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Extended breather line to tail: has anyone done this?

Gash

Gash

Well Known Member
First off, my apologies if this has been discussed already. I tried searching on this and came up with nothing...

I am flying a half hour of aerobatics everyday in my RV-8 as I prepare for this year's IAC contests. I recently replaced my ASA oil separator with a full Christen inverted oil system and have been very happy with it...except for one thing. My IO-360 spits out exactly one quart of oil per 30 minutes of Sportsman level aerobatics. I realize this is the cost of doing business in aerobatics, BUT I'm getting pretty tired of the dripping, sloppy mess on my belly everyday. It's time to fabricate a solution!

My breather line currently exits near the exhaust pipes. I would like to route a breather tube through the firewall along the fuselage interior somewhere and then all the way back to the tail. I'm thinking that a tube penetration somewhere forward of the tailwheel arm would be good, with the tube continuing sufficiently aft to keep oil off the tailwheel (similar to what I've seen on the Extra 300).

Has anybody else done this? How has it worked out for you? Do you have any photos or recommendations? Thank you from the bottom of my belly! :)
 
Commonly done on other aircraft, as you know. I am aware it being a factor in a Pitts forced landing in MN during the winter where the breather froze over. A whistle slot or some other similar provision would probably be advisable.
 
1. Reduce your starting oil level by .5 qts and see. I only fly with 6 qts when doing acro.

2. Route your breather line INTO your exhaust. Instead of having a breather line running all the way to the tail, adding all that weight, just run it into the exhaust and it will burn off any overflow as harmless puffs of smoke.

As for the details how to route it into the exhaust, have to ask someone else, but I have seen it done. It is what I would do if I were to do it myself.
 
The Christen install instructions call out the breather to be ran to the back. Not saying it has to be, that is just what they show in the manual. My Bucker is set up that way. Rubber hose to fire wall mounted bulkhead fitting, hard line back to exit aft of the tailwheel, which is forward of the tail on the Bucker. I can not see what is coming out of the breather line in flight but it leaves no residue on the tail surfaces. However, on the ground, after flight, it drips a few tablespoons of a nasty caustic soup that will eat concrete!

I run my RV6 at 5 quarts, measured on the stick, never more than 5 1/2, which is really 6-6 1/2 quarts total as most of one quart gets sucked up into the fuel filter.

Hope your doing well Gash. Haven't seen you since the Phoenix "50".

"JJ"
 
JonJay said:
The Christen install instructions call out the breather to be ran to the back. Not saying it has to be, that is just what they show in the manual. My Bucker is set up that way. Rubber hose to fire wall mounted bulkhead fitting, hard line back to exit aft of the tailwheel, which is forward of the tail on the Bucker. I can not see what is coming out of the breather line in flight but it leaves no residue on the tail surfaces. However, on the ground, after flight, it drips a few tablespoons of a nasty caustic soup that will eat concrete...
Click to expand...

Ditto my setup and experience on my Hiperbipe... Except for the concrete eating part.
 
1. Reduce your starting oil level by .5 qts and see. I only fly with 6 qts when doing acro.

2. Route your breather line INTO your exhaust. Instead of having a breather line running all the way to the tail, adding all that weight, just run it into the exhaust and it will burn off any overflow as harmless puffs of smoke.

As for the details how to route it into the exhaust, have to ask someone else, but I have seen it done. It is what I would do if I were to do it myself.
Click to expand...

I actually thought about routing the breather directly into the exhaust. I could just attach the breather hose to the existing stem I welded into an exhaust pipe that was used with my Anti Splat Aero oil separator before I installed the Christen system. My big concern with that, however, is that burned oil residue could build up around the stem opening and plug up, causing back pressure and subsequent crank seal blowout. You may recall that this is exactly what happened to me back in Oct 2015 because I had failed to regularly check for coking of the stem opening. It only happened that one time--afterwards I inspected / cleaned every 50 hours and never had a problem again.

