Jacobs R-830

The Jacobs R-830 or L-5 is a seven-cylinder, air-cooled, radial engine for aircraft manufactured in the United States by the Jacobs Aircraft Engine Company, beginning in 1935.^[1]

R-830
Type	Radial engine
Manufacturer	Jacobs Aircraft Engine Company
First run	1935
Developed from	Jacobs R-755
Developed into	Jacobs R-915

Design and development

The R-830 was effectively an enlargement of the R-755 with strengthened stressed parts. With a bore and stroke of 5.0 in × 5.5 in (140 mm × 127 mm) the displacement was 831 cu in (13.6 L), takeoff power was around 285 hp (212 kW). The engine features steel cylinders with aluminum-alloy cylinder heads.

Applications

• Beechcraft Model 18B & S18B Expeditor
• Beechcraft B17B and C17B Staggerwing
• Fleet 50J Freighter (prototype only)
• Fleetwings Sea Bird
• Howard DGA-9
• Spartan 7X Executive (prototype only)
• Waco ZKC-S, ZKS-6 & 7 Standard Cabins
• Waco YOC-1 ZQC-6 ZGC-7 Custom Cabins
• Waco ZVN-8 Custom Cabin
• Waco ZPF-6 and ZPF-7

Specifications (L-5)

Data from FAA TCDS^[2]

General characteristics

• Type: 7-cylinder air-cooled radial piston engine
• Bore: 5.5 in (140 mm)
• Stroke: 5.0 in (127 mm)
• Displacement: 831 cu in (13.6 L)
• Dry weight: 515 lb (234 kg)

Components

• Valvetrain: 2 valves per cylinder (pushrod-actuated); sodium cooled exhaust valves
• Fuel system: Stromberg NA-R7A carburetor
• Fuel type: 73 octane
• Cooling system: Air-cooled
• Reduction gear: Direct drive, right hand tractor

Performance

• Power output: 285 hp (212 kW) at 2,000 rpm at sea level
• Compression ratio: 6:1
• Power-to-weight ratio: 0.55 hp/lb (0.9 kW/kg)

See also

Related development

• Jacobs R-755
• Jacobs R-915

Comparable engines

• Armstrong Siddeley Cheetah

Related lists

• List of aircraft engines