Imp I; Ref No. RL 781

For first publication morning papers Friday May 3rd

Britain's newest mini-car, the Hillman Imp

The Hillman Imp, with comfortable seating for four. An aluminium power unit - outstanding feature of this new car - develops 42 gross brake horse power at 5,000 r.p.m., producing a top speed of 75 miles per hour.

With the 875 cubic centimetres power unit mounted above the rear wheels and luggage space at the front and the rear, this car is the first to be manufactured in Scotland for over 30 years.

The alunimium engine is a fascinating feature of this new car. Weighing only 170 pounds, approximately half the weight of a similar cast iron engine unit, it gives increased efficiency, lower petrol consumption and reduces wear on tyres and brakes to provide better all-round performance.

The engine is the result of close collaboration between the car manufacturers, Rootes Group, and Coventry Climax, who with their experience of designing racing engineshave been intimatly concerned with aluminium engines.

Another interesting feature of this new car is the use of a completely new accelerator system. This involves the use of air pressure to replace the conventional rod or cable, linking the motion of the accelerator pedal with the carburettor. This unit is simple, economical and, above all, aids driving by increasing sensitivity of control.

Manufacturer: Rootes Group, Devonshire House, Piccadilly, London, ZZZ 110414 (MA20)
April, 1963


The Imp Site

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imp n child of the devil; little devil; (playfully) mischievous child. --Oxford dictionary

Imp (basic)

May 63 - Sep 65; Oct 69 - Sep 73

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.

After introduction on the market, Rootes made some changes, leading to the Mark II in september 1965

clutch; early and standard
A standard change made quite early on in the Imp's life was to fit a larger clutch. The original 5½ in. dia. became 6¼ in. and the thrust race was improved, too.
throttle cable
The pneumatic throttle was replaced by a cable and this in turn has been modified by Rootes. The photo shows a longer cable from Nathan Racing.
engine mountings
To cut down noise in the Imp, larger engine mountings were fitted. If you have the earlier model and it's noisy, check that this has not been carried out.
door handle
Due to the angle of the door handle and lock, water could get into the lock mechanism.
A change was made and the new type is stronger, easier to use and has a key slot cover.
brake lining
There has been one change in brake linings. Now Ferodo MS2s are fitted to avoid sqeal. Hard linings (VG95) and a Powerstop brake booster are a very good combination.

The engine drives forward to the gearbox, then back through an orthodox differential to independently sprung rear wheels.
It delivers 39bhp at 5000rpm, giving the Imp a top speed of around 80mph (126 km/h) and 45mpg. Output of the BMC Mini was 37. The Imp weighs 1560 lbs (708 kg) and is longer than a Mini, and just a wide and high. It has 12in. wheels. It has smart but not spectacular styling, after the Corvair fashion. A deep contoured flash down the side gives it a bit of character.
It has good allround visibility: the rear side windows stretch much farther back than in most small saloons.

Instrumentation is simple, with two same-size dials for speedometer and auxiliary gauges gauges. Trim is simple but practical in the Rootes tradition.
The new car was one of the few British saloons to have a heater as standard equipment; it utilises the main cooling fan and pumps air to rear as well as front passengers. To compensate for the lack of any opening side windows apart from the ones in the doors, the Imp's designers have given the trailing edge of the roof a cutaway contour and provided built-in extractor slots for stale interior air.

For the Swedish market the Imp was appearantly called a Sunbeam 900

new Hillman Imps in a row at the factory

A row of brandnew Hillman Imps at the factory near Linwood, Scotland.


De Telegraaf, 03-mei-1963


Hillman Imp, kleine maar vinnige wagen

DE opklapbare achterruit van de Hillman Imp fungeert als 'doorgeefluik' van de bagage, die eventueel ook op de neerklapbare achterbankleuning kan worden geplaatst.


De Telegraaf, 03-May-1963


Hillman Imp, small but agile car

THE hinged rear window of the Hillman Imp acts as a 'serving hatch' for the luggage, which may also be placed on the folding rear backrest.


