1 - Overview of high-speed direct injection diesel engines

Abstract

This chapter traces the historical development of the high-speed direct injection (HSDI) diesel engine and reviews some of today’s engines. The European passenger car diesel market share rose rapidly over the last decade to reach above 50% at present. This has been due to significant improvements in performance and refinement, demonstrated by premium luxury manufacturers offering diesel engines for their top of the range models. Performance has been increased by higher fuel injection pressures, improvements in turbocharger design and efficiency, and more sophisticated electronic controls. Complex exhaust gas recirculation (EGR) systems and exhaust after-treatment have facilitated keeping pace with emissions legislation. Greater flexibility of injection timing and number of injections have greatly improved noise levels. HSDI engine designs and development are reviewed from the first production eight-valve four-cylinder engines with pump-line-nozzle fuel systems in the mid-1980s to the typical 16-valve four-cylinder common rail engines of the present day. A survey of some of today’s notable engines is covered, including a 48-valve 12-cylinder engine with a 2000bar common rail fuel system producing 368kW and 1000Nm torque. The chapter concludes with a contemplation of the future.