adding air oil seperator to Piper Archer ii

TheGolfPilot

TheGolfPilot

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Golfpilot
My Piper Archer ii is spitting out oil above 5.5 quarts. My partner suggested we look into getting an air oil separator. I had no idea what this was 24 hours ago. After reading about them they seem to be very finicky. It needs to be placed in the right place and must operate over 212 degrees, even then it is likely to put oil mist into the air going to the cylinders. Am I reading the wrong things?

The engine runs great even at 5.5 quarts. I personally think its just the engine's sweet spot. Oil temps seem to stay down and I don't think fidgeting with a well working engine is a great idea.

Does anyone here have any experience with the air oil seperators? Is this a must install thing or is running the plane at 5.5 quarts and watching the temps a better strategy?
 
TheGolfPilot said:
My Piper Archer ii is spitting out oil above 5.5 quarts. My partner suggested we look into getting an air oil separator. I had no idea what this was 24 hours ago. After reading about them they seem to be very finicky. It needs to be placed in the right place and must operate over 212 degrees, even then it is likely to put oil mist into the air going to the cylinders. Am I reading the wrong things?

The engine runs great even at 5.5 quarts. I personally think its just the engine's sweet spot. Oil temps seem to stay down and I don't think fidgeting with a well working engine is a great idea.

Does anyone here have any experience with the air oil seperators? Is this a must install thing or is running the plane at 5.5 quarts and watching the temps a better strategy?
Click to expand...
I put one on my Pathfinder back in 2003. (Cherokee 235)

If it made much difference, it was hard to tell. We probably didn't have to clean the belly as often. Not sure that justified the cost, which, with installation, was not insignificant.

The solution to your problem is to find a level where it stops spitting oil. In our case, with the same engine as your Archer (Lycoming O-360) that's 8 quarts. 5.5 quarts sounds...strangely low. Are you sure it's spitting it?

Sent from my SM-T700 using Tapatalk
 
5.5 quarts does sound a little low but not horrible. How close to level is the aircraft actually setting? Level ground and leveled struts.

I run a TSIO-360 at 7 quarts.
 
Jay Honeck said:
I put one on my Pathfinder back in 2003. (Cherokee 235)

If it made much difference, it was hard to tell. We probably didn't have to clean the belly as often. Not sure that justified the cost, which, with installation, was not insignificant.

The solution to your problem is to find a level where it stops spitting oil. In our case, with the same engine as your Archer (Lycoming O-360) that's 8 quarts. 5.5 quarts sounds...strangely low. Are you sure it's spitting it?

Sent from my SM-T700 using Tapatalk
Click to expand...

Pretty sure it is going out the breather on the bottom. Add a quart to bring it to 6.5 and go fly, it will be 5.5 when the engine cools. Last time I flew it was at 5.5, flew for two hours and the next morning I checked the oil and it was at 5.5. I don’t know for sure if it is spitting it out, but the oil level goes from 6.5 to 5.5 in no time flat and doesn’t leave 5.5 for at least 2 hours of running.
 
TheGolfPilot said:
My Piper Archer ii is spitting out oil above 5.5 quarts. My partner suggested we look into getting an air oil separator. I had no idea what this was 24 hours ago. After reading about them they seem to be very finicky. It needs to be placed in the right place and must operate over 212 degrees, even then it is likely to put oil mist into the air going to the cylinders. Am I reading the wrong things?

The engine runs great even at 5.5 quarts. I personally think its just the engine's sweet spot. Oil temps seem to stay down and I don't think fidgeting with a well working engine is a great idea.

Does anyone here have any experience with the air oil seperators? Is this a must install thing or is running the plane at 5.5 quarts and watching the temps a better strategy?
Click to expand...

From the A&P's point of view:

I've found them to mostly be a waste of money. They accomplish little except to put any moisture the collect back onto the engine.

How much time on your engine? Sounds like you are getting a lot of blow-by from the cylinders.
 
On another note, an air-oil separator will work when installed correctly and blow-by isn’t excessive. I put a wet vacuum pump on the ‘kota and the air-oil separator was required as part of the instal. Oil consumption was improved for a little while but then the engine started puking oil through the separator. Top overhaul resulted in nearly zero oil consumption.
 
I fly a cherokee 180, and put 7 qts in at an oil change (1 for the filter, 6 for the tank). Anything over 6 qts on the stick is a waste of money and oil and will get the bottom of the airplane even dirtier than it usually is. Right now, at 10 hrs after annual (oil and filter change) the stick is showing just below 6 qts.

Don't panic. Spend the money on something else.
 
TheGolfPilot said:
My Piper Archer ii is spitting out oil above 5.5 quarts. My partner suggested we look into getting an air oil separator. I had no idea what this was 24 hours ago. After reading about them they seem to be very finicky. It needs to be placed in the right place and must operate over 212 degrees, even then it is likely to put oil mist into the air going to the cylinders. Am I reading the wrong things?

The engine runs great even at 5.5 quarts. I personally think its just the engine's sweet spot. Oil temps seem to stay down and I don't think fidgeting with a well working engine is a great idea.

Does anyone here have any experience with the air oil seperators? Is this a must install thing or is running the plane at 5.5 quarts and watching the temps a better strategy?
Click to expand...

Golf:
Just for discussion sake, is the oil dipstick the right one for your engine? And during your oil/filter changes did the oil levels match the amount of oil you put in the engine after the first run?
 
