what exaclly is this called? in Technical Posted October 10 6 minutes ago, Pfeil said: the VW Porsche system really forces the air through. Which means that it really is not a "road draft" system . . . . Sounds like more of a 'positive' flow type system. . . . ?? I think 41 Buick was the first with a positive flow (intake vacuum) crankcase ventilation. . . . ? The Ford system relied ONLY on the suction that resulted from moving forward. Hardly any suction at road speeds, and nothing when stopped. And with out a consistent flow of ventilating air, the 'excrement' vapors are condensing inside the cooler parts of the engine (valve covers, lifter area) becoming solid carbon particles. As I remember the Pontiac flat eight never used an oil filter?? There was something about the design of the oil pick up in the pan that acted as an oil cleaner?? Remember that Oil filters were an optional accessory on engines for many years. If you can add one to a car today, I would advise it.