jamied

It might provide some lubrication but the rotors should not touch the case...not that I know of. I've built a couple of harleys and oil in the intake lowers the octain of fuel causing the motors to knock, it is critical not to let oil into the intake at least on an air cooled hi comp HD. I would think it's the same for any motor.
Jamie

CataclysmGT

The rotors shouldn't touch the case or each other, so lubrication isn't required. It is true that oil can act as a sealing agent, but this would only need to be required if tolerances are to great.