Oil pressure drops as RPM increases

[JMD]

Lots of great information there, I really appreciate the help. I’ll try running just 5 quarts in it tomorrow.

I don’t understand why this is suddenly a problem. For the past 2000 miles I’ve run this engine at 3000rpm for hours with zero issues, always with the oil level on the “Full” mark on the dipstick. So unless I didn’t get the dipstick tube installed properly after I reinstalled the pan, I don’t see how oil level would be the issue.

[burnin oil]

are the rod and main bearing clearances tight? Could it be that as the motor wore in that oil pressure is controlled by the bypass once its up to temp? In other words as the RPMs come up the volume of oil and pressure is forcing the bypass to open and now the break in wear is enough to see the pressure drop on the gauge. I did run a BBC oil pump in a sbc once and saw similar results on the gauge. High oil pressure with a drop once it warmed up. It did do its job of high volume at lower pressure in that application.

[JMD]

*SOLVED*
Turns out that this is just another case of not checking the simple things first. It was a quart high on oil. The 5 quarts must have raised the oil level enough to get beat into a froth by the crankshaft. I drained the oil and put 4 quarts in, so it’s probably around 4.5 quarts with what was left in the filter and oil galleys. It reads a full quart low on my piece of garbage aftermarket dipstick, but the pressure stays at 60lbs from 3000rpm to 5500rpm so I’m going to run with it. Thanks for all the help guys.

[Ironangel]

Originally Posted by JMD

*SOLVED*
Turns out that this is just another case of not checking the simple things first. It was a quart high on oil. The 5 quarts must have raised the oil level enough to get beat into a froth by the crankshaft. I drained the oil and put 4 quarts in, so it’s probably around 4.5 quarts with what was left in the filter and oil galleys. It reads a full quart low on my piece of garbage aftermarket dipstick, but the pressure stays at 60lbs from 3000rpm to 5500rpm so I’m going to run with it. Thanks for all the help guys.

Cool.