Oil pressure relief? Bypass?

[docdog]

Does anyone have info on a (possible) check valve located inside the boss/housing for the oil filter? When I changed the filter on my Z20 ('84) the ball was lying inside below the filter gasket surface and the spring was in the hole @ abot ten o'clock position aft of the filter stem. I talked to Nissan parts counter and he could only find something that looks to be inside the pump itself. The ball is about 1/4" dia and the spring is tapered. I'm running 60psi oil press and wonder if its too high (blowby) because the ball is not able to stay in the hole... Are there other parts or an assy?
Thanks!
Doc

[PEZi]

I can't lie to you right now, I am extremely tired and and need to come back to this. I just want to give you a response for now that may help... and yes, 60 is WAY too high. 40 is all you should see at rev and less than that at idle. I'll review this further once I have some time, my friend.

[docdog]

A rebuilder tells me that the ball is pressed into the hole to keep the other parts from coming out. seems an odd way to do it... also said that it is done at the factory and isn't removed during a rebuild - just left in when the block is tanked. That no parts replacement is available - which I'm learning from my search.
I don't know how reliable this info might be. How about you?