Model Page

Morris Minor MM

Morris Minor MM Side

Production Run:


Production Date:

1948 - 1953


918cc Morris Side Valve


Cowley (UK)


29.2 Secs

Max Speed:

58 Mph

The Original Morris Minor MM was released in 1948 and remained in production until 1952, seating four adults the vehicle was available as a two door saloon, four door saloon or a convertible powered by a 0.9 litre in line four cylinder engine. The Morris Minor MM was the first new model produced by the Morris Motor Company since the end of World War 2. Production of the Minor continued for nearly 25 years, the Series II replacing the Original Minor in 1952.

The Managing Director of Morris Motors Miles Thomas, Vic Oak and designer Alec Issigonis discussed a concept for a new vehicle following the end of World War Two. They identified the need to manufacture a small saloon car that would be cheap to manufacture with a price point affordable for the working class, a car that would be easy to maintain but include a range of luxuries.

Morris Minor MM Front

Morris Minor MM Front

Alec Issigonis is perhaps better known for his work on the ingenious Mini, however it was with his design work on the Morris Minor that he first drew mainstream attention. The design team was led by Issigonis working with Jack Daniels and Engineer Reg Job, Issigonis opted to ditch the traditional separate chassis with bolt on body tub method of construction instead choosing to use a steel mono-construction body.

The car featured independent suspension at the front by method of torsion bars, Issigonis had wanted to install independent rear suspension and had begun development of such a configuration however cost constraints meant that the live rear axle from the Morris Eight was installed this using semi elliptic leaf springs. Steering was positive thanks to the rack and pinion setup that required 2.6 turn lock to lock, braking was unsurprisingly Lockeed Hydraulic 7” drums front and rear. Power was delivered to the rear wheels through a four speed manual gearbox (no automatic available), the unit had synchromesh on the top three gears.

The car was fitted with many features that were usually only available on larger vehicles such as safety doors that were front hinged, safety glass, private lock to the driver doors, a safety catch for the passenger door and bonnet lock with safety catch.

Morris Minor MM Rear Profile

Morris Minor MM Rear Profile

Issigonis had anticipated installing a new design horizontally opposed four cylinder engine into the car and the engine bay was designed to be wide enough to take this power plant, four distinctive gaps remain in the engine bay to accommodate it. Management decided that the car did not warrant the extra development costs of a completely new engine and so opted to use the existing Morris side 918cc four cylinder side valve engine that was used in the Morris Eight Series E – the new flat four design was not taken any further. The engine had a bore of 57mm and stroke of 90mm, with an eight valve design and a compression ratio of 6.6:1 the engine developed 29.5 bhp @ 4,400 rpm and generated 39 lb/ft of torque @ 2,400 rpm the unit achieving a respectable 36 mpg.

Head of Morris Motors Lord Nuffield disliked the design of the car and called it a “Poached Egg”, the MD of Morris Motors Miles Thomas and Issigonis retained their faith in the model believing that it would ultimately prove successful, in 1947 disillusioned with the project being held up by management Thomas resigned, Thomas was replaced by Reggie Hanks who fortunately was also a believer in the model. At this point the name of the car which was originally destined to be the Morris Mosquito was changed by the direction of Lord Nuffield to “Minor” a name that was used on a model produced some 15 years previous.

Ever the perfectionist Issigonis was not completely satisfied with the design of the prototypes, the car was ready for production and in fact some components had already begun manufacture. Despite this he instructed engineers to cut the car in half proceeding to move both parts away until the car looked right thus widening the dimensions of the car. This last minute change in the design can be identified on the production models by a 4” wide strip down the middle of the bonnet.

Had it not been for the uncooperative upper management the car could have been launched nearly 12 months previous to its official launch at the Earls Court Motor show in London on 20th September 1948.

Morris Minor MM Interior

Morris Minor MM Interior

At launch the car cost £382 and was available in two models – a two door saloon and a convertible (Tourer), only three colours were available namely Black, Grey, Green and Maroon. The car proved immensely successful particularly in overseas markets so much in fact that in 1949 75% of production was exported to the US, this increased to 80% in 1950 and further still to 90% in 1951.

The Minor received much praise from the press and motoring public with the car drawing positive comments for its handling, stability and steering feel. The vehicle quickly developed a strong reputation and was noted for its good reliability record, the only drawback noted was with the ageing side valve engine. With such a poor power output the car struggled to achieve a top speed of 58 Mph – this would not be rectified until the introduction of the Series II.

With such large numbers of cars being exported to the US the car was not as frequent a sight on British Roads as it could have been. To comply with US regulation car exported to the states had the headlamps removed from the grille and mounted higher on the wings differing from the British variants - in 1951 the change became standard on all cars manufactured.

The Morris Minor MM was replaced by the Series II in 1952 with Morris having sold 250,962 the majority of which were sold to the US. The new model was introduced to address weaknesses of the first model and featured an improved enlarged engine that helped to resolve the cars main failing - its shortfall in performance.

The Facts


Morris Side Valve In Line 4





Compression Ratio:


Fuel System:

SU H1 Carburettor

Maximum Power:

29.5 bhp @ 4,400 rpm.

Maximum Torque:

39 lb/ft @ 2,400 rpm.


Manual 4 speed.

Top Gear:



Hydraulically Operated Front Drums / Rear Drums

Kerb Weight:

742 Kg

Max Speed:

58 Mph


29.2 Secs