4.5 ENGINES AND CAR PARTS The Engine The basics An engine is a machine designed to convert a form of energy into mechanical energy. Engines that work with heat – – burn fuel to create heat, which is then used for a specific function. There are two types of combustion engines: combustion engines , where the fuel burns outside the engine to heat water and create steam that motion inside the engine. Old steam trains and steamboats are examples. The external combustion engine sets up 1 , which is fed with fossil fuels that burn inside the engine. Nowadays, there is a growing use of renewable fuels to reduce toxic emissions and air . This engine is a lot more efficient (it consumes less fuel per mile) and is much smaller than the external combustion engine. The internal combustion engine 1 2 pollution MORE The was the first steam locomotive to carry passengers on a public rail line, the Stockton and Darlington Railway, in England. It was built by George Stephenson in 1825. 1 Locomotion No. 1 DO What fossil fuels can burn in a combustion engine? 1 DO What renewable energy sources do you know of? 2 The internal combustion engine In an internal combustion engine (ICE), the combustion of a mixture of air and fuel occurs in a combustion chamber. The main parts of the cylinder block (the space in which a piston moves) of an ICE are: 2 , which controls the movement of the engine valves. The exhaust camshaft , which controls the flow of the air/fuel mixture. The camshaft intake , used to deliver electrical current from the ignition system to the combustion chamber. The sparkplug (blue for , red for ), which open in the intake and exhaust strokes. The valves intake exhaust , whose purpose is to transfer force from the expanding gas in the cylinder to the crankshaft. The piston , which is a series of holes that maintains the temperature. The cooling water jacket , which connects the piston to the crankshaft and transmits the compressive and tensile forces from the piston. The connecting rod , which is a rotating that converts the motion of the pistons into rotational motion. The crankshaft shaft MORE The cylinder is generally made of cast iron or aluminum. In some engines, the cylinders are lined with sleeves that can be replaced when they become worn. 2