Abstract: An engine oil fill assembly includes a tubular pipe portion with an upper end forming with an oil inlet and a lower end forming an oil outlet and air inlet adapted to be connected to the engine crankcase. The fill pipe inlet has an enlarged mouth to facilitate the introduction of oil. The fill assembly has an air vent mechanism to vent air from the engine crankcase when its pressure is greater than atmosphere. A positive crankcase ventilation valve inhibits a reverse flow of air into the crank case. A baffle member in the fill pipe portion intercepts and collects oil from an intermixture of air and oil form the crankcase preventing the oil from passing to the engine air intake system.

Abstract: This invention relates to an oil separator for use in an engine ventilation system for allowing air flow alternately into and out of the engine crankcase without permitting the escape of significant quantities of oil with the air flow. A tube within a tube design forms a compact and effective configuration subjecting the flow to several directional changes and a decrease in velocity effective to cause oil to separate from the flow.