I saw this on TV the other night on where a guy put 20w50 in his small airplane motor. This plane operated north of Fairbanks in the winter time. I found that rather interesting given how cold it gets north of Fairbanks. Do airplane motors operate differently then a regular motor vehicle?? I am thinking a small piston driven prop plane motor would be rather similar to a motor in a car or truck. But I could well be wrong. My other thought was starting that badboy up in -30 to -40°C with 20w50 seemed either a) really stupid by the guy putting that in there or b) that motor must somehow operate differently than a vehicle motor. What do you all think??
20w50 north of Fairbanks Alaska??
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JHZR2
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Im not so sure the temperature on the ground is what matters, rather how cold it is at altitude.
If its an air cooled engine, it may still be fairly warm.
Also, whats to say theres no pre-oiler, heater, etc., etc?
If its an air cooled engine, it may still be fairly warm.
Also, whats to say theres no pre-oiler, heater, etc., etc?
My brother bought a Cessna 172. I went with him to the aviation shop where they do the maintenance. The oil they had stocked was a Phillips 66 aviation oil in 20w50. This of course in Texas.
Well ground temps there do go down well below -30°C on a routine basis. Plus short daylight hours in the winter means that motor sits all night long and even with a warming blanket could well lose all of it's heat I would think. But, hey I could be wrong about that too!
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AeroShell Semi-Synthetic 15W-50 is what I use in 80% of aircraft engine oil changes I do.
The other 20% is AeroShell 100 (50) A.D. oil.
I haven't ordered any Phillips/66 Trop-Arctic 20W-50 in a while, but I still have a couple bottles around. I used to use it in my Harley-Davidson Shovelhead.
The other 20% is AeroShell 100 (50) A.D. oil.
I haven't ordered any Phillips/66 Trop-Arctic 20W-50 in a while, but I still have a couple bottles around. I used to use it in my Harley-Davidson Shovelhead.
Aircraft engines have somewhat looser clearances than modern automotive engines. They are more akin to air cooled motorcycle engines than to water cooled cars and trucks. Many, many are simple flat fours, twin magnetos and carburetors. Bigger and slicker planes get six's. Really slick planes get fuel injection.
A little plane like a PIPER CUB or a SUPER CUB will not have a pre-heater. May not even have a starter. May have to start it by pulling the prop through
The idea that 20W or 15W is thick is a BITOG thing. 20W and 15W are good to well below zero. The motor will fire and run fine. By the time you have completed ground check, and taxied to the runway, the engine is warm. It's also on full rich and manifold heat is on (warming intake charge off exhaust) so that the motor is ready to go full power.
Once airborne, you can lean it out manually, drop manifold heat and get the EGT (exhaust gas temp) you want with RPM and mixture controls.
The reason they turn slower than car engines is that the props are running at crankshaft speed and you don't want to over-speed the prop. It looses efficiency and gets very noisy. Four and five foot long two-blade props don't need a lot of RPM to have the tips exceed the sound barrier, and then they are not making any thrust ...
All airplanes are about airfoil efficiency (wing and prop). That's how they fly. They use larger displacements to make the torque to turn the prop at the required speed to maximize thrust. Cubic inches is your friend, RPM's are not. Reduction boxes that allow engines to rev are added weight. Cubic inches does not cost much weight. It's the better trade off
A little plane like a PIPER CUB or a SUPER CUB will not have a pre-heater. May not even have a starter. May have to start it by pulling the prop through
The idea that 20W or 15W is thick is a BITOG thing. 20W and 15W are good to well below zero. The motor will fire and run fine. By the time you have completed ground check, and taxied to the runway, the engine is warm. It's also on full rich and manifold heat is on (warming intake charge off exhaust) so that the motor is ready to go full power.
Once airborne, you can lean it out manually, drop manifold heat and get the EGT (exhaust gas temp) you want with RPM and mixture controls.
The reason they turn slower than car engines is that the props are running at crankshaft speed and you don't want to over-speed the prop. It looses efficiency and gets very noisy. Four and five foot long two-blade props don't need a lot of RPM to have the tips exceed the sound barrier, and then they are not making any thrust ...
All airplanes are about airfoil efficiency (wing and prop). That's how they fly. They use larger displacements to make the torque to turn the prop at the required speed to maximize thrust. Cubic inches is your friend, RPM's are not. Reduction boxes that allow engines to rev are added weight. Cubic inches does not cost much weight. It's the better trade off
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Originally Posted By: BrocLuno
... The reason they turn slower than car engines is that the props are running at crankshaft speed and you don't want to over-speed the prop.
... They use larger displacements to make the torque to turn the prop at the required speed to maximize thrust. Cubic inches is your friend, RPM's are not. Reduction boxes that allow engines to rev are added weight. Cubic inches does not cost much weight. It's the better trade off.
Interesting! Many years ago I saw an article considering the feasibility of running the prop off the engine camshaft to allow smaller aircraft engines to develop adequate power and torque. Of course that would require stronger cam drives and bearings, but it seemed plausible that that might be a good compromise. I take it that the idea never worked out?
