Originally Posted By: Shannow
A Harman,
I've got a little experience in trying to catch the droplet phase stuff...have a look at the top of the turbine house here
http://www.spec-net.com.au/press/0509/cly_200509.htm
and see the four streaks across the roof, they are residue of the oil mist that comes out of the turbine main oil tank...bane of every turbine engineer's existance, as you can see the oil mist from the car park, and it leaves mess everywhere.
OEM came with a wire packed separator, which did a poorly decent job, big advantage being low restriction, but the couple of micron particles still whip through.
Using "coalescing filters" in their place grabbed all of the particles, but rapidly produce a high DP, requiring the filter to be paritally bypassed...didn't seem to matter how much filter surface area we provided, they'd blind (doing their job), and have to be in bypass.
My view for collection the droplet phase is that you need an impingement surface where the gasses are forced to violently change direction, and oil has a chance to impact and form a film...after that, steel wool, made up of layers with baffle plates to change direction a few times and extend the tortuous path.
The vapor phase ?
Go with Joe90_guy.
Here's a Honda paper on some of their systems.
https://www.hondarandd.jp/point.php?sid=41&pid=1027&did=1027&lang=en
I did a similar thing with a very worked Ford Cleveland.
I was running the PCV against the recommendations of all and sundry. The hot trend is to run a catch can.
I was getting very high oil consumption when the engine was opened up(high RPM's with large throttle openings).
The oil was literally pooling in the bottom of the inlet and being mixed with the intake charge below the Carb.
The runners and backs of the intake valves were quite wet-damp with oil.
Drawing on my Marine Engineering background with water vapour separating screens of incoming air to the engines(Salt water mist is a quick death to highly developed Marine Diesel engines).
The screens use a series of rapid change of direction and small scoops to separate the water mist from the incoming air and drain it overboard.
I modified the area around the PCV pick up inside the Rocker cover complete with an integrated dripper at the bottom of the baffling to allow the condensed oil to run down and away from the opening, then fall back into the flowing oil gathered in low parts the inside of the rocker cover.
The intention was to attempt to imitate the action of the screening on the boats.
The system worked very, very well, and reduced the oil consumption to about half but couldn't really bring it down to an acceptable level.
Coming back to the title and subject matter of the thread.
At the end of the day, it was revealed the engine builder had spec'd and ordered the wrong ring diameter by mistake because they failed to take into consideration the actual bore diameter of this particular engine.
The result was ring tension on the very bottom side of acceptable even though the intension was for low tension rings.
The final remedy was to do a rebuild with much better consideration to the final ring tension by altering the ring pack slightly.
Oil consumption issues were completely cured at that point with no catch can.