Routing breather onto exhaust pipes?

[Dan O'Brien]

On breather routing, both the newer ES and Legacy manuals say "Secure the exit to the firewall such that any oil discharged
the breather line drips onto the exhaust and is burned off." I see installations with the breather ported into the exhaust after an air oil separator, and installations with no air oil separator and the breather routed overboard away from the exhaust (mine). Are people also dripping the breather onto the top of the exhaust to burn off? I haven't seen that without an A/O separator,, but given the instruction in the manual, I would think some folks are doing. Does it work. Is there reason not to do it?

Reason for asking is growing tired of cleaning oil off the belly. There are long discussions about the same issue on the COPA (Cirrus) BeechTalk lists. Like many others with an IO5XX series engine, anything over about 2/3rds sump capacity blows out of mine, and even filling to that level greases up my belly and many others. Mike Busch says to avoid an oil/air separator and suck it up and clean the belly or live with it being oily. He doesn't like putting discharge back into the engine and thinks doing so also eliminates a useful diagnostic. Others use a/o separators and are happy. There are endless debates about this on all the IO5XX series discussion boards. But if a simple solution is to drip it on the exhaust pipes and burn it off even without an a/o separator, that would be great. Is there a reason not to do this?

Happy and safe flying,
Dan

[Ryan Riley]

Dan, great topic. The great thing about Experimental is you can give it a try. My ES breather is routed like yours is currently. My belly also gets coated, which sucks to clean. I try to keep my oil level between 5-6 Qts. I add at 5 and don't fill past 6. I choose to leave it as-is because I don't know enough about the pros/cons of having the exhaust burn it off. I'm curious to find out what you decide to do.

[Hamid Badiozamani]

I was told by my mechanic that getting an air-oil separator would be the better option.

[DrewDickinson]

Hi guys,

The oil on the belly was driving me nuts, so I took a swipe and this works well.
Connected a Air Oil separator ( I think it is an Andair) to the main breather line, and from that unit, there is a small (like 1/4" line) that you could return to the crank case. Nope, after seeing the sludge that comes out of that 1/4" line, no way am I putting that back in the engine - so I have it dripping into a small plastic bottle that is vented, and zip tied the plastic bottle to the rear mount, so it rest against the fire wall. Located next to the other drains at the bottom of the fire wall. I tried to get fancy and purchased a "catch cannister" that had a small breather on top, used on race cars - but was too large and no good mounting options. So plastic bottle it is.

Engine - IO 550N19 - and I run at 7 quarts, never 8, adding oil at 6.
The plastic bottle, depending on how may hours flown, easy to empty once every 6 months or so.
It catches like a tablespoon of oil sludge every flight hour or so (just a guess). All of that would be on the belly.

Been like this since just after original flight, and there is ZERO oil on the belly....always 100% DRY.

Could send pics next time cowling is off if interested.

Drew

[Ryan Riley]

Drew, photos would be great. If the oil separator works that well, it sounds like a no-brainer.

[Dan O'Brien]

Drew, I am definitely interested, thanks!


Sent from my iPhone using Tapatalk