... The reason they turn slower than car engines is that the props are running at crankshaft speed and you don't want to over-speed the prop.
... They use larger displacements to make the torque to turn the prop at the required speed to maximize thrust. Cubic inches is your friend, RPM's are not. Reduction boxes that allow engines to rev are added weight. Cubic inches does not cost much weight. It's the better trade off.
Interesting! Many years ago I saw an article considering the feasibility of running the prop off the engine camshaft to allow smaller aircraft engines to develop adequate power and torque. Of course that would require stronger cam drives and bearings, but it seemed plausible that that might be a good compromise. I take it that the idea never worked out?
Originally Posted By: CR94
Interesting! Many years ago I saw an article considering the feasibility of running the prop off the engine camshaft to allow smaller aircraft engines to develop adequate power and torque. Of course that would require stronger cam drives and bearings, but it seemed plausible that that might be a good compromise. I take it that the idea never worked out?
Already tried that!
Continental aircraft engines (CAE) tried this with the "Tiara" engines.
GREAT concept, but find one flying today.
I can remember seeing those engine gathering dust and cobwebs in the back of old hangars ALL OVER in the 80's and 90's.
I'll bet I could still go find some that haven't moved!
https://en.wikipedia.org/wiki/Continental_Tiara_series
Interesting! Many years ago I saw an article considering the feasibility of running the prop off the engine camshaft to allow smaller aircraft engines to develop adequate power and torque. Of course that would require stronger cam drives and bearings, but it seemed plausible that that might be a good compromise. I take it that the idea never worked out?
Already tried that!
Continental aircraft engines (CAE) tried this with the "Tiara" engines.
GREAT concept, but find one flying today.
I can remember seeing those engine gathering dust and cobwebs in the back of old hangars ALL OVER in the 80's and 90's.
I'll bet I could still go find some that haven't moved!
https://en.wikipedia.org/wiki/Continental_Tiara_series
If you go to the local flying club on the cold days, and someone is planning to go up, you can see some engines bundled up very tightly.
Inside storage is prohibitively expensive.
Originally Posted By: Linctex
Originally Posted By: CR94
Interesting! Many years ago I saw an article considering the feasibility of running the prop off the engine camshaft ....
Ask, and you shall receive:
Thanks...when the topic was mentioned earlier on in the thread, I was going to respond that with all of the power being transferred to a half speed assembly, it was essentially a reduction gearbox that coincidentally drove the camshaft.
Your pics demonstrate that ably.
Originally Posted By: CR94
Interesting! Many years ago I saw an article considering the feasibility of running the prop off the engine camshaft ....
Ask, and you shall receive:
Thanks...when the topic was mentioned earlier on in the thread, I was going to respond that with all of the power being transferred to a half speed assembly, it was essentially a reduction gearbox that coincidentally drove the camshaft.
Your pics demonstrate that ably.
Originally Posted By: BrocLuno
Aircraft engines have somewhat looser clearances than modern automotive engines. They are more akin to air cooled motorcycle engines than to water cooled cars and trucks. Many, many are simple flat fours, twin magnetos and carburetors. Bigger and slicker planes get six's. Really slick planes get fuel injection.
A little plane like a PIPER CUB or a SUPER CUB will not have a pre-heater. May not even have a starter. May have to start it by pulling the prop through
The idea that 20W or 15W is thick is a BITOG thing. 20W and 15W are good to well below zero. The motor will fire and run fine. By the time you have completed ground check, and taxied to the runway, the engine is warm. It's also on full rich and manifold heat is on (warming intake charge off exhaust) so that the motor is ready to go full power.
Once airborne, you can lean it out manually, drop manifold heat and get the EGT (exhaust gas temp) you want with RPM and mixture controls.
The reason they turn slower than car engines is that the props are running at crankshaft speed and you don't want to over-speed the prop. It looses efficiency and gets very noisy. Four and five foot long two-blade props don't need a lot of RPM to have the tips exceed the sound barrier, and then they are not making any thrust ...
All airplanes are about airfoil efficiency (wing and prop). That's how they fly. They use larger displacements to make the torque to turn the prop at the required speed to maximize thrust. Cubic inches is your friend, RPM's are not. Reduction boxes that allow engines to rev are added weight. Cubic inches does not cost much weight. It's the better trade off
Great explanation, great post. Thanks.
Aircraft engines have somewhat looser clearances than modern automotive engines. They are more akin to air cooled motorcycle engines than to water cooled cars and trucks. Many, many are simple flat fours, twin magnetos and carburetors. Bigger and slicker planes get six's. Really slick planes get fuel injection.
A little plane like a PIPER CUB or a SUPER CUB will not have a pre-heater. May not even have a starter. May have to start it by pulling the prop through
The idea that 20W or 15W is thick is a BITOG thing. 20W and 15W are good to well below zero. The motor will fire and run fine. By the time you have completed ground check, and taxied to the runway, the engine is warm. It's also on full rich and manifold heat is on (warming intake charge off exhaust) so that the motor is ready to go full power.
Once airborne, you can lean it out manually, drop manifold heat and get the EGT (exhaust gas temp) you want with RPM and mixture controls.
