2 stroke vs 4 stroke
09-24-2009, 02:08 PM
#1
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2 stroke vs 4 stroke
Which is better and why? I am currentally looking at a 2 stoke o.s. .46 and a 4 stroke o.s. .40. I am building my first arf, its a tower trainer mk II. Thanks for any help givin
09-24-2009, 02:53 PM
#2
RE: 2 stroke vs 4 stroke
Neither is better, they are just different.
However, while I generally prefer 4-strokes, they are slightly more complicated, more expensive, and more easily damaged.
So for a beginner, I usually recommend going with a 2-stroke.
That said, spend the extra money and get a ball bearing 2-stroke, they are worth the extra $$$
However, while I generally prefer 4-strokes, they are slightly more complicated, more expensive, and more easily damaged.
So for a beginner, I usually recommend going with a 2-stroke.
That said, spend the extra money and get a ball bearing 2-stroke, they are worth the extra $$$
09-24-2009, 03:37 PM
#3
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RE: 2 stroke vs 4 stroke
2 stoke, 4-stroke. Those are old news. I'm gonna get me one of these new 5-stroke engines
: http://www.nitroplanes.com/fm01-20-f...troengine.html
I know it's a little off topic but someone sent it to me and I had to do a double-take. Talk about a typo...
As for the original question, the .46 2-stroke will be perfect for that airplane.
: http://www.nitroplanes.com/fm01-20-f...troengine.htmlI know it's a little off topic but someone sent it to me and I had to do a double-take. Talk about a typo...
As for the original question, the .46 2-stroke will be perfect for that airplane.
09-24-2009, 04:01 PM
#4
RE: 2 stroke vs 4 stroke
ORIGINAL: bigwill5686
Which is better and why? I am currentally looking at a 2 stoke o.s. .46 and a 4 stroke o.s. .40. I am building my first arf, its a tower trainer mk II. Thanks for any help givin
Which is better and why? I am currentally looking at a 2 stoke o.s. .46 and a 4 stroke o.s. .40. I am building my first arf, its a tower trainer mk II. Thanks for any help givin
09-24-2009, 04:05 PM
#5
RE: 2 stroke vs 4 stroke
Also, 4 strokes generally have the 2/3 the power of a similar sized 2 stroke but they do offer more torgue. You would need to go with at least a 60 or larger 4 stroke to match the power of the .40. Take the time to break it in properly. Very important for trouble free use down the road. Good luck on the ARF assembly.. any questions. .ask away!
09-24-2009, 04:43 PM
#6
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RE: 2 stroke vs 4 stroke
That's pretty basic old school thinking about the power difference between the two and four strokes. There is still some power difference but the four strokes have gotten a lot closer these days to the power of the two strokes, it isn't anything like it used to be with the old fours. The smallest four stroke I have today is the OS .91 and it pulls the same plane every bit as well as my two stroke .91. Isn't as fast but it has about the same power.
09-24-2009, 04:50 PM
#7
RE: 2 stroke vs 4 stroke
ORIGINAL: Gray Beard
That's pretty basic old school thinking about the power difference between the two and four strokes. There is still some power difference but the four strokes have gotten a lot closer these days to the power of the two strokes, it isn't anything like it used to be with the old fours. The smallest four stroke I have today is the OS .91 and it pulls the same plane every bit as well as my two stroke .91. Isn't as fast but it has about the same power.
That's pretty basic old school thinking about the power difference between the two and four strokes. There is still some power difference but the four strokes have gotten a lot closer these days to the power of the two strokes, it isn't anything like it used to be with the old fours. The smallest four stroke I have today is the OS .91 and it pulls the same plane every bit as well as my two stroke .91. Isn't as fast but it has about the same power.
09-25-2009, 01:49 PM
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RE: 2 stroke vs 4 stroke
Bigwill:
While I agree with all of the above comments regarding 2 vs 4 strokes, for a Tower Trainer MKII I'd recommend using the 2 stroke for a couple of reasons:
1) Prop clearance. The MKII was probably designed with a 40-46 2S in mind, probably turning a 10x6 prop. If you're leaning towards a 70 sized 4S, it'll want to spin a 12" prop, so now your prop tips are going to be closer to the ground. Any sort of nose-heavy landing will probably end up trimming your prop tips or breaking them off, especially if you're flying off grass or weeds. Which means you'll need bigger wheels, or making the landing gear taller, or both.
2) Weight and CG. The 4S will probably be heavier than a 2S. Since it's hung off the front of the airplane, it'll shift the CG forward, meaning you'd probably have to add weight to the tail. So your 5-1/2lb trainer may all of a sudden end up weighing 6lbs between the extra weight of the engine and balancing lead. Using a Saito might help with this problem, as they seem to be lighter than their OS/Magnum/ThunderTiger equivalents.
If this is your first build, I'd use the 2S just to keep things simpler and "by the book".
