2-stroke Boxer Twin Cylinder Engine

Discussion in 'General Questions' started by Fabian, May 18, 2013.

  1. Fabian

    Fabian Well-Known Member

    Last edited: May 18, 2013

  2. Samdallas214

    Samdallas214 Member

    still a dam find engine
  3. darwin

    darwin Well-Known Member

    Notice the weight, 1.4 kg. That's close to 3lbs. Must be an RC engine. Can't figure the dimensions if they're in centimeters or? Each cyl is 26cc, very confusing........1kg =2.2 lbs.
  4. Fabian

    Fabian Well-Known Member

    Don't worry about being confused.

    It makes 5.5 horsepower - that will fix all of your confusion

    I'm in :tt1: with that concept.
  5. darwin

    darwin Well-Known Member

    If that motor weighs 3lbs you better put it on a kids trike, have fun.
  6. Fabian

    Fabian Well-Known Member

    A standard Chinese bicycle engine wouldn't weigh much less; might even weigh more?
  7. darwin

    darwin Well-Known Member

    Honda 35cc weighs 7lbs, if you remove the gas tank and all plastic it looks like a toy motor. I think that weight is wrong. Chinese descriptions often are.......me thinks Fabian messed up. That's an R/Cmotor for a boat or? Look at the website name, Hobbyking.
  8. Fabian

    Fabian Well-Known Member

    It is an R/C plane motor, but i can't see why it could not be adapted for motorized bicycle use. The engine could be mounted vertically along the seat post tube or on the downtube?
  9. darwin

    darwin Well-Known Member

    That would be interesting and cool if you could make it work.
  10. wheelbender6

    wheelbender6 Well-Known Member

    The vintage Maytag twin cyl engines looked somewhat similar. Maybe we could study a Maytag build to get some guidance on mounting the the little HobbyKing twin.
  11. Fabian

    Fabian Well-Known Member

    It would be really interesting and super cool if SickBikeParts could get it to work with their shift kit :evilgrin:
  12. 5-7HEAVEN

    5-7HEAVEN Active Member

    1 kg (kilogram) = 2.2 LBS. 1.477kg = 3.25 lbs. Two 26cc cylinders = 52cc.

    The CY460 engine I've mounted on my MB's is also used in radio-controlled hobby toys. The key to an inexpensive fit is that it utilizes the conventional 76mm clutch. To retrofit that clutch to any engine would be VERY expensive. Gopedders have done so on the GP62 R/C engine, at a cost of close to $1,000.00.

    Update: This might be a better choice, albeit much wider:


    It's 6.38lbs., uses a 54mm clutch. You'd need an adaptor to convert to 76mm clutch, but easier than the Boxer twin.
    Last edited: May 20, 2013
  13. Skyliner70cc

    Skyliner70cc Active Member

    Since we are talking RC model airplane engines, how about this beauty? http://www.rcslot.com/pc-radio-control-slot-cars/EVOE7260.html?gclid=CMOmssaeprcCFcU7Mgod8kUAbA

    The problems with RC engines:
    1. Most require battery power for CDI/spark
    2. Will most likely overheat in a bike application (high power, small cooling fin area, require high forward speed and prop wash for cooling
    3. Better suited for constant speed and may not have torque desired for our applications without reduction gearing.
  14. Fabian

    Fabian Well-Known Member

    :bigcry: Skyliner you perfectly rational logic is getting in the way of my starry eyed dreams :bigcry:
    Last edited: May 20, 2013
  15. Skyliner70cc

    Skyliner70cc Active Member

  16. 5-7HEAVEN

    5-7HEAVEN Active Member

    I have used this engine with great success:


    No batteries needed, no overheating. My friend ran his without any shrouds. Enough power for bike applications w/friction drive, Staton drive, but REALLY shines w/NuVinci or shift kit with optimum gearing. Driveability @ any speed. In fact, I'm building a 460 R/C powered bike as we speak.
  17. HeadSmess

    HeadSmess Well-Known Member

    i dont even need to look at the motor, i know exactly what it is.

    ideal, except the boxer part makes for length...

    r/c engines. my drawbacks are gunna be different.

    theres the length of it being the boxer.

    widthwise, theyre great. smooth, grunty, and that 5.5hp is without pipes... :D

    on singles, theyve removed the fan and replaced the cdi with a nice low profile hub.

    the hub is a hub and not a flywheel. the prop is the flywheel. so they need a flywheel attached. some kind of weight.

    starting is hard as, with a prop, you generally flick it or use a nosecone starter. once you use a centrifugal clutch, there goes clutch starting. tricky.

    theyve generally got no provision for a pull starter. fuji/imvac comes to mind. its a standard robin/subaru (subaru is fuji) with a modified flywheel (no shroud) and the starter has been removed, used for a mounting plate. cranks cut short. it also costs twice the price? go figure...

    use a slip belt clutch or some other type of manual clutch, and you have a sweet engine :)

    having no starter and a short crank means they will fit between the cranks on most standard MTB's... if you want to go with an "in frame" build.

    cooling is usually fine, youre meant to be moving on a pushy. simple air shroud can be made easily if worried.
  18. IbedaYank

    IbedaYank Member

    rc airplane motors have no flywheel or clutch... also gearing down a 15,000 rpm motor to use on a bicycle would be a challange. Not to mention how you would start one as they have no recoil starter
  19. HeadSmess

    HeadSmess Well-Known Member

    these larger petrol engines run at much the same as a brushcutter...9000 rpm usually being rated operational speed. on a plane, its about torque to spin big high pitch props, not small ones. the small nitros might get anywhere up to 20K for competition use(and cars get much higher), but aerodynamics tends to make them ineffecient on simple prop drives. gotta keep the tips below the sound barrier! ducted fans are a bit different. unloaded and loaded speeds are also different. what might make max power at 9 will easily overev to 15 on a dive...

    the starting is an issue but using a manual clutch gets around that, just like the HT's... simple slip-belt would be easiest to implement.