By 1923, when this AC Empire was built, AC Cars Ltd had already launched their 2-litre overhead-cam 6-cylinder engine that was produced by the company with continual improvements until 1963. But this AC 12 hp is powered by a side-valve, 1,496 cc 4-cylinder made by Anzani. It has three-speed transmission, quarter-elliptic front and rear suspension and drum brakes on the rear wheels only.
An auction catalogue for a similar car from 1926 explains that at the rear of the driveshaft, protruding through the differential, is a rotating disc, which can be clamped to stop the car when the driver needs to park.
Having only a single door and having six wheel nuts per wheel both identify this car as an Empire model, rather than the slightly more upmarket Royal that, strangely, has only four wheel nuts per wheel. In 1966 only 10 Empire models were known to exist – so this must be a rare car.
Photo courtesy of Peter McFadyen. See his website: http://petermcfadyen.co.uk
Both Royal and Empire versions of the 4 cylinder AC had only a single door (I have both models). Oddly, 4 cylinder cars have 6 nut wheels, 6 cylinder cars have 4.