Oil level

[Joe Larussa]

Where do you like to keep your oil level? I usually like it at 6 quarts if I’m doing flights around and hour or two. Long trips I like to start at seven. Do you notice any indications when it falls below a certain level?

[Jim Peace]

7 minutes ago, Joe Larussa said:

Where do you like to keep your oil level? I usually like it at 6 quarts if I’m doing flights around and hour or two. Long trips I like to start at seven. Do you notice any indications when it falls below a certain level?

same on a 64c 180hp......I find anymore than 6.25 just ends up on the belly.....

[carusoam]

IO550...8 qts.

Excess oil doesn’t seem to find the vent.

-a-

[PT20J]

Five flight schools I've been associated with had a standard practice of filling Lycoming IO-360, O-360, O-320 engines to 7 qts on the dipstick and adding a quart when it got down to 6. I've run both my M20Js that way with very little oil on the belly from the breather.

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[Joe Larussa]

5 minutes ago, PT20J said:

Five flight schools I've been associated with had a standard practice of filling Lycoming IO-360, O-360, O-320 engines to 7 qts on the dipstick and adding a quart when it got down to 6. I've run both my M20Js that way with very little oil on the belly from the breather.

Skip

Ever notice a twitchy oil pressure reading below 6 quarts?

[Andy95W]

19 minutes ago, Joe Larussa said:

Ever notice a twitchy oil pressure reading below 6 quarts?

In the winter during cold temperatures I'll let mine go down to 5 1/2 or so. JPI oil pressure and temperature stay rock solid in cruise.

[Ragsf15e]

23 minutes ago, Joe Larussa said:

Ever notice a twitchy oil pressure reading below 6 quarts?

Twitchy, no.  But maybe on a long flight that starts at 6 qts, maybe, if I really analyze it, maybe a few (like 5) degrees warmer oil and a psi or 2 less pressure on the jpi.  But still steady.  I try to start all flights short or long at 6 or it gets real oily underneath.

[carusoam]

Twitch when oil levels drop is typical of air bubbles getting drawn into the system...

My Chevy will do it too...

Even though the pick-up for the oil is way down at the bottom... 

The oil is spread around the engine really well when flying...

The oil gear pump has no difficulty delivering air that sneaks in to the other side...

PP thoughts only,

-a-

[kerry]

When it gets below 5 quarts I add a quart.  Anything above 6 goes thru the blow by.  O-360.

[kpaul]

9 hours ago, carusoam said:

IO550...9 gal.

Excess oil doesn’t seem to find the vent.

-a-

9 Gallons? Are you running a big radial on your O?

 

[EricJ]

I went to the Lycoming rep's talk at the recent IA seminar here and he explained that anything above 6 qts in an I/O-360 is essentially in the windage of the crank and is susceptible to getting blown out.   The 8 qt capacity meets the FAAs requirement of being able to run for a certain number of hours (I think 4 hours?  May have had to do with the tank capacity.) at the maximum oil consumption rate before starvation.

I think the pump still makes pressure at 2 Qts or something like that.  If the pressure is starting to twitch at much higher levels there may be a pickup problem.

 

[carusoam]

4 hours ago, kpaul said:

9 Gallons? Are you running a big radial on your O?

 

I put in so much oil, I must have slipped and fell on all the excess.... 

For penance, I tried to find a decent resource... proving my dipstick being longer than all the other IO550s...

Oil Capacity for the IO550s is only 8 quarts.  But, if you fill it after a flight... you will find an extra quart showing up on the dipstick a day later...

The following should be (was supposed to be) a link to an interesting read for the IO550 engine...

 

Penance part III...

http://www.continentalmotors.aero/xPublications/Maintenance Manuals/OI-16ELEC_2015-07-15/

 

I highly recommend finding the engine manufacturer’s manual for your engine... Compare to your POH written by Mooney... And your STC written by Rocket Engineering...

They all cover the same ground, but do it in an interesting way specific to the plane...

Fuzzy PP memories only, not a mechanic...

Best regards,

-a-

[jaylw314]

3 hours ago, EricJ said:

I went to the Lycoming rep's talk at the recent IA seminar here and he explained that anything above 6 qts in an I/O-360 is essentially in the windage of the crank and is susceptible to getting blown out.   The 8 qt capacity meets the FAAs requirement of being able to run for a certain number of hours (I think 4 hours?  May have had to do with the tank capacity.) at the maximum oil consumption rate before starvation.

I think the pump still makes pressure at 2 Qts or something like that.  If the pressure is starting to twitch at much higher levels there may be a pickup problem.

