Prop size
 

Hi all, just need to clear up a couple of things. I have a RCS 215. The "Test Run" sheet that was included with the engine shows it was bench tested with a 32-18 prop. Now what I would like to know is what effect would putting a 32-12 prop on engine have?. I know there are other factors to consider but when I asked Mike at RCS what prop he would recommend he said a 32-8 and others say that is way to small a pitch for my applacation. I have flow my Waco on a 32-8 and it seemed fine, but I also have used a 32-12 on it and that worked too. Just want to be sure I'm not doing the wrong thing.

RE: Prop size
 

The 32x8 would make for an awfully powerful brake at idle on approach.

Bedford

RE: Prop size
 

Thanks, but why the braking power over a 32-12? I don't understand this concept. With a big bi-plane and all the built in drag in bi-planes wich would be a better choice of props? I fly the thing very easy with just a few loops and rolls nothing that requires a bunch of power ALL the time. After all it is a 1930's design aircraft. The 215 puts out so much power that I fly this 46 pound plane at about 1/3 power after take off.

Thanks

RE: Prop size
 

A 32x8 will provide a lot of braking at idle due to the 8" of pitch which is very low for a prop this size. The pitch is the theroetical distance the prop will travel thru a viscous liquid in one rotation, hence the lower the number the slower the plane generally speaking. Hope this clears it up somewhat?

RE: Prop size
 

the lower pitch prop is less load on ths engine - so heat build up in cylinders will be less - that is likely why Mike recommended it
-If you set mixture correctly and use throttle carefully (as you mention) - use any prop you like which will make good performance for you and not overspeed or over tax the engine -
the relative prop drag on that model is pretty small.
I would suspect you don't do much full bore flying --

RE: Prop size
 

Yes that is right. I don't use full power except for go arounds and some loops. other than that I fly the engine at about 1/3 power.
Thanks for the info.
Steve