Ed, "If you turn 2400 rpm, your speed should be about the same, maybe exactly the same as if a C-85 or C-75 were turning the same prop the same rpm."
I think you are probably correct there. I hadn't really though of it in those terms, but the speed at which the prop turns governs the thrust it produces. The new engine will be working less hard (more torque per revolution) than the old engine. To see a curise benefit, I would have to re-pitch the prop, which I may do after evaluating the pro/con. Spinning the engine faster is not authorized because it's still a C-85, although theoretically it should be physically able to run at the 2750 O-200 limits. But I can potentially run at the recommended O-200 cruise RPM of 2500 and stay under the C-85 2575 limit. Later, Dave --- In [email protected], "Ed Burkhead" <e...@...> wrote: > > > > Dave, > > If you turn 2400 rpm, your speed should be about the same, maybe exactly > the same as if a C-85 or C-75 were turning the same prop the same rpm. > > If you move through the air faster without changing the airframe, you'll > need to expend more fuel. If you are willing to burn the fuel, you can > get cruise speed improvement from spinning the engine faster. > > Your climb with the C-85/O-200-crank engine should climb better and > owners report significantly better climb (though I'm always skeptical of > self-reported improvements. > > The Kinney wheel pants haven't been reported to provide much if any > speed improvement as they were designed without benefit of aerodynamic > software or wind tunnel. > > Mark Huesden installed a new windshield that has a much milder slope, > extending forward almost to the fuel cap. He's done some other things I > can't itemize. > > Ed >
