Ford GAA engine
| Ford GAA | |
|---|---|
 | |
| Overview | |
| Manufacturer | Ford Motor Company |
| Production | 1940 - 1950 |
| Combustion chamber | |
| Configuration | 60° V8 |
| Displacement | 1,100 cu in (18.0 L) |
| Cylinder bore | 5.4 in (137 mm) |
| Piston stroke | 6.0 in (152 mm) |
| Valvetrain | DOHC |
| Compression ratio | 7.5:1 |
| Combustion | |
| Fuel system | Naturally aspirated (i.e., unsupercharged), Stromberg NA-Y5-G carburetors[1] |
| Fuel type | Gasoline |
| Output | |
| Power output | 450 hp (336 kW) @ 2600 rpm |
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,[2] dual magnetos and twin spark plugs making up a full dual ignition system,[2] and crossflow induction.[3]
The GAA was used to power several models and derivatives of the M4A3 Sherman tank. The engine displaces 1,100 in3 (18 l) and puts out over 1000 ft lbs of torque from idle to 2600 rpm. Maximum rated output was 525 hp @ 2800 rpm, though most models were rated at 450 hp.
Development
Immediately preceding World War II, Ford developed an aircraft engine similar to that of the Rolls-Royce Merlin and Allison engines of that era. It was a 60 degree V-12 with aluminum block and head, dual overhead camshaft, and four 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 United States Navy's decision to only use radial engines 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 four 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, T95, and M45 (185).
- The Ford GAN, powered the T23 (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 vehicles were rebuilt from M4A3s, which used the GAA.[4]
See also
Notes
References
- Berndt, Thomas. Standard Catalog of U.S. Military Vehicles. Iola, WI: Krause Publications, 1993. ISBN 0-87341-223-0.
- Sprowl, Bob. Ford's First Dual Over Head Cam V-8.
- Aircraft Engine Historical Society.Aircraft Engines in Armored Vehicles
- Hunnicutt, R. P. Firepower: A History of the American Heavy Tank. Novato, California: Presidio Press, 1988. ISBN 0-89141-304-9
External links
- http://www.youtube.com/watch?v=W2ghTjFtNPo engine running
- "1,500 H.P. Ford V-12" a 1941 Flight article on the Ford V-12 aero engine the GAA was based on