Not to start an argument, but I have to disagree ; ) How a prop works on a particular airplane is based on the amount of air moved (past the cowl, not smashing into it) and the velocity of that air. I have never been able to find a real reference to the ?large diameter prop=better climb? theory nor have I seen it work in real life.
On Pete?s KR, the Cloudcars 52x54 out climbs the 56x52 Sterba. Lots of factors there, but to sum up, the smaller diameter allows the engine to spin up more and make more power. The increased pitch makes up for the lesser disk area. On my SI, I have tried about 2 dozen prop variations from a 54x42 down to a 47.75x50. Climb performance between the two are about the same, but the top speed is radically more with the later. I?m not saying that a prop that small would work on a KR since the frontal area is greater. I would be curious to hear from someone that has experimented to find just how small of a prop is still effective on a KR. I recently put up some prop, climb and speed data on my blog here: http://schmleff.blogspot.com/2014/04/skye-racer-history-part-1.html Jeff Lange Race 64 - Skye Racer Blog:?http://schmleff.blogspot.com Youtube Channel:?https://www.youtube.com/schmleff On May 9, 2014, at 10:47 AM, tommy waymack via KRnet <krnet at list.krnet.org> wrote: > The longer the prop the better climb performance of the aircraft. >
