I was wondering, would a baffled PCV in the valve cover like most engines I've ever seen make more sense, with a baffled breather on top of the draft tube, or at the other end of the valve cover?
Or, with a filtered breather on the outlet of the draft tube.
It makes perfect sense.That is why newer engines were fitted with them eventually.
I brought his very point up when Deve proposed his current design years ago.
All you would need to do is use an early draft tube which came with a oil fill cap, put a filtered oil cap on it, and close the lower end of the draft tube. Then put PCV valve on the top of the valve cover.
These old engines are prone to blow by when brand new due to loose tolerances compared to modern engines. This results in contamination of unburned gasoline and water vapor into the crank case. A good portion of these contaminants end up migrating upward and and can be seen wafting out of the vents of the valve cover at idle after a long drive. It also is the white oily gunk seen on the inside of the valve cover.
Having the PCV valve at the top of a ventless valve cover would effectively remove those contaminating fumes.
Having the PCV valve at the draft tube clearly would not. In fact, these fumes will be sucked down through drain holes in the heads and end up in the oil before the draft tube PCV has a chance to sip the fumes out of the crankcase. (PCV systems have a significant amount of restriction in them, so there is not huge amount of air rushing through them. If they did, it would act like a giant vacuum leak.)
Carl
resident armchair expert of nothing, but wordy, nonetheless