But now with the amount of oil that goes overboard during aerobatics, I am worried that the exhaust pipe stem could plug up much more quickly. I might be wrong, but I'm hesitant to go out and test the theory since a negative result can be rather catastrophic.

If anyone else here is running their aerobatic inverted oil system breather to an exhaust pipe stem, I'd really like to learn what results you're getting.
 
If you want to know if this has been on done on an RV, I can tell you absolutely yes - we found a long tube extended from the firewall to the tail on the RV-1 during its restoration! I think that Van said it was original when he built the plane.
 
The Christen install instructions call out the breather to be ran to the back. Not saying it has to be, that is just what they show in the manual. My Bucker is set up that way. Rubber hose to fire wall mounted bulkhead fitting, hard line back to exit aft of the tailwheel, which is forward of the tail on the Bucker. I can not see what is coming out of the breather line in flight but it leaves no residue on the tail surfaces. However, on the ground, after flight, it drips a few tablespoons of a nasty caustic soup that will eat concrete!

I run my RV6 at 5 quarts, measured on the stick, never more than 5 1/2, which is really 6-6 1/2 quarts total as most of one quart gets sucked up into the fuel filter.

Hope your doing well Gash. Haven't seen you since the Phoenix "50".
Click to expand...

Thanks JJ! Great to hear from you. Yes, the Phoenix 50 was a blast...

Since Christen inverted systems are an Aviat product, it makes sense that they'd put it in the instructions to run the line to the tail. I do like the idea of rubber hose to a firewall fitting, then metal tube inside the fuselage (except for some hose for joggles).

I'm really hoping that somebody else has already done this in their RV so that I can learn from their experience.
 
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If you want to know if this has been on done on an RV, I can tell you absolutely yes - we found a long tube extended from the firewall to the tail on the RV-1 during its restoration! I think that Van said it was original when he built the plane.
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That's really interesting Paul! I always like to hear little bits and pieces like this about the RV-1.
 
Gash,
The rv-4 plans has that set up. I thought it was weird but they show the hose going through the firewall, rudder pedal tunel, under the seats, baggage compartment and out by the tail wheel.
 
Well..

You might be well advised to run a line to the aft bulkhead, but you MIGHT want to switch to a std fwd system in the winter...that long line could freeze. A 'whistle slot' would keep you flying, but...

Carry on!
Mark
 
Gash said:
First off, my apologies if this has been discussed already. I tried searching on this and came up with nothing...

I am flying a half hour of aerobatics everyday in my RV-8 as I prepare for this year's IAC contests. I recently replaced my ASA oil separator with a full Christen inverted oil system and have been very happy with it...except for one thing. My IO-360 spits out exactly one quart of oil per 30 minutes of Sportsman level aerobatics. I realize this is the cost of doing business in aerobatics, BUT I'm getting pretty tired of the dripping, sloppy mess on my belly everyday. It's time to fabricate a solution!

My breather line currently exits near the exhaust pipes. I would like to route a breather tube through the firewall along the fuselage interior somewhere and then all the way back to the tail. I'm thinking that a tube penetration somewhere forward of the tailwheel arm would be good, with the tube continuing sufficiently aft to keep oil off the tailwheel (similar to what I've seen on the Extra 300).

Has anybody else done this? How has it worked out for you? Do you have any photos or recommendations? Thank you from the bottom of my belly! :)
Click to expand...

I haven't done that but I am having the same problem so please let us know how it goes if you do it. I dropped about 1 qt per practice before I installed my half Raven system. Now it's much less but still quite noticeable.

As others have stated I also fly with max 6 qt. Everything above that I can as well poor on my hanger floor right away.... . At this point I consider the oil on my belly ( and somehow it's not only on the outside but also on the inside) corrosion protection.

Now on another note I ask myself why I am still doing oil changes. I mean I go through enough oil between intervals that everything should have been exchanged... .

Oliver
 
I've seen installations where the breather tube is run down the landing gear and out the back of the wheel pant.

There appears to be sufficient separation that none migrates back to the tail surfaces - probably due to the downwash off the wing.
 
