[...]... cars and motorcycles To obtain higher output power, the number of valves used in car engines has increased 8 Science and technology of materials in automotive engines 11 0 10 0 bo s 90 ur lt tro 70 60 Pe Specific power (kW/L) 80 Car diesels 50 40 30 Pe t en rol gin es 20 Truck diesels 10 0 19 0 019 10 19 20 19 30 19 40 19 50 19 60 19 70 19 80 19 90 2000 Year 1. 4 Development of power output of petrol engines and. .. or indirect injection With direct injection engines (DI) the fuel is injected directly into the cylinder and initial combustion takes place within the bowl that is machined into the piston head itself With indirect injection engines (IDI) the fuel is injected and initial combustion takes place in a small pre-combustion chamber formed in the cylinder head The burning gases then expand into the cylinder... Turbocharging with an intercooler is used in large engines Diesel engines produce lean combustion, having an air-fuel ratio of about 15 :1 up to 10 0 :1 The diesel’s leaner fuel mixture generates higher fuel economy compared to that of a petrol engine The peak cylinder pressure can be in excess of 15 MPa The HC and CO contents in Engines 5 the exhaust gas are lower compared to those of petrol engines, but the particulate... engines A Stirling engine is another type of engine that uses a piston-cylinder construction There are, however, other engines, such as the rotary and gas turbine engines, that do not use the piston-cylinder mechanism 1. 2 Advantages and disadvantages of reciprocating engines An engine with a piston-cylinder mechanism has the following advantages: 1 It is possible to seal the gap between the piston and. .. from the combustion chamber Figure 1. 1 illustrates an engine containing four valves per cylinder The camshaft pushes the valves into the combustion chamber The repulsive force of the valve spring drives the backward motion The valves and valve seats fitted in the cylinder head then seal the combustion gas The following chapters will discuss the main components of the engine in more detail As the mechanism... difficult In the past, petrol engines almost universally used3 a carburetor However, the requirements for improved fuel economy have led to an increasing use of 4 Science and technology of materials in automotive engines fuel injection In a petrol engine the fuel is normally injected into the inlet manifold behind the inlet valve The atomized fuel mixes with air When the inlet valve is opened, the combustible... drawn into the cylinder However, a recent development has occurred in direct injection petrol engines whereby fuel is injected directly into the combustion chamber, as with direct injection diesel engines 1. 1.3 The diesel engine The name diesel comes from the inventor of the diesel engine, R Diesel There are both four- and two-stroke-cycle diesel engines Most automotive diesels are four-stroke engines The. .. Engine components and typical materials 1. 3 .1 Components The reciprocating engine generates rotation from combustion pressure using the piston, connecting rod and crankshaft Now let us look at the cutaway image of the four-stroke cycle petrol engine in Fig 1. 1 and its actual parts in Fig 1. 3 The basic functions of the various parts are as follows: the piston receives combustion pressure; the connecting... and the connecting rod and crankshaft mechanism converts this pressure into rotation This is the basic mechanism of a reciprocating engine The reciprocating mechanism was originally inherited from steam engines and has been used for more than 200 years One of the earliest mechanisms using a piston and cylinder can be seen in a 15 09 drawing by Leonardo da Vinci, the famous painter and scientist of the. .. characteristics of engines are directly associated with the materials used and their methods of production This book has been written for those who are interested in automotive technologies, engineers and others who are engaged in the business of car parts and materials, and students who are learning mechanical engineering or materials engineering The topics are centered on recent technologies as well as standards . 248 11 .1 Functions of the turbocharger 248 11 .2 The turbine wheel 249 11 .2 .1 Turbine and compressor designs 249 11 .2.2 Investment casting 252 11 .3 The turbine housing 256 11 .3 .1 Cast iron 255 11 .3.2. increasing use of Science and technology of materials in automotive engines4 fuel injection. In a petrol engine the fuel is normally injected into the inlet manifold behind the inlet valve. The. Ltd, India Printed by T J International Limited, Padstow, Cornwall, England Contents Preface xi 1 Engines 1 1 .1 The reciprocating engine 1 1 .1. 1 The four-stroke engine 2 1. 1.2 The two-stroke engine