Oil usage?

JOhnH

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I don't have a problem but another thread got me to thinking,

I have an IO520 in the Bonanza. When I get an oil change I have him put in 10 qts oil and two 12oz cans Avblend. I show a slow but steady oil drop till I add more. Usually I'm down to around 9 qts by time I get my next 25 hour oil change so I rarely have to add oil between changes. I will add a qt if I am under 9.5qts before a 3 hour or more flight, just to be safe.

But how low do you recommend I let it get before adding more. I hate adding a qt just before I have it changed, but oil is SO MUCH CHEAPER than engines.
 
What does the manual say?

My O-290 holds 8 quarts, but much over 5 and it blows out the breather, so that's what I add at oil changes. The manual says two quarts is the minimum. I add a quart when it gets close to 4. If I'm going on a long flight I'll top it off to 6.
 
I never let the oil go much below 6 in the O360. It’s an 8qt sump, so I’ll fill to 7 or so and then monitor.
 
I'll bet almost every airplane owner puts the maximum amount of oil in an engine which it will not blow out on the first hour, and replenishes it when 1 quart below that. Many engines will blow out some oil quickly at full capacity. For my O-320, it put in 7 (max capacity 8) and add a quart when it gets to 6.
 
how low do you recommend I let it get before adding more.
Seems every engine type and on occasion specific engines have their own natural oil level setting. What I usually recommend is to service it per the book then keep a journal of its usage per hour. Note any loss and if that loss seems to level off. Once you determine that optimum oil level for your engine and have a good idea of how much oil is uses on average you can then guesstimate when you need to add oil.
 
I'll bet almost every airplane owner puts the maximum amount of oil in an engine which it will not blow out on the first hour, and replenishes it when 1 quart below that. Many engines will blow out some oil quickly at full capacity. For my O-320, it put in 7 (max capacity 8) and add a quart when it gets to 6.
You would lose your money on that bet.
 
I'll bet almost every airplane owner puts the maximum amount of oil in an engine which it will not blow out on the first hour, and replenishes it when 1 quart below that. Many engines will blow out some oil quickly at full capacity. For my O-320, it put in 7 (max capacity 8) and add a quart when it gets to 6.

1qt below? Nope. I add when I’m about 2 gallons below.
 
Our '57 172 holds 8. Anything much over 6 gets blown overboard. I keep it between 6 and 7 for flights around an hour or two. Oil is cheap and more oil may or may not add to cooling. I forget the minimum for the 0-300 but I think it is 4 quarts.
 
I’ve been told that most of the oil that’s spit out the breather of a Lycoming is slung out by the accessory case gears. Adding a vertical rise before turning the breather hose down may solve most of the problem. I’m not a fan of air-oil separators on Continentals but I use one on my Lycoming.
 
I’ve been told that most of the oil that’s spit out the breather of a Lycoming is slung out by the accessory case gears. Adding a vertical rise before turning the breather hose down may solve most of the problem. I’m not a fan of air-oil separators on Continentals but I use one on my Lycoming.
On some Lycomings, maybe, on mine the breather is near the front of the engine, nowhere near the accessory case.

I just added an oil separator to mine, too soon (only a few hours) to see how well it works.
 
On some Lycomings, maybe, on mine the breather is near the front of the engine, nowhere near the accessory case.

I just added an oil separator to mine, too soon (only a few hours) to see how well it works.
What's your take on the oil separator w/>year worth of use?
 

IO-520-A,& -J TCDS: oil sump capacity
12; 7 unusable at 20°noseup and 6 usable at 10°nosedown attitudes for -A
10; 7.8 usable at 20°noseup and 6.7 usable at 10° nosedown attitudes for -J.

For IO-520-B, -BA, -BB
12; 10 usable at 18° noseup and 14°nosedown attitudes

For IO-520-C, -M, CB, -MB
12; 7 usable at 20° noseup and 7 usable at 15°nosedown attitudes for -C, -CB
12; 6.1 usable at 26°noseup and 6.1 at 13.5°nosedown for M, MB

When the DRS first replaced the RGL it was painfully slow. I would need a shave before the data was retrieved and displayed. They seemed to have fixed that.
 
My current IO-550B is rock solid at 11 quarts. It went through the first quart (probably threw it overboard rather quickly).
My older one used to run down to about 9.5 and stay stable.

I suspect that the sumps hold 12 so that they meet the certification requirements.
 
I never let the oil go much below 6 in the O360. It’s an 8qt sump, so I’ll fill to 7 or so and then monitor.


That’s close to what I do with my O-360. I fill to 6.5, add a quart when it gets down to 5.5. Anything over approximately 6.5 gets blown out, so there’s no point in filling over that.
 
Forget the Lycoming comments when discussing an IO-520. Read your manual. 520s in Skywagons require almost full oil. You nose dragger types may see different, but what the manual says matters. I put 11 qts of oil and a pint of Camguard in my 520. My mechanics do the same if they change the oil. I see very little loss in 25 hours.
 
What's your take on the oil separator w/>year worth of use?
It's made a significant reduction in the amount of oil I'm cleaning off the belly of the plane, especially after doing aerobatics. Oil would spill out of the vent holes in the old catch can if I didn't maintain positive g. Running the hose uphill from the breather to the separator instead of straight down under the engine to the catch can no doubt helps as well.
 
It's made a significant reduction in the amount of oil I'm cleaning off the belly of the plane, especially after doing aerobatics. Oil would spill out of the vent holes in the old catch can if I didn't maintain positive g. Running the hose uphill from the breather to the separator instead of straight down under the engine to the catch can no doubt helps as well.

My Decathlon AFM says aerobatic minimum is 6 quarts. I found anything over 6.5 winds up on the belly when I do acro. Haven't paid attention to whether it is different when I only do positive G.
 
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