Chrysler A57 multibank
The Chrysler A57 Multibank is a 30-cylinder engine that was created in 1941 as America entered World War II. It consists of five banks of inline-6 cylinder engines. It was born out of the necessity for a rear-mounted tank engine to be developed and produced in the shortest time possible for use in the M3A4 Lee medium tank and its successor M4A4 Sherman medium tank. Each had lengthened hulls to accommodate the A57. In order to use existing tooling, five Chrysler flathead engines (bore , stroke ) were arranged around a central shaft, producing a unique 30-cylinder engine in a relatively compact but heavy package. The combined assembly consisted of five of these straight-six engines mounted in a pseudo-radial fashion upon a central cast-iron crankcase. The arrangement employed a common radiator, water pump, oil pan & dual oil pumps, with each of the five component crankshafts fitted with a geared flywheel that meshed with a central sun gear that drove a main shaft running through the central crankcase. Each of the six-cylinder sub-blocks had an iron head and featured a Carter TD-1 carburetor and a 6.2:1 compression ratio, with tuned pipes that fed into a common exhaust; output was at