[Ed Wright]

On my old chassis dyno, taking the belt on & off the pump was a consistent ten hp at the tires. Probably worth 12 to 15 hp on an engine dyno. I can not imagine the vacuum pump causing a bearing problem. I also plug the bypass in the oil filter mount, so all oil goes through the filter. Keeps crap out of the bearings better. 60 psi has always been enough in mine. Ran 45 for years with zero issues. I'm no professional engine builder, so more knowledgeable pros here may have more info.