Lycoming O 540

Design and development

Generally these engines produce 230 to 350 horsepower. They are installed on a large number of different aircraft types. Their main competitive engine is the Continental IO-520 and IO-550 series.

The AEIO version was developed for high-performance competition aerobatics aircraft. Starting at 260 hp (190 kW), the power was then improved to 300 hp (220 kW). The AEIO-540 family has achieved tremendous results in competition aircraft such as the Extra 300, CAP 232, and Zivko Edge 540.

Variants

All engines have an additional prefix preceding the 540 to indicate the specific configuration of the engine. There are also numerous engine suffixes, denoting different accessories such as different manufacturers' carburetors, or different magnetos.

O-540

Standard, direct-drive, normally aspirated Opposed engine, equipped with a carburetor.

IO-540

Normally aspirated engine with fuel Injection.

AEIO-540

Normally aspirated engine with fuel injection and inverted lubrication for Aerobatic use.

TIO-540

Turbocharged and fuel-injected.

TEO-540

Turbocharged with independent Electronic sensors and fuel injection controls for each cylinder which manage detonation and exhaust gas temperature making the engine compatible with a range of fuel compositions producing up to 350 horsepower.

LTIO-540

Left-hand (opposite-direction) rotation, turbocharged, fuel-injected; used as the right-hand engine on Piper PA-31-325 Navajo C/Rs and Piper PA-31-350 Chieftains to prevent critical engine control issues. Also used for the left hand side of the Aerostar 700P.

IGO-540

Gearbox at the front end of the crankshaft to drive the propeller fewer revolutions per minute than the engine, normally aspirated with fuel injection. Dry sump engine built specifically for the Aero Commander 560F.

TIGO-540

Turbo-charged, injected and geared

IGSO-540

Supercharger driven by the engine, gearbox to drive propeller, and fuel injection (up to 380hp).

VO-540

Vertically mounted engine for use in a helicopter, normally aspirated and equipped with a carburetor.

IVO-540

Normally aspirated engine with fuel injection, mounted vertically for use in a helicopter.

TVO-540

Turbocharged engine equipped with a carburetor, mounted vertically for use in a helicopter.

TIVO-540

Turbocharged engine with fuel injection, mounted vertically for use in a helicopter.

HIO-540

Helicopter engine mounted horizontally as in fixed-wing aircraft, normally aspirated with fuel injection; not used in any fixed-wing aircraft.

TIO-541

Same as a TIO-540, except the "1" indicates an integral accessory drive.

TIGO-541

Same as a TIGO-540, except the "1" indicates an integral accessory drive.

Specifications (IO-540-K1A5)

Data from FAA Lycoming IO-540 Series Type Certificate. Retrieved: 1 September 2008.

General characteristics

Type: Six-cylinder air-cooled horizontally opposed engine

Bore: 5.125 in (130.2 mm)

Stroke: 4.375 in (111.1 mm)

Displacement: 541.5 in³ (8.9 L)

Dry weight: 438 lb (199 kg)

Components

Valvetrain: Two overhead valves per cylinder

Fuel system: Fuel injection

Fuel type: 100 octane rating gasoline

Cooling system: Air-cooled

Performance

Power output: 300 hp (223 kW) at 2,700 rpm at sea level

Specific power: 0.55 hp/in³ (25.14 kW/L)

Compression ratio: 8.7:1

Power-to-weight ratio: 0.68 hp/lb (1.12 kW/kg)