Big Block Chevy Oil Pressure Problems

[Triangle Speed]

I was wondering if anyone could offer suggestions as to the reason that a newly rebuilt BBC would drop oil pressure when running it hard. Oil pressure at idle is 38-40 lbs. Cruising oil pressure is 65-70 lbs. Everything is ok until you hit the throttle while going down the road. Oil pressure will drop from 65 lbs to 30 lbs quickly. The motor is a 454, stock crank and rods, dome pistons, flat tappet solid lift cam, melling m77-hv pump, 8 quart deep sump pan, matching pickup for the pan. Pick up is set at 1/2" above the bottom of the pan. Varying the oil level does not help. Pump seems to be cavitating as it only happens when cruising down the road and hitting the throttle. When the motor is revved up while sitting still, no low oil pressure is seen. Pickup was checked for cracks and tack welded to the pump. Any ideas?

[DraginRat]

Any chance the oil is going to the back of the pan under hard acceleration?

Ken Gasbarri

[Triangle Speed]

We found the problem. The oil was being agitated at high rpms and we installed a windage tray and stopped the pressure drop.

thanks