The Continental IO-346 engine is a fuel-injected four-cylinder aircraft engine that was developed especially for the Beechcraft Musketeer Custom III by Continental Motors. It was produced for that aircraft between 1965 and 1969.^[1]

There is no carbureted version of the engine, which would have been designated O-346 and therefore the base model is the IO-346.^[1][2]

The IO-346 was designed to run on 91-98 avgas. The engine has a dry weight of 269.75–297 lb (122–135 kg) including the generator and starter. The ignition system consists of dual magnetos, one Scintilla S4RN-201 and one S4RN-205 or, alternatively, two Slick Electro 449 magnetos.^[1][2]

IO-346-A

Base model, certified 27 July 1962^[2]

IO-346-B

Identical to IO-346-A except it incorporates provisions for a hydraulic propeller control. Certified 23 June 1964.^[2]

• Beechcraft Musketeer^[1]
• Gadfly E.S 102^[1]
• Piel Emeraude^[1]
• Stampe SV-4D^[1]

Reference: Engines for Homebuilt Aircraft & Ultralights^[1]

• Type: 4-cylinder air-cooled horizontally opposed aircraft piston engine
• Bore: 5.25 in (133 mm)
• Stroke: 4.00 in (102 mm)
• Displacement: 346 cu in (5.7 L)
• Length: 30 in (762 mm)
• Width: 33.38 in (848 mm)
• Height: 22.4 in (569 mm)
• Dry weight: 297 lb dry, with starter and generator (135 kg)

• Valvetrain: One intake and one exhaust valve per cylinder
• Fuel system: CMC fuel injection
• Fuel type: 91/98 octane avgas
• Cooling system: Air-cooled

• Power output: 165 hp (123 kW) at 2,700 rpm
• Specific power: 0.47 hp/in³ (21.2 kW/L)
• Compression ratio: 7.5:1
• Power-to-weight ratio: 0.56 hp/lb (0.90 kW/kg)

• List of aircraft engines