AX-O said:
Gash,
The rv-4 plans has that set up. I thought it was weird but they show the hose going through the firewall, rudder pedal tunel, under the seats, baggage compartment and out by the tail wheel.
Click to expand...

I'd be interested to see that sometime Axel. Thanks for letting me know.
 
Marc Bourget said:
I've seen installations where the breather tube is run down the landing gear and out the back of the wheel pant.

There appears to be sufficient separation that none migrates back to the tail surfaces - probably due to the downwash off the wing.
Click to expand...

This is exactly what I was thinking! I'm in the middle of my aerobatic -4 build and have lost a lot of sleep over what to do with the vent line from my Raven system. I know Pitts and other aerobatic planes run the vent to the tail but for me I put a smoke tank in my front middle tunnel and can't run a 5/8-3/4 line through there anymore. Even if I could a hard line to the tail posses some concerns to me, 1) weight, 2)freezing, 3)back pressure, 4) low spot could cause oil to pool and cause back pressure. I have considered venting into the exhaust but this would require a close eye to make sure it does not plug up as to many have found. Also can you run the Anti Splat vent system with a 4-pipe exhaust, will it work on a single cylinder pipe? I feel running the vent down a gear leg might be a great option.

On a side note I have been considering adding a crankcase pressure sensor or just a simple idiot light. It would be very easy to add a simple sender in the crankcase to trigger if crankcase pressure got to high. This would help at lease give you warning before your crank seal blew out from a blocked vent line.

Does anyone know how big the vent line really needs to be? Stock appears to be -12 but would a -10 work?
 
Gash said:
First off, my apologies if this has been discussed already. I tried searching on this and came up with nothing...

I am flying a half hour of aerobatics everyday in my RV-8 as I prepare for this year's IAC contests. I recently replaced my ASA oil separator with a full Christen inverted oil system and have been very happy with it...except for one thing. My IO-360 spits out exactly one quart of oil per 30 minutes of Sportsman level aerobatics. I realize this is the cost of doing business in aerobatics, BUT I'm getting pretty tired of the dripping, sloppy mess on my belly everyday. It's time to fabricate a solution!

My breather line currently exits near the exhaust pipes. I would like to route a breather tube through the firewall along the fuselage interior somewhere and then all the way back to the tail. I'm thinking that a tube penetration somewhere forward of the tailwheel arm would be good, with the tube continuing sufficiently aft to keep oil off the tailwheel (similar to what I've seen on the Extra 300).

Has anybody else done this? How has it worked out for you? Do you have any photos or recommendations? Thank you from the bottom of my belly! :)
Click to expand...

Well, I guess losing considerable oil during aerobatics is fairly common. I should count my self lucky then. I assume you meant IO-360A1A as opposed to the other parallel valve IO-360's. If so, I have the same set-up, an IO-360A1A and the full Christen inverted oil system and I don't lose any measurable amount of oil during practice. The only difference between my system and a stock system is the addition of a B&C VAC-2, http://www.bandc.aero/vac-2invertedoilpickup4-cylinderlycoming.aspx. I'm not sure if that makes any difference in retaining oil.

I typically run my oil level at 6 1/2 - 7 quarts. Be careful using too low of an oil quantity. The IO-360A1A (angle valve) motor has a different sump design and consequently has a different placement for the oil pickup in upright conditions with the installed inverted oil system. I found that as my oil level approached 6 quarts, I would lose some oil pressure during steep dive angles and rapid deceleration. If using a compact-hub (non-aerobatic) prop, the blades go flat resulting in a potential severe overspeed. The reason this happens is because the pick-up enters the sump on the aft side and the oil sloshes forward. It has happened to others here on VAF. Be careful.

Anyway, it's time for me to go out and practice now. I'm looking forward to the several competitions this year!
 
Breather

Factory option on the Pitts is a second, normally unused breather forward of the firewall. Connected for cold weather operation.
 
