Lycoming IO-720

The engine has a fuel injection system which schedules fuel flow proportionally to the airflow, with fuel vaporization occurring at the intake ports. The engine has a displacement of 722 cubic inches (11.8 litres) and produces . The cylinders have air-cooled heads cast from aluminum alloy with a fully machined combustion chamber. The first IO-720 was type certified on 25 October 1961 to the CAR 13 standard as amended to 15 June 1956 including 13-1, 13-2, 13-3, 13-4. ==Variants==

;IO-720-A1A :Eight-cylinder, horizontally opposed, air-cooled direct drive, fuel injection, internal oil jet piston cooling, 722 cubic inches (11.8 litres), , certified 25 October 1961 ;IO-720-A1BD :fuel-injected, 722 cubic inches (11.8 litres), , same as -A1B except has a dual magneto, certified 30 December 1976 ;IO-720-B1A :fuel-injected, 722 cubic inches (11.8 litres), , same as -A1A except for top exhaust cylinders and offset exhaust valve shroud tubes, certified 4 November 1965 ;IO-720-B1B :fuel-injected, 722 cubic inches (11.8 litres), , same as -B1A except equipped with Bendix S8LN-1208 and S8LN-1209 magnetos and Bendix RSA-10ED1 fuel injection, certified 22 February 1971 ;IO-720-B1BD :fuel-injected, 722 cubic inches (11.8 litres), , same as -B1B except has a dual magneto, certified 30 December 1976 ;IO-720-C1B :fuel-injected, 722 cubic inches (11.8 litres), , same as -A1B except that it has up-exhaust cylinder heads, certified 22 December 1971 ;IO-720-C1BD :fuel-injected, 722 cubic inches (11.8 litres), , same as -C1B except has a dual magneto, certified 28 January 1977 ;IO-720-D1B :fuel-injected, 722 cubic inches (11.8 litres), , same as -A1B except has a rear type air inlet housing instead of a front inlet, certified 29 October 1973 ;IO-720-D1BD :fuel-injected, 722 cubic inches (11.8 litres), , same as -D1B except has a dual magneto, certified 28 January 1977 ;IO-720-D1C :fuel-injected, 722 cubic inches (11.8 litres), , same as -D1B except equipped with an angled fuel injector adapter, certified 15 April 1982 ;IO-720-D1CD :fuel-injected, 722 cubic inches (11.8 litres), , same as -D1C except has a dual magneto, certified 10 June 1977 ==Applications==

;IO-720-A1A • Northwest Ranger - factory installation • Piper Comanche 400 - factory installation ;IO-720-A1B • Beechcraft 80 - Excalibur and Queen Air conversions ;IO-720-B1A • Northwest Ranger C-6 - factory installation ;IO-720-B1B • Aero Commander - MR. R.P.M. conversion ;IO-720-B1BD • Aero Commander - MR. R.P.M. conversion ;IO-720-D1B • Embraer EMB 202 Ipanema - factory installation ;IO-720-D1C • Piper PA-36 Pawnee Brave - Johnson Aircraft conversion ;IO-720-D1CD • Piper PA-36 Pawnee Brave - Johnson Aircraft conversion ==Specifications (IO-720A)==