The reason they turn slower than car engines is that the props are running at crankshaft speed and you don't want to over-speed the prop. It looses efficiency and gets very noisy. Four and five foot long two-blade props don't need a lot of RPM to have the tips exceed the sound barrier, and then they are not making any thrust ...
All airplanes are about airfoil efficiency (wing and prop). That's how they fly. They use larger displacements to make the torque to turn the prop at the required speed to maximize thrust. Cubic inches is your friend, RPM's are not. Reduction boxes that allow engines to rev are added weight. Cubic inches does not cost much weight. It's the better trade off
Great explanation, great post. Thanks.
My Lycoming manual requires pre-heating the engine at any temperature below 20 degrees F. There is no alternative procedure.
Whats the difference between 20w and 15w???
API ranks the first number and the letter W from the oldest to the
newest on its ability to lube your engine during critical cold start up...
20w
15w
10w
5w
0w
If you wish to employ the latest in oil technology then you want an one with
an low number API W rank...
BTW If you ask API they will state that the W does not mean "winter" or "weight'
Shell oil actual viscosity numbers in centistokes at 40C (104F) and 100C (212F)
AeroShell Oil Sport Plus 4 10w40
94.2cSt @40C
14.4cSt @100C
Aeroshell Oil 15W 50 is a semi-synthetic multigrade ashless dispersant
oil blend of a mineral oil and synthetic hydrocarbons with an additive
package.
AeroShell Oil 15W-50
140cSt @40C
19.6cSt @100C
AeroShell (straight mineral) They are blended from selected high
viscosity index base stocks and contain a minimum quantity of
additives.
AeroShell Oil 65 (30wt)
90.9cSt @40C
11.8cSt @100C
AeroShell Oil 80 (40wt)
150cSt @40C
14.6cSt @100C
AeroShell Oil 100 (50wt)
230cSt @40C
19.7cSt @100C
AeroShell Oil 120 (60wt)
380cSt @ 40C
24.8 @ 100C
AeroShell 'W' ashless dispersant with non-metallic dispersant additives.
AeroShell Oil W65 (30wt)
91cSt @ 40C
12cSt @ 100C
AeroShell Oil W80 (40wt)
113cSt @ 40C
14.0cSt @ 100C
AeroShell Oil W80 Plus and W100 Plus are single-grade ashless
dispersant with the extra anti-wear and anti-corrosion additive
package of AeroShell Oil 15W-50.
AeroShell Oil W80 Plus (40wt)
113cSt @ 40C
14.0cSt @ 100C
AeroShell Oil W100 (50wt)
200cSt @ 40C
20.2cSt @ 100C
AeroShell Oil W100 Plus (50wt)
195cSt @ 40C
19.9cSt @ 100C
AeroShell Oil W120 (60wt)
270cSt @ 40C
24.8cSt @ 100C
API ranks the first number and the letter W from the oldest to the
newest on its ability to lube your engine during critical cold start up...
20w
15w
10w
5w
0w
If you wish to employ the latest in oil technology then you want an one with
an low number API W rank...
BTW If you ask API they will state that the W does not mean "winter" or "weight'
Shell oil actual viscosity numbers in centistokes at 40C (104F) and 100C (212F)
AeroShell Oil Sport Plus 4 10w40
94.2cSt @40C
14.4cSt @100C
Aeroshell Oil 15W 50 is a semi-synthetic multigrade ashless dispersant
oil blend of a mineral oil and synthetic hydrocarbons with an additive
package.
AeroShell Oil 15W-50
140cSt @40C
19.6cSt @100C
AeroShell (straight mineral) They are blended from selected high
viscosity index base stocks and contain a minimum quantity of
additives.
AeroShell Oil 65 (30wt)
90.9cSt @40C
11.8cSt @100C
AeroShell Oil 80 (40wt)
150cSt @40C
14.6cSt @100C
AeroShell Oil 100 (50wt)
230cSt @40C
19.7cSt @100C
AeroShell Oil 120 (60wt)
380cSt @ 40C
24.8 @ 100C
AeroShell 'W' ashless dispersant with non-metallic dispersant additives.
AeroShell Oil W65 (30wt)
91cSt @ 40C
12cSt @ 100C
AeroShell Oil W80 (40wt)
113cSt @ 40C
14.0cSt @ 100C
AeroShell Oil W80 Plus and W100 Plus are single-grade ashless
dispersant with the extra anti-wear and anti-corrosion additive
package of AeroShell Oil 15W-50.
AeroShell Oil W80 Plus (40wt)
113cSt @ 40C
14.0cSt @ 100C
AeroShell Oil W100 (50wt)
200cSt @ 40C
20.2cSt @ 100C
AeroShell Oil W100 Plus (50wt)
195cSt @ 40C
19.9cSt @ 100C
AeroShell Oil W120 (60wt)
270cSt @ 40C
24.8cSt @ 100C
And most of the big radials used 120, and oil dilution systems that is where the gasoline was allowed to mix with the oil to lower the viscosity for starting in the cold weather. Heaters would also be used before attempted starts in real cold conditions.
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