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 × 5 in (133mm × 127mm) the displacement was 757 cu in (12.4 L), power ranged from 200hp to 350hp (150kW - 260kW). The engine features steel cylinders with aluminum-alloy cylinder heads. An R-755E variant was developed for use in helicopters.

Variants

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

2. R-755A2:300hp variant.

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

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

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

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

7. 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.

Specifications (R-755-A1)

See also

References

External links

• The Jacobs Engine - Nanton Lancaster Society

• FAA Type Data Certificate Sheet - R-755

• Jacobs Engine Powered Plymouth Truck