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crankcase breather

Soaringbum

Registered User
Southern New Mexico
Does anyone have a photo of their crankcase breather routing. I am thinking of bending some aluminum tubing to replace the electrical conduit. 20231126_163349.webp20231126_163520.webp
 

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After rereading that thread it makes me realize how much I will miss Stewart for however long he decides to be gone this time.
 
On my C180, I kept the standard aluminum breather tubing back to where it goes through the aft engine baffling, then went to rubber hose back to & down the firewall.
Then back to aluminum tubing at the bottom to incorporate a whistle slot.
It stops about even with the bottom of the firewall, or just below.
After reading stewart's post on the linked thread, I might shorten it up just a whisker--
maybe get less oil on the belly that way.
 
On my C180, I kept the standard aluminum breather tubing back to where it goes through the aft engine baffling, then went to rubber hose back to & down the firewall.
Then back to aluminum tubing at the bottom to incorporate a whistle slot.
It stops about even with the bottom of the firewall, or just below.
After reading stewart's post on the linked thread, I might shorten it up just a whisker--
maybe get less oil on the belly that way.
I tried all sorts of things to eliminate oil on the belly of the 185, including all you've mentioned. The best was a homemade air-oil separator which returned the oil to the sump.
 
In cold I like the last few inches of the vent to be clear plastic. To see and dislodge any ice buildup. The rest gets fuel sleeved for insulation, especially on Continentals with the breather forward on the case.

Gary
 
Whatever you do, make certain you have a whistle slot somewhere up in the warm part of the engine compartment. In my experience, vent tubes that hang very far out of the cowling at the bottom freeze up pretty regularly. Otherwise, I'm not sure it matters much where it's routed.

As Pete says, if you want to keep oil off the belly, install an air/oil separator. Otherwise, plan on cleaning the belly occasionally. Or, if you're like me, call it a corrosion proofing program.

MTV
 
Experimental cub… I just reworked mine. CNC’d some brackets that hold it to the firewall. Still have to cut the whistle slot but it’s been sitting and hasn’t done much flying this winter due to other issues!

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Just replaced the rubber hose on mine with it tube.IMG_0742.webpIMG_0742.webp
 

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Just a thought............what if you had the breather cut short and drip oil onto the exhaust. Shouldn't be much different than a smoke system.
 
I’ve been running my breather into a crankcase ventilator fitting that’s plumbed into the exhaust stack for years. Works great but you do have to check it every 50 to 100 hrs for build up. Every other oil change is a safe bet.
 
I just installed the Anti Splat Aero crank case vent system on my experimental-12. A good friend of mine has run the system for several years with no issues. It works great and no more oil on the landing gear.


Sent from my iPhone using SuperCub.Org
 
What aluminum tubing are you folks using for the breather line?

There’s 3003 Versatube which is easily flexible but Spruce is out of stock until March…maybe. Plus, 5/8” is the biggest tube and the breather hose is 3/4”. The rest of the aluminum tubing requires a 6’ minimum order at eye popping $/foot.
 
I got mine from airframes in Anchorage. It was $5 a foot for 3/4”. Mechanic said they used to be able to get old tent poles all the time. Little harder to find nowadays.
 
Doing the math it was 12 holes to equal same volume figured I would stop at 1/3 of that :). Working great flew at -36 the other day.
 
Or just order one that fits properly……..

It mounts to the engine mount not the firewall.

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I've had both metal and aircraft oil/fuel tubing as a vent line. When it gets cold and concerned about freezing the outlet, at least insulate the thin metal with fire sleeve or pipe insulation. Rubber is more resistant to cold. Don't extend the outlet of either into a blast of below zero air and expect it to not form a mixture of ice and oil.

I put a piece of clear tubing on the vent outlet of three aircraft so I could monitor any plugging. All it takes is an hour in real cold to start that process. And unless it's melted or removed between flights it just keeps on building up until.

Gary
 
All it takes is an hour in real cold to start that process. And unless it's melted or removed between flights it just keeps on building up until.

Gary
I had one freeze over and blow out the dipstick in 1/2 an hour. After that happened, an AD note came out to install the whistle hole. The nose seal didn't move. Doesn't make sense, but the dipstick did unscrew and blew out with such force I heard it hit the cowl on a Colonial C-1. The tail was covered with oil.
 
Local A&P's added the whistle holes, then would stick a phillips driver in and bend the handle up to form an upper hole deflector/lower lip. Slows the oil inside draining down from running right out the hole.

Another way to loose a nose seal is ice on the forward crankshaft glued to the seal. Can come from melted snow that's refrozen or any moisture source exposed to cold there. Then the seal rotates with the crank and can wear loose. Catalytic preheaters in the engine compartment were one source of water, but there's several like parking a warm engine exposed to falling snow. Covering the seal area is done as it's a tight spot to preflight.

Gary
 
Before I started venting into the exhaust stack via a crankcase ventilation fitting I always used 5/8” heater hose. Cut your whistle hole on top with a razor blade and it will stay closed unless pressure buildup forces it open.
 
I ordered tubing from Summit. https://www.summitracing.com/parts/SUM-G2558
I go over the top to an oil separator and from oil separator out the bottom on the opposite side.
Try not to focus on the mess - pulling the engine for an IRAN.

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