Ford GAA engine
Encyclopedia
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 carburetor
s, dual magneto
s and twin spark plug
s, and crossflow induction.
The GAA was used to power several models and derivatives of the M4A3 Sherman tank
. The engine displaces 1100 cu in (18 l) and puts out over 1000 ft lbs of torque from idle to 2600 rpm. Maximum rated horsepower was 525@2800 rpm though most models were rated at 450HP.
and Allison engines of that era. It was a 60 degree V-12 with aluminum block and head
, dual overhead camshaft, and 4 valves per cylinder. The intention of this design was to help Ford break into the anticipated large market for fighter engines. This engine was built to typical aircraft standards: it was light, high performance, and highly reliable. Everything was safety wired or staked with close attention to detail on every part. Available information suggests this design performed well.
However, this engine never went into production as an aircraft engine due to the US Navy's decision to only use radial engine
s for its aircraft, and the Army's contractual commitments to existing engine manufacturers.
With the approach of war, increasing orders for the M4 tanks were causing supply issues with the existing engine. The U.S. Army decided they needed to source an engine supplier, so Ford removed 4 cylinders from the design and it went into production as a V-8.
Ford Motor Company
Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...
during World War II. It featured twin Stromberg
Stromberg
-People:*Lyndon Stromberg, American sculptor and designer*Karl Stromberg, the villain in the James Bond film The Spy Who Loved Me*Joseph R. Stromberg, historian with the Ludwig von Mises Institute*Glenn Strömberg, Swedish soccer player...
NA-Y5-G 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, dual magneto
Magneto
A magneto is a type of electrical generator.Magneto may also refer to:* Magneto , permanent magnetic alternating current rotary generator* ignition magneto, magnetos on internal combustion engines...
s and twin spark plug
Spark plug
A spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed fuels such as aerosol, gasoline, ethanol, and liquefied petroleum gas by means of an electric spark.Spark plugs have an insulated central electrode which is connected by...
s, and crossflow induction.
The GAA was used to power several models and derivatives of the M4A3 Sherman 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...
. The engine displaces 1100 cu in (18 l) and puts out over 1000 ft lbs of torque from idle to 2600 rpm. Maximum rated horsepower was 525@2800 rpm though most models were rated at 450HP.
Development
Immediately preceding World War II, Ford developed an aircraft engine similar to that of the Rolls-Royce MerlinRolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
and Allison engines of that era. It was a 60 degree V-12 with aluminum block and head
Cylinder head
In an internal combustion engine, the cylinder head sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber. This joint is sealed by a head gasket...
, dual overhead camshaft, and 4 valves per cylinder. The intention of this design was to help Ford break into the anticipated large market for fighter engines. This engine was built to typical aircraft standards: it was light, high performance, and highly reliable. Everything was safety wired or staked with close attention to detail on every part. Available information suggests this design performed well.
However, this engine never went into production as an aircraft engine due to the US Navy's decision to only use radial engine
Radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s for its aircraft, and the Army's contractual commitments to existing engine manufacturers.
With the approach of war, increasing orders for the M4 tanks were causing supply issues with the existing engine. The U.S. Army decided they needed to source an engine supplier, so Ford removed 4 cylinders from the design and it went into production as a V-8.
Production
- The GAA was used in the M4A3 (1,690), M4A3(75)W (3,071), M4A3(76)W (1,400), M4A3 (105) (500), M4A3E2 (254), M4A3(76)W HVSS (3,142), M4A3(105) HVSS (2,539), M10A1 (1,413), and M7B1 (826).
- The Ford GAF powered the M26 (2,222), M26A1, and M45 (185).
- The Ford GAN, powered the T23T20 Medium TankThe Medium Tank T20 was part of a series of medium tanks designed by the United States during the Second World War, to be the successor to the Medium Tank M4 "Sherman", and culminated in the M27.-Design and development:...
(248) and M4A3E2 (254). - In order to meet the need for a larger engine, Ford resurrected the V-12 as the GAC, which produced 770 hp and powered the T29 (6).
- A number of M74 tank recovery vehicleM74 Tank Recovery VehicleThe M74 tank recovery vehicle was an engineer vehicle used by the U.S. Army in the 1950s.-History:Based on the M4A3 medium tank, it was developed to cope with the heavier M26 Pershing and M47 Patton which were entering service, which the M32 was unable to retrieve. Using the standard Ford GAA and...
s were rebuilt from M4A3s, which used the GAA.