It helps to understand that the oil pressure itself (what you read on the gauge) is *not* what supports the bearings. The hydrodynamic shearing of the oil between the crankshaft and the bearing surfaces is what supports the bearings. That is a fact. You only need enough pressure to get the oil to the interface. You would need thousands of PSI of oil pressure to support the bearings if the pump was what produced the pressure that supports the bearings. Do some reading on your own if you don't believe me. I'm sure if you do a net search for "hydrodynamic shear oil" you will find a lot of facts on it. It is fluid dynamics and there are relatively simple formulas that will show you that a .001" film of oil between two flat plates will support thousands of pounds on the small top plate as it's dragged across the large bottom plate. An engine survives on the same principle. How does a lawnmower live if there is no positive displacement oil pump in 90+% of all 4 cycle lawn mowers that are in use? Splash gets the oil to the crankshaft/connecting rod junction, and the hydrodynamic shear is what supports the connecting rod off of the crankshaft.