Originally Posted By: Joe90_guy
A catch-pot, just like a complex PCV oil separator, will not prevent oil recirulation/burning problems unless some effort is made to cool (or alternatively compress) the volatalised oil out of the vapour phase and into the liquid phase where it can be mechanically separated. Rather than having a catch-pot, you want a 'condensation pot' where the condensate (mainly oil) can be returned to the sump.
It strikes me that these things would function far more effectively if they were designed by chemical engineers rather than mechanical engineers. Oil refiners do this kind of thing all the time but on a far larger scale...
I've been thinking that the catch cans should be stuffed full of stainless steel wool, or some kind of non-corrosive mesh that would catch the pulverized oil, consolidate the drops and let it drain to the bottom of the can. Don't know how to take care of the water vapor that comes in the crankcase gases along with the oil mist. Having the water mixed with the oil would make it a definite no-no to drain the catch can into the sump. Maybe heat the catch can to boil off the water?
I have modified the PCV system on my high-miles Camaro. I was having a lot of trouble with detonation occurring on hard acceleration after long periods of idle or low-power operation. I theorized that the foul air tube running to the intake manifold was carrying oil, and causing the detonation, so I disconnected it and capped the fitting on the manifold. I ran the hose into a catch bottle, and it solved the detonation problem. On the first track day that I did with this setup, I checked the level in the bottle, and found 4-6 ounces of oil in it after every session.
I was satisfied that I was keeping this much oil from going through the combustion chambers, eliminating the possibility of detonation. During subsequent track days, the amount of oil being carried into the catch bottle got less and less to the point that it was only catching the "dirty-whipped cream" water-oil emulsion. The engine runs noticeably better now, probably freeing up stuck rings.
A problem that I found running the PCV into the catch bottle was that over 2-3 months of street driving (low-rpm, low-power, day after day in the winter) was that it would fill up with the dirty whipped cream, and start belching that stuff out into the engine compartment. I think there has to be a way to pull the blowby gases through the system, such as an electric AIR pump. I worry about losing the "Positive" aspect of PCV.