Ditto
Mel said:
I've tried several air/oil separators, certified and experimental. I have never found one that I like. I have removed them all. I know several people who swear by them, but my experience has not been worth it.
Ditto. You will read much hype and propaganda from the people that sell air/oil separators, but a healthy Lyc blows out very little from the breather. A lot of air oil separators where for wet vacumn pumps that did need a separator.
Oil gets on the belly from those little drips & drabs of oil that fall into the bottom of the cowl while you work on your plane or from little leaks.
Save the money, weight and clutter under the hood. Speaking of money many of these top secret space age miracles (they claim) are just a CAN with a tube, which they charge $300 for.
As you point out the acid & crud that comes out the bottom of a oil/air separator is not something you want going back into the engine. Also why save it in a seperate container (which is what I did for a while). Just do as Van has recommended per plans for decades, run it to the top of the hot exhaust pipe and burn it off.
One exception. If you do lots of near Zero-G acro, with occasional light excursions into negitve-g's, the air/oil separator may keep a little more oil off the belly. However most "gentleman's acro" is done at +0.3 g's or above. As far as negative-g's, when you're in turbulance you bounce into negative all the time, right. It's just sustained inverted that's a no-no.