High RPM

Discussion in 'Yakima' started by Duck, Sep 20, 2012.

  1. Duck

    Yakima, WA
    So a question for everyone: What is the highest revving motorcycle currently in production? And before some smart-ass comments about how RPMs don't equal power or speed, I don't really care and that's not the question.
  2. My 06 r6 had a 17500 red line!

    And rpm absolutely equals hp. There are only two other numbers that are part of the formula and one is a constant.
    #2 fastfoodfred, Sep 20, 2012
    Last edited: Sep 20, 2012
  3. king_ogre


    Engine: Rolls Royce Allison, 250 series gas turbine
    Power: 320-HP @ 52,000-rpm, (286-HP @ rear wheel)
    Torque: 425-ft/lbs @ 2,000-rpm

  4. WaGigKPN

    Gig Harbor, WA
    I Ride:
    2000 XR650R
    I imagine other bikes will max out around there as well. In order to get the 20k+ RPM you need to have pneumatic valve "springs" IE, valves are pushed back by compressed air, not springs. I heard F1 car engines before all the rules were made were getting engine rpm's of close to 30k! (have not fact checked that, i am sure you can google it)
  5. WaGigKPN

    Gig Harbor, WA
    I Ride:
    2000 XR650R
    and the other being??? Displacement...

    I dont know the formula but i really doubt its just rpm displacement and a constant...There are so many other variables...right?
  6. Hp=rpm x lb/ft / 5252

    That's it. Rpm times torque divided by 5252 equals hp.
  7. If you can increase rpm without sacrificing torque too much, or increase torque, you will have more hp.
  8. WaGigKPN

    Gig Harbor, WA
    I Ride:
    2000 XR650R
    Learn something new everyday...thanks.
  9. RPM will dictate HP only in the relationship of how fast you can generate RPM.
    If HP is how fast an engine will make power and torque is how much work it will do, this applies. The only constant is the torque and horsepower will always cross paths at a 5250 rpm and HP will continue to rise and torque will drop (I suppose there may be a few exceptions to this rule as this formula is specific to piston driven engines).

    From what I remember, Cosworth got an F1 engine to run a little over 20,000 RPM years ago but the issue was not mechanical but rater the inability to get any more air into the engine without forced induction. This means they have gotten air to travel at terminal velocity into the runners and it simply could not "pull" any more air in.
  10. Big T

    I believe the early Honda RC racers, like the RC149, revved to 20k back in 1966
    fastfoodfred likes this.
  11. http://www.youtube.com/watch?v=eaRop_ZMwo0

    here is an RC166, 250 cc. I believe it rev'd over 21,000 rpm. the tach is marked at only 18k, but I am looking now for real info. the end of the video sends chills up my spine.

    edit*- I guess it's merely 18 grand.
    #11 fastfoodfred, Sep 20, 2012
    Last edited: Sep 20, 2012
  12. Uhhh, no. The formula is applicable to anything in rotary (as opposed to liner) motion.

    It is the rotary version of: (force x distance) / time = power
  13. at 60 hp, this thing cranked out a whopping 17.5 lb/ft or ground pounding torque. its all about rpm! in other words, it could almost make a bolt finger tight.

    torque is what flips your feet out from under you when you bend your pecker into the toilet with morning wood
  14. DiveR-1

    DiveR-1 Mr. Pecs

    Medford Oregon
    Those particular R6's actually redlined at 16,000 rpm. That redline was about 1500 RPM optimistic. here's the link to a roadracing world story from a few years back. http://www.roadracingworld.com/news/article/?article=25009
  15. Yes but with no RPMs... so no horsepower; only hosepower.
  16. That RC166 was a 6 cylinder 250cc's. Think about that for a second.
    If I remember right it was like 10mm bore and 9 or 10mm stroke.
    Oh yea, it was 4 valves per cylinder too. The valves looked like stick pins.
    If you take a 1/4" drive 8 or 9mm socket that's about the size of the piston.

    Yes rpm is everything. More RPM, more power strokes per minute.
    RPM has a lot to do with flame front travel. How long does it take for the charge to burn from one side of the piston to the other. The bigger the bore, the longer it takes. Bigger bore = heavier parts = slower revving.
    Tanker ships make huge amounts of power but only run at like 250-300 rpm with a 6' bore.
  17. I always loved the sound the RC166 made, just awesome. There isn't a idle circuit on the carbs for the RC166, probably why you will never hear one idle below 5,000 rpm. Fascinating.


    The Honda NR500, although unsuceesful, it ran at 19,500 rpm in race tune for 81.

    http://www.motorcyclespecs.co.za/model/Classic Racers/honda_nr_500_gp_racer_1979.htm

    But the '66 RC116 was 21,500 rpm putting out 16hp with 50cc's. Pretty incredible.

  18. I believe the ZX2R revs to 20,000. Highest that I know if for a motorcycle.
  19. Well maybe not quite that small, but...
    Just found this neat rc166 writeup.
    Exact specs are apparently more than a quick google search away.
    Think about it though, 10mmx10mm x 6 cylinders won't get you to 249cc.
    I so want one of those bikes.
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