RV8Squaz:

I'm using that same vacuum pad adapter. You almost have to use it with our airplanes to get all the hoses and hardware to fit in the RV.

My engine is actually an IO-375 M1B from Aero Sport Power. I've gotten in the bad habit of telling people I just have an IO-360 because folks (not on this forum) usually go "huh?" when I tell them it's an IO-375. My engine has the horizontal oil screen.

I guess for now I'm going to just run the oil a little lower, no more than 6 quarts. I'm also going to figure out how to run a breather line with a constant downhill slope from the firewall to the tail. I'll take lots of pictures to post here when I get this project going.

In the meantime, I'd love to see if anybody else has done something like this.
 
Quick update on this topic folks. I've taken a hard look at running a breather tube on the inside of the fuselage from FWF back to the tail. My opinion now is that it's not feasible in the RV-8. Too many joggles and obstacles.

So....what I've decided to try is running a breather line to the tail on the outside of the aircraft along the centerline of the belly, all the way back to the tail. I'm thinking about using rivnuts and clamps to hold the tube in place. I might fabricate a fairing to put over the tube along its length. Anytime I want to remove the tube assembly, I would just put screws in the empty rivnut holes.

I'm not sure if this will look like a complete redneck solution (no offense to any rednecks here). I'm going to experiment with this idea in a few days and will post photos later.

Any comments on this idea?
 
Sounds like a lot of work just for the sake of a few pints of oil and a clean belly for your occasional aerobatics Gash. The Pitts, my Bucker, dedicated aerobatic mounts, fabric, wood stringers, airplanes that could be difficult to clean if they where oil saturated. RV's wipe down with a rag.
Are there other benefits?
 
A minor mod to your idea:

Gash said:
So....what I've decided to try is running a breather line to the tail on the outside of the aircraft along the centerline of the belly, all the way back to the tail. I'm thinking about using rivnuts and clamps to hold the tube in place.

Any comments on this idea?
Click to expand...

If you're gonna go to that trouble, why not try running it down the aft edge of the gear leg 1st as an experiment? Duct tape could be used for this quick 15min flight...might add some tie wraps over the tape in case things get warm..

Terminate the line near the axle with a curve to put the outlet 2-4" away from the wheel pant. If it works (doesn't dump oil on the empennage), you could add an interior line w/connector to the pant to put the outlet at the aft end of the pant, kinda like the fuel tank vents on a B-25.

Your Plan A would also work, but it's gonna generate plenty of remarks..

Carry on!
Mark
 
JonJay said:
Sounds like a lot of work just for the sake of a few pints of oil and a clean belly for your occasional aerobatics Gash.
Click to expand...

I know what you mean JonJay, but I don't fly occasional aerobatics :). I actually fly aerobatics once a day, sometimes twice a day. Each time I go up I run through the IAC Sportsman sequence at least four times per flight. I am spitting out an amazing amount of oil on my belly. All the time wasted wiping up oil afterwards is getting out of control. They say "necessity is the mother of invention" and my little invention brain is revving up!
 
F1Boss said:
If you're gonna go to that trouble, why not try running it down the aft edge of the gear leg 1st as an experiment?
Click to expand...

Mark, I think that's a cool idea. I have the airfoil Grove gear legs, so I'm not sure how well that would work to put a 3/4" or 5/8" tube on the trailing edge of the gear. It might be better than a full-length belly tube though. I gotta think about this one. Thanks.
 
Why not run it into your exhaust like you had it before, and put a tee with a 0.25psi pop-off valve to an emergency line that will dump it on your belly in case the exhaust tap gets blocked? (Yes, I'm looking at the Anti Splat Aero Crankcase Vacuum Kit Complete right now :cool:)
 
Gash said:
I know what you mean JonJay, but I don't fly occasional aerobatics :). I actually fly aerobatics once a day, sometimes twice a day. Each time I go up I run through the IAC Sportsman sequence at least four times per flight. I am spitting out an amazing amount of oil on my belly. All the time wasted wiping up oil afterwards is getting out of control. They say "necessity is the mother of invention" and my little invention brain is revving up!
Click to expand...

