|
| M Type Profile |
The M type MG, the first ‘Triple-M car’ built by the MG Car Company, went into production in 1929 having been introduced to the public at the 1928 London Motor Show. The car was based largely on the Morris Minor, introduced in 1928, sharing the same chassis layout, engine and running gear. The chassis was of conventional, ladder frame design, with side frames pressed into a ‘C’ section and swept up over the front and rear axles. Chassis cross bracing was by inverted steel channel, riveted to the side frames, while the suspension was by semi-elliptic springs, pinned at their front ends and having shackle plates at their rear. The cars were fitted with four wheel, 8" diameter drum, brakes, mechanically operated by rod and cable. Early cars were fitted with a separate transmission hand brake. The engine was a four cylinder unit of 847cc and very similar to the production Morris Minor which itself, derived from an 8hp design from the Wolseley Company which Morris had bought in 1927. The engine featured a single overhead camshaft, driven at the front, by two sets of bevel gears off the crankshaft and utilising the armature of the vertically mounted, six-volt dynamo to transmit the drive. The short crankshaft had only two main bearings, the one at the front being a large diameter double row ball race, which also located the crankshaft, and the one at the rear being a white metal lined bronze sleeve. An oil pump, driven from a gear on the front of the crankshaft, which also drove the distributor, fed oil under high pressure, via an external filter, to the rear main bearing through a gallery cast into the side of the block and from there to the four big-ends through the hollow crankshaft. The front main bearing was lubricated by a combination of the excess oil from the pump, and oil draining from the cylinder head, venting into the front engine housing and through the ball-race on its way back to the sump. The crankcase and block, manufactured in iron, were in one piece and the crankshaft was fitted through an opening in the front of the block, there being no main bearing caps, resulting in quite a ridged structure. The overhead valves were adjusted through eccentrically mounted ‘fingers’, which interplayed between the camshaft and valve stem. The whole engine was very neat and compact and developed 20 bhp, which endowed the car with a top speed of about 65mph - a very creditable performance for the late 1920s. The engine drove the rear wheels through a non-syncromesh three speed gearbox of Morris design, through a prop shaft fitted with fabric ‘universal’ joints to a conventional back axle with spiral bevel gears and two star differential. The standard M type body was an open, two-seater of wooden frame construction covered in a Rexene like fabric, which was commendably light and cheap to make. Later cars had all steel body coverings. Neat, domed topped, ‘cycle’ wings covered the wheels. No running boards were fitted so the exposed chassis under the door was covered with a deep, slotted metal plate, giving the car a lower look on the road. A small ‘boot’ at the back contained the spare wheel and some luggage accommodation, the petrol tank being incorporated in the scuttle above the driver’s legs and fed the engine by gravity. A closed bodied, two-seat variant was also available known as the ‘Sportsman’s Coupé’. As was the convention at the time, the cars could be bought in ‘chassis only’ form and a number of coach-building firms produced their own body styles fitted out to customer’s specification. Principle among these was the coach-building firm of Jarvis. The M type was certainly a popular car, judged by the relatively large number built, especially considering the niche market that existed for small, two-seat sports cars.
M type specification
Wheelbase
Track
Steering
Brakes
Wheels
Tyres
Chassis weight
Weight of complete car:
'fabric' two-seat
'fabric' Coupé |
6' 6" (1.98m)
3' 6" (1.06m)
Adamant
8' drums, rod & cable operated
2.50" x 19" centre laced wire, bolt on
4.00" x 19"
8 cwt 23 lbs (416.8 kg)
10 cwt 14 lbs (514.4 kg)
11 cwt 70 lbs (590.6 kg) |
Bore
Stroke
Capacity
Power output |
57mm
83mm
847cc
20 bhp, later cars 27 bhp |
| 13th April 1929 |
to 1st June 1932 |
| Cars produced: |
Total 3235 |
‘Fabric’ two-seat
‘Fabric’ Coupé
‘Metal’ two-seat
‘Metal’ Coupé
12/12 Replicas
Chassis only |
2329
493
273
37
21
82 |
M type pictures:
|
|
|
|
