Packard 1A-2500
American V-12 liquid-cooled aircraft engine
From Wikipedia, the free encyclopedia
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.[1] 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.[citation needed]
| 1A-2500 | |
|---|---|
| A preserved Packard 3A-2500 on display at the National Museum of the United States Air Force | |
| Type | Liquid-cooled V12 engine |
| National origin | United States |
| Manufacturer | Packard |
| First run | 1924 |
| Number built | 258 |
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[citation needed]
- 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[citation needed]
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[citation needed]
- 4M-2500
- Marine version, 1200 hp (895 kW), subsequently upgraded in stages to 1500 hp (1,150 kW).[citation needed]
- 5M-2500
- Marine version, larger supercharger, aftercooler, and power output of 1850 hp[citation needed]
Engines on display
- A Packard 3A-2500 is on display at the National Museum of the United States Air Force.[2]
- A Packard 3A-2500 is in storage at the National Air and Space Museum.[3]
- A Packard 3A-2500 is on display at the New England Air Museum.[4]
- A Packard 4M-2500 is on display at the Packard Proving Grounds Historical Site in Shelby Twp., Michigan.[citation needed]
- A Packard Series 142 Diesel Model 1D-1700 is on display at the Packard Proving Grounds Historical Site in Shelby Twp., Michigan.[citation needed]
- Three working Packard 5M-2500s are installed in the only operational PT boat, Higgins PT-658 in Portland, Oregon.[citation needed]
Specifications (1A-2500)
Data from Aircraft Engine Historical Society[5] and Race With the Wind By Birch Matthews [citation needed]
General characteristics
- Type: 12-cylinder 60° V engine
- Bore: 6+3⁄8 in (162 mm)
- Stroke: 6+1⁄2 in (165 mm)
- Displacement: 2,540 cu in (41.6 L)
- Dry weight: 1,120 lb (510 kg)
Components
- Valvetrain: Four valves per cylinder, overhead camshaft
- Fuel type: Petrol
- Cooling system: Liquid-cooled
Performance
- Power output: 850 hp (630 kW) at 2,500 rpm
- Specific power: 0.33 hp/in³ (15.2 kW/L)
- Power-to-weight ratio: 0.76 hp/lb (1.25 kW/kg)
