The Lycoming IO-390 engine is a horizontally opposed, four-cylinder aircraft engine, manufactured by Lycoming Engines. There is no carburetted version of the engine, which would have been designated O-390 and therefore the base model is the IO-390.
The engine was originally conceived in the 1970s as the IO-400-X, but the project was never pursued.
First run in 2002, the IO-390 family of engines, which Lycoming refers to as the IO-390-X, produce 200 hp (149 kW) to 210 hp (157 kW). The IO-390 was developed from the similar IO-360 engine, by using cylinders from the IO-580 to increase the O-360's cylinder bore. It features a tuned induction system, roller tappets and Slick Start ignition. The engine has a fuel injection system which meters fuel in proportion to the induction airflow with fuel vaporization taking place at the intake ports. The engine has a displacement of 390 cubic inches (6.39 litres). The cylinders have air-cooled heads.
The IO-390 was first introduced at AirVenture 2002. It has a factory recommended TBO of 2000 hours and requires a dynafocal engine mount. The IO-390 was initially marketed through Lycoming's custom engine subsidiary, Thunderbolt Engines, prior to the engine's certification and was at that time only available for installation on non-certified aircraft. The IO-390 was certified on 30 March 2009 to FAR 33 effective February 1, 1965, as amended by 33-1 through 33-24.
In January 2009 the base price of the IO-390-EXP version was USD$$32,650.00.
In November 2009 Lycoming announced that they had obtained an FAA Supplemental Type Certificate to replace the originally fitted Lycoming O-360 engines in the Mooney M20E, M20F and M20J with a new or remanufactured IO-390-A3A6 engine.
Four-cylinder, fuel-injected, horizontally opposed, air-cooled direct drive, 390 cubic inches (6.39 litres), 210 hp (157 kW) at 2700 rpm, dry weight 308 lb (140 kg), The "X" designation is a generic indicator for all engines in the family.
Four-cylinder, fuel-injected, horizontally opposed, air-cooled direct drive, 390 cubic inches (6.39 litres), 210 hp (157 kW) at 2700 rpm, dry weight 308 lb (140 kg), non-certified engine for experimental aircraft assembled by Lycoming's Thunderbolt division.
The initial certified version: four-cylinder, fuel-injected, horizontally opposed, air-cooled direct drive, 390 cubic inches (6.39 litres), 210 hp (157 kW) at 2700 rpm. This model includes provisions for a single-action controllable pitch propeller. Certified 30 March 2009.
Certified version: four-cylinder, fuel-injected, horizontally opposed, air-cooled direct drive, 390 cubic inches (6.39 litres), 210 hp (157 kW) at 2700 rpm. This model includes provisions for a single-action controllable pitch propeller. This model is similar to the A1A6 but has its propeller flange bushings reindexed. Certified 27 August 2009.
MSW Votec 221
Van's Aircraft RV-7
Van's Aircraft RV-8
Van's Aircraft RV-14
Cessna 177RG - available in July 2009 under an STC
Mooney M20 E, F & J - available in November 2009 under an STC
Piper PA-28R Arrow - proposed under STC
Symphony SA-160 - proposed as a factory installed 200 hp (149 kW) version, but aircraft no longer in production
Lancair Synergy T-90 Colombian Air Force
Type: 4-cylinder fuel-injected horizontally opposed aircraft engine
Bore: 5.319" (135 mm)
Stroke: 4.375" (111 mm)
Displacement: 389 in³ (6.37 litres)
Length: 30.70 in (78.0 cm)
Width: 34.25 in (87.00 cm)
Height: 19.35 in (49.1 cm)
Dry weight: 308 lb (140.1 kg) dry
Fuel system: fuel-injection
Fuel type: 100LL avgas
Cooling system: air-cooled
Power output: 210 hp (157 kW) at 2700 rpm
Specific power: 0.54 hp/in³ (26.0 kW/L)
Compression ratio: 8.70:1
Fuel consumption: 11.1 gallons per hour (42 litres per hour) at 65 percent power
Power-to-weight ratio: 0.68 hp/lb (1.11 kW/kg)