Abstract
This thesis investigates how injection timing and pressure affect the efficiency and exhaust emissions of an atmospheric diesel engine. For this purpose, an existing test engine was converted to a common rail injection system with an open ECU, allowing injection parameters to be precisely adjustable. Data was analysed at three load points, after which it was observed that at low load, the engine runs more efficiently at low injection pressure with early injection timing (SOI = 25° BTDC, Pinj = 350 bar). As the load increases, it is more efficient to inject later at a higher injection pressure (SOI = 10° BTDC, Pinj = 750 bar). After further analysis on exhaust gas composition, the conclusion could be formulated that ideal combustion is difficult to achieve when both efficiency and emissions have to be optimised.

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