Isn't the job of the PCV valve to 1, scavenge out any oil vapors or other flamable vapors to prevent crankcase fires. 2. to help maintain a negative pressure (relative to ambient atmospheric pressure) which hepls make a pressure differential between the top and bottom of the piston. The theory being that the effectiveness of the piston rings to make a seal is partly dependent upon the pressure differential between the top and bottom of the piston.
Or is there more to it than that?
