The Jacobs R-915 or Jacobs L-6 is a seven-cylinder, air-cooled, radial engine for aircraft manufactured in the United States, production started in 1936.[1]
| R-915 | |
|---|---|
| |
| Type | Radial engine |
| Manufacturer | Jacobs Aircraft Engine Company |
| Developed from | Jacobs R-755 |
Design and development
editThe R-915 was effectively an enlargement of the R-755 with strengthened stressed parts.[2] With a bore and stroke of 5.5 in × 5.5 in (140 mm × 140 mm), for a displacement of 915 cu in (15 L). Take-off power was around 330 hp (250 kW). The engine features steel cylinders with aluminum-alloy cylinder heads.
Variants
edit- R-915A1
- Baseline variant; an enlarged R-755
- R-915A3
- Similar to the A1 but with Scintilla magnetoes
- R-915A4
- With a power take-off for autogyros
Applications
editEngines on display
edit- A preserved Jacobs R-915 is on display at the Nanton Lancaster Society.[3]
- A Jacobs L-6 is on display at the Canadian Museum of Flight[4]
Specifications (R-915A1)
editData from Jane's[5]
General characteristics
- Type: 7-cylinder air-cooled radial piston engine
- Bore: 5.5 in (140 mm)
- Stroke: 5.5 in (140 mm)
- Displacement: 915 cu in (15 L)
- Length: 40 in (1,030 mm)
- Diameter: 45.5 in (1,160 mm)
- Dry weight: 555 lb (252 kg)
Components
- Valvetrain: 2 valves per cylinder (pushrod-actuated); sodium cooled exhaust valves
- Fuel system: Single Stromberg NA-R7A carburetor
- Fuel type: 80 octane
- Oil system: One pressure pump, two scavenge pumps
- Cooling system: Air-cooled
- Reduction gear: Direct drive, right hand tractor
Performance
- Power output: 330 hp (246 kW) at 2,200 RPM at sea level
- Specific power: 0.36 hp/cu-in (16.4 kW/L)
- Compression ratio: 6:1
- Power-to-weight ratio: 0.6 hp/lb (1 kW/kg)
See also
editRelated development
Comparable engines
Related lists
References
editNotes
edit- ^ Gunston 1989, p.85.
- ^ Wilkinson, Paul H. (1950). Aircraft engines of the World 1950 (8th ed.). London: Sir Isaac Pitman & Sons Ltd. p. 161.
- ^ Nanton Lancaster Society: Jacobs L-6 MB Retrieved: 23 July 2015
- ^ The Canadian Museum of Flight - L-6 Retrieved: 31 January 2009
- ^ Janes 1989, p.305.
Bibliography
edit- Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
- Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1989. ISBN 0-517-67964-7
External links
edit
Wikimedia Commons has media related to Jacobs L-6.
- Jacobs L-6 MB, Bomber Command Museum of Canada - Nanton Lancaster Society
- FAA Type Data Certificate Sheet - R-915