Skip to content

Lycoming Igso 540 A1essays

The Lycoming O-540 is a family of air-cooled six-cylinder, horizontally opposedfixed-wing aircraft and helicopter engines of 541.5 cubic inch (8,874 cc) displacement, made by Lycoming Engines. The engine is a six-cylinder version of the four-cylinder Lycoming O-360.

Design and development[edit]

Generally these engines produce 230 to 350 horsepower.[1] They are installed on a large number of different aircraft types.[2] 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.


All engines have an additional prefix preceding the 540 to indicate the specific configuration of the engine.[1] There are also numerous engine suffixes, denoting different accessories such as different manufacturers' carburetors, or different magnetos.

Standard, direct-drive, normally aspirated Opposed engine, equipped with a carburetor.
Normally aspirated engine with fuel Injection.
Normally aspirated engine with fuel injection and inverted lubrication for Aerobatic use.
Turbocharged and fuel-injected.
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.[3]
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[4] to prevent critical engine control issues. Also used for the left hand side of the Aerostar 700P.
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.
Turbo-charged, injected and geared
Supercharger driven by the engine, gearbox to drive propeller, and fuel injection (up to 380hp).
Vertically mounted engine for use in a helicopter, normally aspirated and equipped with a carburetor.
Normally aspirated engine with fuel injection, mounted vertically for use in a helicopter.
Turbocharged engine equipped with a carburetor, mounted vertically for use in a helicopter.
Turbocharged engine with fuel injection, mounted vertically for use in a helicopter.
Helicopter engine mounted horizontally as in fixed-wing aircraft, normally aspirated with fuel injection; not used in any fixed-wing aircraft.[2]
Same as a TIO-540, except the "1" indicates an integral accessory drive.[5]
Same as a TIGO-540, except the "1" indicates an integral accessory drive.[5]


Specifications (IO-540-K1A5)[edit]

Data fromFAA 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 in¬≥ (8.9 L)
  • Dry weight: 438 lb (199 kg)



See also[edit]

Related development
Comparable engines
Related lists


External links[edit]

An LTIO-540 mounted on the right wing of a Piper Chieftain. The turbocharger can be seen in the upper right of the image.

Re: IGSO-540 or 500hp LS with reduction

Postby farmboy » Mon Jun 02, 2014 9:03 pm

[quote="kwanjangnihm"]both have had great success on airboats!

both have great torque!

the stock 540 psru limits gear ratio - the LS has better gearbox offerings!

540 will probably need a cooling shroud!

nod may go to the LS with more prop thrust!

The 1:5 gear that comes on the IGSO's is all you'll ever need. Trust me! We have tired different gears with different props but the stock gear is very hard to beat!
As far as the cooling shroud that just depends on your carb & fuel system if you'll need it or not.... I don't run one on my boat and know several others that don't either and have never had any issues with CHT's.
And thrust....??? My $$$$ will be on that IGSO 540!
14ft JB Hull,Lycoming GSO480 w/water-meth injection,Sensenich 3-blade "R",ButtRaxx seats,B&S Trailer.

Member of Glades Airboat & Buggy Association / Kissimmee River Valley Sportsman Association