Having just spent a couple of unpleasant hours on my back cleaning oil off the belly of my 6A, I'm ready to install an oil/air separator. What's the best system that works and isn't too complicated to install. John
works and isn't too complicated to install
Nothing works better and you can upgrade to a full inverted system later on.
https://vansairforce.net/community/showthread.php?t=51286&highlight=half+raven
Cleaning oil from the belly is a time honored tradition and I encourage people to enjoy it.
Aviation is all about risk vs reward, what's the risk of a clogged vent system vs not having to clean the belly?
Dump nasty vent by-products back into my sweet engine, no thanks on that one either.
I added a ball of coarse stainless steel wool to help vapor condensation....
I must be the oddball - i have the 1/2 Raven and still get oil on the belly, no aero, just straight and level.
Totally agree, and based on what people like Ed Kollin say, you really want that stuff out of your engine case.
https://www.youtube.com/watch?v=Ia-zgGr2pKg
Having just spent a couple of unpleasant hours on my back cleaning oil off the belly of my 6A, I'm ready to install an oil/air separator. What's the best system that works and isn't too complicated to install. John
Apologies, I inadvertently linked my experience so far with my new engine without a separator and the relative ease of cleaning the belly to Ed's comments on what happens with combustion gasses that go into the oil. I was agreeing with Walt - get the nasty byproducts out of the engine. I'm told that this can safely be done with a good separator but I don't have any direct experience. Ed didn't say separators are bad (that I can recall), he spoke about the byproducts of combustion that a good oil package needs to capture and that we need to vent out all the moisture we can, which of course everyone knows.Not just Ed. But where did he say anything bad about separators?
A good separator system at operating temperature only returns substances with low vapor pressures, oil being foremost. All substances in the return flow are already in the oil, in the same percentage as in the sump, because they did not vaporize. The only way to get them out of the engine is to remove the oil...an oil change.
If the separator system temperature is held at or near the temperature measured at the case outlet (i.e. in the case), it condenses none of the high vapor pressure substances. They continue out the exit in vapor phase.
The vapor pressure of motor oil is roughly 10Pa at 20C. Water is about 2400 Pa.
I was agreeing with Walt - get the nasty byproducts out of the engine.
Note "good". "Bad" is a separator system running at low temperature, because it acts as a condenser. It is always returning water and other **** to the sump, if it lowers the temperature of the outflow gasses below the dew point of those substances. Keep your separator warm!
When at normal temperature, measured breather outflow at my accessory case port is about 200F, roughly 15 higher than indicated oil temp. Outflow measured in the line connecting separator can to exhaust tap is 170~175F.
Dan - This 15F delta between the case port and the indicated oil temp - is this a normal temperature spread, or are you getting this spread BECAUSE you have insulated your breather tube?