Air/Oil separator

[1524J]

I've got a A3B6D engine and I'm trying to determine the best spot for an M20 air/oil separator. I know all the arguments for and against installing one as I purchased the one I've got 4 years ago. The intent was to install the M20 during the engine overhaul and go straight to the oil sump but that's a whole other story. Anyhow, the AP/IA I use is more of a Bonanza/Cessna guy as there are only two Moonies on the field. My concern is getting enough height to allow for the gravity drain into the rocker panel. Pictures would be great!! 

[N201MKTurbo]

Mine is installed to the motor mount tubing just behind cylinder 3. The cylinder 3 oil drain tube was modified to add a Y with a nipple that has a hose to the bottom of the separator.

[cnoe]

Mine is high on the right firewall and drains into a "Y" in the #3 oil-return line like 201MK's.

Here's an old pic of the layout prior to my JPI installation and general under-cowl cleanup. Still the separator location remains the same. You can't quite see the "Y" as it's hidden behind the old scat tubing.

 

[1524J]

10 minutes ago, N201MKTurbo said:

Mine is installed to the motor mount tubing just behind cylinder 3. The cylinder 3 oil drain tube was modified to add a Y with a nipple that has a hose to the bottom of the separator.

That makes more sense.....for some reason we've been focused on the left side of the engine going to the #4 cylinder. Any idea how much clearance you've got between the M20 and the cowl? I might be able to open the oil filler door and take pictures with a phone while trying to get maximum height without contacting the cowl. 

[N201MKTurbo]

There is plenty. If you are not in a hurry, I'll take some pictures next time I have the cowl off.

[cnoe]

It's not even close to the cowl; here's another pic of the unit on the firewall. I'll be at the hangar tomorrow and could shoot a pic thru the oil filler door if you like.

 

[N201MKTurbo]

CNOEs looks like a better place then mine, go with what he has.

[cnoe]

That's where it was when I bought the plane and it's been no issue.

The hard part is finding the sweet spot with regards to length of the discharge/scat tubing. Too long and it'll get in the slipstream and pull a slight vacuum. Too short and you'll get a little oil mist coming out the lower cowl camlock holes. I repositioned mine to the firewall a couple of inches in from the side cowling and a few inches above the exhaust pipe which seems to keep things pretty clean. 

[1524J]

Great pics cnoe! My voltage regulator is in the exact spot as your air/oil separator. I think the reason we've been focused on the left side is that's where the vent tube is routed. We've also been focused on the rocker panel which makes it very difficult to get a constant gravity drain. I'll have to inquire about getting the #3 or #4 oil drain line modified with a "y". 

[1524J]

20 minutes ago, N201MKTurbo said:

There is plenty. If you are not in a hurry, I'll take some pictures next time I have the cowl off.

It's been sitting in the hanger for four years, well....two...... And two years in the in the AP/AI shop because it was supposed to have been installed during the overhaul. I guess you could say I'm not In a hurry.  

[cnoe]

I think that Y is easily obtained.

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[1524J]

Just now, cnoe said:

I think that Y is easily obtained.

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You think it can be purchased or easily modified? I haven't been able to find something I could purchase. Most of the air/oil separators I've seen either drain into the sump (best option) or into the rocker panel. Rocker panel isn't difficult other than it's borderline high on the A3B6D with the cowling.

[N201MKTurbo]

My Y tube doesn't look like a purchased part, it looks like a field mod. If I recall the mod is talked about in the STC.

[1524J]

Just now, N201MKTurbo said:

My Y tube doesn't look like a purchased part, it looks like a field mod. If I recall the mod is talked about in the STC.

I was thinking it was a mod. I'm not sure that's something I could have done locally. I don't know anything about welding (although I've sweated lots of copper) but it's got to take some skill to take a 1/4 aluminum line and add a "Y". All the more frustrating it didn't get installed during the overhaul. Thanks to you and cnoe for the input!!

[DrBill]

I had one installed for a few months tied to the motor mount behind 4.  The drain went to an empty waterbottle.  I got nothing in the bottle in 10 hours so we took it out and put the stock vent hose back. 

Bill

 

[1524J]

51 minutes ago, DrBill said:

I had one installed for a few months tied to the motor mount behind 4.  The drain went to an empty waterbottle.  I got nothing in the bottle in 10 hours so we took it out and put the stock vent hose back. 

Bill

 

Never thought about that but I'm assuming the oil on the belly is coming from the vent hose.....

[cnoe]

I'd give Airwolf a call at 800-326-1534 and ask about the return tube. They say... "As you can see, you get a pile of parts in the this kit for the $450 price. We are not like the competition who says to just have your mechanic build and or purchase all the parts needed for the installation like it is no big deal. It is a big deal to get all the parts in the box and it is a bigger deal not to have to spend $75/hr for your mechanic to make parts."

My return tube doesn't appear to be fabricated in the field.

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[cnoe]

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From my documentation...

[1524J]

Dang.....bought the competition. Really appreciate the info cnoe!! Maybe I can get this air/oil separator installed in the next four years.  

[DrBill]

2 hours ago, 1524J said:

Never thought about that but I'm assuming the oil on the belly is coming from the vent hose.....

so did I that's why I did the test.  I borrowed the M20 from another pilot at the field.

[davecusto]

is an air/oil separator STCed for my Mooney M20F?  I'm pretty new to the plane and spent a fair amount of time getting most of the oil off the belly.  The guys down at the Hangar told me the engine will blow out oil until it finds a level it likes.   Mine seems to like 4 1/2 quarts, which seems low.  It still blows a little, about 1/2 qt every 3-4 hours.   It mostly lands on the gear door and leading edge.   Anyway, is a separator STCed for the M20F?

 

[MikeOH]

@davecusto

Yes. I have an M-20 Oil Separator on my 1970 M20F.  I'm very happy with it as there is never anything on the belly.

It is STC SA02033AT from M-20 Oil Separator LLC out of Boca Raton, FL

No idea, however, if they are still in biz.

[Shiny moose]

I have a complete AW set up, removed from my 67f , the seperator is slightly dented but all parts and drain tubes are there! I might even have a new gasket that airwolf wants replaced each time you open the seperator ?

Wont take much of an offer to have me send  this to someone who needs it  

[A64Pilot]

If you are a welder, they aren’t hard at all to make. I put one on my Maule and copied the M20 design, I did it because I was putting an Airwolf (Pesco) vacuum pump on and they discharge oil in their exhaust.

The photos will show the internal piece parts, the brownish color is where I alodined them. 

 

[N201MKTurbo]

24 minutes ago, A64Pilot said:

If you are a welder, they aren’t hard at all to make. I put one on my Maule and copied the M20 design, I did it because I was putting an Airwolf (Pesco) vacuum pump on and they discharge oil in their exhaust.

The photos will show the internal piece parts, the brownish color is where I alodined them. 

 

Nice work!