oil pressure

[Just40]

I have wilsonia gauges in both my cars and the oil pressure sits about 10psi at idle and about 26-27psi when driving, anyway i put another motor in my sedan to go to mt gambier and compression test was good but the oil pressure sit about 24psi at idle and 27-28psi when driving, now will this be harmful to the motor. I have taken the tappet cover off and there is plenty of oil getting up to the rockers.

[Geoff_K]

Hi Just40,
I think a little more detail may be helpful.
1. What oil / grade etc is being used, is it the same as in the other motors.
2. Is the engine, oil pump brand new, fully reconditioned etc.
3. What happens to the oil pressure when you drop back to idle, after running at a constant 50mph (or above) for at least 40 minutes (to ensure oil temp is up to water temp).
Having high oil pressure at idle is not a problem in its own right, however, it could indicate another problem ie a major blockage/restriction elsewhere (eg along main oil gallery).  I can't actually image where that could/may be, but at idle the pump can only move so much oil, and the resistance is not enough to get the pressure up (worn motors have even less resistance and thus lower pressure)
Assuming the worst, and that you have say 1, 2, or 3 main bearings being starved of proper oil flow is a serious problem for a working motor.
On the other hand, you may have an exceptionally high quality/build oil pump, in a very fresh high quality/build motor.
Regards, Geoff_K

[Just40]

its a 138 that i mate had sitting around for 6 years,(he has 8 of them) looked like it has been a reco,we did a compression test all pots 120 and looked at the timing gears all clean with no sludge or crap to be seen.
the motor runs sweet as with no noise other than a slight tappet noise running 50/20 oil , i have run to the coast twice and when i get off the highway at the lights i drops back to around 24psi at idle.
anyway i am putting a new dash in Monday with a reco oil gauge and see what i get then.