4 Stroke/ 2 Stroke comparison
02-09-2008, 09:41 PM
#1
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4 Stroke/ 2 Stroke comparison
Can anyone tell me where i could find a chart to compare engine sizes. I am looking for an equivalent 2stroke that is equal in size/power to a 1.20 4 stroke. i would like to have a chart for all engine sizes. Thanks
02-10-2008, 06:35 AM
#4
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RE: 4 Stroke/ 2 Stroke comparison
Right now, Tower advertises the OS120 4stroke for $380 and it's weight as 32oz. And the OS91FX for $210 and 24oz.
The rule of thumb for power is that a 90 2stroke would match up against a 1.35 4stroke (if any were made) or that a 1.20FS would be equalled by an 80 2stroke.
The rule of thumb for power is that a 90 2stroke would match up against a 1.35 4stroke (if any were made) or that a 1.20FS would be equalled by an 80 2stroke.
02-10-2008, 10:38 AM
#5
RE: 4 Stroke/ 2 Stroke comparison
I wont try to guess why you might prefer 2-stroke over 4-stroke or vice versa. That's like arguing Ford vs. Chevy vs. Dodge. Each engine type has its advantages though. For example:
- More power per ounce from a 2-stroke.
- 4-stroke of that size sips fuel compared to a comparable 2-stroke.
- 2-stroke less expensive than a 4-stroke
- More torque from a 4-stroke
- Some like the more throaty sound of a 4-stroke
- Technically, 4-stroke is more complex than a 2-stroke
- More power per ounce from a 2-stroke.
- 4-stroke of that size sips fuel compared to a comparable 2-stroke.
- 2-stroke less expensive than a 4-stroke
- More torque from a 4-stroke
- Some like the more throaty sound of a 4-stroke
- Technically, 4-stroke is more complex than a 2-stroke
02-10-2008, 10:41 AM
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RE: 4 Stroke/ 2 Stroke comparison
Here is the Plane i am going to buy http://www.texasrcplanes.com/cap2321201.html , would a 1.20 be too much for this or should i go with a .90? Thanks for the help and replies.
02-10-2008, 06:43 PM
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RE: 4 Stroke/ 2 Stroke comparison
A CAP 232 is not the type of plane that you want to fly with marginal power.
If I were going to use a two stroke on that plane, I'd use the 1.20AX rather than the .91FX.
If I were going to use a two stroke on that plane, I'd use the 1.20AX rather than the .91FX.
02-11-2008, 07:48 AM
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RE: 4 Stroke/ 2 Stroke comparison
4-Stroke vs. 2-Stroke
Four stroke
Cons
-More expensive
-More maintenance
-Less powerful per capacity
-Much poorer power to weight ratio
-Can be harder to operate than two strokes
Pros
-Lower fuel consumption
-Quieter
-Can run a much bigger prop
-Fit better and look better in most scale planes
-Sounds cool, very scale like
-More low end torque than two strokes
Two stroke
Cons
-Higher fuel consumption
-Noisier when propped for very high rpm or inadequately silenced
-Peakier power curve
Pros
-Inexpensive
-Wider selection
-Robust
-Powerful for capacity
-Excellent power to weight ratio
-Can run high rpms
Austin
Four stroke
Cons
-More expensive
-More maintenance
-Less powerful per capacity
-Much poorer power to weight ratio
-Can be harder to operate than two strokes
Pros
-Lower fuel consumption
-Quieter
-Can run a much bigger prop
-Fit better and look better in most scale planes
-Sounds cool, very scale like
-More low end torque than two strokes
Two stroke
Cons
-Higher fuel consumption
-Noisier when propped for very high rpm or inadequately silenced
-Peakier power curve
Pros
-Inexpensive
-Wider selection
-Robust
-Powerful for capacity
-Excellent power to weight ratio
-Can run high rpms
Austin
02-11-2008, 08:20 PM
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RE: 4 Stroke/ 2 Stroke comparison
If four strokes make more torque than two strokes, why does OS recommend bigger props for the 1.20 AX than for their 1.20 four stroke engine?
Look at this video of a four-stroke engine being tested on a dyno and notice the low rpm and pleasant putt-putt exhaust note.
http://www.youtube.com/watch?v=o_QyUD6V5_I
Look at this video of a four-stroke engine being tested on a dyno and notice the low rpm and pleasant putt-putt exhaust note.
http://www.youtube.com/watch?v=o_QyUD6V5_I
02-11-2008, 11:21 PM
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RE: 4 Stroke/ 2 Stroke comparison
ORIGINAL: acarter
4-Stroke vs. 2-Stroke
Four stroke
Cons
-More expensive
-More maintenance
-Less powerful per capacity
-Much poorer power to weight ratio
-Can be harder to operate than two strokes
Pros
-Lower fuel consumption
-Quieter
-Can run a much bigger prop
-Fit better and look better in most scale planes
-Sounds cool, very scale like
-More low end torque than two strokes
Two stroke
Cons
-Higher fuel consumption
-Noisier when propped for very high rpm or inadequately silenced
-Peakier power curve
Pros
-Inexpensive
-Wider selection
-Robust
-Powerful for capacity
-Excellent power to weight ratio
-Can run high rpms
Austin
4-Stroke vs. 2-Stroke
Four stroke
Cons
-More expensive
-More maintenance
-Less powerful per capacity
-Much poorer power to weight ratio
-Can be harder to operate than two strokes
Pros
-Lower fuel consumption
-Quieter
-Can run a much bigger prop
-Fit better and look better in most scale planes
-Sounds cool, very scale like
-More low end torque than two strokes
Two stroke
Cons
-Higher fuel consumption
-Noisier when propped for very high rpm or inadequately silenced
-Peakier power curve
Pros
-Inexpensive
-Wider selection
-Robust
-Powerful for capacity
-Excellent power to weight ratio
-Can run high rpms
Austin
02-12-2008, 01:48 AM
#12
Senior Member
RE: 4 Stroke/ 2 Stroke comparison
Its always better to be a little overpowered rather than underpowered. The plane you are planning on will fly with a 90 sized 2 stroke, but the 120AX will really bring it to life. The AX is the same weight as the recomended 120 4 stroke so the plane should balance like it should.
PS: The AX series kind of closes the gap on 4 stroke advantages, they are built for torque rather than high rpm and run quiet on the stock muffler.
PS: The AX series kind of closes the gap on 4 stroke advantages, they are built for torque rather than high rpm and run quiet on the stock muffler.
02-12-2008, 07:00 AM
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RE: 4 Stroke/ 2 Stroke comparison
A lot if not all of the two strokes in the 1.2 and up size range are designed to turn big props at about 9000 rpm or so instead of screaming at 13, to 16k with a tiny prop so they will indeed turn the same size if not larger props than the four strokes, the exception being YS AC engines which is a supercharged four stroke. These engines are equal in power to two strokes.
Another benefit to "overpowering" it is that often, a large two stroke that's loafing along at half throttle most of the time will burn less fuel that a small engine that's always screaming at WOT. If you need the nose weight anyway, it might as well be a bigger engine, the throttle works both ways.
Another benefit to "overpowering" it is that often, a large two stroke that's loafing along at half throttle most of the time will burn less fuel that a small engine that's always screaming at WOT. If you need the nose weight anyway, it might as well be a bigger engine, the throttle works both ways.
