[blucar]

Positive Crankcase Ventilators (PVC) are probably one of the most misunderstood items ever installed on an engine. PCV's became mandatory on all vehicles built in 1963 and later, there-in the term smog motors was coined.
With the introduction of PVC's, 95% of the emissions generated by an engine were eliminated.
The PCV eliminated blow-by escaping into the atmosphere, while at the same time eliminating condensation within the engine. Introducing the blow-by back into the fuel mixture tends to act as an upper cylinder lubricant. It is also true that the fuel/air ratio needs to be leaned down a bit to offset the oil fume introduction into the engine.
I have figured out ways to adapt PCV's to every engine I own, or have owned for the past forty years. This adaptation has been on Ford Y blocks in my '56 & '57 T-Birds, my '59 Ford 100's w/292 Y blocks and my '36 Ford 59 AB engine.
On many of the cars I work on I am up grading the engine to a later engine so I use the PCV system that came on he engine.
I have found it to be very interesting that many mechanics insist on eliminating PCV's on early cars with later engines in them.