We used the Omaka based Sopwith Pup which is fitted with a Cams new built Gnome 100 HP Monosoupape engine to trial 2 different props. The first prop is what it normally flys with and the second prop is slightly larger and also has more pitch. Engine speed is slightly lower with the larger prop, performance is also a little better. Have only cut out a little part where we changed props in the middle so video is basically uncut and there is a lot of time taxiing which you may want to fast forward through.