can't reach max RPM

I can't find my manual unfortunately, so I don't have a reference for properly setting the governor.

 

[nwngunner]

Dave send me a pm with your email address i will get my service manual out and get in contact with you about the governor adjustment.