Sorry for assuming. That's a lot of aero!
 
Krynn said:
Why not run it into your exhaust like you had it before, and put a tee with a 0.25psi pop-off valve to an emergency line that will dump it on your belly in case the exhaust tap gets blocked?
Click to expand...

I thought about that Krynn, but I have such a high volume of oil going overboard (about 1/2 quart per flight) that I'm worried about the fitting getting blocked by cooked oil, and then the pop off valve getting sloshed with oil and failing.
 
JonJay said:
Sorry for assuming. That's a lot of aero!
Click to expand...

Hey no problem! I know it's out of the ordinary to fly so much aerobatics...I'm just trying to make sure I don't make a darn fool out of myself when I go to the first IAC contest this year! :eek:
 
Well, then...

Gash said:
Mark, I think that's a cool idea. I have the airfoil Grove gear legs, so I'm not sure how well that would work to put a 3/4" or 5/8" tube on the trailing edge of the gear. It might be better than a full-length belly tube though. I gotta think about this one. Thanks.
Click to expand...

Put it on the front....less drag there. I'll bet a 1/2" line would work fine, unless your engine has LOT of blow-by. Heck, it's only an experiment unless it works!

Carry on!
Mark
 
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F1Boss said:
Put it on the front....less drag there. I'll bet a 1/2" line would work fine, unless your engine has LOT of blow-by. Heck, it's only an experiment unless it works!
Click to expand...

Good thinking Mark. Leading edge makes sense, and yes, 1/2" is plenty big for this application. Next problem is figuring out how to get the radius bends to work right in 1/2" line. I'll need two 90 degree bends. I thought about using rubber hose at the bends, but can't risk having the hose collapse.
 
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Standard bender

Gash said:
Good thinking Mark. Leading edge makes sense, and yes, 1/2" is plenty big for this application. Next problem is figuring out how to get the radius bends to work right in 1/2" line. I'll need two 90 degree bends. I thought about using rubber hose at the bends, but can't risk having the hose collapse.
Click to expand...

I'm running 1/2" fuel lines on my current build - the bender I have can roll the 1/2" tube in a ~2" radius. I'll bet you can borrow one like it....

Carry on!
Mark
 
What about automatic transmission hose to connect the lines, it is designed for hot oil, not easy to kink in a bend.
 
Those are all good ideas guys, thanks. I think I'm going to stick with aluminum tubing. I did find a guy who I can borrow a bender from. The other reason to use metal tubing is it allows me to minimize the number of attachment points to the gear leg. I would need more attachments for poly or rubber (1 each at beginning and end of bends). But with metal tubing I think I can get away with one attachment at the top of the gear leg and one at the bottom. This way I should be able to keep the installation looking more clean.
 
This won?t be helpful I suppose but I have the Christen system on my old RV-4 and when I do negative G acro I don?t lose any oil at all, nothing on the belly and no loss on the dip stick. Isn?t trapping oil what the big canister is for that?s part of the system? I do have the Sky Dynamics Maxie sump maybe that makes a difference, I don?t know.
 
Russ McCutcheon said:
This won?t be helpful I suppose but I have the Christen system on my old RV-4 and when I do negative G acro I don?t lose any oil at all, nothing on the belly and no loss on the dip stick. Isn?t trapping oil what the big canister is for that?s part of the system? I do have the Sky Dynamics Maxie sump maybe that makes a difference, I don?t know.
Click to expand...

I have no experience to speak of as I'm still building my -4 but I have both the Raven and the Christen system sitting on my workbench right now and they appear to be identical. I'm worried now hearing about how much oil Gash is losing even with Inverted oil so I'm planning on running the vent line down my gear leg.

Gash any chance ther is something wrong with your inverted system? I have both systems at my house right now in north Scottsdale if you want to borrow anything for testing.

