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Airwolf Minisep Air/Oil Separator

Darrel Starr

Darrel Starr

Registered User
Plymouth, MN
A couple of weeks ago, I made a flight into Wisconsin stopping at seven airports. Normally with the original breather tube installation, I would get a few drops of oil on the boot cowl after a ride around the patch. But all that stopping and starting left quite a mess on the bottom of the boot cowl and left gear leg. Apparently some oil condenses in the aluminum breather tube and blows out on restart.
So last week I installed an Airwolf Minisep air/oil separator. Today I took a short ride just to make sure all was well and in 0.2 hr with the oil temp at 180F I got no noticeable residue out of the Minisep outlet. Then Vivian and I flew it for an hour at 2350 rpm, 195F oil temp. At the end of the flight I had no oil residue inside the cowl but had a moist crescent on the right side of the boot cowl where the water vapor had re-condensed after being sucked out through the right cheek. So far so good. I like being able to see that water vapor isn't just draining back into the engine. Next, I'll make one of those multi stop trips to see what happens.
P1050518.JPG

P1050496.JPG
 
Sir,

Your Supercub is gorgeous !

May I ask what made you chose the Airwolf air/oil separator vice the M20 air/oil separator?
 
Musket, thanks for the comment.
I didn't use the M20 because:
(1) A friend had an M20 on his Super Cub and saw no improvement so he gave it away then bought an Airwolf Minisep. It still lets a few drops of oil through (not as effective as the full size Airwolf/Walker separator on his Cessna 172) but still pretty good.
(2) Another friend had an M20 installed on his 201 Mooney and he doesn't think it does much.
(3) Darrell Bolduc at Bolduc Aircraft (rebuilds aircraft engines) doesn't think the M20 works either.
(4) The cut away of the M20 on the Airwolf web site does not show much in the inside -- a tube inside a tube basically.
So I decided to go with the Airwolf product -- I think this will work pretty well, I only wish I had room for the full size Airwolf/Walker unit. The first hour of operation was very effective.
Darrel
 
I had plenty of belly oil on my pa18 before i installed the M20 about a year ago and i haven't had a drop since. The overflow on my M20 drains back into the oil sump neck as M20 suggests. If installed correctly i can't see why there would be any oil on the belly.
garyh
 
My guess is that a lot of the success or failure of any of these devices has to do with:
1. Keeping the vapors hot into and through the separator so the moisture can, as vapor, go out the bottom.
2. Have a simple free flowing downhill drain to get the oil back into the sump.
3. Exhaust the water vapor and air into a quiet spot where it won't experience a siphoning action that will suck the oil through into the exhaust.
This can probably be done quite well with the M20, possibly a little easier to make the installation meet these goals with the Airwolf separator.
Darrel
 
Hi, Mr. Starr, you Supercub does look quite nice, but I see a flaw in the wheel alignment. In the photograph taken from above, it appears that your right and left main gear are not symmetrical, relative to the towels on the floor. You might want to take a look at that:)

I have inspected the photos carefully, and must say that, other than the wheel alignment your cub is spotless and bugless (sp?)

rsc
 
Randy (aka "windonhisnose"), gosh you are right, I am so embarrassed. I'll fix the offensive alignment right away. Thanks much for being so observant.
Darrel
 
Darrel, I'll look forward to hearing how the device works for you. I like the installation you put together...it looks terrific.

So does your Supercub. Really beautiful work of art, actually.

Take care.

Randy
 
And Randy, I truly appreciate your first note. I see now that my affliction, Progressive Analy Brained Disease, has not yet gone beyond reasonable hope for recovery. Yours was an encouraging word.
Darrel
 
Darrel I'm looking at the Air Wolf separator for my cub but when reading up on the separator it says that it uses some vacuum from the vacuum pump which i don't have. What unit did you buy and how hard was it to plumb?
 
