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Combustion zone (flame) propagation and flow velocities are measured using optical measurement techniques in a single-cylinder direct injected diesel engine. Combustion and, hence, flame propagation is detected by optical fibers and flow velocities have been measured by a new single-color, 2 dimensional Laser Doppler Velocimeter (LDV). Flame propagation and flow velocities could not be measured simultaneously. Consequently, pressure traces which were recorded during each measurement served as a criterion for selecting similar combustion cycles from flame and flow velocity measurements. The operational speed of the engine was 1100 rpm and the power cylinder was configured with a combustion bowl in the piston. For the purpose of the tests, the intake swirl number was either 1.8 or 4.2, the latter corresponding to the application of a shrouded inlet valve. It has been shown that variation of several significant engine parameters influences both combustion and fluid flow history.