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breather tube to exhaust

A

A5555

Well Known Member
fwiw, I used a automotive water line hose (6 inch) to extend the breather tube onto the exhaust pipe. the breather tube burns to contour against the pipe. coldest temperatures flown -27C at high altitude and -20C at low altitude. no other holes in vent piping. this is only a data point and I fully support an additional hole in the vent pipe if you feel the need.

IMG_20150327_165903.jpg




upper vent piping silicone elbow is holding up well.

IMG_20150327_165147.jpg
 
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At the end of the hose above the exhaust, I inserted an 8" piece of copper tubing. Not sure if it makes any difference but my process of thinking is; the copper tubing will conduct heat from the exhaust, lessening the chances of a freeze-up blockage. I previously had a whistle slot but it was making an oily mess.
 
Pardon My Ignorance

I see your hose going to the exhaust pipe at the firewall and was curious as to why you would dump oil vapor right on hot exhaust?
 
dongor2 said:
I see your hose going to the exhaust pipe at the firewall and was curious as to why you would dump oil vapor right on hot exhaust?
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This has been pretty much "standard procedure" for many, many years. The hot exhaust pipe tends to "burn off" the oil residue keeping the belly of the aircraft a bit cleaner.
 
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The liner of automotive heater hose doesnt like oil and oil vapors too much. Yep-makes a nice install because of the pre-molded bends. Its pretty inexpensive. If I wee going to do that install, I'd buy several of them and change them yearly at conditional time.
There are other alternatives-----

Tom
 
I was thinking the rubber hose, the oil and the flow of air leaking around the baffles could ignite with the temperature of the exhaust pipe and then the hose and oil would be fuel for combustion? I noticed the hose in the pictures is touching the E pipe and had "burned to contour". Just sayin.... I recently helped a guy with his -4 and this same hose had become perforated the entire length from oil contamination and was wet to the touch. I purchased some 5/8" AEROQUIP Blue hose to retro fit, its rated for gasoline and oil, should last a long time. Maybe one of the engineers here could calculate the flash point temperature the hose would need, soaked in oil, and compare to exhaust temp that far from the head and give us a thumbs up or down.
 
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Here's what I came up with:

5b795g.jpg


A short piece of tube with a leg welded on. Just clamps to the exhaust with a hose clamp. Works great
 
I've spoken of it before, but here's a picture of the other end:

IMG%5D


I fabricated a 45 degree fitting on the engine (angled up) and added this automotive valve cover breather with a short rubber coupler. My oil consumption has dropped dramatically compared to the standard overboard dump that came on the engine from the factory.
 
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valve cover breather

this probably pays for itself in oil savings in a couple of years plus reduced oil on the belly. I like it.
 
Toobuilder said:
I fabricated a 45 degree fitting on the engine (angled up) and added this automotive valve cover breather with a short rubber coupler. My oil consumption has dropped dramatically compared to the standard overboard dump that came on the engine from the factory.
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This is cool - clever thinking! Where does the outlet go - does it terminate in the normal place above an exhaust pipe I assume?
 
ChiefPilot said:
This is cool - clever thinking! Where does the outlet go - does it terminate in the normal place above an exhaust pipe I assume?
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Yes, vented to the outside of the exhaust pipe. See post #8.

Despite the fact that this is a factory new engine, I was losing a bunch of oil out the breather with the standard setup. I hoped that more vertical distance, a plenum, and screened mesh would all combine to get the oil mist out of suspension and keep it in the crankcase where it belongs. I don't know which of those factors is the most compelling, but the combination sure works on my engine. The mess on my exhaust pipe dropped to almost nothing immediately after the install.

I think the only possible downside to this setup is the fact that there is stainless steel mesh inside the breather, and if you let it go long enough it could clog up. So compared to an open hose, there is a slight added maintenance requirement, but it's not much. I have about 50 hours on mine and it's shown no signs of gumming up. On the plus side, there is about a billion miles of service history in cars with this setup.
 
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Moroso

Toobuilder said:
I've spoken of it before, but here's a picture of the other end:

https://vansairforce.net/community/attachment.php?attachmentid=13748&d=1626548288

I fabricated a 45 degree fitting on the engine (angled up) and added this automotive valve cover breather with a short rubber coupler. My oil consumption has dropped dramatically compared to the standard overboard dump that came on the engine from the factory.
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Hi Michael,

How about a long term report on this Moroso valve cover breather. Looks like you’ve been using it for 8+ years.

Thanks,
.
 
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