The Chrysler A57 multibank is a complex American powerplant developed during World War II for use in the M4 Sherman medium tank. Consisting of five 6-cylinder engines arranged in a radial pattern around a central crankshaft, the A57 had a total of 30 cylinders and a displacement of 21L, producing around 370 hp. Designed to overcome shortages of large tank engines, the A57 was a creative solution, but its complexity made it difficult to maintain compared to simpler engines. Despite this, the engine proved reliable in combat, and hundreds of Shermans equipped with the A57 saw action, particularly in the European theatre.