Stock replacement 60PSI with no modifications? From what I've seen, it's 3 things (at least)
Relief ball hanging in bore and giving abormal low pressures
Erratic oil pressure near relief setting (oil pressure dancing 45-60 PSI with hot oil above 3000 RPM)
Endplate isn't flat, so would result in oil pressure loss due to leaks between pump body and endplate. Also impacts gear endplay. I'm guessing could cause lower oil pressure at hot idle.
After reading through my original write up, I forgot to show where I pressure tested the pump in the block. I made a block off plate out of an old filter adapter and screwed an oil pressure gauge into it. So I was measuring deadhead pressure while running pump with drill. I filled the pan with cheap 10w30. I got 65 PSI while running the pump with a cordless drill. It stayed at 65-67 no matter how fast I spun the drill. The pressure might be a bit higher when actually running, because the pump RPM would be higher and pressure wouldn't be slamming the ball off the seat, like it does testing deadhead.
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I could explain all this to the girl at the parts store, but she'd probably call the asylum.
White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
Last edited by chiphead; 07-27-2023 at 12:48 PM.
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