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Stereoscopic particle-image velocimetry (PIV) is used to investigate the non-reacting flow field in the combustion chamber of a motored direct-injection spark ignition (DISI) engine with tumble intake port. The in-cylinder flow is controlled by variable valve timing (VVT), i.e., shifting of the intake cam shaft to earlier or later crank angles (cam phasing). VVT systems are already implemented in production combustion engines, e.g., BMW's Vanos system, to improve the volumetric efficiency and to reduce pumping losses. In the present study, the underlying flow phenomena, i.e., the effect of VVT on the tumble development and turbulent kinetic energy, are analyzed. The flow field is investigated at a set of early, intermediate, and late intake valve opening (IVO) positions during the intake and compression strokes, thus enabling the analysis of the temporal development of the main flow structures.