Packard 1A-2500

The Packard 1A-2500 is an American V-12 liquid-cooled aircraft engine designed by Packard in 1924 as a successor to the World War I-era Liberty L-12. Five aero variants were produced, of which the 3A-2500 was the most numerous. Three marine versions, used most prominently in American World War II PT-boats, the 3M-2500, 4M-2500, and 5M-2500, were also derived from it.

Applications

 * Boeing TB
 * Heinkel HE 8
 * Martin T3M
 * Naval Aircraft Factory PN
 * Huff-Daland LB-1
 * PT boats - marine versions of the 3M/4M/5M-2500
 * Packard-Bentley one-off race car
 * USSR World War II torpedo boats and sub-chasers, which were fitted with 535 4M-2500 engines with W-8 modification under Lend-Lease

Variants

 * 1A-2500:1924, 800 hp. Six built.
 * 2A-2500
 * 1925, 800 hp. 75 built.


 * 2A-2540:? Huff-Daland XHB-1
 * 3A-2500:1926, Geared propeller drive option, 800 hp. 175 built.
 * 4A-2500:1927, fitted with a supercharger, 900 hp. One built.
 * 5A-2500:1930, experimental use only, 1500 hp. One built.
 * 3M-2500:Marine version
 * 4M-2500:Marine version, 1200 hp (895 kW), subsequently upgraded in stages to 1500 hp (1,150 kW).
 * 5M-2500:Marine version, larger supercharger, aftercooler, and power output of 1850 hp

Engines on display

 * A Packard 3A-2500 is on display at the National Museum of the United States Air Force.
 * A Packard 3A-2500 is in storage at the National Air and Space Museum.
 * A Packard 3A-2500 is on display at the New England Air Museum.
 * A Packard 4M-2500 is on display at the Packard Proving Grounds Historical Site in Shelby Twp., Michigan.
 * A Packard Series 142 Diesel Model 1D-1700 is on display at the Packard Proving Grounds Historical Site in Shelby Twp., Michigan.
 * Three working Packard 5M-2500s are installed the only operational PT boat, Higgins PT-658 in Portland, Oregon.