This study involves the development of high speed flow visualization and laser doppler velocimetry (LDV) systems which are used to study the fuel spray-air mixing flow characteristics within the combustion chamber of a motored rotary engine. A 40-watt copper vapor laser is used as the light source. Its beam is focused down to a sheet approximately 1 mm thick. The light plane is passed through the combustion chamber, which allows complete optical access, and it illuminates smoke particles which were entrained in the intake air. The light scattered off the particles is recorded by a high speed rotating prism camera. Movies are made showing the air flow within the combustion chamber. The results of a movie showing the development of a high speed (100 Hz) high pressure (68.94 MPa, 10000 psi) fuel jet are also discussed. The visualization system is synchronized so that a pulse generated by the camera triggers the laser's thyratron. The camera is run at 5000 frames per second; the trigger drives one laser pulse per frame.