Andys Rootes Hillman Imp Home Page

Rootes Hillman Imp

The Imp was innovative in more than a few ways : In complete contrast to the Mini, which was then in its fourth year, the Imp had a rear-mounted 875cc overhead camshaft, all aluminium engine and driving the rear wheels through a combined four speed gearbox and final drive unit (transaxle). Few other cars of that time had an aluminium alloy die-cast engine. The Hillman Imp was Britain's first mass-produced car with engine block and cylinder head cast in aluminium. This engine slants sharply from left to right, canted over at 45 degrees, to lower the centre of gravity (and leave room on top for luggage).
The single overhead camshaft design;
its unusually high compression ratio of 10 to 1, possible because of an advanced combustion chamber shape.
It had one of the first truly ergonomic facias.
Most obvious of all: it was the first mass-production British car ever to have the engine in the back.
Opening rear window: it lifts to give access to luggage room above the engine. Combined with the folding seat squab, it anticipated the hatchback.
The Hillman Imp was the first car to use a Diaphragm Spring Clutch.
In 1963 it had many features that would not become common in other cars until the end of the 70s: a third 'door'; special folding bench seat in the back; automatic choke; no grease points; gauges for temperature, voltage and oil pressure; light, responsive steering.