Auto conversion to airplane engines. On the site of an automobile assembly line, this battery of Bullard boring machines used in manufacturing of airplane engines, now stands. With normal operations of this automobile factory suspended for the duration, conversion to war production was a gigantic task involving remodelling of machinery, removal of old and installation of new equipment and extensive rebuilding of the plant itself. These boring machines are used to rough cylinder barrels of airplane engines before heat treatment is applied. Chevrolet, Buffalo, New York