Ford GAA engine


The Ford GAA engine is an American all-aluminum 32-valve DOHC 60-degree liquid-cooled V8 internal combustion engine designed and produced by the Ford Motor Company before and during World War II. It features twin Stromberg NA-Y5-G carburetors, dual magnetos and twin spark plugs making up a full dual ignition system, and crossflow induction. It displaces and puts out well over of torque from idle to 2,200 rpm. The factory-rated gross output was at 2,600 rpm.
The GAA powered several models and derivatives of the M4A3 Sherman medium tank.

Development

Immediately preceding World War II, Ford developed an aircraft engine similar to that of the American Allison V-12 V-1710. It was a 60 degree V-12 of 1,650 cubic inch displacement with a matching set of cylinder bore/piston stroke figures to the Rolls-Royce Merlin aviation engine, using an aluminum block and head; dual overhead camshafts, and four valves per cylinder. The intention of this design was to help Ford break into the anticipated large market for fighter aircraft 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, it 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 manufacturers.
With the approach of war, increasing orders for M4 Sherman tanks were causing supply issues with the 9-cylinder radial Wright R-975 Whirlwind engine used. The U.S. Army decided it needed to source additional engine suppliers, choosing a version of the Ford GAA cut down from twelve cylinders to eight for various vehicle applications.

Production