I need some input on this problem, I have searched and found no answer.

My problem is when I start the car cold, I have good oil pressure around 60psi, car warms up oil pressure drops to around 18-20psi idle and 40-42 cruse. This is the funny part, if I accel under heavy load, 6 gear under 2000rpms, the oil pressure drops from 40 to 30 psi, if I let off the gas it pops up again. This only happens under heavy load 5 and 6 gears under 2000 rpm.

About the motor, 350 board .020, balanced and blueprinted, stock oil pump with white spring, cc306 cam, REV valve springs, crane lifters, pro-mag rockers

 

my car did something similar a couple times. i had used lucas stabilizer in my oil and the cruise oil pressure was around 45psi. after about 1k miles the cruise pressure was 35psi but when i went to pass someone the pressure would dip until i let off the gas then it went back up. changed the oil back to straight 10w-30 mobil 1 oil pressure back to normal.

does this only happen under 2k or in any other gears?

 

Seems to only happen under 2000 rpms, but only notice it in upper gears. If you accel in 1 - 4 gears the rpms come up quick, 5 and 6th dont, so the oil pressure drops. But the same thing happens, if I let off the throttle, oil pressure goes up.

 

I also changed my oil from 15-50 to 10-30, and removed my oil cooler, though it was clogged. Cut my oil fliter open, no gold or sliver flakes. Car does not overheat, has lots of power

 

Generally if you hace 10psi per 1000 rpms or close to that you are ok. As far as losing oil pressure under accel it could be just a the main bearings are wearing a little. How many miles are on it?

 

Since the rebuild about 30K

 

Yep, don't worry too much about it if you have 10psi per 1k rpm... mine has similar pressure to yours..20psi or so at idle, 40psi at cruise...been that way for years. I have 95k miles on the bottom end.

 

Sounds like ya got too much main brg. clearance for the oil ya are running. Change oil weights till it acts right.

 

It could be you oil pressure sending unit going bad