Altitude Performance of Allison V-1710-93 Engine and Two-Stage Supercharger

Bench tests have been made of an Allison V-1710-93 engine at simulated altitudes of 17,000 and 29,000 feet to determine the performance of the engine, the characteristics of the induction system, and the modifications required in the induction system for the center dot development of 1840 brake horsepower at 17,030 feet and 1200 horsepower at 29,000 feet. With the engine speed maintained at a constant value of 3000 rpm, the tip speed of the auxiliary-stage supercharger was varied from the minimum to the maximum speed. Measurements were made to determine engine power, fuel and air consumptions, and pressure and temperature changes introduced by each component of the induction system.

Although the over-all pressure ratios of the superchargers agreed with those determined from previous sea-level bench tests of these units, the over-all temperature rise was -generally much lower than had been anticipated. In order to obtain the desired brake horsepower, some form of charge-air cooling is essential; the carburetor should either be enlarged or removed; and the minimum gear ratios of the engine-stage and the minimum gear ratios of the engine-stage and the auxiliary-stage superchargers should be 8.1:1 and 8.08:1, respectively.