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, production started in 1935.[1]

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

Design and developmentEdit

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.


Specifications (L-5)Edit

Data from FAA TCDS[2]

General characteristics


  • 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


See alsoEdit

Related development

Comparable engines

Related lists



  1. ^ Gunston 1989, p.85.
  2. ^ FAA TCDS Retrieved: 31 January 2009


  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

External linksEdit

  • The Jacobs Engine - Nanton Lancaster Society