I was reading about the 60 size engine and the rpm was low 1200-6000 wow i do not think i have seen such a large engine with that low rpm forget speed iam guessing power for larger props and planes

RCV60-SP
Specification Imperial Metric
Manufacture CNC Machined from Solid
Engine Type 4-stroke - Glow ignition
Displacement 0.6 cu inch 10 cc
Max Power (approx.) 0.9 bhp 0.67 kw
Weight (exc. silencer) 20.7 oz 570 g
Length 4.11 inch 104.4 mm
Cowling Radius R36
Propeller shaft diameter 5/16" UNF
Practical RPM range @ prop 1,200 - 6000 rpm

Example Prop Sizes 2 Blade 14x14, 15x12, 16x12
3 Blade
13.4x13.5
4 Blade
13x13, 14.5x11
Recommended Fuel 10% Nitro / 15% Oil including max 6% Castor
price 269.00