Bell206 said:
Golf:
Just for discussion sake, is the oil dipstick the right one for your engine? And during your oil/filter changes did the oil levels match the amount of oil you put in the engine after the first run?
Click to expand...

Interesting idea. I’d be willing to bet the oil dipstick was never checked to be the right one for the engine. That would be something funny.
Since the plane has been with us it’s pushed the oil out right away to below 6. Before and after oil changes. It’s “new” to us. Less than a year and 100 hours at this point. It’s at 1000 hours
 
TheGolfPilot said:
Interesting idea. I’d be willing to bet the oil dipstick was never checked to be the right one for the engine. That would be something funny.
Since the plane has been with us it’s pushed the oil out right away to below 6. Before and after oil changes. It’s “new” to us. Less than a year and 100 hours at this point. It’s at 1000 hours
Click to expand...

Compressions? Any leakage past the rings?
 
Long time Piper Archer 2 owner here. I will confirm that in my O360, 7 Qts on my dipstick is where normal consumption can be counted on; above that is nearly a waste. I personally would be uncomfortable running an engine at 5.5 qts, if real, on long cross countries. One has to account for your normal or abnormal rate of consumption that would decrease the level further.
 
MajorTurbulence said:
Long time Piper Archer 2 owner here. I will confirm that in my O360, 7 Qts on my dipstick is where normal consumption can be counted on; above that is nearly a waste. I personally would be uncomfortable running an engine at 5.5 qts, if real, on long cross countries. One has to account for your normal or abnormal rate of consumption that would decrease the level further.
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Uncomfortable at 5.5, why? Lycoming says 2qt is minimum, 5.5 is more than double that. If the engine is not burning a lot, and temps are fine I am perfectly happy running at 5.5 qts. Been running my warrior around there for years, that seems to be the level it likes.


Bob
 
Bob beat me to it!

From Lycoming 360 Series Ops Manual:

OIL SUMP CAPACITY
All Models (Except AIO-360 Series, O-360-J2A) ................................................8 U.S. Quarts
Minimum Safe Quantity in Sump
(Except – IO-360-M1A, -M1B; HIO-360-G1A) ................................................2 U.S. Quarts
IO-360-M1A, -M1B; HIO-360-G1A ..................................................................4 U.S. Quarts
AIO-360 Series ........................................................................................................... Dry Sump
O-360-J2A..............................................................................................................6 U.S. Quarts
 
My discomfort has nothing to do with what a purist could advocate from a technical point in the Lycoming manual, although that is a good source. While I have not read it recently, I thought the minimum was closer to 3.5-4 Qts but you could be right. My discomfort has been formed by my personal misfortune of needing an engine rebuild after having run an engine near 5.5 qts, although there were many other facts that may have been integral to my engine making metal, not the least of which was age.

The main point is that when you start at 5.5, how much could you lose on a long cross country from an engine that was still considered airworthy, but had an excessive consumption rate? After a 4 hour flight you could be, for argument sake, more than 1 qt down. Asume a worst case scenario of mod to greater turbulence in the pattern or on approach causing difficulties in coordinated flight. Could the engine oil intake become unported with a low oil reserve to cause erratic fluctuations in oil pressure? I don't know but am leery enough to not chance it. I know that unporting can occur in fuel tanks under low fuel reserves under similar uncoordinated or turbulent settings. While not the same systems with obvious differences, it might give you food for though.
 
From Lycoming SI# 1427C:

NOTE
The
following formula is used to calculate the
maximum allowable oil consumption limits for all
Lycoming aircraft engines.

0.006 x BHP x 4 ÷ 7.4 = Qt./Hr.

Equates to about 1 quart every 2 hours! :eek:

EDIT

That is after an overhaul.

From the Ops Manual:

upload_2017-11-22_22-37-48.png
 
Last edited:
Jaws, not to be snarky at all, but my engine is an O360 A4M. It is not clear to me from what you posted what the minimum oil level should be for my engine. I do see mention of 2 qts, but for my engine? Forgive me if it's clear to everyone else.
 
MajorTurbulence said:
Jaws, not to be snarky at all, but my engine is an O360 A4M. It is not clear to me from what you posted what the minimum oil level should be for my engine. I do see mention of 2 qts, but for my engine? Forgive me if it's clear to everyone else.
Click to expand...

Here you go! Enjoy. :)

(Hint: Page 3-11-ish!)
 
No reason to doubt you. I should read my Lycoming manual again as it's been awhile. :)
 
JAWS said:
You might also be interested in the following articles.

https://www.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2014-02_high-oil-consumption.pdf
https://www.avweb.com/news/savvyaviator/194208-1.html
https://www.savvyaviation.com/wp-co..._eaa/EAA_2010-04_is-your-engine-airworthy.pdf
Click to expand...

Agreed, interesting reading. Some of my takeaways are that the FAA mandates an oil reservoir double needed for safety. Some engines, like the 310hp Continental can have an an airworthy rate of oil consumption of 1qt per hour. Finding your sweet spot where excess oil is mostly wasted may vary for your engine. Making sure that you have enough oil added for your flight needs to include your consumption rate but those minimal levels were based on 'normal attitude flight conditions' ( my emphasis ).
 
Aircraft manufacture's operating limitations are almost always more conservative than the engine manufacturer regarding minimum oil quantity.
 
My previous Tiger would throw everything above 6.5 over board onto the belly; however, if RPM was kept to 2500 or under putzing around, then would end up with no loss.
 
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