With the ongoing threads about low cost racers, I have been perusing the engine sites looking for likely candidates. What do folks think about the Honda GX690 688cc V-twin? Listed at 22 hp at 3600 rpm it ought to gain a pony or two by removing the cooling fan, so call it 24 hp stripped down. That's not too high an rpm for direct drive and the engines seem very common. A simple conversion with wooden prop ought to run about $3,000 which makes a $10,000 plane possible.
Honda Engines | GX690 4-Stroke Engine | Features, Specs, and Model Info
Engine
Engine Type Air-cooled 4-stroke OHV
Bore x Stroke 78 X 72 mm
Displacement 688 cm3
Net Power Output* 22.1 hp (16.5 kW) @ 3,600 rpm
Net Torque 35.6 lb-ft (48.3 Nm) @ 2,500 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side)
Compression Ratio 9.3:1
Lamp/Charge coil options 2.7A, 17A, 26A
Carburetor Horizontal type, two barrel butterfly valve, internal vent
Ignition System Digital CDI with variable ignition timing
Starting System Electric
Lubrication System Forced lubrication
Governor System Mechanical
Air cleaner Dual element
Oil Capacity 2.1 US qt (2.0l)
Fuel Unleaded 86 octane or higher
Dry Weight 96.8 lb (44 kg)
Dimensions
Length (min) 15.9" (405 mm)
Width (min) 16.1" (410 mm)
Height (min) 17.2" ( 438 mm)
Honda Engines | GX690 4-Stroke Engine | Features, Specs, and Model Info
Engine
Engine Type Air-cooled 4-stroke OHV
Bore x Stroke 78 X 72 mm
Displacement 688 cm3
Net Power Output* 22.1 hp (16.5 kW) @ 3,600 rpm
Net Torque 35.6 lb-ft (48.3 Nm) @ 2,500 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side)
Compression Ratio 9.3:1
Lamp/Charge coil options 2.7A, 17A, 26A
Carburetor Horizontal type, two barrel butterfly valve, internal vent
Ignition System Digital CDI with variable ignition timing
Starting System Electric
Lubrication System Forced lubrication
Governor System Mechanical
Air cleaner Dual element
Oil Capacity 2.1 US qt (2.0l)
Fuel Unleaded 86 octane or higher
Dry Weight 96.8 lb (44 kg)
Dimensions
Length (min) 15.9" (405 mm)
Width (min) 16.1" (410 mm)
Height (min) 17.2" ( 438 mm)