Packard V-type engines were basically scaled-up and modernized versions of the WWI Liberty engine and were produced in standard upright and inverted versions. The geared version drove the propeller at half the engine speed, which doubled the torque to the propeller shaft, giving more thrust for large aircraft carrying heavy loads.
The 2A-1500 series had several special features: Each cylinder and valve assembly could be removed and replace as a single unit, reducing maintenance time. A choice of cast aluminum pistons of various compression ratios was available. Engines with higher compression ratios required a mixture of av-gas and benzol as fuel. Two double-barrel Stromberg NA-Y6P carburetors were provided.
The 2A-1500 was used primarily in US Navy aircraft. The 700 hp version powered the 1926, US Navy, Curtiss R3C-3 Schneider Trophy seaplane race entries during which one established a qualifying speed record of 255 mph. Standard 525 hp versions powered the PN-10 flying boat, Loening OL-6 and XOL-7 amphibians, and Boeing FB-5 fighter. In service, the 2A-1500 lacked the reliability required by naval aviation contributing to the US Navy’s need to standardize radial aircraft engines in the 1930s.
The engine on display is on long term loan from the National Museum of the Marine Corps.