Hi volume oil pump

fishy68, the oil is going past the relief valve and ending up right back in the pan. The motor can only flow so much oil thru the passages. The reason that you are loosing oil pressure at higher rpms is that you are putting so much oil thru the relief valve that it is aerating the oil. Air cant' be introducted into the suction side of a pump, one of the the things that happens is it looses suction or on the pressure side of the pump since air can be compressed the oil will try to take up the space of the air there by lower the pressure.

There is nothing good about running a bigger pump than you need. It takes more HP, it puts more load on the cam gear, puts more load on the timing chain, makes more heat in the oil bypassing all of the time and can aerate the oil.

This is all physics of a hydraulic system, which is what an oil system is.

Here is something else to consider with pumps, as pressure goes up volume goes down. The highest flow you will get out of a pump is at zero psi.


Chuck