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Hey guys, I’m really stumped here. So I have a pretty built 350 (bored .060 over, big cam, aluminum heads, etc) and I can’t figure out my oil issue. Whenever I get on it, the pressure starts to drop at around 4200-4500 rpm. I had a high volume pump with a stock 5 qt pan. I assumed the pan was too small and bought a milodon 7 qt with their preferred pickup. It still drops! Mind you, at crushing speeds it sits nicely at 50 psi and idles at 20 on a hot Florida day. I’m so stumped and would appreciate all the help, thanks guys!
? Too MUCH oil in pan leads to lotsa windage and oil aeration ... air whipped/entrained into oil will cause OP to drop ... verify dipstick and functioning windage tray.
I second the comment about oil level. I fought this same problem, changed pumps etc. Finally noticed parts of one piece gasket broken off on inside where oil whipped by crank was hitting it. I had 7 quart pan on car. Ended up dropping oil level and verifying correct level with stock dipstick. Problem solved. There are other posts on this same situation and I remember a episode on Road Kill where they tested theory. They proved the oil level issue problem, it also affected HP. To test it, drain a quart of oil out of your car and go drive it. See if the problem goes away.
I think he said it started with the 5 quart pan. Could be a bad spring in the pump if that's the case..not sure bearings would go bad so quickly. Maybe a bad gauge even.
Seems it doesn't matter what size pan / sump is ... 4qt or 8qt .. if oil level is so high that windage / aeration ensues ...
... then oil level's too high ... so try and rule out graduation(s) on stick are also too high
As RU737 said, dump a qt or 2 of oil and wring it out.