SrTelemaster150

I'm powering an 8# 1/5 scale J-3 W/an electronic ignition Saito FA91 & want to swing a 16-4 propeller for maximum thrust @ WOT & scale speed @ part throttle.

That 16" scales out to an 6'8" prop. What is the full sized propeller diameter for a J-3? Would a 16" prop look appropriate on a 1/5 scale Cub?

Truckracer

My Feedback: (19)

65 HP Cubs usually have 72' to 74" props ... you do the math. Depends on wood, metal, brand, or in a few cases what the owner had laying around to bolt on.

FLYINMIKE-RCU

My Feedback: (25)

If I Remember Correctly, The Standard Propeller On The Full Scale J3 Is 72" Which Would Make The Correct Scale Size For A 1/5 Scale J3 14.4 Inches.

SrTelemaster150

If I go 14 X 4 I will likely overspeed the engine if I go full power. Going 14 x 6 will make it hard to throttle back for enough for scale flight speed. I want the thrust for vertical performance when I want to play aerobat but still be able to float around like a full sized Cub @ part throttle.

A 15 X 4 prop should not look too far off. That would be 75" scaled up.

FlyerInOKC

My Feedback: (6)

I have a 1/5 scale SIG with a Saito .80 and a 14X4 prop.