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Two piston or 4 piston engine

  1. Dec 22, 2009 #1
    suppose a bike which has 2 piston engine and other is 4 piston. which one is most powerful?
    thanks
     
  2. jcsd
  3. Dec 22, 2009 #2

    mgb_phys

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    Depends on the capacity of the cylinders - you can build high power 2 cylinders and low power 4 cylinders.

    Other than that it's a design decision.
    2 cylinders are smaller and simpler, 4 cylinders allows a smaller capacity/cylinder so they can move faster and so rev higher.
     
  4. Dec 22, 2009 #3

    brewnog

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    Bikes painted red are always faster than bikes painted yellow.
     
  5. Dec 22, 2009 #4

    mgb_phys

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    Unless the yellow ones have noisier exhausts
     
  6. Dec 23, 2009 #5
    Code (Text):
    Bikes painted red are always faster than bikes painted yellow.
    what is the reason behind that?


    let me explain in different manner,
    A bike of 100CC with 4 stroke engine
    a bike of 100 cc with 2 stroke engine

    Now which will be more powerful and fast
     
  7. Dec 23, 2009 #6
    The one where the driver only ate half his burger for lunch.

    It's a totally pointless question, as it relies on so much more than how many cylinders it has. Tuning, gearing, size, weight etc etc etc.
     
  8. Dec 23, 2009 #7

    brewnog

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    Indeed, there are far many more variables than number of cylinders and capacity, making yours an impossible question to answer (hence my comment about colour). If you have a quick look round here there are some excellent posts on all the things which go in to engine power output and vehicle speed.
     
  9. Dec 24, 2009 #8
    2 stroke engines are generally more powerful than 4 stroke engines...
     
  10. Dec 24, 2009 #9
    Oh, I really fail. I'm sorry OP you changed and clarifired the question, but I just read it as 2 cylinder 100cc not 2 stroke.

    2 strokes are more powerful becuase each cylinder fires every crank revolution, as opposed to firing once every 720 deg in a 4 stroke. EDIT: In general.
     
    Last edited: Dec 24, 2009
  11. Dec 24, 2009 #10

    brewnog

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    But it's a generalisation, there are plenty of four stroke engines more powerful than two strokes of the same capacity.

    The answer is: "It depends".
     
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