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Rare British aero-engine documentation from the Pobjoy era

This historical manual collection brings together two original Pobjoy Airmotors publications covering the distinctive geared, seven-cylinder radial engines that powered a small but memorable group of British light aircraft.

Pobjoy Airmotors & Aircraft, Ltd. introduced its engines in 1928 and produced approximately 670 engines between 1930 and 1940. The range evolved from the Pobjoy P prototype through the R, Cataract, Cascade and Niagara families, with outputs from approximately 67 to 142 hp. Their helical reduction gearing allowed high engine speed with low propeller-tip speed, giving Pobjoy installations their characteristic offset propeller hub.

Included in this collection

  • Pobjoy “R” Type Aero-Engine, 80 H.P. Operation, Installation and Maintenance, second edition, issued November 1932, Publication C103. Operator and maintenance coverage for the R-series engine.
  • Pobjoy “Niagara” Series III, “Cataract” Series III and “Niagara” Series IV Installation, Care and Maintenance, issued November 1936, Publication 1000-11-36. A combined service, operator and parts reference for these engine types.

Historical and technical context

  • Geared, air-cooled, seven-cylinder single-row radial engine design
  • 173.0 cu in (2.835 L) displacement, 77 mm bore and 87 mm stroke
  • Approximate range of 67 to 142 hp, depending on variant
  • Associated with aircraft including the Comper Swift, General Aircraft Monospar, Short Scion, British Aircraft Swallow and Fleet Shadower prototypes
  • Today, surviving examples are primarily of museum and historical interest, with a tiny number still flying in vintage aircraft

A compelling reference set for collectors, restorers, historians and enthusiasts researching the engineering, installation and continued preservation of Pobjoy-powered aircraft.

Historical documentation for reference and research. It is not current maintenance or airworthiness guidance.

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