The 2si 540 and 2si 500 are a family of in-line twin-cylinder, liquid-cooled,

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a four-stroke engine which re ...

, dual ignition,

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbin ...

s that were designed for

ultralight aircraft Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and Aircraft flight control system, conventional three-a ...

.Cliche, Andre: ''Ultralight Aircraft Shopper's Guide'' 8th Edition, page G-2 Cybair Limited Publishing, 2001. The basic engine was originally designed and produced by JLO-Motorenwerke of

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

and was later acquired by the AMW Cuyuna Engine Company of

Beaufort, South Carolina Beaufort ( , different from that of Beaufort, North Carolina) is a city in Beaufort County, South Carolina, United States, and its county seat. Chartered in 1711, it is the second-oldest city in South Carolina, behind Charleston, South Carolina ...

and marketed under the ''Cuyuna'' brand name. Later the engine was marketed by Cuyuna under the Two Stroke International (2si) brand. Cuyuna no longer markets engines for aircraft use although the 540 is still in production as a sport vehicle engine.

Development

The 540 is a conventional twin-cylinder engine that weighs in its L70 aircraft version. The engine features dual

capacitor discharge ignition Capacitor discharge ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, gas turbine-powered aircraft, and some cars ...

(single in the sport vehicle version), reed valve porting, tuned exhaust system, two slide venturi-type

carburetor A carburetor (also spelled carburettor or carburetter) is a device used by a gasoline internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the Ventu ...

s, liquid cooling, fuel pump, a cast iron cylinder liner, ball, needle and roller bearings throughout. The aircraft version was offered with an optional gearbox reduction system. Starting is electric starter or recoil starter.Purdy, Don: ''AeroCrafter - Homebuilt Aircraft Sourcebook'', page 69. BAI Communications. The 500L85 is a special engine that was developed from the 540, by reducing the cylinder bore from to . This was done to reduce the displacement to under 500 cc and allow the engine to be used for Formula 500 auto racing.

Variants

;500L-85 :Gasoline sport vehicle engine for Formula 500

auto racing Auto racing (also known as car racing, motor racing, or automobile racing) is a motorsport involving the racing of automobiles for competition. In North America, the term is commonly used to describe all forms of automobile sport including non ...

. Dual carburetors, at 8000 rpm, still in production. ;540-L70 :Gasoline aircraft engine, dual carburetors, at 7000 rpm, weight , out of production. ;540L-90 :Gasoline sport vehicle engine for

kart A go-kart, also written as go-cart (often referred to as simply a kart), is a type of small sports car, close wheeled car, open-wheel car or quadracycle. Go-karts come in all shapes and forms, from non-motorised models to high-performance ...

and

all-terrain vehicle An all-terrain vehicle (ATV), also known as a light utility vehicle (LUV), a quad bike or quad (if it has four wheels), as defined by the American National Standards Institute (ANSI), is a vehicle that travels on low-pressure tires, has a seat ...

applications. Dual carburetors, at 8000 rpm, still in production.

Applications

;Aircraft * RagWing RW8 PT2S ;Automotive * Formula 500

Specifications (540-L70 aircraft engine)

References

{{2si Two-stroke aircraft piston engines

Development

Variants

Applications

Specifications (540-L70 aircraft engine)

See also

References