Engine Oil Pumpability and Related Properties

A bench test has been developed to simulate the ability of engine crankcase oil to flow from the sump to the pump inlet. The design of the system is geometrically equivalent to that found in a Chevrolet 230 CID L-6 engine. A number of crankcase lubricants have been evaluated in the rig to determine the effects of V.I. improver chemistry, soak time, fuel diluent content, and pour point on pumping rig delivery.

In a more detailed phase of this study, the cold flow properties of 10 commercial oils have been compared to pumping rig results obtained at -20 and -30°F. The data suggest that the Brookfield viscometer is a more reliable indicator of oil pumpability than the GM pour time, CCS viscosity, or ASTM pour point.