I took my own advice and put an APC 16 x 8 prop on my Ryobi in the Tiger Moth today. The engine is still breaking in with only about 4 tanks of fuel through it, and it's still puking out some black slop so I know it's not "there" yet. But it just sounded like it was lugging a bit with the 18" prop even though it came up to about 7300 rpms. It turns the 16 x 8 prop at about 7600, and the engine just sounds happier. I know I'll like the extra speed as before the Tiger Moth was flying near full throttle all the time. Now I should be able to throttle back and cruise like I mentioned, with that extra in reserve for when I want to do a maneuver. We'll see how it does with more run (break in) time. Then I may go back to the 18" prop.

Static thrust increases with prop diameter and lessened pitch, but I swear the APC 16 x 8 pulls harder than the Top Flite 18 x 6. I didn't take the time to dig out my fish scale, but it sure seemed to be pulling noticeable harder on my tie down rope!! Now to find the time to get it out and test fly it again!

AV8TOR