Abstract
To improve the thermal efficiency of diesel engines, increasing the compression ratio by extending the stroke length without combustion chamber volume reduction has been suggested as an effective approach by engine combustion CFD simulations. Therefore, experimental evaluation of extended stroke specification about indicated thermal efficiency improvement effects was carried out using a single-cylinder test engine. As a result, extending the stroke length is verified to be an effective approach to improve indicated thermal efficiency, as cooling loss is significantly reduced in high load conditions. In low load conditions, reduction of exhaust loss contributed to improve indicated thermal efficiency.
