You might check this out:
http://www.andair.co.uk/product/oil-air-separator/
They make good stuff, mostly for the experimental market.
Simon
Hi, anybody has experiance with the Andair separator in Cirrus SR22?
Bit late to the race on this but FWIW… I have an IO540 in a TB20 Trinidad. Holds 12 quarts if filled. Most I know run their 540s on 10ish. I fitted an M20 separator for a year. It did reduce the oil loss a tad, but… I removed it when I put a new engine in. My view is that while they help… I don’t believe they are good for the engine because they contribute to moisture retention. Perhaps if you only did long flights they are okay, but for the usual short flights I do I think they are bad. I now leave the oil at 9 quarts except for very long trips (I do a few 5.5 hour flights every now and then) for which I start with 10 quarts. Using 9 quarts as a standard I find I burn/blow out less than half a quart every 10 hours. The oil also has (IMHO) a slightly better look and feel after 10 hours.
A key factor in my decision was that at the time I was using Exon multigrade oil. This oil has a remarkable ability to hold moisture. With the M20 oil air separator fitted I found there was a horrid white sludge in the rocker covers after 10 hours of use. This is the component in the oil that holds the moisture. It caused light corrosion inside the rocker hats. Once I removed the oil air separator this sludge reduced considerably. I also no longer use Exon oil and have reverted to Shell W100 plus which after 38 years in GA I am convinced is that with regular oil changes W100plus is the overall best oil for IO540s.
IO540s need to breathe. Oil/air separators stifle that need.
Still have the M20 if anyone would like to buy it.
That Exxon Elite experience is exactly what I was getting anyway, all the time, so I stopped using it. Yes and got corrosion under the rocker covers too. Yet the shortest flight I do is 1hr.
1quart in 20hrs is excellent.
