hotshoe
"I don't think you can effectively use the PCV valve in one valve cover with an "open" vented cap in the other. The PCV venting system only works when the engine breathes solely through the PCV valve".

it has to be open somewhere else on the motor or you would suck every gasket you have out of the motor. this is the open and closed system. it has to be one or the other.

http://www.clubhotrod.com/forums/att...&postid=100112