 

IIRC the FAA used to require a sump at least twice the capacity of the minimum certified oil volume.   Since the IO-360 has a minimum volume of 4 qts, the sump has to be 8 qts.

I think there is actually one IO-360 meant for aerobatics that is certified down to 2 qts, but I think it still has an 8 qt sump

I'm guessing they changed that with the new part 23 certification requirements?

[rbridges]

I think I read that to be certified, an engine has to run on half the maximum volume.  I generally keep mine between 5-6; closer to 6 for longer trips.

[jaylw314]

24 minutes ago, carusoam said:

I put in so much oil, I must have slipped and fell on all the excess.... 

For penance, I tried to find a decent resource... proving my dipstick being longer than all the other IO550s...

Oil Capacity for the IO550s is only 8 quarts.  But, if you fill it after a flight... you will find an extra quart showing up on the dipstick a day later...

The following should be (was supposed to be) a link to an interesting read for the IO550 engine...

 

I was a little surprised with my oil level--when I fill the motor with 6 qts after an oil change and do the test run, the next time I check the oil level it will say almost exactly 6 qts.  I always thought the oil filter would hold a cup or so, and the oil system would hold another cup.

[bradp]

Long trips I'll do 6.5 and add at 6 (knowing that I've probably got more in the crankcase that hasn't sunk to the sump yet).  Local flights I try to keep it around 6.  If I put 8 in it's on the belly.  If I put 7 in it's not on the belly as much, but my "consumption rate" goes up to 1 qt/4-5 hrs.  If I keep it around 6-6.5 my consumption rate is 1 Qt / 7 hrs and that's the figure I use as my personal consumption baseline.  That and my belly / antennas stay cleaner. 

[carusoam]

24 minutes ago, jaylw314 said:

I was a little surprised with my oil level--when I fill the motor with 6 qts after an oil change and do the test run, the next time I check the oil level it will say almost exactly 6 qts.  I always thought the oil filter would hold a cup or so, and the oil system would hold another cup.

The IO550 has its oil cooler mounted to the engine... lots of surface area that is able to drain back over time(?) and it’s oil filter is mounted  upside down as well...

According to the drawing below....

Best regards,

-a-

[jaylw314]

3 minutes ago, carusoam said:

The IO550 has its oil cooler mounted to the engine... lots of surface area that is able to drain back over time(?) and it’s oil filter is mounted  upside down as well...

That's interesting with the upside down oil filter--that must be a pain in the heiney to change

If the oil cooler is right on the motor, I'd figure it should drain pretty darn quickly, right?  I mean, the IO-360 oil cooler is waaay, back at the firewall in comparison...

[1964-M20E]

I'll leave it at 5 or 6 for short flights.  Long flights 3 hours + I'll put it at 7.

[PT20J]

3 hours ago, jaylw314 said:

IIRC the FAA used to require a sump at least twice the capacity of the minimum certified oil volume.   Since the IO-360 has a minimum volume of 4 qts, the sump has to be 8 qts.

I think there is actually one IO-360 meant for aerobatics that is certified down to 2 qts, but I think it still has an 8 qt sump

IO-360/O-360 oil capacity is: Max 8, Min 2, Aerobatic engines are dry sump.

[PT20J]

17 hours ago, Joe Larussa said:

Ever notice a twitchy oil pressure reading below 6 quarts?

No, but I did note a decrease in oil pressure and an increase in temperature when it got down to 4.

[jaylw314]

4 minutes ago, PT20J said:

IO-360/O-360 oil capacity is: Max 8, Min 2, Aerobatic engines are dry sump.

 

Yeah, now I'm all confused  The TCDS says the minimum usable is 6 qts

[PT20J]

2 minutes ago, jaylw314 said:

Yeah, now I'm all confused  The TCDS says the minimum usable is 6 qts

Usable (not minimum usable) qty is 6 qts. 8 - 6 = 2 minimum.

1E10_Rev_28.pdf

[jaylw314]

16 minutes ago, PT20J said:

Usable (not minimum usable) qty is 6 qts. 8 - 6 = 2 minimum.

1E10_Rev_28.pdf 302.02 kB · 1 download

Oooooh, I get it 

[sdflysurf]

Thank you for starting this thread.  So as a new aircraft/mooney owner I feel (feel as in nothing scientific here - gut telling me only) that my M20F likes to show about 5-6 on the dipstick and any more that I add has been ending up leaking/blowing/whatever out and appearing on the bottom of the plane.  Sounds like that is perfectly normal now and what exactly causes this?  My oil pressure and temp have always seemed fine, I was just getting concerned that I needed to keep a couple of qts of Aeroshell 100w+ in my baggage compartment.