Your experience with Air/Oil separator

[Bavafa]

Just curious how many people have installed an air/oil separator and how much did it improve. It will probably be helpful if one brand has proven to be more effective than the other.

I accidentally posted this in the classified section. Would appreciate help in moving it to general section.

[lr172]

I installed the ACS unit and it was a poor performer. Installed the antisplat version and it works well to control oil on the belly. Doesn't eliminate it, but significantly reduces it.

Larry

[airguy]

Originally Posted by lr172

I installed the ACS unit and it was a poor performer. Installed the antisplat version and it works well to control oil on the belly. Doesn't eliminate it, but significantly reduces it.

Larry

Same experience here with the Anti-Splat. You will need to clean out the exhaust check valve at least annually, but it is quite effective in limiting oil on the belly.

[WingsOnWheels]

I have the antisplat 540 version on my 360, i do not have the version that ties into the exhaust. I maintain the oil level at about 7qts. I have seen no sign of any oil out of the breathet. I do get a tiny bit of oil on the belly from s slow leak i still need to find.

[moosepileit]

Survey needs another option- I choose to NOT use a separator because X Quarts
(6 for my 0-320) is a good level and my breather is properly located.

I put the breather in a happy spot with a 45 degree bias cut outlet. 6 qts, no residue.

Used to have it blow vertically with a 1 inch gap on the left side crossover exhaust, above the bottom of the firewall. That was a mistake. Had all sorts of little leaks that are now gone. That was too high a pressure area. 4 quarts was the least I tried and all results were the same. Not too big a loss of oil, but seeps galore from too much crankcase pressure.

I guess I could try 7 and 8 quarts and see wherethe throwaway point is.

It now exits at the aft end of the coal shovel stock outlet where it should not freeze but has a bit of vacuum.

[Thermos]

I can't resist throwing out this video and associated analogy (read the YouTube comment ) from Mike Busch -

https://www.youtube.com/watch?v=2_pRXfPp5wQ

but to each his own, and we all get to choose as we see fit!



Dave

[DanH]

Originally Posted by Thermos

I can't resist throwing out this video and associated analogy (read the YouTube comment ) from Mike Busch -

https://www.youtube.com/watch?v=2_pRXfPp5wQ

Except it's not the whole story.

Mike's cup 'o **** is exactly what is to be expected if the separator's liquid output is routed to a catch bottle. Each cold start feeds condensed water to the bottle, as the breather gas and separator are not yet hot enough to keep the water in vapor phase. Later, if kept hot, all that water goes overboard.

https://www.danhorton.net/Articles/S...-Condenser.pdf

[TomRV8]

Is there a reason not to just have a well vented catch container on the lower part of the firewall with the overflow tube going directly into it? (I do understand inverted flight would be an issue...)

[mike newall]

Great article Dan !

Not thrilled with Mike Busch's effort though, especially when you relate it to a lot of RV's.

If you are in a cruiser, don't aerobat, keep your oil level at a sensible level - probably at least a quart below full, and change your oil regularly - 25 hrs/4 months, then you should have a healthy engine for life and don't need a separator.

However, if you like the sporting life and don't have a Raven or Christen system, these separator/catchers are invaluable to keep from having a wet belly and yes, we drain the oil straight back into the sump, where it belongs !

We have the Andair system and include a condensate trap. The separator does an excellent job of catching gobs when we draw a line or do a really good hammerhead... The condensate catcher does a fine job of catching milky goo when stood, at start etc etc and gets cleaned regularly.

Cruiser - probably no need

Mild stunter - definitely

Big stunter - man up and get an inverted system

[DanH]

Originally Posted by TomRV8

Is there a reason not to just have a well vented catch container on the lower part of the firewall with the overflow tube going directly into it? (I do understand inverted flight would be an issue...)

If by "overflow tube" you mean the line which drains separated liquid from the separator can, a catch bottle will work. See Fig.1 in the linked article.

However, it's awkward. Gotta pull the cowl to dump it, gotta have a place to dump it, it can still wet the engine compartment, etc.