You should have a Positive Crankcase Ventilation system or a Road Draft Tube. You have neither. The "road pipe" you mentioned, is called a Road Draft Tube. The key word here is Draft. Air passing underneath the car passes the end of the draft tube and creates a low pressure or vacuum inside the tube. This pulls the fumes from the crankcase, and the fumes are replaced with fresh air entering through the breather in the valve cover.
With a PVC system, manifold vacuum pulls fumes from the crankcase through a pvc valve. The fumes are then burned along with the air/fuel mixture. Air enters the crankcase through a filtered valve cover cap or through a tube to the air cleaner. The carb air cleaner then is filtering the air entering the crankcase. There are other ways to set this up, but the idea that you have a closed system is the same.
If you check the links above, you will find some of the ventors supply a conversion for this.
