electric vs gas.

[wpmay]

Seems like this thread is missing the most important point. The AMA indicates that the number one reason for the loss of flying fields is the noise from IC engines. As housing developments continue to encroach on areas that were once more rural this will be an ever increasing problem in the future.

Bill

[Konrad]

Gasoline does change as it is mixed (refined) as the seasonal requirements demand. The fuel is blended differently for the sub zero winter weather verses the 100°F+ summer heat. Most folks want their cars to start in the winter and not vapor lock in the summer. Folks are odd that way:rolleyes:

But the real killer is that the mass (center) of gravity is always changing through out the whole flight. Then there is the tune of the engine, its power changes though out the day as the temps and density change. When flying electric there are actual less variability between the variables, day to day and through out the year.

While I did dyno my engines while I was developing them. I can't actually say that I did any long term decay studies. But I'm sure that there was a decay in the performance of the engines even from the beginning to the end of one racing season.

[Konrad]

Actually the loss of field is as a result of development.

Noise is for the most part an excuse. Folks don't like the idea of folks (Guys, grown men) having fun. I point to the fact that in suburbia folks are fine with the noise of lawn mowers and such as they know you aren't having fun. But as soon as the noise is associated with a fun activity then it MUST be banned. And the most convenient reasoning to ban is noise regardless of dB output.

Now don't think that electrics are quite! I have some that will wake the dead.

[martmichals]

I stand corrected about gas engines in that aspect then, Konrad. Thanks for the other perspective.

[RocketRobin]

Gasoline does change as it is mixed (refined) as the seasonal requirements demand. The fuel is blended differently for the sub zero winter weather verses the 100°F+ summer heat. Most folks want their cars to start in the winter and not vapor lock in the summer. Folks are odd that way:rolleyes:

But the real killer is that the mass (center) of gravity is always changing through out the whole flight. Then there is the tune of the engine, its power changes though out the day as the temps and density change. When flying electric there are actual less variability between the variables, day to day and through out the year.

While I did dyno my engines while I was developing them. I can't actually say that I did any long term decay studies. But I'm sure that there was a decay in the performance of the engines even from the beginning to the end of one racing season.

Pump gas changes for seasonal mixes in some latitudes. We all hope that the octane rating is at least that which is advertised. Those of us that drive cars with high compression/boosted engines know that every time you pull up to a strange pump, it's a crapshoot whether you get a tank of high octane, or some run-off from the pig farm out back. Station owners think we can't tell the difference, but it shows up on the gauges, too. We know when they're shoveling it!

But I digress.

Lipos are a different fuel. They just totally suck arse when they're less than warm, and are essentially useless when cold. Then they have that crazy discharge power curve thing that just gets worse right after you take off. They wear out while as you fly (ever seen an EF1 racer run a battery for more than a one event? It's called "also ran".)
Lipos are, for the most part, convenient for city apartment dwellers that drive compact cars, like me :)

I'm not a pylon racer, but my club is a racing club. They burn nitro in all events except EF1. Apparently nitro is a good fuel to use for racing.... just throwing it out there that it might provide good performance, for events like the World Air Games, etc.

Multi-cylinder nitro power. If I was to compete in scale, that's what I would use (all I need is a house and a PU truck). I would run as much nitro as the engine recommendation and then add 10 points (runs cooler and more stable) and I certainly wouldn't worry about a bean counter calculating the fuel operating costs (and extra glow plugs) for my precious plane and its expensive nine cylinder radial engine.
We all have dreams :rolleyes:

Cheers!
Rocket

[RocketRobin]

My electric rig for my Great Planes P6E.

Cheers!
Rocket

[fhhuber]

Is that smoke for e-power?

I WANT THAT!

[doctormike]

I bought a Great planes SkyBolt bipe for my .91 4 cycle. After much going back and forth, I've decided to convert it to electric. The FMS Pitts is about the same size and weight, so I'm going to use the Pitts power setup and electronics. I'm not sure where that battery will fit. I love that 3 blade prop, too! Doc

[Grossman56]

Hey Konrad, I think you're on to something there! Out here in cowboy country, land of the noisy 4x4s and the Harley Davidsons, not to mention larger caliber weapons, they'll still complain! You have to watch whose property you inadvertently fly over as well, there was an empty field across from the school that I would pass over when landing. One day the guy is standing out there, and I'm wondering if he plans on 'complaining ' or just watching, you never know with people. Last time I flew from there.

