[JFP in PA]

Originally Posted by southernstar

Jeff, there is no question that there are areas in the engine where there is oil, a 'spinning', or at least moving part and air and that this can lead to aeration, necessitating an AOS for emissions purposes. My point is that after the air is pushed out of the bearing during initial start-up, there should be no air in the IMS bearing or housing due to the pressure feed. Without air, I don't see how there can be aeratioin in that part of the engine.

Regardless, it also has to be rememberd that the AOS is there as an emission device, not an aid to lubrication. Furthermore, AOS failures have typically occurred not as a result of marginal increases in aerated oil (as can occur after brisk driving), but due to failure of the rubber components inside the plastic body.

Brad

PS Truly enjoyed this 'debate' but, as Jake Raby points out in a parallel thread, it may utlimately be incapable of resolution.

From what I have seen (videos) of the pressurized oil feed into an open bearing, it does not flood completely while in operation, there definitely seems to be an opportunity for entrainment, much like what happens in the vortex of a kitchen blender.