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.

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

Bedford

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

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?

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 --

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