The Sunbeam Spartan was a British 12-cylinder aero-engine designed and built in 1916.
Sunbeam Spartan Wikipedia
Louis Coatalen concentrated on water-cooled engines for the most part, but did design an air-cooled V-12 named Spartan. Little is known of this engine which had a bore of 105 mm (4 in) and stroke of 130 mm (5 in), capacity of 14.03 l (856 cu in) and output of 149 kW (200 hp) driving a propeller through a reduction gearbox. The single overhead camshaft operated two inlet and two exhaust valves per cylinder via rockers and ignition was supplied by two 6-cyl. Magnetos supplying spark to one spark-plug per cylinder.
Data from Sunbeam Aero-EnginesType: V-12 air-cooled piston engine
Bore: 105 mm (4 in)
Stroke: 130 mm (5 in)
Displacement: 14.03 l (856 cu in)
Designer: Louis Coatalen
Valvetrain: Single overhead camshaft, two exhaust and two inlet valves per cylinder
Fuel system: gravity fed
Fuel type: Gasoline
Oil system: Dry sump, pressure fed
Cooling system: Air-cooled
Reduction gear: ratio not known
Power output: 149 kW (200 hp)