Differences in small 2 stroke engines

Discussion in '2-Stroke Engines' started by DetonatorTuning, Sep 13, 2009.

  1. DetonatorTuning

    DetonatorTuning Active Member

    i had lots of experience with 2stroke dirt bikes and Yam. RZ350's on the street back in the day but have only been involved in the "micro" 50cc range engines for the past couple yrs.

    i've been using a 46cc GP460 exclusively that makes 4.2 HP and 2.35 #'sFt. TRQ. and been surprized at how well this level of power will move a bike when coupled to an appropriate gear ratiio. this engine will move my bike 50mph at13500rpm using a ratio of 20.91:1

    what intrigues me is the level of performance increases achieved thru various tuning practices within this displacement group.

    an engine i'm interested in currently is 8% larger (49.something cc's), uses the same CR and makes 40% more HP, 60% more TRQ. and the peaks for both are only 500rpm apart rather than 3,000rpm for the GP460.

    this engine should be able to move me 50mph @ 9000rpm using a 13.89:1 ratio, achievable in a single step, no jackshaft needed.

    i know many are challenged and upset by this kind of speed being discussed and i only report them as reference for my target constant cruising speed of 40mph, because although i had good performance and economy from the GP460 at that speed, this new engine should be able to provide it while in a much less stressed operating condition.

    end of ramble, please resume riding.

    Last edited: Sep 14, 2009

  2. spad4me

    spad4me Member

    Are you talking about a skopod 60?
    A dax mount with a 13 or 20 to 1 ratio, powered by a Mystery engine.
    The old badness 57.6 the new creamy goodness or else <20
    At least I will stop melting variator weights .
    Good luck..
  3. DetonatorTuning

    DetonatorTuning Active Member

    i saw a mistake in the TRQ reference and changed it. i had been comparing the 2.3 of the 460 to 5 Nm rather than it's 3.68 #sFt. equivelant.

    the dax mount was an idea for something unrelated to this engine.

  4. V 35

    V 35 Member

    You must have some terrific roads to go that fast. Here in Mass. the roads are too lumpy to even think of those speeds.
    On the roads not torn up too bad, the ' occasional ' dip can really sting. Sure, we have some excellent roads, but they
    are heavily traveled by distracted drivers . If I want to ' book ' I go to the industrial park on weekends, smooth pavement,
    no traffic, the wonderful sound of a 2 stroke echoing between buildings .