Marine propulsion engines

84.08 - Compression-ignition internal combustion piston engines (diesel or semi-diesel engines). 8408.10 - Marine propulsion engines 8408.20 - Engines of a kind used for the propulsion of vehicles of Chapter 87 8408.90 - Other engines This headin covers compression-ignition internal combustion piston engines (other than those of Chapter 5), including those for motor vehicles. These engines are of similar mechanical construction to spark-ignition internal combustion piston engines and have the same essential elements (i.e., cylinder, piston, connecting-rod, crank shaft, flywheel, inlet and exhaust valves, etc.), but differ in that the air (or sometimes air mixed with gas) is first admitted to the cylinder where it is rapidly compressed. Atomised liquid he1 is then mjected into the combustion chamber where ~t is spontaneously ignited by the heat developed, the compression being considerably greater than in the spark-ignition engine. In addition to diesel engines, there are intermediate compression-i ition semi-diesel engines which o rate at lower compression. To start this type, the cylinder- ead must be pre-heated by a blow- amp or a glow plug must be used. f? P" Compression-ignition internal combustion piston engines operate on heavy fluid fuels such as heavy petroleum or coal tar oils, shale oils, vegetable oils (ground-nut, castor, palm, etc.). The engines of this headin may have one or several cylinders. In the latter case the connectingrods are coupled to a sing e crank shaft, and the cylinders, fed separately, ma be arranged in various ways, e. ., in a vertical line (upright or inverted), in two syrnmetrrcal o liquely opposed rows ( ~ e n ~ i n e shorizontally ?, opposed on opposite sides on the crank shaft. f g The engines of this heading are suitable for very many uses, e.g., in agricultural machines, for propelling motorcars, tractors, locomotives or slvps or m electric power stations, etc. The engines of this heading may be equipped with fuel injection pumps, ignition parts, fuel or oiI reservoirs, water radiators, 011 coolers, water or oil pumps, blowers, air or oil filters, clutches or power drives, or starting devices (electric or other . Change speed gears may also be fitted. The engines may also be equipped with a flexible sha . It also covers mobile motors consisting of engines mounted on a wheeled chassis or on runners, including those with drivin mechanisms permitting their self-propulsion to a certain extent (but not constituting vehicles o Chapter 87). f The heading excludes variable corn ression motors of the compression-ignitioninternal combustion piston e type designed specially F g p t e r 90). 81-determination of the octane and cetane value of motor fuels PARTS Sub'ect to the general provisions regardin the classification of parts (see the General Exp anatory Note to Section XVI), parts o the engines of this heading are classified in heading 84.09. f