As World War II intensified in 1941, Chrysler engineers faced the urgent task of developing a powerful tank engine quickly using existing resources. Their solution was the A57 Multibank—a 30-cylinder, 1,253-cubic-inch (20.5 L) engine created by combining five Chrysler inline-six engines around a central crankcase, forming a unique five-bank design reminiscent of a radial engine. This innovative configuration produced 370 to 445 horsepower at 2,400 rpm, depending on the source, and up to 1,060 lb