"Tests were made to determine the effect of the reservoir volume on the discharge pressures in the injection system of the N.A.C.A. spray photography equipment. The data obtained are applicable to the design of a common rail fuel-injection system. The data show that an injection system of the type described can be designed so that not more than full load fuel quantity can be injected into the engine cylinders, and so that the fuel spray characteristics remain constant over a large range of engine speeds" (p. 1).

"High-speed motion pictures were taken of fuel sprays injected into the combustion chamber of the N.A.C.A. combustion apparatus. Three fuels, ethyl alcohol, gasoline, and fuel oil, which differed considerably in volatility were tested. By maintaining the engine temperature below that required for ignition the spray could be studied from soon after the start of injection until 130 crank degrees later. The results show that the sprays vaporize appreciably so that it is possible for the ignition in high speed compression-ignition engines to take place from the vapor phase" (p. 1).

As part of an investigation of special compositions of rubber suitable for use as diaphragms for aircraft instruments, six samples were used as taut diaphragms in instruments and allowed to age for five years. Two of the instruments were in operating condition after this period of time and one had remarkably little change in performance. In making the rubber tetraethyl thorium disulfide was employed as a vulcanizing agent.

From Introduction: "The present report gives all the results, including those published in reference 1 and the results of previously un-published tests tests of the airfoils at positive angles of attack."

Note presenting an investigation to determine the possible improvement in performance by using a large amount of valve overlap on a supercharged engine. A series of tests was made on the NACA universal single-cylinder engine of 5-inch bore and 7-inch stroke with varying amounts of overlap from 0 to 100 degrees at five different intake pressures.