A direct acting piston pump, a possible alternate for the diaphragm feed pump, was built and tested in water withoat piston rings and in fuel solution with piston rings. Leakage due to wear rendered it useless in a week in the first case and in a month in the second. Although a development program could probably improve the performance of such a pump, the calculable limitations of it are so severe that it is recommended that the project be discontinued. (auth)