The Packard 1A-2500 is an American V-12 cylinder liquid-cooled aircraft engine designed and first run in 1924. Of the five variants produced the 3A-2500 was the most numerous.
Equipment supplied was a fuel pump, propeller hub attaching parts, and tool kit. Available at extra cost was an Aeromarine starter.
A total of 258 were built. The unit cost for the geared 3A-2500 was $19,375.
The marine version of this engine was used in most PT boats as the 3M/4M/5M-2500.
Type: V-12 water cooled
Approved Type Certificate No.19
Military Rating: 835 hp at 2100 rpm
Commercial Rating: 800 hp at 2000 rpm
Displacement: 2540 cu.in
Compression ratio: 5.1-1
Bore: 6 3/8 in
Stroke: 6 1/2 in
Length: 69 3/4 in
Width: 29 1/2 in
Height: 42 in
Weight: 1210 lb
Fuel consumption: not more than .52 lb/hp/hr
Oil consumption: not more than .025 lb/hp/hr
Ignition: Delco or Sintilla dual
Carburation: Dual Stromberg NAS-12
Spark plugs: 2 per cylinder B.G. Hornet
Price: direct drive $15,625 – geared $19,375