RE: HELP! Prop for O.S. 1.60FX
There's a thread about propping this engine that was started over a year ago and Aerosplat tried a number of props out, search for it and grab a cup of coffee.
If I remember correctly the APC 18 x 6W was the king of thrust for this engine but since the prop is pretty heavy it has a pretty slow spool up. For 3D flying having that throtttle response is probably more important than the extra thrust that the APC provides. Now if your not into flying 3D none of that matters.