Ariel 1934 “4F” Square Four 597cc OHC four cylinder frame # Y 1572 engine # A 184
The Ariel square four’s original design by Edward Turner is said to have been a masterpiece, but it proved too costly to produce commercially and so chief designer Val Page was instructed by the Ariel Board to cut its costs by making any alterations that were necessary.
Page went to work and the production version of the redesigned Four was presented to the public at the London Olympia Show in November 1930. The machine was heavier than the original design and didn’t have the integrated gearbox. The frame and cycle parts were common to those of the existing 500 cc Sloper Model, but it created a sensation, nevertheless.
The 1931 model had a cubic capacity of 498cc; in 1932 the cubic capacity was upped to 597cc. The 498cc model would stay available for a limited period to special order.
The engine is an air cooled square four with chain driven overhead camshaft. The two crankshaft are coupled by gears. The mixture is fed to the engine through a single, front-mounted Amal carb and the lubrication is of the wet-sump type with a plunger pump.
Standard equipment was hand change for the four speed Burman gearbox, this Square Four comes with the optional foot change. The machine’s weight is about 180 kilograms – only about 15 kgs more than the 500cc Red Hunter single! Max power is 24 HP @ 6,000 rpm and top speed amounts to a comfortable 75 mph. New for the 1934 model year were new front forks of stronger construction. Furthermore the internals of the Burman gearboxes were redesigned to provide easier gear changing and a longer operating life. This pleasant-to-ride, vibrationless motorcycle is fitted with a tank top dashboard with speedometer, clock, inspection light and oil pressure gauge. A Bosch electric horn is fitted and there’s a tyre pump on board. This fascinating early Square Four is a well-running older restoration.