Oil Return to Valve Cover
Posted: Thu Apr 06, 2023 2:56 pm
by sonex1084
Hello AeroVee drivers. My Sonex has the original Oil/Air Separator installed, the slanted one shaped to fit the slanted firewall. I’m also using it as a catch can for oil that passes through the crankcase breather tube. After every flight I have to drain 2 to 4 ounces of oil from the separator. It works fine and is just a minor inconvenience. There is no water in the oil I drain. I’ve got a little over 100 flight time hours on the engine. I’ve been contemplating adding a return line to the valve cover on the right side of the engine about halfway down the backside of the cover. I mention that in case I can’t attach a picture. Does anyone see a problem or potential issue with doing that? If the picture posts I can’t figure out how to orient it correctly.
Thanks,
Matt
Re: Oil Return to Valve Cover
Posted: Thu Apr 06, 2023 3:10 pm
by Bryan Cotton
Matt,
I routed mine to the top of the valve cover. I’m happy with it.
Re: Oil Return to Valve Cover
Posted: Fri Apr 07, 2023 12:00 pm
by sonex1084
Thanks Bryan. I would rather have the line return to the top also. Unfortunately, my separator is placed in a bad position for that. I mounted it according to the Sonex instructions which places it lower on the firewall. They originally designed it to return oil to the oil sump plate. I just don’t like that idea too much. I could change out my separator , but only if my planned location for the return line is a bad one. Have fun flying.
Re: Oil Return to Valve Cover
Posted: Thu Apr 20, 2023 9:36 pm
by mike.smith
Mine also returns to the top of the valve cover:
http://www.mykitlog.com/users/display_l … 492&row=95
Re: Oil Return to Valve Cover
Posted: Fri Apr 21, 2023 9:24 am
by Jerry09w
I have mine installed on the rear of the valve cover so the hose is downhill all the way from the seperator to the valve cover., never had a problem. I used an AN flair fitting so it is easy to remove for maintenance.
Re: Oil Return to Valve Cover
Posted: Fri Apr 21, 2023 12:38 pm
by Bryan Cotton
mike.smith wrote:Mine also returns to the top of the valve cover:
http://www.mykitlog.com/users/display_l … 492&row=95
Clever idea on how to build an air-oil separator Mike! Do you know how much yours weighs? Mine is a bit heavy, somewhere over a pound.
Re: Oil Return to Valve Cover
Posted: Fri Apr 21, 2023 8:06 pm
by sonex1084
Jerry09w wrote:I have mine installed on the rear of the valve cover so the hose is downhill all the way from the seperator to the valve cover., never had a problem. I used an AN flair fitting so it is easy to remove for maintenance.
Thanks Jerry. That is exactly what I intended to do unless there was a reason that I shouldn’t. Since there doesn’t appear to be a problem, I will continue on.
Thanks again,
Matt
Re: Oil Return to Valve Cover
Posted: Sun Apr 30, 2023 10:21 pm
by mike.smith
Bryan Cotton wrote:
mike.smith wrote:Mine also returns to the top of the valve cover:
http://www.mykitlog.com/users/display_l … 492&row=95Clever idea on how to build an air-oil separator Mike! Do you know how much yours weighs? Mine is a bit heavy, somewhere over a pound.
It’s just PVC pipe with some plastic scrub pad inside. It probably weighs a little more than your cell phone does. I got the idea from somebody’s automobile page years ago. Here’s one I found by Googling: https://www.tacomaworld.com/threads/diy … an.244981/
Mine also goes to a catch-can in case it backs up or gets blocked. The catch-can also has a vent. I check the can at every annual, and have not found any oil in there.
Re: Oil Return to Valve Cover
Posted: Mon May 01, 2023 11:24 am
by Onex107
I didn’t return mine to the valve cover, as per the Cessna guru Mike Bush?, because it contains acidic moisture. I used a pint Ball jar, calibrated in ounces. With the Ball jar lid you can remove the jar without removing the whole lid making it easy to clean and measure the output. I felt it would be a good idea to record the amount of blow by as an indication of the engine health rather than depending on the hard to read dip stick in the Aerovee engine. The oil blowby and usage in the Aerovee was really different than the Cessna O-200. A quart in 10 was the standard in the Continental where 10-12 ounces in 25 is normal in the Aerovee.