The 2si 690 is a family of in-line three 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-3 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 690 is still in production as an industrial and marine engine.
Development
The 690 is a conventional three-cylinder engine that weighs in its L70 aircraft and marine versions. The aircraft 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 marine and industrial versions), reed valve porting, tuned exhaust system, three 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 pumps, a cast iron cylinder liner, ball, needle and roller bearings throughout. The aircraft version was offered with an optional gearbox reduction dive system and a centrifugal clutch. The current industrial and marine version has an available gearbox with ratios of 2.04, 2.65 or 3.06:1. Starting is electric start only.
Variants
;690-L70 aircraft engine
:Gasoline aircraft engine with triple carburetors, at 6250 rpm, weight , out of production.
;690L-70 industrial and marine engine
:Gasoline industrial and marine engine, triple carburetors, at 6250 rpm, weight , electric starter mounted on the accessory cover end. Still in production.
;690AL-70 industrial and marine engine
:Gasoline industrial and marine engine, triple carburetors, at 6250 rpm, weight , electric starter mounted on the power take-off end. Still in production.
Applications
;Aircraft
*
RagWing RW11 Rag-A-Bond
*
RagWing RW19 Stork
*
RagWing RW22 Tiger Moth
*
Sky Science PowerHawk
*
St Andrews Viking
*
Viking Aircraft Viking II
Specifications (690-L70 aircraft engine)
See also
References
{{2si
Two-stroke aircraft piston engines
Straight-three engines