Ok i'm looking for Propellers Sizes. I have a 26 CC gas engine that i want to put a 3 bladed prop on. It currently has been running a 16X8 2 bladed prop. The recomended prop sizes for the engine are 16x8, 16x10, 18x6, 18x10.

But remember reading somewere in these Forums that when you switch to a 3 bladed prop the Diameter is smaller and pitch. Dont know if that is correct or Not . Suppose i wanted to go to a 4 bladed prop.

Is there a link to a forum and thread that has this information already?? That would be the easiest way i just cant find it. Or is there Someway to Gauge this??

I purchased a Master Airscrew 15x7 3-Blade G/F Nylon Propeller. to experiment with. and 2 normal props for the engine.

Master Airscrew 16x6 Maple Wood Scimitar Propeller

Master Airscrew 18x6 Classic G/F Nylon Propeller

Just in case the 3 balded doesnt work out. But would really like to learn more about how to guage propellers.
About all I know is the 15 is the diameter and the pitch 7 is suppose to be a measurment of the fluid dynamics.

7 inches for each complete 360 degree revolution. I picture it like this probably wrong but when the plane is flying it will move 7 inches foward for each Complete 360 degree revolution of the prop like a screw boring into a peice of wood with a certain pitch will bore into the wood so far for each 360 degree turn.

Well any help here would be Appriciated. A link to another Forum or your experiences with Sizing and gauging Propellers i know that there is alot more to it. ways to measure Thrust Ect.

I'm sure it can get quite in depth.

Thanks Link