It would have been interesting to see that system work out.
In the end we simply chose to attempt to balance the pumping volume more closely to the requirements via changing the drive rates (remember external pump both dry & wet sump) and establishing an acceptable margin of by-pass in excess of the needs, this with the use of fluid flow meters in testing, and establishing driving rates of the pumps generally at ratios less than the standard 1/2 crankshaft speed. This also required consideration in pumping requirements (leakage rates) within the engine, and less use of oil, when already pumping it, isn't always best, though generally when targeting the engine speeds of most interest, one often ended up with quite low pressure numbers at low speeds, particularly idle, but I have a few Detroit Diesels which operating appropriately will display 60+ P.S.I. at speed but only maybe 5 P.S.I. at idle, and the oil must traverse greater distance, their parts are far heavier, and firing loads quite greater, and they do just fine. But by the same token, after say 12 to 14 gallons per minute at higher rotational rates, although the pumps manufactures will say is well within the capacities (area) of these positive displacement units (again "G"-Rotor @ 1.100" length) there begins to become apparent difficulties with cavitation at the inlet area the pump scroll/rotor void, this seems compounded in the longer rotor/scroll lengths (notice how the new high-speed crank-driven gear pumps are relatively shallow in length/thickness!). But then this is not unexpected as the Caterpillar tractor for which this type of unit was originally designed for in the early part of the previous century didn't approach the speeds of applications as used in more recent times!
Scott.
