Universal M50 or 5444 normal oil pressure range?

[scherzoja]

Can anyone who has a Universal M50 or 5444 tell me what the normal oil pressure range is? Took the engine out a year or two ago to rebuild and never took base line readings on oil pressure prior to disassembly.

Post-rebuild, it has been running low (40 - 50 psi when cold, 10 - 30 psi when hot, depending on rpm). Sometimes drops to single digits.

Found improperly installed rear main seal that leaked oil. Took care of that, now I'm fixin to put motor back and and run it. Just wanted to know what pressure range to look for.

Thanks

[mogulskibum]

Going off of memory here, but cold at idle 30-40, hot at idle 15-20, hot under load/high rpm 35-45.

If I remember right, the switch for the oil light (which also shuts off the engine in the kubota v1902 generator that uses the exact same block) doesn't trigger unless the pressure drops below 5 psi (it's either 5 or 10, I think it's 5 - I know it's 5 on the M25, also based on a kubota, essentially the same block just minus a cylinder). Point being that the engine can safely run for a long time at a surprisingly low oil pressure.