ORIGINAL: Showtime100
da Rock, I read through the 4-blade thread in the warbird section and I am not sure if anything got resolved. I have to admit that I am asking only due to "cool" looks and not for performance. I don't need a 100mph PTS mustang, just one that won't be way underpowered. Would I need a larger 4-stroke or is it not that simple?
No, the "efficiency" discussion is not resolved. There probably won't ever be a clear comparison that shows clearly how little that "efficiency" sound byte "knowledge" really applies.
Problem is that we don't have truly similar choices for our props. The prop selection in 2blades is massive. We've usually got 3 choices of pitch for every diameter PLUS we've got maybe 6 manufactures offering those 3 choices for every diameter PLUS they often offer two or three different shapes. So each of us has no problem testing the available 2bladers, and there are thousands of fliers who have experience doing just that for exactly the engine we have. And some of them have tried different props for our engine AND our airplane. There is no problem with the depth of our data base of knowledge when it comes to finding a very good fit of 2blade to whatever airplane/engine we're interested in.
On the other hand, I just looked for a suitable 3blade for a couple of my models. I found ONE each. And they are expensive. The chance that those two props are going to effectively suit those two airplanes is little better than 50-50. And I've got to spend appreciably more to find out than I'd have to spend to try a couple of 2bladers.
So what does our huge modeling community actually know about 3bladers, given the situation ALL of us are in? Not too much. Except that a bunch have heard the sound byte wisdom, "more blades is less efficient". And have no reservation parroting it. And some have turned it into, "more blades suck" or simply blurt out whatever comes to mind.
And we suffer further from not having an accurate way to figure equality between 2blades and 3blades. There is one prop mfg who suggests the appropriate way to choose a 3blade is to reduce the diameter and increase the pitch. A bunch of our prop "experts" have missed the pitch detail and think it's correct to simply reduce the diameter and they've got equality. Ain't even close. And some of them even compare props of different shape and from different mfg. Again, it's apples and oranges when the subject is efficiency.
so what is the deal with the comparisons..............