Chrysler A57 multibank
Encyclopedia
Created in 1941 as America entered World War II
, the A57 Multibank engine was born out of the necessity for a rear-mount tank engine to be developed and produced, in the shortest time possible for use in M4A4 Medium tank
.
In order to use existing tooling, five Chrysler 250.6 in3 (4.12 litre; 3.4375" {87.3 mm} bore and 4.50" {114.3 mm} stroke) L-head
inline six cylinder engines were arranged around a central shaft, producing a unique 30 cylinder 21 litre (1253 in3) engine in a relatively compact but heavy package. The crankshafts were fitted with gears, which drove a sun gear
arrangement. With iron block and head, it featured Carter TD-1 carburetor
s and 6.2:1 compression ratio
, for an output of 470 hp at 2400 rpm. It necessitated a longer hull (same as the M4A6), becoming the M4A4; most of these were supplied to Allied countries under Lend-Lease
.
In a February 1944 advertisement on the magazine Popular Science
, Chrysler claimed the A57 could still move the tank it was fitted in even if 12 out of its 30 cylinders were knocked out.
The M4A4 was largely supplied to the British, the US preferring the M4A3 with a more conventional V8 engine
, and restricting their M4A4s from overseas use.
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the A57 Multibank engine was born out of the necessity for a rear-mount tank engine to be developed and produced, in the shortest time possible for use in M4A4 Medium tank
M4 Sherman
The M4 Sherman, formally Medium Tank, M4, was the primary tank used by the United States during World War II. Thousands were also distributed to the Allies, including the British Commonwealth and Soviet armies, via lend-lease...
.
In order to use existing tooling, five Chrysler 250.6 in3 (4.12 litre; 3.4375" {87.3 mm} bore and 4.50" {114.3 mm} stroke) L-head
Flathead engine
A flathead engine is an internal combustion engine with valves placed in the engine block beside the piston, instead of in the cylinder head, as in an overhead valve engine...
inline six cylinder engines were arranged around a central shaft, producing a unique 30 cylinder 21 litre (1253 in3) engine in a relatively compact but heavy package. The crankshafts were fitted with gears, which drove a sun gear
Epicyclic gearing
Epicyclic gearing or planetary gearing is a gear system consisting of one or more outer gears, or planet gears, revolving about a central, or sun gear. Typically, the planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear...
arrangement. With iron block and head, it featured Carter TD-1 carburetor
Carburetor
A carburetor , carburettor, or carburetter is a device that blends air and fuel for an internal combustion engine. It is sometimes shortened to carb in North America and the United Kingdom....
s and 6.2:1 compression ratio
Compression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...
, for an output of 470 hp at 2400 rpm. It necessitated a longer hull (same as the M4A6), becoming the M4A4; most of these were supplied to Allied countries under Lend-Lease
Lend-Lease
Lend-Lease was the program under which the United States of America supplied the United Kingdom, the Soviet Union, China, Free France, and other Allied nations with materiel between 1941 and 1945. It was signed into law on March 11, 1941, a year and a half after the outbreak of war in Europe in...
.
In a February 1944 advertisement on the magazine Popular Science
Popular Science
Popular Science is an American monthly magazine founded in 1872 carrying articles for the general reader on science and technology subjects. Popular Science has won over 58 awards, including the ASME awards for its journalistic excellence in both 2003 and 2004...
, Chrysler claimed the A57 could still move the tank it was fitted in even if 12 out of its 30 cylinders were knocked out.
The M4A4 was largely supplied to the British, the US preferring the M4A3 with a more conventional V8 engine
Ford GAA engine
The Ford GAA engine is an all aluminum, 32 valve, DOHC, 60 degree V8 engine produced by the Ford Motor Company during World War II. It featured twin Stromberg NA-Y5-G carburetors, dual magnetos and twin spark plugs, and crossflow induction....
, and restricting their M4A4s from overseas use.
External links
- The Chrysler A57 Multi-Bank Engine - An amazing engine by Julian Edgar of AutoSpeed.