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OIL FOR THE A2A PIPER COMACHE 250

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i dont really know what is the best oil for the comache so i am interested in the others opinion please give some tips on what is the best oil for the a2a comache

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The A2A forum is probably the best place to find info on operating their Comanche. Hopefully this topic will help a bit. In short, you won't go far wrong with the multi-weight (20W-50) option.

Cheers,
Nick

 

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It will probably help if you understand a bit about the terminology and what it all means.

In the sim, the A2A Commanche has three different aviation oil types available, these are: Phillips 66 Victory 100AW, Phillips XC 20W-50 and Phillips XC 25W-60. So what does all that malarkey actually mean?

First some terminology.

If you ever see SAE on an oil bottle, it stands for the Society of Automotive Engineers (and by automotive, they don't just mean cars, it's all vehicles, including aeroplanes which the SAE encompassed along with tractor engines too, in 1916, since rotary engines used Castor oil and stationary water cooled ones often didn't, so they needed to introduce some standards for all those WW1 warplanes). So, the SAE is an international standards agency which regulates what all those numbers and initials on an oil bottle mean, thus if you buy a bottle of 20-50 oil in Timbuktu, and some 20-50 in Tyneside, both should meet the same standard.

If you see W on a bottle of oil, it refers to the viscosity of the oil and its suitability for use in colder temperatures, i.e. how quickly it will flow (basically how thick it is and how much it will stick to moving parts in the engine). The W itself actually stands for Winter, so if you use an oil with W on it in winter, it will be a better choice, because it will be a bit thinner, which means in colder temperatures, it will heat up and move a bit quicker and so it will splash onto and cover the moving parts a bit quicker than a summer oil with no W on its label (since it is thicker). This is important because when your aeroplane is parked up, the oil all drips down into the sump, and so when you crank an engine, it takes a while for the oil to be pumped around the engine and for it to splash onto the moving parts such as the camshafts, lifters etc, and if they have no oil on them, the metal is rubbing against other bits of metal, causing friction (heat) and wear. This is why you should never crank an engine up and immediately throttle it up if it has been stood for a while, because you'll wear it out quicker (this is true for your car, truck or motorcycle too by the way, and especially if the engine is a bit older). This is also not helped by the fact that in colder weather, the air is a bit thicker, so you'll take more air into the engine when cranking it up in colder weather, which will mean the fuel/air mixture is a bit more lean, and fuel (before it ignites) also helps to lubricate the engine and carry heat away.

So, the lower the number, the thinner the oil is. This is because when grading oil performance, the SAE basically pour a specific quantity of oil through a calibrated diameter hole at a standard ambient temperature, and time how long it takes to go through the hole, the quicker it goes through, the lower the viscosity number it gets.

20-50, 25-60 etc. Having two numbers on your oil bottle indicates that it is a multi-grade oil, e.g. it may be a blend of 20 viscosity grade oil with 50 viscosity grade oil. This is a compromise solution. The thinner oil heats up and flows quicker, so is better for starting, but the thicker oil in there sticks better and conducts heat away from the moving parts better once the engine is up to operating temperature. Now, some people will tell you that you should definitely not use multigrade with a very low viscosity component because it will be 'too thin' when at operating temperatures, but this is not true, and means they don't properly understand how a multigrade fuel actually works, the thicker component will make it work just the same as a single grade oil of that same thicker viscosity, it's just that the thinner part will assist with starting and getting on the moving parts quicker. It's true that it won't lubricate things quite as well as a single grade thicker oil will when at operating temperatures, but it will still be okay.

Ultimately, thinner grade oils provide a bit less protection against wear and tear, and thicker grades do better in that regard but are less suited to starting an engine up in winter.

So, back to those oil choices in A2A's Commanche...

The Phillips 66 Victory 100AW is thicker, and in this case the AW stands for anti-wear, i.e. it means it has LW-16702 friction and rust reducing additive in the amount recommended by Lycoming, Continental and Pratt and Whitney etc. So, it's good for all year round if you experience fairly mild winters, but it will not cover the moving parts as quickly initially and being a bit thicker until heated up to operating temperatures, it will create some resistance when cranking the engine when in cold temperatures. This is why you see mad Russkies lighting fires under the engines of their Antonov An-2 aeroplanes in really cold weather before trying to start them - they are making the oil go thinner so they don't bend a con-rod when cranking the thing over.

Phillips XC 20W-50 is a blend of thin (20) oil suitable for winter (W), with thicker (50) oil in there too to provide better lubrication when at operating temperatures.

Phillips XC 25W-60 is a blend of not quite as thin (25) oil suitable for winter (W), with a bit thicker (60) oil in there too to provide better lubrication when at operating temperatures.

So, in other words, if you are in the UK, where it was pretty warm this summer, you'd be using 100AW, then when it went colder a few weeks ago, you'd swap it out for 25-60, then if it went really f***ing cold, you'd swap it out for 20-50. Note that you should change the oil every fifty hours of operation too by the way.

So now you know what all that stuff on an oil bottle means.

In simulation terms, what is actually going on with the A2A Commanche, is when you pick your oil, the A2A Commanche Accusim programming notes your choice and it then compares that with the flight sim's ambient weather temperature and your operating temperature. It uses that data to calculate how fast your engine is taking on wear and tear, so if you pick a less suitable oil for the current weather which would offer less protection, or if you picked one which was too thick and would stress the engine when starting it, you will see stuff like the compression in the cylinders dropping a bit when you use the hangar app, as it is simulating more wear on the piston rings and stuff like that. This is among the reasons why the A2A Commanche is the best GA aeroplane for FS.

