Oil pressure
I was at the dyno on friday and started the motor up for first time 60 psi oil pressure........u did some pulls on the motor and the oil pressure dropped slowly by 8 to 10 psi......as the motor warmed up more had same rsults.........my clearnaces are fine on the crank and the rods. At first thought maybe to much oil so we drained some and with same results, so we added some and same results..........ok for the rest of the story........pulled off the oil filter and cut it open and found foam in the oil......we ran quite a few pulls on the motor and did 4 filter changes on the motor...foam was present in all filters.......we changed the oil twice and the oil had some foam in it............the pump has to be cavitying, have you ever seen a oil pump have a crack in it........i pulled the pan off tonight and measured the clearnace between the pan and the pump it was fine............so next i will pull the pump out and check the screen and pull off the pump and look at it.........is there anything else for ideas to check you guys can think of..........also i don't have a gasket between the pump and the block, do u recommend one or not............i don't think i am running out of oil it is 7 quarts oil pan not sure of the oil pump brand suppose to be high output..............thanks for any input