well some think you need 10 pounds for every 1000 rpm s but if you live by this and i do not then at 1000 rmp you need only 10 psi and need 70 at 7000..i think your oil is getting to hot and you may be loose on mains and rods so hot it going to be low hot 20 is fine .when cold it about 40+? long as it builds oil psi under a load .try another oil gauge with a 3/16 line kit