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04-27-2014, 10:43 PM | #1 |
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Nitro VS Gas
I was thinking about putting a 20cc size gas motor in my next plane, a 60 size p-51. Then I started doing a Horsepower to weight comparison and it is not even close. Other than the fact gas is much cheaper I see no benefit to gas power unless you are running something over 50cc. I believe in keeping it as light and as fast as possible, think I will stick with the OS 2 strokes.
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04-27-2014, 11:00 PM | #2 | |
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Re: Nitro VS Gas
Quote:
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04-27-2014, 11:09 PM | #3 |
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Re: Nitro VS Gas
Evolution 20cc pushes 1.68 hp, big deal get 1.62hp out of a OS .46fx. A 15cc OS .91fx pushes 2.8 hp and weights a lot less with out even adding the weight of the extra battery or ignition .
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04-27-2014, 11:17 PM | #4 |
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Re: Nitro VS Gas
HP isn't everything. Torque is a factor too. Do you think that OS 46 will swing a 16" prop at almost 9000 RPM?
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04-27-2014, 11:22 PM | #6 |
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Re: Nitro VS Gas
What I'm saying is that you brought in a comparison motor that was only 0.06HP difference, and as such, you can see it's really not a relevant comparison. Now even with the OS91, where does it develop that peak HP of 2.8? It may not be at an RPM that would be lugged down with a larger prop.
edit: Just looked it up, 2.8HP at 15000 RPM, so what is it at 9000 RPM, this is where the torque value may come in, unfortunately, torque specs are rarely listed.
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04-27-2014, 11:28 PM | #7 |
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Re: Nitro VS Gas
Torque gets you off the ground faster but Horsepower gives you top end. The .91 is a fair comparison it is only 14.95 cc and is good for up to a 17x6 prop.
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04-28-2014, 12:21 AM | #8 |
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Re: Nitro VS Gas
Sure it can turn the prop, but can it maintain it under loads, or does it grunt too hard? What kind of flight performance are you looking for?
Put it this way, lets take 2x 6000 pound trucks, I'll put a 200HP 2.0l 4 banger in yours, and a 200HP 5.7l V8 in mine. They'll both move that truck at 100Kmph, the 4 banger is lighter, will probably burn less fuel, but lets start climbing the steep hill and see who gets there first.. or drive the ups and downs through the mountains and see which performs better. As such, it comes down to what you are looking for in performance. Do you want something that will pull all day long, something that just has ripping speed, or somewhere in between? Just my opinion, I'd rather see a Mustang that can pull it's own vertically and realistically as opposed to one that gets it from ripping around unrealistically like a pylon racer. But that's your choice which way you would like to see it fly.
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04-28-2014, 12:33 AM | #9 |
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Re: Nitro VS Gas
Looking for something that will climb and give great level flight speed. Anything over a 14in. prop on this plane will just cut the grass. A 14in prop on a .91 will turn over 10000 rpm and do very good vertical. If you compare cubic inch to cubic inch it is no contest and the nitro is much lighter.
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04-28-2014, 08:42 AM | #10 |
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Re: Nitro VS Gas
What you have to also consider is the extra weight of the battery and possibly a much more expensive receiver and satellites because of the giant magnetic field created by the ignition system. That 16" prop also comes with a giant torque factor.
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