I'm not sure I follow how a separator keeps oil out of the intake on a S/C car.
My assumption is that the PCV system is hooked up like stock (Meaning no breather on the V/C). Under no-boost situations, the pcv lets air flow from the crankcase INTO the upper intake. If you have the baffle and oil screen in place, this should keep oil out of the lines. Only if you have severe blow-by can I see oil getting into the intake. Meaning you have lots of crankcase pressure forcing it's way past the system.
Under boost, the airflow is actually going the other way - towards the crankcase. So, how would this get oil into the oil seperator? Where is this oil coming from?
The only path I can see to oil in theintake is that if boost gets past the PCV valve, you are pressurizing the crankcase, and the only path for this to go is back through the hose in valve cover fill tube into the Supercharger inlet tube. If you have V/C's without baffles, this could bring oil with it, and then you'd have oil throughout your intake path. This is why people use the Supra or Turbo coupe PCV valve, or a one-way valve (brake booster valve...).
Since I had oil in my intake before I rebuilt my engine, I stuck a seperator in the PCV hose, like is posted on here. I have well over 2000 miles, and several strip passes, and have yet to see any oil in my seperator.
I can only assume that oil in a seperator is coming from the intake baffle and/or screen missing, running a breather (which compared to the tiny little hole the stock PCV system draws through could allow more air flowing faster through the PCV valve and keep the baffle/screen from removing all the oil), or a significant amount of blow-by.
So, does anyone have a good explanation of how boost gets oil in the intake? Or, point out a flaw in my understanding of how the system works?
Dennis
