توضیح فارسی
نوعی موتور پیستونی قدرتمند که به ازای جابه جایی پیستون به اندازه یک اینچ مکعب یک اسب بخار نیرو تولید می کند.
Description
a series of experimental high-performance aircraft engines built with u.s. army and navy financing in the early 1930s. the goal of these engines, which had been unattainable up to that time, was to develop one horsepower for each cubic inch of piston disp