High oil pressure on Ford NAA?

[jgayman]

I just bought a 1954 Ford NAA and I am in the process of doing the usual tune-up and fluid replacements. I changed the oil and used 10W30 which is what I use in a 9N I have. The tractor starts quickly and runs very smooth but the oil pressure guage didn't work when I bought it and upon replacing the guage I see the oil pressure is up around 70lbs when I first start it and then drops down to around 50lbs. Is this normal?

It's still rather cold here in the Northeast and I'm working outside so the engine isn't warming up as much as it should.

Should I be concerned about the high oil pressure? I was thinking of swapping the oil with 5W20 as I normally use my tractors during the winter months for snow plowing.

I also read somewhere that there is a valve or spring in the oil pump that can stick and cause higher than normal oil pressure.

I would appreciate any advice or suggestions from those more experienced with the NAA than I am.

Thanks. - John

 

[Soundguy]

the relief is set around 55psi on the ohv engines. In -florida-, on 15w40 oil and a worn engine I normally see 60-65 psi pressures that drop to 50 at hot throttle and 45 at hot idle.. I have a couple real worn ones that are as loose as a goose and clapped out and still make 45 at startup and 25 at hot idle.. those OHV engines just make good oil pressure.. much better than the N series did..

In a cold area on a better than average engine and new oil.. 70psi? that's not out of the ballpark. could always squander 10$ on another gauge to double check.. but if it drops some when warm.. I'd probably just run it.

a stuck oil relief on a tight engine would liekly make 80+ and some leaks..


soundguy

 

[jgayman]

Thank you very much for the quick reply. I was working on the tractor this afternoon changing the coolant and trans/hydro oil. Afterwards I allowed it to warm up and the idling oil pressure is around 40-50 lbs. So I think I'm in good shape. I think I will go ahead and put in 5W20 the next time I do an oil change.

- John

 

[Soundguy]

sounds like a good tight engine.

if you hit 70.. that's where I'd call it a problem.

soundguy

 

[sawtooth]

Thank you very much for the quick reply. I was working on the tractor this afternoon changing the coolant and trans/hydro oil. Afterwards I allowed it to warm up and the idling oil pressure is around 40-50 lbs. So I think I'm in good shape. I think I will go ahead and put in 5W20 the next time I do an oil change.

- John

Hello soundguy,

i know this is an old thread but speaks of the info i'm looking for. i'm getting ready to change the oil in my NAA. What oil pressures should i be seeing with a 30 weight oil and also a 10w-30? Trying to decide which i want to use. Tractor cranks and runs ok just trying to see how much engine wear i have. Seems like now i'm seeing around 40psi but can't remember if i used 10w30 or just 30 weight.



thanks,

 

[Soundguy]

the relief valve should crack around 55psi.. and with cold thick oil at high idle, on startup you can see 60 psi oil pressures.. that should fall back once the oil warms, unless it is excessively warm oil.

most red tigers hold excelent oil pressur eunless extremely warn.. and even then, can hold better oil pressure than an N

on a average machine with 30w oil.. I bet you see oil pressure in the 40's I personally would use a 15w40 oil.. though on a good engine.. 10w30 should be fine.

if hot idle psi is in double digits, and work psi is higher.. about 6 psi per 1000 rpm.. it's still workable.

even worn red tigers I've seen hold 20-40 psi at pto rpm.

 

[sawtooth]

the relief valve should crack around 55psi.. and with cold thick oil at high idle, on startup you can see 60 psi oil pressures.. that should fall back once the oil warms, unless it is excessively warm oil.

most red tigers hold excelent oil pressur eunless extremely warn.. and even then, can hold better oil pressure than an N

on a average machine with 30w oil.. I bet you see oil pressure in the 40's I personally would use a 15w40 oil.. though on a good engine.. 10w30 should be fine.

if hot idle psi is in double digits, and work psi is higher.. about 6 psi per 1000 rpm.. it's still workable.

even worn red tigers I've seen hold 20-40 psi at pto rpm.

Thanks for the info. Update: I changed the oil and went with a 10w30. So with a warm engine im seeing 39 or 40 psi at idle (475 rpms) and 45 or so at PTO speed. Based on yours and other info it sounds as if the engine is in strong working order.

 

[Soundguy]

40 psi at warm idle? she's fine. got ++decades left in her.

 

[sawtooth]

Thats what i was hoping to hear. We basically restored the entire tractor EXCEPT for the engine. I know this is strange but my grandfather did it a few years before he passed so felt it should still be in great shape. I have a ridicoulous amount of money in everything else on it and could of bought a brand new NewHolland. However, my great grand dad bought it new in 53 so it means alot to me just to have it. Anyway i felt i was wasting money rebuilding the engine again but was a little worried once it was complete. It runs great now but guess i was second guessing my decision. I will post a before and after picture in a few. Thanks again for your help.

 

[sawtooth]

Here are the before and after pictures. I have no idea how many hours are on this tractor. It was basically used along with another tractor to service a 150 acre farm from 1953-1991. Used for feeding, hay, planting / harvesting etc. They sure don't make them like they use too.