Getting the oil out of the PCV system with a Moroso Air-Oil Separator

All combustion engines create crankcase pressure, which is due to the combustion pressure that passes by the piston rings, aka blow-by. Back in the ‘60s, in an effort to reduce the amount of pressure car manufacturers, like Ford, introduced positive crankcase ventilation (PCV) systems to try and remove this pressure by using engine vacuum to literally suck out the excess oil fumes and pressure from the crankcase. Engine vacuum is found on the intake side of the motor and whatever goes through it is burnt during the combustion process. In a well-built stock-type engine that doesn’t see high rpm, this system works very well and little to no performance loss is noticed, but that’s not true for high-performance vehicles. Engine oil is not great for horsepower—not only can too much engine oil foul plugs causing loss in power but oil doesn’t have the same energy potential as gasoline and also doesn’t have as high of an octane rating. Excessive oil can also cause harmful detonation. Obviously these factors can contribute to a substantial power loss but also potential catastrophic engine failure if the overall octane rating dips below the minimum requirement needed for your engine.