Case studies

The three engines that have been chosen as case studies are the Rover K Series spark ignition engine, the Chrysler 2.2 litre spark ignition engine, and the Ford (high-speed) 2.5 litre DI diesel engine. Each engine has been chosen because of its topicality, and characteristics that are likely to be seen also in subsequent engines. The Rover engine uses a pent-roof combustion chamber; this permits the use of a high compression ratio and the combustion of lean mixtures, both of which lead to economical operation. The Chrysler 2.2 litre spark ignition engine is typical of current practice in the USA and thus has low emissions of carbon monoxide, unburnt hydrocarbons and oxides of nitrogen.