Is 1/2" line going to be big enough to keep crank case pressure low? Sounds to small to me compared to the factory breather line of 3/4. I have a digital manometer if anyone wants to run a small 1/4 line into the cockpit and use the manometer to monitor crank case pressure after any vent line modifications.

I would love for us to all figure this out and be able to fly acro all day and have a clean belly. I'm again still building my -4 in north Phoenix but have a fairly complete machine shop if anyone in Phoenix needs anything to experiment with.
 
Russ McCutcheon said:
This won?t be helpful I suppose but I have the Christen system on my old RV-4 and when I do negative G acro I don?t lose any oil at all, nothing on the belly and no loss on the dip stick. Isn?t trapping oil what the big canister is for that?s part of the system? I do have the Sky Dynamics Maxie sump maybe that makes a difference, I don?t know.
Click to expand...

Russ, I think the problem is that a little bit of oil doesn't have enough time to drain back into the engine between aerobatic figures so it ends up going overboard. The maxi sump looks cool, but I don't have room for something like that anymore. Maybe on the next build!
 
SJordan said:
Gash any chance ther is something wrong with your inverted system? I have both systems at my house right now in north Scottsdale if you want to borrow anything for testing.

Is 1/2" line going to be big enough to keep crank case pressure low? Sounds to small to me compared to the factory breather line of 3/4. I have a digital manometer if anyone wants to run a small 1/4 line into the cockpit and use the manometer to monitor crank case pressure after any vent line modifications.
Click to expand...

Thanks for the offer Shawn. I'm pretty sure the system is working correctly. There are a couple notes in the Christen manual about venting oil overboard if there's not enough time spent at positive G between maneuvers. I think that's what is going on in my situation. I don't have any problems maintaining oil pressure when inverted, so the system is doing its job.

Also, good point about 1/2" line. I have a friend/fellow airport bum with 10 times my mechanical knowledge who I spoke with today. He also recommended 3/4" tube for this application. I guess he has personal knowledge that 1/2" is insufficient from a previous project, so I trust him. I can get a 3-inch radius bend with 3/4" tube, and that should work alright.
 
Gash said:
Thanks for the offer Shawn. I'm pretty sure the system is working correctly. There are a couple notes in the Christen manual about venting oil overboard if there's not enough time spent at positive G between maneuvers. I think that's what is going on in my situation. I don't have any problems maintaining oil pressure when inverted, so the system is doing its job.

Also, good point about 1/2" line. I have a friend/fellow airport bum with 10 times my mechanical knowledge who I spoke with today. He also recommended 3/4" tube for this application. I guess he has personal knowledge that 1/2" is insufficient from a previous project, so I trust him. I can get a 3-inch radius bend with 3/4" tube, and that should work alright.
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I'm thinking of going with 5/8 hose (-10) but still a bit worried it's to small. Every engine is going to be different with different amounts of blow by but a simple crankcase pressure check in flight with a manometer should help us verify what's really needed for vent line size of the breather tank. Who knows maybe lycoming made that line 3/4 just to vent enough blowby in a total ring failure situation. Than again I just put a new crank seal in last week and it would not take much crankcase pressure to blow that thing out.
 
Gash said:
Thanks for the offer Shawn. I'm pretty sure the system is working correctly. There are a couple notes in the Christen manual about venting oil overboard if there's not enough time spent at positive G between maneuvers. I think that's what is going on in my situation. I don't have any problems maintaining oil pressure when inverted, so the system is doing its job.

Also, good point about 1/2" line. I have a friend/fellow airport bum with 10 times my mechanical knowledge who I spoke with today. He also recommended 3/4" tube for this application. I guess he has personal knowledge that 1/2" is insufficient from a previous project, so I trust him. I can get a 3-inch radius bend with 3/4" tube, and that should work alright.
Click to expand...


