laser...@juno.com wrote: > I was just looking at a "Cleanex" with the 3100 Corvair (120 HP in his > specs) and it would appear your plane does significantly better with this > engine than the Sonex does. http://www.cleanex.cmsdreams.com/ss1.pdf
I didn't see a cruise speed listed on that page, but it's common knowledge that a KR is faster than a Sonex or Cleanex, as well as most of the other VW powered competition. KRs are smaller and more aerodynamic, generally speaking, Joe Horton's flown with Chris Smith and Dan Weseman, and can tell you that he has to throttle back so they can keep up. And it also depends on your definition of cruise speed. The most accepted standard for cruise speed is the max true airspeed the plane can achieve at 75% while straight and level steady state. Some folks think cruise speed is how fast you can go wide open, and then there are all kinds of "economy" cruise speed ranges discussed (usually economy is something like 55% power). How do you find out your cruise speed? It turns out that on a standard day (29.92" barometric pressure, 59 degrees F at sea level) if you fly at 7500' wide open, you'll be running at about 75% power. So whatever your top speed is at 7500' is your 75% cruise speed. On days that are different than a standard day, and for altitudes different from sea level (that's just about all of them), some adjustments have to be made to compensate for the variations in atomospheric pressure and temperature. It should also be mentioned that "indicated" airspeed is not what is meant by cruise speed...that number is used (assuming it's accurate, or "calibrated airspeed") to calculate true airspeed based on the local pressure and temperature variation from "standard". And then there's always three way GPS verification, assuming the plane is flown at an altitude that is equivalent to 7500' on a standard pressure and temperature day. If you have a manifold pressure gauge, it can also be helpful to determine when you engine is producing 75% power. Mark Langford N56ML "at" hiwaay.net website at http://www.N56ML.com --------------------------------------------------------
