ENGINES .. 2Stroke or 4Stroke???
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ENGINES .. 2Stroke or 4Stroke???
Right. There has been some debate and indeed heated arguement regarding the differences between 2 and 4 stroke engines in Freestyle/AA Models.
I notice the YS seems dominant.. WHY? Can anybody honestly put forward a reason why 2 strokes are not widely used?
I notice the YS seems dominant.. WHY? Can anybody honestly put forward a reason why 2 strokes are not widely used?
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ENGINES .. 2Stroke or 4Stroke???
I'f you'd asked me this 1 year ago I couldn't have given you a real decent opinion base on something other than heresay... but things change.
First of all there is one very important fact on this subject... There are some very, very, very good pilots flying F3A with 2 stroke engines, even though the majority of named pilots are YS'ing. And having said that, it's important to understand choosing a YS over a 2-stroke is NOT going to make you a better pilot. Rigth said it..now heres' my opinion.
After many years with YS. I decided to get onto the 2 skroke jive about 12 months ago.
The main reason? Nothing more exotic than they run on cheaper fuel than the Cool Power 30% heli I swear by.
Cheaper running costs? 12 months on I say a definate no! The OS 1.40 is very thirsty, unscrewing the pump 1.5turns helped the mid range riching and overal econ' but still it drinks!
During a practice day with one aeroplane OS powered and 1 aeroplane YS powered it's basically ...wait for it... twice as much flying/per gallon in the YS favour! This is a major dramatic key fact!
Second, and this you've heard 1 million times before but the throttle response on the YS is simply off the scale! From Idle I can advance the throttle one klick at a time and hear and feel a perfect power increase...one click at a time all the way to the top! This linier power delivery is worth (for me remember) a million bucks.
The 2- stroke can not compare, period.
The classic on/off power delivery of a 2 stroke has been advance light years due to F3A but it is still nothing to talk about... Again this is my personal feeling and preference point..and certainly dosn't make me more competitive.
This is not a conclusion that one can reach quickly, certainly 95% of the folks reading this just wouldn't tell the difference and I certainly isn't worth advising you this way or that. This is something that one has to work out for yourself, over time. And indeed, that proccess of working it out could well lead you towards choosing a 2 stroke because it suits your style.
Don't listen to anyone, find out.
I'd like to say my experince is based only on the OS 1.40 with a standard Hatori set normal, I'm sure with tweeking and changing things would improve.
Second, when I talk 4 stroke I'm only referning to YS and NOT 4 strokes in general.
First of all there is one very important fact on this subject... There are some very, very, very good pilots flying F3A with 2 stroke engines, even though the majority of named pilots are YS'ing. And having said that, it's important to understand choosing a YS over a 2-stroke is NOT going to make you a better pilot. Rigth said it..now heres' my opinion.
After many years with YS. I decided to get onto the 2 skroke jive about 12 months ago.
The main reason? Nothing more exotic than they run on cheaper fuel than the Cool Power 30% heli I swear by.
Cheaper running costs? 12 months on I say a definate no! The OS 1.40 is very thirsty, unscrewing the pump 1.5turns helped the mid range riching and overal econ' but still it drinks!
During a practice day with one aeroplane OS powered and 1 aeroplane YS powered it's basically ...wait for it... twice as much flying/per gallon in the YS favour! This is a major dramatic key fact!
Second, and this you've heard 1 million times before but the throttle response on the YS is simply off the scale! From Idle I can advance the throttle one klick at a time and hear and feel a perfect power increase...one click at a time all the way to the top! This linier power delivery is worth (for me remember) a million bucks.
The 2- stroke can not compare, period.
The classic on/off power delivery of a 2 stroke has been advance light years due to F3A but it is still nothing to talk about... Again this is my personal feeling and preference point..and certainly dosn't make me more competitive.
This is not a conclusion that one can reach quickly, certainly 95% of the folks reading this just wouldn't tell the difference and I certainly isn't worth advising you this way or that. This is something that one has to work out for yourself, over time. And indeed, that proccess of working it out could well lead you towards choosing a 2 stroke because it suits your style.
