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.
The R-830 was effectively an enlargement of the R-755 with strengthened stressed parts. With a bore and stroke of 5.0 in ÃÂ 5.5 in (140 mm ÃÂ 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.