The Armstrong Siddeley 17 HP

The 17 HP model was produced between 1935 and 1939, with a total production of 5,011 vehicles. The 17 HP model was offered in three chassic lengths; the 9'3" wheelbase short chassis, the 9'8" wheelbase standard chassis, and the 10'3.5" wheelbase long chassis, with body styles matched to each chassis. 

By the mid 1930's the side valve motors had been developed as far as possible and in the search for performance, an overhead valve 17HP model was produced to replace the 15HP.

The motor had a bore/stroke of 67mm / 114mm giving an engine capacity of 2,394cc producing a quoted power of 55 to 60bhp at 3,300rpm giving a maximum speed of 73mph (Motor). Drive was via an open propeller shaft and a separately mounted gearbox, which changed to a 'balanced drive' configuration of gearbox mounted to the engine block part-way through production. Petrol consumption was 19mpg. Initially, the gear change pedal was used as a clutch with a centrifugal clutch becoming available in 1937. On the short chassis variant, radius arms were used to relieve the front springs of braking stresses.

In line with current practice of the time, box section side rails were used for the chassis to increase stiffness. Part way through the 17 HP model life, the chassis rail bracing was increased to further improve chassis stiffness.