Oil temperature question

[lr172]

Originally Posted by gmcjetpilot

That moisture and acids, by byproducts of combustion are "emulsified" in the oil.... Oil needs to be heated to about 210F to allow the moisture and the nasty volatilies to gas off and go out the vent. This is not opinion. It is Lycoming's recommendation and it is SCIENCE! Ha ha I love when people invoke the word SCIENCE as an appeal to authority.

I believe that the bulk of the water is NOT in suspension in the oil, though some is. Most remains in a gaseous state, until shut down and cooler temps allow it to condense and rest on top of the oil. Assuming I am wrong and it IS all in suspension, where is your data that says the water precipitates out of suspension in oil at 210 and not at 150.

Larry

[bjdecker]

Originally Posted by gmcjetpilot

"Good Greif". That dismissive statement you made is based on no facts. Proof please.... My comment is based on Lycoming publications. You want your engine oil temp to burn off all the moisture and acids from combustion. That will not happen efficiently unless the oil temp read is about 180F. This jives 100% with Lycoming Oil Temp Green band 185-210F. Lycoming allows 165F for cold weather operations... What is your point? Old notions rooted in fact is not bad, when it is true.

Read the cold weather Lycoming bulletin. 165F is acceptable.

https://www.lycoming.com/content/operating-cold-weather
Third from last paragraph.... I am not kidding I tend to go with the Manufactures recommendations. However I will conceed that the bottom of GREEN on most Certified Planes with Lycoming's is 60F. However if you want to light the fire, take off in sub-zero temps 1-minute after start, with 60F up to you. Lycoming recommends 165F as a MIN operating temperature per Lycoming SB's, SL's and Notices.

You posted twice? I have a degree in mechanical engineering so I understand a little about math and SCIENCE! Also your comment ignores OT as recommended by Lycoming. The other part of your comment is irreverent to operation an internal combustion air (oil) cooled aircraft engines. We blow-by a lot of crud unto the crank case, moisture, acids, by products of combustion. That moisture and acids, by byproducts of combustion are "emulsified" in the oil.... Oil needs to be heated to about 210F to allow the moisture and the nasty volatilies to gas off and go out the vent. This is not opinion. It is Lycoming's recommendation and it is SCIENCE! Ha ha I love when people invoke the word SCIENCE as an appeal to authority.

Your sarcasm and humor noted, read my post above. I agree FOLLOW THE MANUAL. The recommended operating OT is 185-210F. Second your comment about when water boils is irreverent when water in solution with the oil. You want to get the moisture emulsified in the oil, which has acids and combustion by products in solution, BURNED OFF.... Leave that in there and let the engine sit you will have corrosion. What kills engines is disuse and not allowing them to run at full operating temperatures. However do what you like. Your engine. Cheers :-)



Fun fact I had a 1959 PA23-160 Pilper Apache with two O-320 160HP engines. I bought it around 1990 with 1800 hours since engines were new, replaced about 5 years earlier. It was flown by previous owner about 300-400 hours a year. I flew it about 150-200 ours for two years and sold it with 2200 hrs on the engines. All cylinders were high 70's and oil use (as long as I kept the oil level under 6 qts) was about 1 quart every 8-10 hours. This shows you what flying an engine and keeping it within limits can do to add longevity.

BTW More fun facts, LYCS with 8 qt capacity need to be run under 6 qts or less.... Why? It is a FAR that engines have reserve oil capacity. With a wet sump they put that reserve oil there, which in turns increases oil consumption. It reduces overall crankcase volume, increases case pressure and oil splash, which goes out vent. You are far better putting in a PINT in at a time every few flights then topping it over 6 qts. I ran min between 5.5 to 6 qts. I would put in just a tad every few hours.

Agree with the sentiment about disuse.

Speaking of books --

from the Lycoming nnn-360-xxx manual - 8th Edition Part No. 60297-12

OPERATING CONDITIONS
Average *Oil Inlet Temperature
Ambient Air Desired Maximum
Above 80?F 180?F (82?C) 245?F (118?C)
Above 60?F 180?F (82?C) 245?F (118?C)
30? to 90?F 180?F (82?C) 245?F (118?C)
0? to 70?F 170?F (77?C) 245?F (118?C)
Below 10?F 160?F (71?C) 245?F (118?C)
* - Engine oil temperature should not be below 140?F (60?C) during continuous operation.