Airwolf makes separators with and without a vacuum port. When I called them that is one of the things we discussed -- I do not have a vacuum pump. So the one they sold me is item # AFC-W410, MiniSep Complete, 3/4" Breather -- $399.
There is a 3/4" breather line coming in the top -- they send some Mil6000 hose but the bright blue hose I used was about 30 inches of 3/4 ID silicone hose from Aircraft Spruce -- Part No. 05-00671 ($7.50/foot). I think it is the best because you can bend it pretty tightly without it kinking. Run it where the hose and Separator will stay hot.
A 1/4" drain line, also Mil6000, is in the kit along with fittings so you can plumb it into the hole in the right side of the accessory case that now has a 3/8" pipe plug. Make sure it is free flowing and downhill.
The outlet is 3/4" Scat-3 ducting. That is suppose to end inside the cowl in quiet air. Airwolf says to end it at least 6 inches above the bottom of the cowl.
I ended the outlet pointed at the firewall where the vapor will be sucked out the right cheek opening. This was just fine until the engine was hot and we were on final. The breather fumes could be smelled in the cockpit.
So I have a longer piece of Scat-3 ordered so I can run the vapors out toward the left cheek or the left bottom but still up inside the cowl near the firewall. Airwolf warns that it might take several tries to locate the outlet end in a spot that doesn't siphon the vapor out.
Let us know how your installation goes.
Darrel
 
Darrel Thanks for the info. I'm going to order one and see if it will fix my blow by. I may be contacting you for advice. What's your phone number
 
I decided to reroute the output of the Minisep away from the right side of the aircraft because we were getting fumes in the cockpit as we slowed down on final. I have friends with a Vans RV6A. In the RV world it is common to aim the breather at the exhaust pipe. Since my initial few hrs with the Minisep resulted in about one oil drop per hr I have decided to try the following routing that aims the outlet of the Minisep at the exhaust on the left side.

Has anyone had any experience with a similar arrangement?

For one thing, it would end any worries of the outlet freezing. The idea is to sizzle off any oil that gets through the separator.
Darrel
P1050547a.jpg
 
I have always exited out the bottom of the cowl. I have found that by moving the outlet and inch or so can increase or decrease oil blow-by.
 
Darrel,,

Randy WindOnHisNose is very observant,,,, he can help you out with other problems as well... :lol: Not that I have first hand experience,,,,,,,,
 
We just completed 1.5 hr with two stops & cool downs, steep turns and one extended 2000 ft climb. At the end -- not a single drop of oil on the bird. I think I have a pretty good setup now.
Darrel
 
It would be interesting to see what is going back into the engine. Nice oil, or something that looks like a milkshake.


Mike
 
I now have 10 hrs on the MiniSep setup with the outlet pointed at the exhaust -- works perfectly! I had to wipe a couple of drops off the end of the MiniSep outlet tube after a flight when I was making a lot of tight turns. But other than that, I see NO residue.
When I first put the MiniSep on, I ended the outlet near the firewall on the right side. After an hour or so of flight, I would get an oily condensed water film on the right side of the boot cowl and we smelled the breather fumes especially full flaps on final. Now with the Minisep outlet blowing on the exhaust pipe just inside the left cheek, I get no oily film along the left side of the boot cowl at all and no stain on the exhaust pipe. I think the heat from the exhaust is keeping the breather fumes hot enough that it doesn't condense until it separates from the airframe. Or maybe there is just a very very thin layer of oily condensed water over a much larger area -- I just don't feel or see it at all.
Also the oil on the dipstick shows absolutely no milkiness at all.
So I am a happy camper, shooting the outlet at the exhaust just before the fumes exit the cowling was a breakthrough idea that I got from talking to the RV-6A builders in a neighboring hangar.
Darrel
 
Good Job!! Whats that metal tube coming out of the scat.. Is that something you fabricated or bought?
 
Steve, I put the tube on the end so I could clamp securely to the engine mount with Adel clamps and control the distance and angle of the exit. The tube is a piece of 5052-0 Aluminum 3/4 diameter, .035 wall -- Aircraft Spruce Pt # 03-39800. I put a flare on the end of it just for the hell of it. The flare kind of gives it that serious nozzle look.
Darrel
 
Darrel, I'm as impressed as can be, but the question has been nagging me....What happens when you put more than six quarts of oil in? :-?
 
