The ECi O-320 is part of a family of normally aspirated, air-cooled, four-cylinder, direct-drive engines developed for certified and experimental aircraft. Its cylinders are arranged in horizontally opposed configuration and a displacement of 320 cubic inches (5.24 L). It is based on the Lycoming O-320 engine with ECi cylinder assemblies.^[1][2]

Design and development

ECi developed engine kits starting in 1995.^[3]

Variants

O-320 series

ECi O-320

154 hp (115 kW) at 2700 rpm, Minimum fuel grade 100/100LL avgas, compression ratio 7.0:1. Certified Applications

ECi OX-320

154 hp (115 kW) at 2700 rpm, Minimum fuel grade 100/100LL avgas, compression ratio 7.0:1. Experimental Variant

ECi IOX-320

156 hp (116 kW) at 2700 rpm, Minimum fuel grade 100/100LL avgas, compression ratio 7.0:1. Fuel Injected Experimental

Applications

Specifications (ECi O-320)

Data from ECi

General characteristics

• Type: Four-cylinder air-cooled horizontally opposed engine
• Bore: 5.125 in (130.18 mm)
• Stroke: 3.875 in (98.43 mm)
• Displacement: 319.7 cu in (5.24 L)
• Length: 29.07
• Width: 32.27
• Height: 24.8
• Dry weight: 244 lb (111 kg)

Components

• Valvetrain: Two overhead valves per cylinder
• Fuel system: MA4-5 Carb
• Fuel type: minimum grade of 100/100LLavgas
• Oil system: Wet sump
• Cooling system: Air-cooled

Performance

• Power output: 154 hp (115 kW)
• Compression ratio: 7:1