[Todd Gross]

I have a customers LS engine that I installed an energy recovery oil pump in. Last season with a standard volume Mellings pump and 5/20 or 0/20 oil @ 120f max coolant temperature, the car would leave the line at 90PSI and go through at 78 to 82.
With the new pump, first warm hit on the dyno, it shot up to 150 psi and stayed all the way through ( may have been higher as the transducer on the dyno is rated at 150# max). It had the smallest spring and the the poppet ball moved freely.
I talked to Vern S. about the pressure and he was very helpful and talked through things to great extent. In the end he theorized that the oiling system in the engine was very efficient and recommended shortening the spring and teeing the bypass hose to route some of the bypass oil to the screen / box area of the pick up and the other back to the tube as originally designed. He also stated if pressure is still to high to shorten the spring at .030' increments until I get what I want.
Now with that done with warm engine , 0/20 oil, it idled at 40 to 50# and shot up to and leveled at 100 / 105# as soon as the throttle was snapped. Still to high.
I have made adjustment to shorten the spring another .030". Customer will have it running this week and hopes to test.
Has anybody run into a similar experience? This is the first time I have utilized this type of pump and although I understand the theory of the energy recovery pressurizing the inlet side of the pump, I am still really surprised that a thinner pump develops higher pressure ( w/ short spring ) and ramps up so quickly compared to the Mellings on the same engine.