[Walter White]

Bench-top testing isn't as futile as some would think. The first bearing I tested, I had no idea what was going to happen. I figured that maybe a few hours, maybe days, or even weeks, the bearing would begin to vibrate, wobble, screech and then maybe come apart with balls looking like raisins. But when that first piece of the cage came flying out of the bearing after only a matter of minutes it was a total surprise, I just didn't see that coming, literally. Then when I saw pictures of failed bearings with the cage broken in exactly the same areas, it got me thinking in a whole different direction.
Along those lines, I was wondering if the idea of drilling some holes in the IM shaft to equalize pressure has been bench-tested. It doesn't seem too difficult to set up. A piece of 2" PVC pipe, capped at both ends with a grommet in the center of one cap, slip a piece of tubing into the grommet (with a little grease) and connected to a manometer or a bottle of water. Spin the thing at maybe 3k rpm and see if pressure remains equal.