----

from the Lycoming nnn-320-xxx manual 3rd Edition Part No. 60297-30

OPERATING CONDITIONS
Average Oil Inlet Temperature
Ambient Air Desired Maximum
Above 80?F 180?F (82?C) 245?F (118?C)
Above 60?F 180?F (82?C) 245?F (118?C)
30?F to 90?F 180?F (82?C) 245?F (118?C)
0?F to 70?F 170?F (77?C) 225?F (107?C)
Below 10?F 160?F (71?C) 210?F ( 99?C)

----

Interesting differences at the bottom end of ambient

Like you said -- it's your engine

[gmcjetpilot]

Originally Posted by bjdecker

Agree with the sentiment about disuse.

Speaking of books --

from the Lycoming nnn-360-xxx manual - 8th Edition Part No. 60297-12

OPERATING CONDITIONS
Average *Oil Inlet Temperature
Ambient Air Desired Maximum
Above 80°F 180°F (82°C) 245°F (118°C)
Above 60°F 180°F (82°C) 245°F (118°C)
30° to 90°F 180°F (82°C) 245°F (118°C)
0° to 70°F 170°F (77°C) 245°F (118°C)
Below 10°F 160°F (71°C) 245°F (118°C)
* - Engine oil temperature should not be below 140°F (60°C) during continuous operation. Like you said -- it's your engine

Ha ha I was about to post that.
As far as oil capacity I mentioned, shocked to see 2 Qrts. Mins. 6 Qts is my max and 5.5 Qts min to keep from blowing out out vent.

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

Ref Lycoming Operators Manual O-360, October 2005; Part No. 60297-12

[Larry DeCamp]

As noted previously, water does not have to be 180F to completely vaporize. The medical industry standard for DRYING moisture cured substrates, example casting tape, is heating materials to 120F. Other potential corrosives suspended in the oil are probably temperature, agitation and time dependant.

[BillL]

Paul, yes, remove the air side blockage. You can use it down there in LA. As you noted, it appears the OT sensor yielded an incorrect reading.

Back to the vigrous discussion off topic.

[avrojockey]

Originally Posted by gmcjetpilot

Read the cold weather Lycoming bulletin. 165F is acceptable. Can you fly or take off with less? Yes. Should you fly around with 100F oil? No and if you can't eventually get 165F you should block the oil cooler.

Please reread my post...this isn't a debate...I was simply sharing the facts of my operating circumstances. I didn't say you should fly around with 100F oil...I said it was near impossible to get my oil 165F in the winter in WI...prior to takeoff. I would have to do a full power static runup for 10 minutes with limited head cooling to see 165 prior to takeoff, even after preheating my oil to 60F+...I don't know anyone that does or recommends this.

I happily get 165F+ airborne with my oil cooler blocked in the winter.

[Captain Avgas]

Originally Posted by gmcjetpilot

You want your oil to be at or about the water boiling point 212F.

My goodness, after putting my washing out on the clothesline to dry for decades I had convinced myself that they were actually drying...but I guess not...you learn something new on VansAirforce every day.

[gmcjetpilot]

Originally Posted by Captain Avgas

My goodness, after putting my washing out on the clothesline to dry for decades I had convinced myself that they were actually drying...but I guess not...you learn something new on VansAirforce every day.

You must be kidding and trolling me? Ha ha. OK let's just nip this in the bud. It is a strawman argument that water evaporates below boiling. I never said water does not evaporate below boiling. Nope. Clouds form in the sky, as water vapor condensing that evaporated from ocean, lakes and rivers. Sure these bodies of water are not boiling. When I boil water I see water vapor (steam) come off before the bubbles. OK.

Fun fact, water (we are talking liquid H2O) can evaporate (go from liquid state to gas or vapor) at ANY TEMP, just slower at lower temps. At 32F H2O freezes and reaches it "triple point". Water can go from solid to gas without going through the liquid state, and it is called "sublimation" (phase transition). Water is an amazing element and expands when it freezes.

The gases in the crankcase is more than pure H2O. There is H2O mixed with nitric oxide (NO), nitrogen dioxide (NO2), and carbon monoxide (CO) and unburnt fuel and acidic byproducts.

