Jubilee oil pressure

[Guesseral]

Ok I posted this in the vintage section but this seems like a good place also.

I just got done replacing the engine in my Jubilee, I have done several of this style tractor but this time I have a problem I never ran into before. I have been taking my time during the winter (nothing else to do) replacing parts cleaning painting and so on, I replaced the block with a rebuilt block from an engine machine shop because the original one had a crack between the left side water drain plug and the oil filter, I guess my dad had let it freeze at one time. They did all of the normal stuff, crank sleeves pistons bearings cam and what not. Well last night I started it for the first time and everything was great (after I removed and changed the distributor from 180 deg out I hate when I do that) let it idle at a low idle for the oil pump to prime up about 15 to 20 seconds. Thats when I realized I had a problem, the oil pressure shot right up it went to 80 lbs I lowered the idle even more and got it down to 60 lbs but that's the lowest it will go. I have started the tractor several times at that low idle and 60 lbs is what it has. I have never had a problem with the oil pressure on this tractor, and I reinstalled the old pump all I did was to clean it out and replace the gaskets. Can an oil pump go bad to the opposite direction, I mean when they go bad they usually loose oil pressure not gain right. Could the pressure releif have gone bad, it should be running at 40 to 50 lbs if the spring lost it's spring strength wouldn't it have lost pressure? Could there be a clog in the block (god I hope not) but if there were a clog wouldn't the pressure relief valve kick in? Well I hope someone has an idea on this.

 

[Jerry/MT]

Ok I posted this in the vintage section but this seems like a good place also.

I just got done replacing the engine in my Jubilee, I have done several of this style tractor but this time I have a problem I never ran into before. I have been taking my time during the winter (nothing else to do) replacing parts cleaning painting and so on, I replaced the block with a rebuilt block from an engine machine shop because the original one had a crack between the left side water drain plug and the oil filter, I guess my dad had let it freeze at one time. They did all of the normal stuff, crank sleeves pistons bearings cam and what not. Well last night I started it for the first time and everything was great (after I removed and changed the distributor from 180 deg out I hate when I do that) let it idle at a low idle for the oil pump to prime up about 15 to 20 seconds. Thats when I realized I had a problem, the oil pressure shot right up it went to 80 lbs I lowered the idle even more and got it down to 60 lbs but that's the lowest it will go. I have started the tractor several times at that low idle and 60 lbs is what it has. I have never had a problem with the oil pressure on this tractor, and I reinstalled the old pump all I did was to clean it out and replace the gaskets. Can an oil pump go bad to the opposite direction, I mean when they go bad they usually loose oil pressure not gain right. Could the pressure releif have gone bad, it should be running at 40 to 50 lbs if the spring lost it's spring strength wouldn't it have lost pressure? Could there be a clog in the block (god I hope not) but if there were a clog wouldn't the pressure relief valve kick in? Well I hope someone has an idea on this.

What's the owners manual say the pressure should be?

My guess is that your relief valve is stuck closed or partially closed. Let it run for a while to warm up the oil and see what happens. I wouldn't be too worried at this point. Are you using the correct SAE weight oil in it?

If it continues to run with too high oil pressure, than checking the relief valve would be in order. If you have a shop manual it might show you what the oil circuit looks like. Usually the valve train gets the last of the oil in the circuit so see if the top end is getting oil. If it's not than there may be a blockage somewhere. If that the problem, I'd check back with whoever did the rebuild because something is screwed up.

 

[Soundguy]

ditto what jerry said. i'd be pullign the valve cover and see if the valve train is oiling.

ditto on a stuck relief as well.

I'd even pull the oil filter for a looksee

55 psi should be normal max pressure.. with cold throttle pressures up to 60 just beacuse a good tight red tiger can make alot of volume.

I'd run 10w30, or 15w40 in a mahcine like that.

post back what ya find.

soundguy

 

[Guesseral]

The manual states 40 mto 50 lbs. I really didn't want to take the valve cover off till I ran it a while so I could adjust the valves, but I guess your right I do need to see if the oil is getting up there. I really didn't have any time last night but theres always tonight.

 

[Soundguy]

it's obvious there is some kinf of abherent behavior going on.

reluctance to do diagnoistic observation won't get you anywhere.. and if the top end is not oiling.. then waiting is going to be a BAD thing.

sorry.

valve cover ain't hard to pull anyway.

 

[whodat526]

first do the easy thing chage the gauge and see if that is the problem

 

[Guesseral]

Didn't get much time to look at it last night, had to take the wife shoping I know tractors come first but she doesn't seem to understand that. I did get to confirm that the oil is getting to the filter. I also took the breather cover off of the valve cover and I could see (while running) lots of oil running down one of the pushrods just like it is suppose to.
I feel a little better now at least. I will take the valve cover off over the weekend and make sure there is enough oil flow down the entire rocker arm rail, but with that much oil pressure if it's getting there there shouldn't be a problem with that. Oh yea the oil pressure was only like 58 lbs last night so I am hoping the thought of the pressure relief valve being stuck is correct.

 

[Soundguy]

58 is getting close to normal. in fact 60 psi cold throttle for a few minutes is ok.

80 ain't though

 

[Jerry/MT]

Didn't get much time to look at it last night, had to take the wife shoping I know tractors come first but she doesn't seem to understand that. I did get to confirm that the oil is getting to the filter. I also took the breather cover off of the valve cover and I could see (while running) lots of oil running down one of the pushrods just like it is suppose to.
I feel a little better now at least. I will take the valve cover off over the weekend and make sure there is enough oil flow down the entire rocker arm rail, but with that much oil pressure if it's getting there there shouldn't be a problem with that. Oh yea the oil pressure was only like 58 lbs last night so I am hoping the thought of the pressure relief valve being stuck is correct.

As long as you getting all that oil on the valve train I think your 'll find the problem in the relief valve. It may have been stuck or the spring was a little cocked in it, since you said you cleaned it up. It might work itself loose.

 

[Soundguy]

i agree. 68 psi is getting darn close to 'super' normal pressure for a tight cold engine.