I agree with you in that engine manufacturers misstate their specs, and support them with all kind of unrealistic paper calculations, and voodoo mathematics. Even the automotive industry was recently forced to adopt a more realistic standard of calculating HP figures. Until recently the industry measured their engines bare, no accessories, or transmission. The recent adoption of ISO standards has forced them to measure power at the drive shaft.

It would be nice if hobby engines manufacturers standardized their testing and supported their allegations with factual dyno testing, using specific props and muffler combinations. In my experience the most accurate measure of engine performance is how much thrust an engine/prop combination can produce. Evolution states the 58 can turn a 26x10 prop. I doubt that it will turn it more than or even close to 6000 RPM. But we don't know how much thrust it will produce. I also doubt that a ZDZ 60 will turn a 22x10 at 7300 RPM and put out 36.79 Lb. of thrust in the process. Are there any reliable "field observations" to support this claim?

The bottom line is that the "ideal" engine taken wingloading in consideration should provide a considerable difference in thrust to weight ratio. Even an 18 Lb. plane powered 2:1 thrust to weight ratio will fly ballistic. A 10 pound brick powered by 100 Lb. of thrust will fly like a missile (i.e. the F-104, the Saturn rockets, etc.) If a 4.75 Lb. engine can produce over 40 Lb. of thrust, I will consider it as very viable powerplant for up to 33% models. Leo Loudenslager vision in building aerobatic planes was to keep the airframe weight as low as possible and the power as high as the airframe could withstand.

You are correct in that the proof is in the pudding. And there is very little data out there on the Evolution engines. So we will have to wait and see what they really can do in real life.

Remember the old cliché, When it comes down to engine power: Lots is good, more is better, and too much is just enough.