PCV valve location

[Tommy]

The very nature of gases in an enclosed space and the principle of entropy means that even if there is a momentary local region of higher pressure, it will very quickly even out within the enclosed space. So if the crankcase pressure in one area (e.g., the driver side valve cover) were higher than that in another connected area (e.g., the passenger side valve cover), they would very quickly equalize. With all the blow-by pressure dumping into a common oil pan area, unless there was some system of intentional or unintentional one way valves inside the engine, I can't see how the crankcase pressure would be inherently higher under one valve cover than the other.

Credentials: BA Aerospace Engineering