The 1.5-litre Cambridge — the big-selling middle of Austin’s first unitary family saloon.
The A40 and A50 Cambridge were announced together in September 1954 to replace the A40 Somerset. They share one new unitary four-door body and differ in the engine: 1.2 litres for the A40, 1.5 for the A50. The A50 was much the bigger seller — 114,867 against 30,666 — and it is the car that put the B-series into an Austin saloon. Austin made a point of the brakes at launch, the friction area rising from the Somerset’s 85 square inches to 121. Nissan was building Austins under licence in Japan through the same years, 20,855 of them between 1953 and 1959.
Three dates decide most A50 parts. The door glass changed within weeks of launch, the original counterbalanced drop windows giving way to conventional wind-down winders, so early and late doors are not the same inside. Semaphore trafficators gave way to amber flashers in early 1955. And in the autumn of 1956 the car came down from 15in wheels to 13in on 5.90-13 tyres, which moves wheels, tyres, hubs and the speedometer drive all at once; the compression ratio went up to 8.3:1 at the same time. The brakes are Girling throughout, 9in drums all round — not the Lockheed of the A30 and A35, which is worth remembering if you own both.
Austin A50 — specification & changes within the model
- Built
- September 1954 – 1957, Longbridge. 114,867 built. Four-door saloon only — a two-door was designed but never made.
- Engine
- 1489cc BMC B-series (73.025 × 88.9mm), three main bearings, 50bhp @ 4400rpm, 74lb ft @ 2100rpm, single Zenith. Compression raised to 8.3:1 in October 1956.
- Gearbox
- Four-speed, column change. Borg-Warner overdrive optional from early 1956 (5.125:1 final drive with it, 4.875:1 without). Manumatic two-pedal semi-automatic optional from late 1956 — rare.
- Brakes
- Girling hydraulic, 9in drums all round, 121 square inches of friction area.
- Suspension
- Independent coil front on a cross-member; semi-elliptic rear with an anti-roll bar. Cam-and-peg steering.
- Wheels
- 15in to autumn 1956, then 13in on 5.90-13 tyres.
- Doors
- Counterbalanced drop windows at launch, conventional winders within weeks.
- Indicators
- Semaphore at launch, amber flashers from early 1955.
- Family
- The A40 Cambridge is the same body with the 1.2. The A55 Mk I from January 1957 is the same mechanical package with a longer tail and a bigger wrap-around rear screen.
