The second test engine formed the basis of the patent version, which Daimler presented to the public on 3 April 1885. Labelled the Grandfather Clock Engine, it featured a closed crankcase, above which the air-cooled cylinder was located.
The intake valve worked automatically; the discharge valve was operated using curved-groove control invented by Daimler. A floating carburettor was also used. The single-cylinder engine weighed a mere 60 kg, had a capacity of 264 cm³ and produced 0.5 hp at 650 rpm. Its low weight and compact dimensions enabled it to be incorporated in vehicles. The initial test carrier was a two-wheeled carriage – what became known as a "riding car". The vision of a high-speed, light-weight universal petrol-driven engine had become reality.