Don't listen to anyone, find out.
I'd like to say my experince is based only on the OS 1.40 with a standard Hatori set normal, I'm sure with tweeking and changing things would improve.
Second, when I talk 4 stroke I'm only referning to YS and NOT 4 strokes in general.
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ENGINES .. 2Stroke or 4Stroke???
I think a personality thing also comes into play. I choose not to become intimately familiar with the complexity of the YS 4-cycle. Once my FZ hit the skids and I heard about what it was going to take to fix it, my "intermediate-pilot" mind said, "I can buy a brand new ST2300 for the price of parts that might fix the FZ." I switched to the ST2300 and suffered the woes, but made it work well using stock parts, Perry equipment, or a Cline regulator. Now, after becoming a better pilot and wanting to purchase an engine you did not have to mess with, I went to the Webra 1.45 R, then the AAR. I think that "in-general" the 2-cycles are easier to run day and day out, with less maintenance. AFter all, the part count is considerably less. Most of my engine maintenance is crack-a-beer and change-a-plug, finish-the-beer. Changing engines is not going to turn you into world champion - but there are differenace. If cost is a factor, consider the 2-cycle.
Jim
Jim
#4
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Your talking A.A right
Well since A.A. stuff is inherently requiring instant throttle response and high torque in the middle of the power curve (torque rolling) the 2 strokes tend to be harder to utilize.....
This was my finding.....Now I'm a YS Performance sponsored flyer....but at the time I was comparing motors I was running the OS 140EFI...I have also run the Webra...Both good motors and perform well.....but not up to speed for F3A compared to the 4stroke..
I think what happens is just like the TOC free style people are assuming that A.A. is lots of 3D stuff....and it can contain that stuff. But as Mike Hurley stated in the Model Aviation article about the TOC......"The crowd wanted Monster Trucks and Quique gave them Swan Lake"....
Well I like the swan lake thing better...but you can do some cool stuff with our pattern models flying 3D and some A.A stuff....the spool up and spool down of the 2 stroke as well as the pipe action of coming on or going off will make this 3D stuff more difficult to do. And if you use a muffler instead of a tuned exhaust I'm gonna beat you on power with the DZ....But with the tunned exhaust you get that peaky issue to deal with....it just makes life tougher
I feel that the instant power power of the YS is the best for this.....If you are talking top end full throttle power...then its a wash.....The OS 140, Webra, and YS DZ all make the same power same prop same RPM...same same at full throttle.....The DZ running 30% nitro and the 2 strokes running 25% nitro....
If you run 15% in the 2 stroke I'm gonna beat you on the top end with the DZ running the 30%.....
A.A. seems to feature some slow and demanding power performance...torque in the middle and thats where the Dingo carries the Day
Troy Newman
YS Performance Rep
This was my finding.....Now I'm a YS Performance sponsored flyer....but at the time I was comparing motors I was running the OS 140EFI...I have also run the Webra...Both good motors and perform well.....but not up to speed for F3A compared to the 4stroke..
I think what happens is just like the TOC free style people are assuming that A.A. is lots of 3D stuff....and it can contain that stuff. But as Mike Hurley stated in the Model Aviation article about the TOC......"The crowd wanted Monster Trucks and Quique gave them Swan Lake"....
Well I like the swan lake thing better...but you can do some cool stuff with our pattern models flying 3D and some A.A stuff....the spool up and spool down of the 2 stroke as well as the pipe action of coming on or going off will make this 3D stuff more difficult to do. And if you use a muffler instead of a tuned exhaust I'm gonna beat you on power with the DZ....But with the tunned exhaust you get that peaky issue to deal with....it just makes life tougher
I feel that the instant power power of the YS is the best for this.....If you are talking top end full throttle power...then its a wash.....The OS 140, Webra, and YS DZ all make the same power same prop same RPM...same same at full throttle.....The DZ running 30% nitro and the 2 strokes running 25% nitro....
If you run 15% in the 2 stroke I'm gonna beat you on the top end with the DZ running the 30%.....
