The results are presented of preliminary design studies conducted to define feed pumps that satisfy the performance requirements for the following Rankine cycle automotive power systems which are under development: (1) Steam Engine Systems; (2) Aerojet Liquid Rocket Company; and (3) Thermo Electron Corporation. The approach followed in this study consisted of establishing feedpump requirements for the three applications. Investigations revealed that the feedpump developed by Lear Motors Corporation satisfies the basic requirements of the three system contractors. This feed pump was used as a baseline for the preliminary design and performance study presented here. A description of the Lear feedpump and its operating principle is presented. A summary of the flow requirements and estimated brake horsepower for the 3 system contractor feedpumps is shown graphically. Details of the contracts technical requirements and the Lear Motors approach for each system contractor are also presented.