Frozen crank case vent

02-17-2010, 06:58 AM

mike reibling | Frozen crank case vent

Hi guys.

Mike Reibling from sunny Saskatchewan.

Last Sunday I went for a rip and when I was putting her away I noticed my crank case vent was frozen completely over. Has anybody had the same thing happen? How serious is this? I did not notice any issues as a result.

It was a very nice day sunny and about + 10 f.

Your thoughts!

Yes, I know…. the nice day and + 10 are all relative…….

02-17-2010, 10:58 AM

Tony Jurcan | Frozen crank case vent


Sounds like great flying weather. a blocked crankcase breather tube can lead to oil bleeding out of engine seals. There should be a slit (whistle slot) in the breather hose near the engine where it is warm to allow the engine to vent in case the tube is frozen.

Tony Jurcan

02-17-2010, 11:24 AM

Planemakers | Frozen crank case vent

Hi Mike,

Tony is right. There should be a slit or vent of some sort in the CC vent line in the engine compartment. Sometimes it is a slit in the rubber hose that goes from the engine to the aluminum tube in the tail and sometimes it is a hole drilled in a metal fitting that was used to adapt the different sized hoses that might be coming off of the engine and the tube in the tail.

Have a great day,

John J

03-01-2010, 10:15 PM

Ed Lynch

The long breather tube on the Seawind really invites freezing over in cold weather, and gumming up with "mayonnaise" ( an emulsion of water, oil, and blowby gasses) any time. So I didn't connect mine. I have an Airwolf oil recovery tank, and a vent tube straigt down out of the cowl. A drop of oil on the turtledeck after each flight is a small price to pay for a cleanly vented crankcase. Chronic poor crankcase ventilation will really shorten the life of your engine from acid accumulation as well as the mentioned blown seals. Ed

03-09-2010, 09:50 PM

keithw | Frozen crank case

Hi Ed I would like to see how you confgured your Air Wolf as I have the long Alu. tube out the back. I would like to do the AirWolf breather etc. Keith

03-11-2010, 09:57 PM

Ed Lynch | Oil recovery system

Hi Keith- My oil recvery system consists of a small cylindrical tank which has a drain back into the crankcase, and vents straight down out of the cowl. The swirling of the vapors removes a lot (not all) of the oil from what goes out the vent. On second thought, mine might be an M-20, not an Airwolf. They are both similar, work the same, and cost about $200. Tom Saccio has the same system, so you may have seen it at the splash in. The tank mounts high, by the cowl flap; the small oil drain line taps back into an existing plug in the case, and the vent goes out the bottom. Needs a little room, though. I'll look for a picture. Ed

03-12-2010, 08:29 AM



Some had talked about a vent line to the rear of the plane....???

If you have a picture of you installation....that would be great


03-14-2010, 11:22 PM

mike reibing | Thanks everyone for the insight.

That's a lot of good information. I will be looking for that vent hole at my next oil change.

On another note....I just sent my flaps to Plane Makers for some repairs. At my last inspection I found cracks that quickly grew larger on my flaps. The cracks were on both flaps and about 6 to 10" long. They were located on the leading edge close to the fuselage. Has any one else had this issue?

Mike Reibling