A.A. seems to feature some slow and demanding power performance...torque in the middle and thats where the Dingo carries the Day
Troy Newman
YS Performance Rep
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ENGINES .. 2Stroke or 4Stroke???
Quantifying 2 stroke performance is like trying to hit a moving target. Things are constantly changing as we get better at optimizing the setups.
With our Greve tuned exhaust the engine goes "on the pipe" at idle so there is no transition to the pipe through the mid-range. We also discovered that the APC props, while good, are significantly less efficient than Bolly props. With the Webra, 15% nitro and an APC 17x12 I was generating around 3.6 horsepower. With the Bolly 17.5x12 I'm getting over 4.5 horsepower.
AA or 3D is about the only place one can use that much horsepower - pulling out of hovers and such, so most all flying is done in the engine's mid-range. Again, because the Greve has no mid-range transition to the pipe the throttle has a linear response and one can adjust partial throttle settings to whatever is appropriate.
As to fuel economy: OS's are thirsty. This has never been an issue with the Webras. I don't have any info on the 3M. I've always been able to run twice through Masters or FAI, with plenty of fuel to spare, on a 20 oz tank. With the increases in efficiency we've acheived it wouldn't surprise me if 16 oz will now do the job. The weather broke on this miserable winter we've had on the east coast this year, so I actually get to go flying today and try some things out. Finally!
With our Greve tuned exhaust the engine goes "on the pipe" at idle so there is no transition to the pipe through the mid-range. We also discovered that the APC props, while good, are significantly less efficient than Bolly props. With the Webra, 15% nitro and an APC 17x12 I was generating around 3.6 horsepower. With the Bolly 17.5x12 I'm getting over 4.5 horsepower.
AA or 3D is about the only place one can use that much horsepower - pulling out of hovers and such, so most all flying is done in the engine's mid-range. Again, because the Greve has no mid-range transition to the pipe the throttle has a linear response and one can adjust partial throttle settings to whatever is appropriate.
As to fuel economy: OS's are thirsty. This has never been an issue with the Webras. I don't have any info on the 3M. I've always been able to run twice through Masters or FAI, with plenty of fuel to spare, on a 20 oz tank. With the increases in efficiency we've acheived it wouldn't surprise me if 16 oz will now do the job. The weather broke on this miserable winter we've had on the east coast this year, so I actually get to go flying today and try some things out. Finally!
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ENGINES .. 2Stroke or 4Stroke???
Thanks for your reply... however.. I have already made a choice on airframe and engine and I suddenly stopped and questioned this 'automatic' response... I mean if we take the OS91FX, we fit a marine pipe, combating the peakiness we save A LOT of weight. The YS110 is heavy and the manifold and pipe combo does not add to the situation. Same airframe, same everything (and ability).. which will out perform the other?
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Lee Davis
Hey there Mr. Davis..... how was the flying back in NC this weekend? I'm moving to Greensboro in late may.... what field do you fly at...? I've been wanting to put my name on the list for a kit of yours, I'd like to see some of you're new pattern stuff.
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ENGINES .. 2Stroke or 4Stroke???
Esport, we have an active pattern community flying at BARKS, south of Burlington. Depending on where you live in Greensboro, about 30-45 minutes away from you. It's an equal opportunity location. It seems no matter where you live in the vicinity it takes 30 minutes to get there. I live in Chapel Hill.
It's a great area for Pattern. There is something like 6 contests during the season that I can commute to from home - don't need a motel room. If you're a real Pattern junkie there is a contest just about every weekend within reasonable driving distance.
Drop me a line when you're settled and we'll get you hooked up with "The Carolina Mob".
It's a great area for Pattern. There is something like 6 contests during the season that I can commute to from home - don't need a motel room. If you're a real Pattern junkie there is a contest just about every weekend within reasonable driving distance.
Drop me a line when you're settled and we'll get you hooked up with "The Carolina Mob".
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Lee Davis
thanks for the info Lee, looking forward to meeting the MOB,,, haha. I'm sure you'll have me in a Temptation or Focus in no time. I'll be back in late may. see ya then! Eric