Jacobs R-755

The Jacobs R-755 (company designation L-4) is a seven-cylinder, air-cooled, radial engine for aircraft manufactured in the United States by the Jacobs Aircraft Engine Company.

Design and development

The R-755 was first run in 1933 and was still in production in the 1970s. With a bore and stroke of 5.25 in ÃÂ 5 in (133 mm ÃÂ 127 mm) the displacement was 757 cu in (12.4 L), power ranged from 200 hp to 350 hp (150 kW - 260 kW). The engine features steel cylinders with aluminum-alloy cylinder heads. An R-755E variant was developed for use in helicopters.

Variants

R-755A1:The base-line direct drive production version.

R-755A2:300 hp variant.

R-755A3:Similar to A1 but with Scintilla magnetoes.

R-755B1:De-rated version of the R-755A to drive a fixed pitch airscrew.

R-755B2:De-rated version of the R-755A to drive a variable or controllable pitch airscrew.

R-755E:Up-rated engine with reduction gearing.

R-755EH:Developed to power the Jacobs Type 104 Gyrodyne.

Applications

Engines on display

A preserved Jacobs R-755 is on display at the Arkansas Air Museum.
A Jacobs R-755 is on public display at the Aerospace Museum of California
A preserved Jacobs R-755 is on display at Super T Aviation Academy in Medicine Hat, Canada.
A restored Jacobs R-755A is on display at the House of Whitley.

Jacobs R-755

Design and development

Variants

Applications

Engines on display

Specifications (R-755-A1)

See also

References

External links