So I had no oil scavenge going on in a newly built motor.
It would fire up and run fine but oil pressure would drop from 50psi to 7 or 8 psi after running about a minute or so. Verified with a mechanical gauge.
Hmmm, oil tank was empty. OK, drain crank case of 12 quarts of oil, pour back in oil tank, repeat. Same outcome.
Thought I had lost or crimped an oil pump oring, on tear town, no such luck, all orings virginal and accounted for.
Examined oil pump and the scavenge side has roughly a 1/4" of end play
What do you guys think?