Nothing I am saying is controversial and not sure why I got you all "triggered". Ha ha. Lycoming says 185F is min OT for normal Ops. They recommend 165F OT Min in cold temps. In extreme conditions 140F OT is the Min for continuous operations. Low OT is not the normal complaint of pilots in lower 48

Originally Posted by lr172

I believe that the bulk of the water is NOT in suspension in the oil, though some is. Most remains in a gaseous state, until shut down and cooler temps allow it to condense and rest on top of the oil. Assuming I am wrong and it IS all in suspension, where is your data that says the water precipitates out of suspension in oil at 210 and not at 150.Larry

Yes good point. Also what happens, when you shut down lots of hot high humidity air fills your crankcase; it will condense to liquid water as your engine cools and cover all the metal parts inside your engine. The next time you start most of water is still there and oil mist gets mixed like a blender as the camshaft, crank and gears in accessory start mixing it like an oil water milkshake. This is why you want to get your engine up to normal operating temperature to get all the moisture out the oil and engine... Also oil has viscosity and needs to flow and create film boundary in the "Babbitt" bearings. Too cold the oil will not flow properly.

[DanH]

Originally Posted by gmcjetpilot

You must be kidding and trolling me? Ha ha. OK let's just nip this in the bud. It is a strawman argument that water evaporates below boiling. I never said water does not evaporate below boiling.

These days, that is known as a "Fake News" response.

To be specific, what you wrote was...

"You want your oil to be at or about the water boiling point 212F. Oil Temp in the cylinder heads near the exhaust valves is about 30F higher than what you are reading. So 180F measured at oil temp probe near oil filter is the bottom of the normal operating."

...which is simply not true on several levels.

Most notable? The boiling point of water is irrelevant.

Nothing I am saying is controversial and not sure why I got you all "triggered". Ha ha. Lycoming says 185F is min OT for normal Ops. They recommend 165F OT Min in cold temps. In extreme conditions 140F OT is the Min for continuous operations.

Actually no, no, and no.

Lycoming's recommendations vary, apparently depending on who created the particular manual, and who (if anyone) reviewed it, even across a relatively small publication date range for the same engine. I will use the IO-390 as an example, since I have watched and read most of the new manuals as released.

None call out 185F "min OT for normal ops". The Lycoming Operation Reference Manual IO-390 Series (June 2007) for the IO-390-EXP states:

G. For maximum engine life, the desired oil temperature should be maintained between 165°F (73.8°C) and 200°F (93.3°C) in level-flight cruise conditions.

The original 390-A manual (revised 2009) simply says:

For maximum engine life, maintain desired oil temperature (sic) is 180F.

...with the same in the "B" manual, complete with grammatical error.

The AEIO 390 manual (April 2012) doesn't list a max life recommendation, only minimums of 140F for takeoff and 170F for cruise.

The HIO 390 manual (Oct 2017) lists the same 140F takeoff minimum, despite allowing 2800 RPM....and it returns to the optimum oil temperature for maximum engine life statement of 165F to 200F.

The latest IO-390 C (Jan 2017) and D (March 2020) manuals include this line...

The best way to decrease the risk of engine corrosion is for the aircraft to be in flight at least every 30 days for at least 1 continuous hour at oil temperatures between 180°F to 200°F (80°C to 93°C), depending on location and storage conditions.

...but then go on to state in another section "Oil Temperature (for maximum engine life) 180ºF"

Oh yeah, recall the "140F for takeoff" listed above? Almost all the manuals otherwise state...

"Engine is warm enough for take-off when the throttle can be opened without the engine faltering and the oil pressure is not less than the minimum pressure specified in this operation reference manual.

Point is, there is not a lot of basis for claiming one particular number is best. Digging around in Lycoming specs to prove it is a lot like digging around in the Bible...a decent preacher can find support for almost any view, and make it sound good come Sunday morning

[Bavafa]

Originally Posted by DanH

Point is, there is not a lot of basis for claiming one particular number is best. Digging around in Lycoming specs to prove it is a lot like digging around in the Bible...a decent preacher can find support for almost any view, and make it sound good come Sunday morning

As I was going thru my morning reading, I came upon this thread again and asked myself, am I going to learn anything new here by clicking on this thread again!
Sure as taxes, well worth clicking. I can?t say I learned much as what temp the water boils but sure enough, now I understand the preacher's word when one day up is up and another day up is down.

THANK YOU Dan, again.