The Hillman Imp was the first mass-produced British
car to have the engine in the back, and the first to use
a light aluminum alloy die-cast engine.
from left to right to lower the centre of gravity (and
leave room on top for luggage), the single overhead camshaft
design had an unusually high compression ratio of 10 to
The first car to use a Diaphragm Spring Clutch, it also
featured many standard inclusions that would not become
common on other vehicles until much later.
The list included a third rear hinged 'door' (hatch), a special folding
bench seat in the back, automatic choke, no grease points,
gauges for temperature, voltage and oil pressure.
The engine drove forward to the gearbox, then back through
an orthodox differential to independently sprung rear
Delivering 39 bhp at 5000 rpm, the Imp was good
for a top speed of around 80mph (126 km/h). Sitting on
12in. wheels, it had smart but hardly spectacular styling
- similar to the Corvair fashion.
It had good all-round visibility with easy to read instrumentation
(set inside two same-size dials for speedometer and auxiliary
gauges). Trim was simple but practical in the Rootes tradition,
but the Imp was one of the few British saloons to have
a heater as standard equipment.
Providing an efficient heating system was cleverly developed
by the engineers, their devising a system whereby heated
water was passed up to the front luggage space via the
left hand sill and returned by the right hand sill to
the engine bay.
In the luggage bay the water went to a conventional heater
fan unit located in either the space beneath the right-hand
headlight to that side of the air intake box or to an
internal heater on the internal bulkhead with air coming
through a fan mounted in the area below the headlight. It is a shame then that the heater was standard on only
some models, and most Australian versions were not fitted