4-stroke = more torque?

Discussion in '4-Stroke Engines' started by iwasgandhi, May 30, 2014.

  1. iwasgandhi

    iwasgandhi New Member

    The Honda GX35 4-stroke (with 1.6 hp) has 37.5% less horse-power than than the Tanaka PF-4000 2-stroke (with 2.2 hp), but does that mean it also has less torque for climbing long, steep hills at lower speeds?

    I ask becaue I'm trying to decide between the two engines for a Staton-inc axle mounted kit which I plan to purchase next week. I used to own a Staton axle kit with a Honda GX35 on it, but I wasn't satisfied with the torque for the hills in my area, even when gearing my kit for the slowest speed/most torque.

    A larger 4-stroke, such as the Honda GX50 is not an option for me. There are various reasons for that, but that's another story.

    I've read on motoredbikes.com that some people think that a 4-stroke, such as the Honda, generally has more low-end torque than a 2-stroke. Is that true and, if so, is it true for these two engines in particular?

    Thanks for any info and insights. :D
     

    <
  2. butre

    butre Well-Known Member

    horsepower=(rpm*torque)/5252

    you should be able to find out which has more torque by reversing that formula
     
    Steve Best likes this.
  3. wheelbender6

    wheelbender6 Well-Known Member

    In general, 4 strokes make torque and 2 strokes make horsepower.
    In general, 2 strokes rev higher.
    In general, 4 strokes use less fuel per mile.
    However, four strokes can be tuned for high rpm and two strokes can be tuned for more torque if you are willing to spend enough money.
     
  4. Fabian

    Fabian Well-Known Member

    :iagree:

    My Chinese 2-stroke centre mount engine gives a surprising amount of torque with a reed valve intake system; fighting strongly all the way down to 2,200 rpm and will pull down to 1,600 rpm, with the engine stalling at 1,500 rpm; all at wide open throttle.

    Without the reed valve system, the engine is dead in the water at anything below 3,000 rpm
     
  5. darwin

    darwin Well-Known Member

    OP Staton sells a mits 43cc clone that will work with your axle kit, might check it out. It's priced right too.
     
  6. jaguar

    jaguar Well-Known Member

    torque=(horsepowerx5252)/RPM

    4 strokes have a more linear power/RPM graph than 2 strokes but generally speaking a 4 stroke has the same peak power as a two stroke with half the engine size.
    But 2 strokes can be modified much more than a 4 stroke for whatever you want it to do. You are pretty much stuck with the stock package when you buy a 4 stroke.
     
    Steve Best likes this.
  7. poolpool1

    poolpool1 Guest

    ADD AN OCTANE BOOSTER< IT HELPS>> MUCH MORE TORQUE< BUT GETS HOTTER<< MUCH BETTER POWER..RACE GAS IS EVEN BETTER IF U CAN GET IT 1o5 octane rocks..
     
  8. poolpool1

    poolpool1 Guest

    an octane booster really helps, but bad for carb gaskets. melts em. but u get 30 % beter mpg too way higher torque for hills pick up on throttle
     
  9. jaguar

    jaguar Well-Known Member

    go to Google images and look up dynos and take note of how the curves of 2 and 4 strokes vary.
    4 strokes have a fairly linear power graph till peak power whereas 2 strokes have more of a logarithmic graph which shows how weak they are at low RPM
     
  10. CrazyDan

    CrazyDan Active Member

    The higher the octane the slower the burn so it produces less heat and power. You only use higher octane when compression is increased or anything else that may cause predetonation. The lower power is acceptable because the other option is a blown engine. You sir, are backwards...
     
  11. butre

    butre Well-Known Member

    unless that octane booster happens to contain hydrazine then none of this info is anywhere near correct
     
    Steve Best likes this.
  12. KCvale

    KCvale Motorized Bicycle Vendor

    Exactly.
    Octane inhibits per-combustion in really high compression engines and just a waste of money on comparatively low compression MB's.
     
  13. Old Bob

    Old Bob Member

    Octane only resists unstable compounds from forming, the rate of burn and combustion temp values of high and low octane fuel are virtually the same. Rate of burn is within 1meter/second and temps are within 50-100° C

    This relates to pump gas, real race gas can be had in slow and fast burn rates.
     
Loading...