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Lycoming IO-720

Horizontally opposed, eight-cylinder aircraft engine

Field	Value
name	IO-720
engine_type	Piston aero-engine
manufacturer	Lycoming Engines
national_origin	United States
first_run	1961
produced	1961–present
developed_from	Lycoming O-360
major_applications

The Lycoming IO-720 engine is a large displacement, horizontally opposed, eight-cylinder aircraft engine featuring four cylinders per side, manufactured by Lycoming Engines.

There is no carbureted version of the engine, which would have been designated O-720 and therefore the base model is the IO-720. The IO-720 is the only flat-eight configuration aircraft engine currently in production.

Design and development

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 400 hp. 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.

In 2009 a new IO-720-A1B cost US$113,621, with a rebuilt engine retailing for US$75,435 and a factory overhaul priced at US$66,289.

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), 400 hp, certified 25 October 1961 ;IO-720-A1B :fuel-injected, 722 cubic inches (11.8 litres), 400 hp, same as -A1A except equipped with Bendix S8LN-1208 and S8LN-1209 magnetos, certified 22 February 1971 ;IO-720-A1BD :fuel-injected, 722 cubic inches (11.8 litres), 400 hp, same as -A1B except has a dual magneto, certified 30 December 1976 ;IO-720-B1A :fuel-injected, 722 cubic inches (11.8 litres), 400 hp, 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), 400 hp, 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), 400 hp, same as -B1B except has a dual magneto, certified 30 December 1976 ;IO-720-C1B :fuel-injected, 722 cubic inches (11.8 litres), 400 hp, 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), 400 hp, same as -C1B except has a dual magneto, certified 28 January 1977 ;IO-720-D1B :fuel-injected, 722 cubic inches (11.8 litres), 400 hp, 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), 400 hp, same as -D1B except has a dual magneto, certified 28 January 1977 ;IO-720-D1C :fuel-injected, 722 cubic inches (11.8 litres), 400 hp, 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), 400 hp, 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
Helio Courier - Helio Courier H-800 factory installation
Pacific Aerospace FU-24-954
Piper PA-36 Pawnee Brave - Johnson Aircraft conversion

;IO-720-A1BD

Barr 6

;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)

and start a new, fully formatted line with -- |power/weight=0.67 hp/lb (1.10 kW/kg)

References

[[Lycoming Engines]]. (n.d.). "Lycoming IO-720".
[[Federal Aviation Administration]]. (February 1988). "TYPE CERTIFICATE DATA SHEET NO. 1E15, Revision 6".
[[Lycoming Engines]]. (2004). "Specialty datasheet".
[[Lycoming Engines]]. (2009). "2009 Lycoming Service Engine Price List".
[[Lycoming Engines]]. (n.d.). "Engine Finder".
Demand Media. (2008). "The Piper PA-24 Comanche".
Morrison, Steve. (8 August 2008). "Morrison 6 Specifications".

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

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