Racor CV4501-04L crank case breather filter unit with left hand flow. This crankcase unit has a die cast head and a glass-filled nylon and black powder epoxy-coated steel bowl. The Racor CV4501 crankcase vent system is an open breather filter for naturally aspirated engines, where emissions are returned to atmosphere after filtration. It does not have a bypass valve, so should be regularly serviced to prevent damaging pressure building up within the crankcase. The Racor CV open crank vent breather filter system will prevent oil pollution by collecting the engine blow back and separate out the oil mist. The collected oil is then returned to the engine sump.

Racor offers a rough guide for selecting the right crankcase vent system for your engine. This is to take the rated horsepower and divide by 20 for Open Crankcase systems. This will give the rough cubic feet per minute flow rate you will require from your crankcase system.