Air / oil separator. . . .

I do aerial photo / video work with our GA-8 Airvan (turbo) and one issue I've had with it since new is that it blows a lot of oil out of the crankcase vent tube and down the belly of the plane, which results in frequent cleaning of the camera equipment to keep the pictures sharp. As I'm writing this, our mechanic is installing the Airwolf air / oil separator in hopes that it will fix this problem. Does anyone have experience with that product? Pros / cons? The POH says to keep the oil level at 9 qts. (12 qt. sump). I've run it as low as 7 quarts with no apparent improvements. Aircraft: 2013 GippsAero GA-8, Lycoming TIO-540 turbo TT: 200 hrs. since new --Rob
 

Astro14

$100 Site Donor
Staff member
Messages
13,113
Location
Virginia Beach
Originally Posted By: Olas
have your mechanic put the end of the vent tube in a 5 gal. bottle to catch the oil and dispose/return to sump when you land.
I think the Home Depot 5 gallon bucket is TSO'd , right? Just punch a hole in the firewall, run that tube of flammable stuff through the cockpit into the rear seat, should be fine... duh duh duh
 
Last edited:
Messages
10,699
Location
Jupiter, Florida
Yes, they help reduce oil on the belly, and will somewhat reduce oil consumption on some engines. However, most oil consumption is past the piston rings.
 

Robster

Thread starter
Messages
674
Location
Cumberland County, Pennsylvania
Thanks Cujet. . .in this case, I think most is from the crankcase vent. After shutdown, it starts dripping immediately and overnite will leave a 6-8" diameter puddle on the hangar floor. I'm really hoping this will fix it.
 
Messages
4,597
Location
Manchester, England
nobody mentioned cutting holes or directing anything tbrough the passenger compartment, and the bucket/bottle *may* benefit from rudimentary baffles..but its not readily flammable or the CAA wouldnt let you saturate the u.derside of your vehicle with it. extend the hose to vent rearward of the lense?
 

Astro14

$100 Site Donor
Staff member
Messages
13,113
Location
Virginia Beach
Originally Posted By: Olas
nobody mentioned cutting holes or directing anything tbrough the passenger compartment, and the bucket/bottle *may* benefit from rudimentary baffles..but its not readily flammable or the CAA wouldnt let you saturate the u.derside of your vehicle with it. extend the hose to vent rearward of the lense?
OK...so, just where would you suggest he place this bucket to catch the oil in flight?
 
Last edited:
Messages
9,797
Location
Central Coast, Calif.
Originally Posted By: Astro14
Originally Posted By: Olas
nobody mentioned cutting holes or directing anything tbrough the passenger compartment, and the bucket/bottle *may* benefit from rudimentary baffles..but its not readily flammable or the CAA wouldnt let you saturate the u.derside of your vehicle with it. extend the hose to vent rearward of the lense?
OK...so, just where would you suggest he place this bucket to catch the oil in flight?
Obviously you'd hang it on a Pitot tube.
 

Robster

Thread starter
Messages
674
Location
Cumberland County, Pennsylvania
Despite Olas' suggestions I still have to believe that the best place for the engine oil is IN THE ENGINE and not being vented overboard. Due to an unforeseen delay caused by Oshkosh, we didn't get the part until today. . . I'll take some pics of the install after it's done.
 
Messages
4,597
Location
Manchester, England
Originally Posted By: Astro14
Originally Posted By: Olas
nobody mentioned cutting holes or directing anything tbrough the passenger compartment, and the bucket/bottle *may* benefit from rudimentary baffles..but its not readily flammable or the CAA wouldnt let you saturate the u.derside of your vehicle with it. extend the hose to vent rearward of the lense?
OK...so, just where would you suggest he place this bucket to catch the oil in flight?
in the engine bay, where almost all catch cans are fou.d
 
Messages
4,597
Location
Manchester, England
Originally Posted By: Robster
Despite Olas' suggestions I still have to believe that the best place for the engine oil is IN THE ENGINE and not being vented overboard. Due to an unforeseen delay caused by Oshkosh, we didn't get the part until today. . . I'll take some pics of the install after it's done.
then we stumble upon the issue of oil spewing out of tbe vent tube, and how to make it stay in tbe engine... a drain from the catch can back to thesump, maybe?
 

Robster

Thread starter
Messages
674
Location
Cumberland County, Pennsylvania
The air / oil separator is installed, but I forget to get pics--sorry, I'll get them next time I have it un-cowled. Anyway, the make of the air / oil separator is Airwolf and it works like this (according to documentation): The engine vents the air / oil mixture to a small holding tank (about two quart size) where it's mixed with hot (212F) air from a tube connected to the exhaust side of the dry vacuum pump--this hot air vaporizes any moisture and sends it out the vent tube at the bottom of the engine cowl. Any oil that is vented from the engine gets directed from the holding tank (pressurized by the vacuum pump exhaust) through tubing to a return line back to the oil sump. The separation of the air / oil takes place within the holding tank as a result of the varying densities of the two substances and the application of the hot air from the vacuum pump exhaust. As of this writing I've only flown a short test flight since installation. I'll report back on it's effectiveness after I've flown an extended mission. The theory behind this seems solid--I'm hopeful that it'll solve our problem.
 

Robster

Thread starter
Messages
674
Location
Cumberland County, Pennsylvania
UPDATE: I had the air / oil separator removed from the aircraft. After exhaustively trying different configurations / tweaks, the Air Wolf made the oil loss WORSE on this aircraft. I really wanted this to work and we put a lot of time into giving it a go, but eventually we had to get the aircraft back flying missions.
 
Messages
10,699
Location
Jupiter, Florida
Wow, that's interesting that the oil consumption is worse with the oil sep installed. The crankcase may have more pressure inside with that unit, and more oil past the rings... Just a guess.
 

Robster

Thread starter
Messages
674
Location
Cumberland County, Pennsylvania
It's not consuming oil (i.e. burning), but with the sep installed, there was more venting out the breather. It seems like the sep system was pressurizing the crankcase more. Air Wolf says you need to properly place the outlet tube so it is in a neutral area of pressure, but I found that to be an elusive goal in this application.
 
Top