Grossman56

[Konrad]

I built FAI F3D pylon engines some from my own casting/bar stock. This is a zero nitro engine with full wave tuned pipe. I flew AMA F-1,428 Q500 and 0.15 Quarter Midgets all with Nelson engines. I was involved with the refining of petrochemicals, and built cars engines and chassises for the then Camel GT light class. And later I wrote repairs for flight turbines that produce over 100K lb. of thrust. That's my quick and dirty, basic back ground in liquid powered power plants.

Yes, I fly EF-1 I've even dabbled with a few FAI F5D racers. I have been pushing electrons at high currents since 86 with the Sanyo 1200SCR cell and Astro cobalt motors.

From a competitive power stand point electrics are the only viable power source (with very few exceptions). I have a dozen multi cylinder glow engines both 2 cycle and 4 cycle. I can tell you from first hand experience that the best place for them is on the mantel piece!:@

I think I said it best to the OP's question early on, DON'T DO IT! And this is from a guy that has been at the extreme edge of power generation on both sides of the debate Glow verses Electrics.

Now what I'd like to learn more about are the heat exchangers on that P-6E.

[OV10]

I'm with you on wanting to know more about what that contraption is on the P-6E. I'm leaning towards fhhuber's comment on it being smoke set up because of the conspicuously placed fuel tank above the motor. Ok RocketRobin, spill your guts on this please!

[Iowa54]

From someone who is just getting started in this hobby I can say electric all the way! I want stick time not tuning time. Not saying that my thoughts won't change but, I think the hobby its self is heading towards electric power.

[PlaneCrazy]

Prop choice can bring back the sound... at least half of the noise was from the tips of the props.

Also, MrRCsound can help the need for noise!!!

[fhhuber]

The prop is about $5....

[Arthur89777]

You know, the gas/glow engines have the advantage that they don't consume a lot of current as the electros.
But they are quete expencive and haven't high efficiency as brushless motors. For example, the diesel engine has efficiency only 40%.
While the brushlesss motor has it upper than 90%.
You can read about the measurements here:

http://www.rcfair.com/en/blogs/view_entry/12786/

[doctormike]

Rocket...Rube Goldberg couldn't have done a better job! Really curious! Doc

[Konrad]

You know, the gas/glow engines have the advantage that they don't consume a lot of current as the electros.
But they are quete expencive and haven't high efficiency as brushless motors. For example, the diesel engine has efficiency only 40%.
While the brushlesss motor has it upper than 90%.
You can read about the measurements here:

http://www.rcfair.com/en/blogs/view_entry/12786/

I've been seeing the cost of the model glow engine drop as they become less and less practical in today's environment.

I'd like to see that diesel! I assume you are talking about thermal efficiency. Now there are some turbo-compound engines (diesel and turbine coupled, not the same as a turbo charged diesel ) that get close to that.

As to the often claimed 90% efficiency for electric motors, those are usually the larger ones. What we play with usually have a peak efficiency in the 80's

[Ron1950]

gave up nitro planes few years ago and got into electric boat racing....had a lot of batteries and chargers etc so when I started flying I went electric and love it...no muss no fuss and no oil to clean up on plane...also sense there are hardly any bulsa kits left to build (and I don't build that great anyway) and I wanted to fly war birds ... where else can I get a plane that looks scale and flys great except for the electric foamies? love em and the price is right....

[TSHobbies]

I too used to fly nitro..and there were a few factors that made me change..
#1 foam planes are cheaper
#2 got tired of getting nitro to run right in the temp/humidity changes
#3 the formentioned slime clean up...messy..especially when doing #2, all that exhaust coming out on your hands arms and legs ...and your plane
I do miss the sound, and the current sound systems dont quite match it,but I think with time they will get better,and may even surpass the sound of piston engines.

[JFandL]

I have a lot of very large scale war birds that have gas engines, I don't have any Nitro engines around any more nor-fixed wing aircraft that run on nitro. I do have 6 Helicopters that are Nitro, but they have been in the hanger since 2004. Electric everything up to 40cc then Gas. I even have a 7 foot Black hawk, electric and it's 38lbs. Maybe one day everything will be electric,

John