[Walter White]

As my attempts to provide a better seal for the IMS bearing seem to be harder than I was hoping at this point, I have been thinking of ways to improve the flow of engine oil to the bearing. At times I have considered that if the pressure inside the IM shaft, or just behind the bearing, was lower than outside the shaft, oil mist and vapor might flow through the bearing at a higher rate than normal. Then I realized that if holes were drilled into the shaft, those holes may produce a low pressure inside the shaft when the shaft was turning.
I drilled a 1/16" hole in 2" pipe with a manometer connected to the pipe end and spun it on a lathe.
At 1K rpm, I got peaks of -.15 inches of water, and at 2.5K rpm I got peaks of -.3 inches of water pressure differential.
Drilling the hole bigger produced less pressure differential.
Drilling additional 1/16" holes had no affect on the initial pressure differential of the original 1/16" hole. But I would think that additional holes would provide high volumes of flow.
Not a lot of pressure differential. I wonder if it would even help any in increasing oil flow through the bearing.