The V-12 engine designed by the Italians Vincenso Bertarione and Walter Becchia for Sunbeam utilized two cylinder blocks resembling the1923 and 1924 two-litre Grand Prix Sunbeam, in turn harking to the 1922 winning Grand Prix Fiat Tipo 404. A single Roots supercharger was used but the casing was found to crack due to distortion; it was nevertheless used for the Land Speed Record and was made by Captain J S Irving, Experimental Department head, to last the 3 minutes required at full power; it was subsequently changed to two Roots blowers.

The chassis though longer was closely related to the previous year’s Grand Prix chassis, which originated in the 1922 Ernest Henry Sunbeam G.P. design and was used in these cars from 1926 to 1932.

In 1932 new chassis and mechanical components conceived by Thomson and Taylor was fitted with the two original V-12 engines.