I usually run between 7.0 or 7.2 max down to around 6.2 min. I sometimes only put in one half quart at a time but just the other day it was at 6.2 so I put the whole quart in. It seems to behave just as I described above throughout that range. I have read some of the Airwolf testamonials and one of the comments that comes up is that the folks generally say they can run with higher oil levels without the oil just being thrown out. I thought maybe I would see at least a little improvement in oil consumption but it is still at 9 hr/qt on the just barely broken in engine.
Darrel
 
I just installed the Air Wolf and here is a pic of it.. I used the same blue hose that Darrel used, and I bought a longer 3/4 scat 3 hose since the one that comes with the kit is not long enough.. I ran it out to the left side of the plane and kept it a couple inches above the bottom of the plane.. After flying for about an hour and a half, there was absolutely no oil coming out of the breather tube,, even when I stuck my finger in it there was no oil residue...Since I have a dynafocal mount, I attached the separator to it... I had 7 qts oil and 1 pint of camguard in the engine..

The oil drain coming out of the separator, I ran into a baby bottle. You can see the results,,, NO oil drained out,, only moisture as can be seen in the bottom of the bottle... I would hate to put this back in the engine..

IMG_2854-1.jpg




IMG_2852-1.jpg
 
so I assume this page at spruce is wrong about needing a vac pump on the mini version, since I don't see one in Darell's picture....

we used to run the big version on every thing we had and were sad to see the company go away, glad they are back!

to bad I just made a nice breather tube for this project, will have to check with customer see if he wants this.....

I think maybe the return line with a low spot/jar and a drain to separate out the moisture like a combination of Steve's & Darrel's installations...... I guess that's kinda redundant, a separator after the separator... but then you could choose to dump the moisture before letting rest of it it back into your engine....

kinda like the cold running Wigeon with geared engine, preflight- drain a half cup of water from crankcase before starting :)
 
Steve, all I can say is YIKES! I possibly could still be OK because there is one difference in our installations. If you look up at my photos. my MiniSep is positioned right above my right hand exhaust pipes in an effort to keep the MiniSep warm. It has to be hot enough to keep the water vapor from condensing in order to allow the separation. So mine might be accomplishing that -- remember, I did see oily water on the boot cowl when the outlet was on the right side of the plane -- but I have no way of proving mine doesn't allow water back into the engine short of also putting the oil return into a bottle. I am coming up on an oil change. I think next I will look for any signs of milkiness or water bubbles in the drained oil.
Mike, Airwolf sells the MiniSeps both with and without the vacuum connection. I bought the one without the vacuum connection -- Part # AFC-W410.
Darrel
 
Darrel,

In the airwolf install manual,, they suggest the firewall, motor mounts or on the back of the baffle, as you did... If you install on the firewall, I cant imagine the separator getting hot enough to get rid of the water vapor... I mounted it on the mount because it was a real easy deal. After my flight, I opened the cowling immediately and felt the separator and it was very warm,, not hot..

Like I said, I had no moisture or oil in the breather tube that I could feel with my fingers and none on the plane... An easy way to figure out if moisture is coming out of the oil drain on the bottom of the separator is to just stick it in a bottle like I did..... Let us know if you try it..

Steve
 
SteveE said:
Darrel,

In the airwolf install manual,, they suggest the firewall, motor mounts or on the back of the baffle, as you did... If you install on the firewall, I cant imagine the separator getting hot enough to get rid of the water vapor... I mounted it on the mount because it was a real easy deal. After my flight, I opened the cowling immediately and felt the separator and it was very warm,, not hot..

Like I said, I had no moisture or oil in the breather tube that I could feel with my fingers and none on the plane... An easy way to figure out if moisture is coming out of the oil drain on the bottom of the separator is to just stick it in a bottle like I did..... Let us know if you try it..

Steve
Click to expand...

I have seen them wrapped in asbestos blankets up here, must of been to keep it warm ;-)
 
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