Fred
While I agree with all of the above comments regarding 2 vs 4 strokes, for a Tower Trainer MKII I'd recommend using the 2 stroke for a couple of reasons:
1) Prop clearance. The MKII was probably designed with a 40-46 2S in mind, probably turning a 10x6 prop. If you're leaning towards a 70 sized 4S, it'll want to spin a 12" prop, so now your prop tips are going to be closer to the ground. Any sort of nose-heavy landing will probably end up trimming your prop tips or breaking them off, especially if you're flying off grass or weeds. Which means you'll need bigger wheels, or making the landing gear taller, or both.
2) Weight and CG. The 4S will probably be heavier than a 2S. Since it's hung off the front of the airplane, it'll shift the CG forward, meaning you'd probably have to add weight to the tail. So your 5-1/2lb trainer may all of a sudden end up weighing 6lbs between the extra weight of the engine and balancing lead. Using a Saito might help with this problem, as they seem to be lighter than their OS/Magnum/ThunderTiger equivalents.
If this is your first build, I'd use the 2S just to keep things simpler and "by the book".
Fred
09-25-2009, 05:16 PM
#9
RE: 2 stroke vs 4 stroke
ORIGINAL: Mr67Stang
I think you may be confusing power and torque. You can spin a larger prop on the four srokes because they have the torque to do so, so your .40 4 stroke can spin about the same prop as a .40 2 stroke but that 2 stroke will spin it at a higher RPM (power).
ORIGINAL: Gray Beard
That's pretty basic old school thinking about the power difference between the two and four strokes. There is still some power difference but the four strokes have gotten a lot closer these days to the power of the two strokes, it isn't anything like it used to be with the old fours. The smallest four stroke I have today is the OS .91 and it pulls the same plane every bit as well as my two stroke .91. Isn't as fast but it has about the same power.
That's pretty basic old school thinking about the power difference between the two and four strokes. There is still some power difference but the four strokes have gotten a lot closer these days to the power of the two strokes, it isn't anything like it used to be with the old fours. The smallest four stroke I have today is the OS .91 and it pulls the same plane every bit as well as my two stroke .91. Isn't as fast but it has about the same power.
Right... hence the comment about not pulling as fast. Manuf reccommending a .60 2s will also require a .90 4s. However I am new to 4s myself and am currently breaking in a .52 and 70. I'm planning on putting the .70 in a GP .40 cub with a clipped wing. It reccomends a .48 to .80 4s so I think it will be a real nice match for scale aerobatics. Not sure about the .52 yet.
09-25-2009, 09:52 PM
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RE: 2 stroke vs 4 stroke
ORIGINAL: FallDownGoBoom
Bigwill:
While I agree with all of the above comments regarding 2 vs 4 strokes, for a Tower Trainer MKII I'd recommend using the 2 stroke for a couple of reasons:
1) Prop clearance. The MKII was probably designed with a 40-46 2S in mind, probably turning a 10x6 prop. If you're leaning towards a 70 sized 4S, it'll want to spin a 12'' prop, so now your prop tips are going to be closer to the ground. Any sort of nose-heavy landing will probably end up trimming your prop tips or breaking them off, especially if you're flying off grass or weeds. Which means you'll need bigger wheels, or making the landing gear taller, or both.
2) Weight and CG. The 4S will probably be heavier than a 2S. Since it's hung off the front of the airplane, it'll shift the CG forward, meaning you'd probably have to add weight to the tail. So your 5-1/2lb trainer may all of a sudden end up weighing 6lbs between the extra weight of the engine and balancing lead. Using a Saito might help with this problem, as they seem to be lighter than their OS/Magnum/ThunderTiger equivalents.
If this is your first build, I'd use the 2S just to keep things simpler and ''by the book''.
Fred
Bigwill:
While I agree with all of the above comments regarding 2 vs 4 strokes, for a Tower Trainer MKII I'd recommend using the 2 stroke for a couple of reasons:
1) Prop clearance. The MKII was probably designed with a 40-46 2S in mind, probably turning a 10x6 prop. If you're leaning towards a 70 sized 4S, it'll want to spin a 12'' prop, so now your prop tips are going to be closer to the ground. Any sort of nose-heavy landing will probably end up trimming your prop tips or breaking them off, especially if you're flying off grass or weeds. Which means you'll need bigger wheels, or making the landing gear taller, or both.
2) Weight and CG. The 4S will probably be heavier than a 2S. Since it's hung off the front of the airplane, it'll shift the CG forward, meaning you'd probably have to add weight to the tail. So your 5-1/2lb trainer may all of a sudden end up weighing 6lbs between the extra weight of the engine and balancing lead. Using a Saito might help with this problem, as they seem to be lighter than their OS/Magnum/ThunderTiger equivalents.
If this is your first build, I'd use the 2S just to keep things simpler and ''by the book''.
Fred
My favorite 46 size two stroke is the Thunder Tiger 46pro second choice would be the OS 46AX.
Either one of these engines is very user friendly and very reliable.
There are lots of cheaper engines, but either one of these will almost guarantee a good experience.
