how much compression does a diesel engine have
Diesel engine In the true diesel engine, only air is initially introduced into the combustion chamber. The air is then compressed with a compression ratio typically between 15:1 and 23:1. This high compression causes the temperature of the air to rise. At about the top of the compression stroke, fuel is injected directly into the compressed air in the combustion chamber. This may be into a (typically toroidal) void in the top of the piston or a pre-chamber depending upon the design of the engine. The fuel injector ensures that the fuel is broken down into small droplets, and that the fuel is distributed evenly. The heat of the compressed air vaporizes fuel from the surface of the droplets. The vapour is then ignited by the heat from the compressed air in the combustion chamber, the droplets continue to vaporise from their surfaces and burn, getting smaller, until all the fuel in the droplets has been burnt. Combustion occurs at a substantially constant pressure during the initial part of the power stroke. The start of vaporisation causes a delay before ignition and the characteristic diesel knocking sound as the vapour reaches ignition temperature and causes an abrupt increase in pressure above the piston (not shown on the P-V indicator diagram). When combustion is complete the combustion gases expand as the piston descends further; the high pressure in the cylinder drives the piston downward, supplying power to the crankshaft.[69]
Renault Clio The range of petrol engines consists of three options: a 1.2-litre 16 valve straight-4 engine, with a maximum power output of 75 hp (56 kW), a turbocharged 0.9-litre 12 valve straight-3 engine, developing 90 hp (67 kW), which can have a CO2 emission level of 99 g/km and a 1.2 litre turbocharged engine which produces 120 hp (89 kW). A turbocharged 1.6-litre four-cylinder engine, capable of producing 197 hp (147 kW), will be featured on the Renault Sport version.[50]