Jacobs R-915
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
    
The 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
    
- 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
    
    
Engines on display
    
- 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)
    
Data 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
    
Related development
Comparable engines
Related lists
References
    
    Notes
    
- 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.
 
External links
    
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
 
    This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.