 

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WOW! i think i just learned a whole book abaout oil im just got in aviation a got the basics but i never learned about how the engine functions it seems i will be learning a whole more stuff about airplanes and great explenation! you helped me allot!

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20 hours ago, Chock said:

It will probably help if you understand a bit about the terminology and what it all means.

In the sim, the A2A Commanche has three different aviation oil types available, these are: Phillips 66 Victory 100AW, Phillips XC 20W-50 and Phillips XC 25W-60. So what does all that malarkey actually mean?

First some terminology.

If you ever see SAE on an oil bottle, it stands for the Society of Automotive Engineers (and by automotive, they don't just mean cars, it's all vehicles, including aeroplanes which the SAE encompassed along with tractor engines too, in 1916, since rotary engines used Castor oil and stationary water cooled ones often didn't, so they needed to introduce some standards for all those WW1 warplanes). So, the SAE is an international standards agency which regulates what all those numbers and initials on an oil bottle mean, thus if you buy a bottle of 20-50 oil in Timbuktu, and some 20-50 in Tyneside, both should meet the same standard.

If you see W on a bottle of oil, it refers to the viscosity of the oil and its suitability for use in colder temperatures, i.e. how quickly it will flow (basically how thick it is and how much it will stick to moving parts in the engine). The W itself actually stands for Winter, so if you use an oil with W on it in winter, it will be a better choice, because it will be a bit thinner, which means in colder temperatures, it will heat up and move a bit quicker and so it will splash onto and cover the moving parts a bit quicker than a summer oil with no W on its label (since it is thicker). This is important because when your aeroplane is parked up, the oil all drips down into the sump, and so when you crank an engine, it takes a while for the oil to be pumped around the engine and for it to splash onto the moving parts such as the camshafts, lifters etc, and if they have no oil on them, the metal is rubbing against other bits of metal, causing friction (heat) and wear. This is why you should never crank an engine up and immediately throttle it up if it has been stood for a while, because you'll wear it out quicker (this is true for your car, truck or motorcycle too by the way, and especially if the engine is a bit older). This is also not helped by the fact that in colder weather, the air is a bit thicker, so you'll take more air into the engine when cranking it up in colder weather, which will mean the fuel/air mixture is a bit more lean, and fuel (before it ignites) also helps to lubricate the engine and carry heat away.

So, the lower the number, the thinner the oil is. This is because when grading oil performance, the SAE basically pour a specific quantity of oil through a calibrated diameter hole at a standard ambient temperature, and time how long it takes to go through the hole, the quicker it goes through, the lower the viscosity number it gets.

20-50, 25-60 etc. Having two numbers on your oil bottle indicates that it is a multi-grade oil, e.g. it may be a blend of 20 viscosity grade oil with 50 viscosity grade oil. This is a compromise solution. The thinner oil heats up and flows quicker, so is better for starting, but the thicker oil in there sticks better and conducts heat away from the moving parts better once the engine is up to operating temperature. Now, some people will tell you that you should definitely not use multigrade with a very low viscosity component because it will be 'too thin' when at operating temperatures, but this is not true, and means they don't properly understand how a multigrade fuel actually works, the thicker component will make it work just the same as a single grade oil of that same thicker viscosity, it's just that the thinner part will assist with starting and getting on the moving parts quicker. It's true that it won't lubricate things quite as well as a single grade thicker oil wil when at operating temperatures, but it will still be okay.

Ultimately, thinner grade oils provide a bit less protection against wear and tear, and thicker grades do better in that regard but are less suited to starting an engine up in winter.

So, back to those oil choices in A2A's Commanche...

The Phillips 66 Victory 100AW is thicker, and in this case the AW stands for anti-wear, i.e. it means it has LW-16702 additive in the amount recommended by Lycoming, Continental and Pratt and Whitney etc. So, it's good for all year round if you experience fairly mild winters, but it will not cover the moving parts as quickly initially and being a bit thicker until heated up to operating temperatures, it will create some resistance when cranking the engine when in cold temperatures. This is why you see mad Russkies lighting fires under the engines of their Antonov An-2 aeroplanes in really cold weather before trying to start them - they are making the oil go thinner so they don't bend a con-rod when cranking the thing over.

Phillips XC 20W-50 is a blend of thin (20) oil suitable for winter (W), with thicker (50) oil in there too to provide better lubrication when at operating temperatures.

Phillips XC 25W-60 is a blend of not quite as thin (25) oil suitable for winter (W), with a bit thicker (60) oil in there too to provide better lubrication when at operating temperatures.

So, in other words, if you are in the UK, where it was pretty warm this summer, you'd be using 100AW, then when it went colder a few weeks ago, you'd swap it out for 25-60, then if it when  really f***ing cold, you'd swap it out for 20-50. Note that you should change the oil every fifty hours of operation too by the way.

So now you know what all that stuff on an oil bottle means.

In simulation terms, what is actually going on with the A2A Commanche, is when you pick your oil, the A2A Commanche Accusim programming notes your choice and it then compares that with the flight sim's ambient weather temperature and your operating temperature. It uses that data to calculate how fast your engine is taking on wear and tear, so if you pick a less suitable oil for the current weather which would offer less protection, or if you picked one which was too thick and would stress the engine when starting it, you will see stuff like the compression in the cylinders dropping a bit when you use the hangar app, as it is simulating more wear on the piston rings and stuff like that. This is among the reasons why the A2A Commanche is the best GA aeroplane for FS.

 

best explenation ever! you helped me allot!

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Please don't quote an entire post. I agree it offers great information, but quoting it wastes space on the forum.

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