By DAVID PIKE

The rear-engined Hillman Imp, first launched in 1963, remained in production until the mid-1970s. Over that period more than 440,000 variants were produced but the number could have been greater had it not had to compete with BMC's popular Mini and the Rootes group had not had financial problems.

In an unusual move it seemed strange for the Rootes group, with a good history of building conventional cars in the Hillman, Humber and Sunbeam families, to make a decision to develop a new small car which was somewhat unconventional. No doubt a quick survey of the available competition, which included the Mini with its front wheel drive, Ford Anglia and Triumph Herald, caused Rootes to think outside the square.

To give Rootes a marketing point of difference they opted for a rear-engined car. The design called for the engine to be mounted in the tail with the transmission ahead of it. Some motoring people believe the rear-engined Chevrolet Corvair provided some inspiration for this design. It did, however, require a completely new alloy engine, transmission and all-independent suspension layout.

The new four-cylinder, single overhead camshaft engine was based on a Coventry Climax racing design with a bore and stroke of 68 x 60.4 mm and a capacity of 875 cc. Whilst small this engine delivered 27.5kW at 4800rpm and had a top speed of 125 km/h.

The swing axle front independent suspension, and semi trailing arms at the rear were extremely effective. Though the Imp's main weight was basically towards the rear, it was described by testers as being a good handler, with precise steering and excellent traction. Storage space was adequate with plenty of room for luggage at the front and further storage space behind the rear seats, ahead of the engine. It had much more room than the Mini, and also had a useful lift-up rear window.

Initially the Imp had some reliability problems that took some two to three years to be eliminated. These, coupled with pricing a little above the competition, proved somewhat of a sales retardant. Better price points might have been achievable if the cars could have been built at a single location but for political and employment purposes, Rootes had been obliged to build Imps in Scotland with an inexperienced workforce whilst engines and transmissions were being assembled in the English Midlands.

Rootes was sufficiently happy with the Imp design that, as well as Hillman, it eventually appeared under the Singer, Sunbeam and Commer marques. Some of these various marques had either more powerful engines or came as sporty versions, including fastback coupes, but in spite of these interesting variants Rootes was never able to obtain a level of sales that matched those of its competitors.

© Copyright David Pike