The final derivative of the Cossack family was the Sunbeam Matabele, retaining the Aluminium alloy blocks and 122 mm (5 in) bore of the Saracen. The Cossack was a twin overhead camshaft V12, with four valves per cylinder. The Matabele fitted this with two of the blocks from the Saracen, using aluminium instead of the Cossack's cast iron. The Saracen's bore was slightly larger at 122 mm (from the Cossack's 110 mm) and with the same stroke of 160 mm this gave a capacity of 22.4 litres (1,370 cu in). Ignition was by four magnetos (two per bank), with twin sparkplugs. A propeller reduction gear of 1.63:1 was fitted. First run in May 1918, the V-12 Matabele delivered 420 hp (313 kW) at 2,000 rpm.
Developed in two versions, the Sunbeam Matabele I, for aviation use, was fitted with four magnetos, whilst the Sunbeam Matabele II was only fitted with two magnetos supplying a single ignition system for non-aviation use.
Used mainly in Airco DH.4 bombers, the Matabele also found favour as a power-boat and speed-record car engine. No Matabeles were built during the First World War, but prototypes and at least eight production engines were built after the war for various applications.
The Matabele was tested successfully in a DH.4 from May 1918. The only order for the engine, came from France, where the engine was used to power the Nieuport-Delage NiD 30 airliner.