The Armstrong Siddeley 12hp model introduced in 1929 had sold very well, however,  by 1935 it was evident that to continue to compete with the new models from other manufacturers the car required a facelift together with a more powerful engine.

A new overhead valve engine of 1,666cc,  RAC rating 14hp, was fitted to the existing body in October 1935; the model was renamed the 12 plus. Customers seeking a modern looking 12 plus had to wait until November 1935 when a new chassis and body were introduced with a more up-to-date appearance, this model became known as the 14hp.

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The following images are all of the 14hp fitted with a Burlington body.