Design and development
The engine was originally conceived in the 1970s as the IO-400-X, but the project was never pursued.
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 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 November 2009 Lycoming announced that it 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. Also on November 12, 2009 Commander Aircraft received an STC for its model 112B using the MTV-12-B/188-59b propeller.
- 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.
- Amateur-built aircraft
- Glasair Sportsman
- Lancair ES
- MSW Votec 221
- Pipistrel Panthera
- Van's Aircraft RV-7
- Van's Aircraft RV-8
- Van's Aircraft RV-14
- Certified aircraft
- 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
- Military Aircraft
- 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
- Lycoming Engines (undated). "Lycoming IO-390-X". Retrieved 2009-01-07. Check date values in:
- Lycoming Engines (2004). "Specialty datasheet" (PDF). Retrieved 2008-12-20.
- Lycoming Engines (2008). "Lycoming's Certified IO-390 Series Engine". Retrieved 2009-01-07.
- Federal Aviation Administration (March 2009). "TYPE CERTIFICATE DATA SHEET NO. E00006NY". Retrieved 2009-06-21.
- Lycoming Engines (January 2009). "Thunderbolt Engine Configurator". Retrieved 2009-01-06.
- Grady, Mary (November 2009). "Lycoming Gets IO-390 STC For Legacy Mooneys". Retrieved 2009-11-15.
- Federal Aviation Administration (12 November 2009). "Supplemental Type Certificate, STC Number: SA00291BO". Retrieved 30 March 2014.
- Federal Aviation Administration (August 2009). "TYPE CERTIFICATE DATA SHEET NO. E00006NY Revision 1". Retrieved 2009-11-19.
- Grady, Mary (July 2009). "Cessna News Update: ASTM Compliance For SkyCatcher". Retrieved 2009-07-28.
- Burnside, Joseph E. (Jeb) (July 2009). "Lycoming: Bringing More Technology To An Airplane Near You". Retrieved 2009-07-28.
- AVweb Editorial Staff (August 2008). "AVwebFlash Complete Issue: Volume 14, Number 31e". Retrieved 2008-08-01.
- Aero-News Network (February 2009). "Lancair To Provide Colombian Air Force With Training Aircraft". Retrieved 31 July 2010.