The TR 247 is a one-off prototype 2.47 cc diesel constructed by Gordon Cornell in 1960 during his tenure as chief engineer for the E.D. company. It was one of a group of three protoypes constructed by Gordon as potential replacements for the then-venerable E.D. Racer. Gordon had previously designed and constructed his remarkable one-off TR 148 front rotary valve diesel which has been reviewed separately.

The TR 247 was the only one of the three 2.5 cc prototypes to utilize an "inside-out" rear drum valve in which the drum's central gas passage was open to the atmosphere rather than the crankcase, with the valve discharging near-vertically directly into the crankcase. Gordon termed this the "centrifugal" drum valve, using it again later in his superb little Dynamic .049 diesel. The concept was subsequently widely adopted by team race engine designers, being developed by HP and others into the so-called "bell valve" arrangement. However, it was Gordon who showed the way.

To make his point to E.D. management, Gordon used this engine in the team race event at the 1960 British Nationals, unfortunately not making it onto the leaderboard. Although the design clearly had great potential, E.D. management were not in a financial position to authorise its series production.  Accordingly, the illustrated example was the only one ever constructed.

A full review and test of this remarkable unit may be found elsewhere on this website.