Van onze speciale verslaggever
WASSENAAR, vrijdag

Een achterin gemonteerde 875 cc-motor uit lichtmetaal (gewicht 76.5 kg!) met een acceleratietijd van 0-80 km in 15 à 16 seconden en een opklapbare achterruit, die toegang biedt tot de bagageruimte dat zijn twee van de eigenschappen van de sedert lang verbeide Hillman Imp, die gisteren in alle Westeuropese landen tegelijk werd gepresenteerd. In ons land geschiedde dat door de daadwerkelijke medewerking van de Britse ambassadeur, Sir Andrew Noble, zelf stammend van dezelfde bodem als deze kleine vinnige wagen, nl. Schotland. Een (te) korte testrit in de omgeving van kasteel Oud-Wassenaar leerde, dat de watergekoelde 42 pk-motor met zijn compressie van 10:1 in eerste, tweede en derde versnelling bijzonder pittig optrekt en waarschijnlijk goed is voor een top van rond 120 km. De vierde versnelling dient eerder als een soort overdrive te worden beschouwd. Opgegeven benzineverbruik 1 op 15 à 16 km.

Plezierige rit

De 'zit' in de zg. bucketseats is plezierig en waarschijnlijk zelfs over grote afstand niet vermoeiend. De hoofdruimte is in deze vierpersoons wagen overal uitstekend, de beenruimte is voorin best en achterin geheel afhankelijk van de lichaamsstructuur en de mate van egoïsme van bestuurder en naast hem zittende passagier.

Fraaie afwerking

Wegligging en remvermogen goed. Het motorgeruis is niet hinderlijk. Afwerking in- en exterieur fraai. Er is naar behoren aandacht geschonken aan ventilatie en verwarming. Geen smeerpunten, olieverversen om de 8000 km. De Hillman Imp is in het najaar leverbaar tegen een prijs van f.5690 (inclusief kachel en montagebeugels voor veiligheidsriemen).


From our special reporter

A rear-mounted 875 cc alloy engine (weight 76.5 kg!) with an acceleration of 0-80 km in 15 to 16 seconds and a folding rear window, which provides access to the luggage compartment - these are two of the characteristics of the long since awaited Hillman Imp, which was presented yesterday at the same time in all Western European countries. In our country this came to pass through the effective cooperation of the British ambassador, Sir Andrew Noble, himself stemming from the same soil as this small agile vehicle, i.e. Scotland. A (too) short test drive nearby castle Oud-Wassenaar taught that the water-cooled 42 hp engine with its compression of 10:1 accelerates very snappily in the first, second and third gears and probably good for a top speed of around 120 km. The fourth gear should rather be regarded as a kind of overdrive. Claimed fuel consumption 1 at 15 to 16 km.

Enjoyable ride

The 'sit' in the so-called bucket seats is enjoyable and probably not tiring even over long distances. The head space in this four seater is excellent everywhere, legroom in front pretty good and in the rear completely depending on the body structure and the degree of selfishness of driver and passenger seated next to him.

Attractive finish

Roadholding and braking suitable. The engine noise is not bothersome. Finishing of interior and exterior beautiful. Attention as duly to ventilation and heating. No lubrication points, oil change every 8000 km. The Hillman Imp is available in the autumn at a price of f.5690 (including heater and mounting brackets for safety belts).


In the beginning there were overheating problems. Not only due to faulty radiators, but due to water leaks and to faulty water pumps. Blown cylinder head gaskets were far too common. The situation was worsened by the fact that an aluminium head could warp if it got too hot.
Good detail development work solved these problems but not before the Imp was sadled with an image problem.

In October 1969 basic Imps came avaialble again.

Ref. No. R61910 - reg. no. WHS 88H (Renfrewshire; H= Aug 69 - July 70)
The new Hillman Imp saloon (Ref. no. R61910)

The Haynes Motor Museum appears to have a 1968 Hillman Imp. In Hall 1 they exhibit their "Small family cars of the 50's,60's and 70's" Collection, which features an Imp.
Haynes motor museum, Sparkford, Somerset, BA22 7LH, UK. (01963) 440804


an inspiration in light car design

From a Japanese leaflet of C.Itoh Automobiles:

Hillman Imp with light coloured upholstery

Polar white Imp, the chairs are neither black nor red.

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