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

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of 5.25 in × 5 in (133 mm × 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

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s. 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

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(B17L, C17L, E17L) * Boeing-Stearman PT-18 Kaydet * Cessna AT-17 Bobcat * Cessna 195 * Funk F-23 * Grumman G-164 Ag Cat * Kellett KD-1 * Lascurain Aura * Morane-Saulnier MS.505 Criquet * Waco F series (YMF, YPF) * Waco Custom Cabin series (YOC, YQC) * Waco Standard Cabin series (YKC, YKC-S, YKS-6) * Waco PG-3 (twin-engined powered version of Waco CG-15 glider, prototype only)

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 a
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)

References

External links

The Jacobs Engine - Nanton Lancaster Society

FAA Type Data Certificate Sheet - R-755

Jacobs Engine Powered Plymouth Truck
{{US military piston aeroengines 1930s aircraft piston engines Aircraft air-cooled radial piston engines Jacobs aircraft engines