Gash,

Shawn may be onto something. As discussed previously, I have an IO-360A1A with the full Christen inverted oil system and don't lose any appreciable oil, maybe a couple of drops on the hangar floor and some very short streams on the belly. I'm also flying once to twice per day doing the sequence 3 times each. I have even hung inverted for up to 5 minutes at a time for a photo op. I was very careful to install the Christen system as close to the manual as possible. Be sure the air/oil separator and valve are installed in the proper locations. I can't remember what they were, but there were some very specific locations in the manual. I also don't remember what size hose I have, but it's whatever was in the manual, either 5/8 or 3/4. Good luck. I know oil messes are a pain.
 
So I'm going to try out the tube down the gear leg idea here in a couple days, and realized that I have no idea which gear leg to install this extended breather tube on. Since the prop is turning clockwise, I wonder from which side I should vent oil to minimize mess under the wing, on the tail, etc.

I'm sure that propwash as it swirls around the fuselage will have a different effect on the right or left gear leg...I just don't have the aero engineer brain to figure out which side would make less mess.

Can anybody smarter than me (that would be all of you :D) please chime in with ideas?
 
Gash said:
So I'm going to try out the tube down the gear leg idea here in a couple days, and realized that I have no idea which gear leg to install this extended breather tube on. Since the prop is turning clockwise, I wonder from which side I should vent oil to minimize mess under the wing, on the tail, etc.

I'm sure that propwash as it swirls around the fuselage will have a different effect on the right or left gear leg...I just don't have the aero engineer brain to figure out which side would make less mess.

Can anybody smarter than me (that would be all of you :D) please chime in with ideas?
Click to expand...


My Vote would be the left gear leg due to the spiral slipstream. Though I hope smarter people than me say the right as my air/oil separator is above my right gear leg.

Gash where do you have your air/oil separator? I just read the install manual and its says mount it as high as possible and off to one side. Than run the oil return to the opposite side of the oil sump. They say this is key to get the oil to drain back quick. Maybe just moving your return oil line could help you.
 
SJordan said:
My Vote would be the left gear leg due to the spiral slipstream. Though I hope smarter people than me say the right as my air/oil separator is above my right gear leg.

Gash where do you have your air/oil separator? I just read the install manual and its says mount it as high as possible and off to one side. Than run the oil return to the opposite side of the oil sump. They say this is key to get the oil to drain back quick. Maybe just moving your return oil line could help you.
Click to expand...

Shawn, I have the separator on the center of the firewall, very top as high as it will go without hitting the top of the cowl. My oil return goes to the special vacuum pad adapter supplied by Aviat. I knew it was critical to get the separator as high as possible, so at least I got that part right!
 
Gash said:
Shawn, I have the separator on the center of the firewall, very top as high as it will go without hitting the top of the cowl. My oil return goes to the special vacuum pad adapter supplied by Aviat. I knew it was critical to get the separator as high as possible, so at least I got that part right!
Click to expand...

Gash,
That vac pad is a pick up as far as I have seen. The oil return should be going to the sump.
 
I fly a Decathlon and a friend flys an Eagle, neither of us loos any significant amount of oil during aerobatics, are you running too much oil in the sump?
 
wbecker said:
I fly a Decathlon and a friend flys an Eagle, neither of us loos any significant amount of oil during aerobatics, are you running too much oil in the sump?
Click to expand...

I don't think so. I have run it as low as 5 quarts and still lose about a 1/2 quart after 30 minutes of aerobatics. I'm hesitant to go much lower than 5 qts.
 
David Paule said:
Just be sure that the drippage can't get to the brake area. Brakes can get pretty hot.
Click to expand...

Good point David! Yep, I'm planning on terminating the tube at the end of the gear leg before the wheel pant fairing. I haven't decided whether to point the opening straight down or aft.
 
Gash said:
Good point David! Yep, I'm planning on terminating the tube at the end of the gear leg before the wheel pant fairing. I haven't decided whether to point the opening straight down or aft.
Click to expand...

For some reason I'm reminded of a picture I saw once of some relief tube exits on the "screwdriver blade" of the wheel pant (labeled "his" and "hers"). It would be a little more work to tie in but I think something like that for a permanent installation would almost completely prevent any chance of oil getting onto the airframe.
 
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