Pusher Plane Prop
 

Good Morning ,
I have a pusher plane and have a APC 6x4 prop on it at this time , and would like to speed the plane up a little . I was thinking of replacing this prop with a APC 5x3 to speed up the plane but am not sure about this . Any advice would be appreciated , Thank You
David

Without knowing what powers the airplane, it is impossible to know what effect the prop change will have. What is the engine?

If you are talking .049/.051 power, then there is about a 9.5/10 chance changing to the 5-3 will speed things up. 6-4 is a very high shaft load for nearly all .049's and clamps down the rpm and power.

The Grish company sold a yellow nylon pusher prop of around 5 x 4 size. They are a swap meet or ebay item now. I've cut this one down to about 4.25" for a .049 powered pusher speed plane project. A decent TD should tach about 22-23,000 rpm.
You can also take your 6 x 4 APC and chop it down to experiment a little bit, but APC props work best if you can find the correct size to begin with.

It would be good to know what the engine is. With luck it's a reedie and he has a whole catalog of props available.

Thanks Everyone

Don't forget 2 strokes will run hot with excessive shaft load, so when you then put that in a pusher setup you have potential for a temperamental arrangement. So if this is a Cox .049, I'm not a fan of that 6-4 (even in a tractor setup. Let 'em spin, keep 'em cool and happy - 5-3 good prop. I'm not saying it is a disaster waiting to happen, just not a direction I would be comfortable with.

If it is something else.. then what is it rcdf?