RCU Forums

RCU Forums (http://www.rcuniverse.com/forum/)
-   Questions and Answers (http://www.rcuniverse.com/forum/questions-answers-154/)
-   -   2 stroke or 4 stroke? (http://www.rcuniverse.com/forum/questions-answers-154/11302146-2-stroke-4-stroke.html)

johndavis 11-18-2012 08:26 PM

2 stroke or 4 stroke?
 
was wondering the positive's and negitives of both.

jester_s1 11-18-2012 08:49 PM

RE: 2 stroke or 4 stroke?
 
In a nutshell...

2 stroke positives: More power for engine size and weight, simpler operation, lower price, higher RPM performance for high speed flight
2 stroke negatives: peaky torque curve, less fuel efficient for the horsepower it makes, sounds like a constipated mosquito

4 stroke positives: more torque for turning larger props, accelerates faster and more smoothly, more fuel efficient, sounds more like a real airplane engine
4 stroke negatives: costs more, often heavier for the same amount of power, must be roughly 25% bigger to make the same power, valves have to be adjusted right, tuning requires a little more skill, tops out around 10k rpm so has a much smaller RPM range.

Gray Beard 11-18-2012 09:35 PM

RE: 2 stroke or 4 stroke?
 
Depends on the brand of the engines too. I don't see a negative with either except price. I just like four strokes better then two strokes, good four strokes. I have found a cheap two stroke I like a lot too.

JohnBuckner 11-19-2012 04:36 AM

RE: 2 stroke or 4 stroke?
 
Entirely dependant upon the mission of the airplane and I do use and fly a wide variety of just about every power system type that has ever been used, but for basic sport flying I much prefer the "Constipated Mosquitos":D

John

jetmech05 11-19-2012 05:31 AM

RE: 2 stroke or 4 stroke?
 
I think jester nailed it

jester_s1 11-19-2012 05:50 AM

RE: 2 stroke or 4 stroke?
 
I agree with you JohnBuckner. The 2 stroke is really the best power system for most planes simply due to its light weight and big RPM range. 4 strokes make sense when you need a lot of torque to spin a big prop (like on 3D aerobats) or want a full scale sound.

johndavis 11-22-2012 06:29 PM

RE: 2 stroke or 4 stroke?
 
thank you for your great responces. im going with the 2 stroke . i have experience with the 2 stroke engines i race rc cars. i have never been around the 4 strokes i will try one of them later on after i learn how to fly. im going to build my first airplane for the experence of doing it. and building your own will teach me how to repair it after i crash it a time or two. lol


All times are GMT -8. The time now is 05:51 AM.