av8tor1977,
i just read your post about engine efficiency and prop size, i dont mean to be adverse here at all but i just thought i would give my two cents. the word efficiency as you are using it sounds like static thrust efficiency. it is true that as far as static thrust numbers go, a heavy, low horsepower motor can make more thrust than a lighter high horsepower motor. emphasis on the heavier and lighter wich has to do with torque at the crankshaft. but in defense of the sweet little modern engines, they are designed to be efficient along a wide range of flight envelopes, not just static thrust wich is mostly felt during takeoff or any other low airpseed situation(hovering). try this next time you are out on the field so you dont have to take my word for it. take any aircraft and put a small high pitch prop on it fly it around a little, then put a big low pitch prop on it. the small prop sure did go fast, but the big prop doesnt go as fast, which one is more efficient? it all depends on the way you use the word, if i am a speed man then the small prop is efficient. but anyhow i just wanted to make my wife mad by sitting here and writing this. but physics in general is no walk in the park much less the part of it that is aerodynamics, heres some useless info for ya did you know that out of all the engineering fields aeronautical engineering uses the most math! thats scary, i am glad i am just a user and a fixer.