At the end of the 1920’s the first six-cylinder engine was in production and became the foundation for the large six-cylinder cars produced throughout the 1930’s and up to the Second World War. In true Alvis tradition these cars were technically advanced with the world's first all-synchromesh gearbox, independent front suspension and servo assisted brakes.
The six cylinder engine was the basis of the design for all six cylinder engines used in ther Silver Eagle, Speed 20, Crested Eagle, 3.5 Litre, Speed 25 and 4.5 Litre models.
The 14.75 engine (capacity 1870cc) had separate castings for the cylinder head, cylinder block, crankcase and sump, the last two being aluminium. Valves were push rod operated and a transfer port at the rear of the head and block obviated the need for a water tight joint. This, together with the timing arrangements now at the rear of the engine, were features used on all future six cylinder engines.
The chassis of the 14.75 differed little from that used for the 12/50. These cars were in production during 1928 (type TA) and 1929 (type TB).