Armstrong Siddeley 18hp This page is under development
Armstrong Siddeley 1927 Mk II 18hp Stirl

Armstrong Siddeley 1927 Mk II 18hp Stirling Saloon

Following the 1920 motor show it was quickly apparent that John Siddeley had found a winning formula in the new 30HPcar. Also he was aware that there was substantial interest from would be purchasers who's pockets were not quite deep enough. So, only 12 months later the 18HP car was launched. Chassis priced at £575 while the complete Tourer was an attractive £670 which made it about the same price as the chassis only version of the larger car. Still not cheap, but of a quality which brought continuing Royal patronage.  Prince Henry, Duke of Gloucester, acquired a 18HP saloon whilst Prince Albert purchased two 18HP cars, one an open sports and the other for state occasions.

Armstrong Siddeley 30hp and 18hp compari

Technical Specification

Technical Specification

Public awareness was further strengthened by a 10,000 mile day and night trial overseen by the RAC with an 18hp achieving an average 24.5mpg. Today some Club members would be happy with such a return using their later cars.


Technically the car was very much after the design of the larger 30 HP. The engine was a six cylinder Bi-block of 2386cc capacity, whilst the wheelbase was 1foot 3inches shorter at 10feet.

As was common practice at the time breaking was accomplished using the rear wheels only. Interestingly these drums contained two sets of shoes. The inner being operated by the foot pedal and the outer by the handbrake. Later cars were fitted with four wheel brakes which had aluminium shoes fitted with friction lining material and operated in large drums all round. These were unusual and certainly the latest technology of the day. Henri Perrot a French pioneer automobile engineer while working for the Argyle motor manufacturing company in Scotland had developed a system which allowed the brakes to be applied to all four wheels by use of either foot pedal or brake lever. This system was patented in America and would be more familiar to us as, Bendix 'servo' braking, not to be confused with modern servo power hydraulic braking. This was 1921 and it shows John Siddeley's awareness of the fast developing automotive engineering industry in that it would take till 1925 before some 50 makes of car had such braking


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