Just added a link to the best explanation I've seen, as to why there is a need for a separator on the PCV system:
http://www.jegs.com/p/Steeda/Steeda-Oil-Separator/961403/10002/-1The FE has used some sort of crankcase breather since day one. I stumbled on a real early cast iron FE intake at a machine shop about a year ago and was impressed with the elaborate stamped metal tray and 3-5 inch square brass mesh panel suspended above the valley pan (protected from splash) that served to de-mist the gas stream leaving via the road draft tube. Of course years later in mid 60s FoMoCo went to a PCV system and pulled the nasty's out through a PCV and baffle on the rocker cover and introduced "clean air" via a mesh stuffed breather on the opposite rocker cover.
Found this (linked - 2013 GT500 Oil Separator Shootout) interesting. I double checked to insure I actually saw the stated 20-PSI feed utilized to test the separators and not that it was 2.0-PSI.
(1) Surprised me, I did not think a common pump-spray bottle could "buck" 20-PSI to inject oil into the "T" connection.
(2) How on earth a small piece of a paper towel banded over the hose end holds up as a final filter and does not blow out stumps me, (this could be a great paper-towel test). Making it even harder to comprehend the paper towel is dampened with oil mist. Just a WAG but I have a feeling the tested separators may restrict flow so badly it allows a dry/dampened paper towel to survive over the hose end.
(3) Why they would use 20-PSI as a test pressure to synthesize crankcase pressure kind of got me? thought motors like FE could only build up a couple pounds crankcase pressure before its vital lube would be hemorrhaging from everywhere including flowing ass-backwards out the "breather side of the PCV system.
(4) I wonder why they did not test the factory Ford GT500 separator w/good 5/8th's passages - maybe there is not one and its just hoses?
But of course THIS testing is for separators for a GT500 that may well in fact pass-gasses that strongly under boost. I can only guess on modern GT500s any breather to allow clean-air into the crankcase may actually have a check-valve to insure the EPA is kept happy with emissions even when the motor/crankcase itself is under boost?...
I found it odd not a single manufacturer of these separators used cylindrical media and all went with a flat surface, though some used wadded up metal mesh and others used woven wire cloth. You will note even the testers stated "Bigger is Better for Oil Separation" . In the filter industry they call this "residence time"
https://www.youtube.com/watch?v=k2akU6d_onwAmusing in the videos comments where the head honcho of a separator Co got into it. Granted these separators seem aimed at boosted applications but here's a Moroso separator on I guess blown (by the whine sound) Caddy.
https://www.youtube.com/watch?feature=player_embedded&v=Y9klkDCItEYNeedless to say oil mist in combustion chambers is not a good thing - even on a NA Ford FE. Just keep in mind what/how they control oil mist leaving a motor
