Joe Berk posted some interesting information about the OCS in this CSC blog post ...
http://californiascooterco.com/blog/?p=21317
He recently changed his OCS to the official orientation and has gotten no liquid in the tube like he used to.
I'm interested in his results because they were the opposite of mine. I wonder if his results will be consistent over time and if he is certain his catch tube is well sealed at the bottom. many people think they aren't collecting fluid because it leaks out around the plug.
I tested three scenarios last year with the OCS, and the unofficial position collected the least amount of fluid.
My test conditions:
- Clean and sand the bottom cap to ensure a good seal.
- Take the same route to work (about 40 miles round trip).
- Maintain approximately the same speed during each commute. mixed city and highway from 35 mph to 60 mph.
- Travel at approximately the same time and temperatures.
My results:
My conclusions:
With two filter surfaces (side and top) in the unofficial position, I collected the least fluid. With one filter wall (side only, open at top), I collected some fluid. With no filter wall (drilled through), I collected the most fluid.
My data indicates an inverse relationship between the amount of filter material in the OCS and the amount of fluid collected.
Spud theorized that the reduced filter material from drilling a hole in the media increases the speed of the gases from the crankcase, lowering vapor pressure and increasing condensation ... which would explain why the tube fills faster with less filter media in the way.
Increasing the amount of filter media, by passing crankcase gases through two filter walls in the unofficial orientation, slows down the vapor. This raises vapor pressure, reduces condensation and sends more fuel vapor to the air intake to be burned during combustion ... leaving less liquid in the catch tube.