Austin A40, A50 and A55 Cambridge (1954 to 1958)

The first Austin to carry the Cambridge name arrived in late 1954 as the replacement for the separate-chassis A40 Somerset. It was a significant car for Austin and for the newly formed British Motor Corporation: a steel monocoque body, with the engine and front suspension carried on a rubber-mounted subframe to keep vibration out of the cabin, and the debut of the BMC B-series engine that would go on to power everything from the MGA to the Morris Oxford. Two engine sizes were offered from launch. The A40 had the 1.2-litre B-series and the A50 the 1.5-litre unit, in an otherwise identical four-door body.

Styling was deliberately restrained, modern without leaning on American fashion, and the Cambridge earned praise for good forward visibility over its sloping bonnet and for an effective fresh-air system fed through the grille badge. In 1957 the A40 was dropped and the A50 was facelifted into the A55, with a longer tail, small fins and a much larger rear window, before the Farina-styled A55 Mk II took over late in 1958.

On the road the A40 feels slow among modern traffic, while the A50 and A55 are livelier and cope with today's A-roads. Expect a soft, comfortable ride, some roll and gentle understeer. The cars have a reputation for solid construction and roomy cabins, offset by a strong appetite for rust and limited supplies of body panels and trim.

• Years built: A40 and A50 Cambridge from autumn 1954 to early 1957; A55 (later called Mk I) from January 1957 until the Farina A55 Mk II replaced it in 1958.
• Body style: four-door saloon. A two-door A40 was announced or planned, but sources disagree on whether it reached customers in any number (Wikipedia says it did not reach production; other sources say it was listed and soon dropped). Half-ton van and pick-up derivatives followed from 1957.
• Engines: A40, 1.2-litre (1,200cc) B-series four with a single Zenith carburettor, 42bhp claimed. A50, 1,489cc B-series, 50bhp at 4,400rpm and 74lb ft at 2,100rpm. A55, same 1,489cc unit with higher compression, 51bhp at 4,250rpm.
• Gearboxes: four-speed manual with column change as standard. Borg-Warner overdrive and Manumatic two-pedal clutch control were options on the 1.5-litre cars. A floor change became available in 1958.
• Final drive: the club gives 5.125:1 for the A40 and 4.875:1 for the A50.
• Performance (A50, period test): about 74mph and 0 to 60mph in roughly 29 seconds.
• Production: A40 about 30,600 to 30,700 (Wikipedia gives 30,666; Grace's Guide rounds to about 30,000); A50 114,867; A55 roughly 154,000 (Wikipedia). Treat these as best available figures rather than certified totals.
• Also built under licence in Japan by Nissan.

• Late 1954: A40 and A50 Cambridge launched. Early cars have semaphore trafficators and counterbalanced drop glass in the doors.
• Early 1955: amber flashing indicators and conventional wind-down windows replace the semaphores and drop glass (the Cambridge-Oxford Owners Club says the window change came within weeks of launch).
• 1956: Borg-Warner overdrive offered on the A50 (the club dates this to early 1956, Classic & Sports Car to October 1956). Manumatic two-pedal transmission added as an option.
• October 1956: wheels reduced from 15in to 13in and compression ratio raised to 8.3:1. A 1956 car may therefore be on either wheel size depending on build date.
• January to February 1957: A40 dropped; A50 becomes the A55 with longer boot, fins, revised lights and a wrap-round rear screen. Vans and pick-ups introduced.
• 1958: floor gear lever offered. The Farina A55 Mk II replaced the saloon in the autumn.
• De Luxe trim brought leather seat facings, carpets, armrests, a heater and extra brightwork; base cars are plainer.

Bodywork and structure

• Rust is the main enemy, and it is the reason so many Cambridges disappeared. The bodyshell is load-bearing, so corrosion matters structurally, not just cosmetically.
• Check the sills, floors, bulkhead and door bottoms, and look closely at the rear wings, which one owner quoted by Classic & Sports Car calls a serious rust trap.
• Take a magnet to the lower panels to find filler, and look for rippled or bubbling paint that hints at rot beneath. Assess the quality of earlier repairs as much as fresh corrosion.
• Repair panels are scarce, so a car needing extensive panel work is a much bigger project than its mechanical simplicity suggests.
• Confirm the body matches the claimed model. An A55 has the longer tail and larger rear screen; an A40 or A50 has the shorter, rounded rear.

Engine

• The B-series is robust and widely shared across BMC, so rebuild parts are plentiful for the 1.5. Specific 1200 parts are harder to find.
• Listen for rattles and knocks and look for blue smoke on start-up. Poor running is often the carburettor or tired ignition rather than the engine itself.
• Ask about valve seats. Unleaded fuel can eventually damage original seats, and long periods of storage can lead to stuck or broken piston rings.
• These engines can run warm on modern fuel. Look at the radiator, hoses and water pump for leaks and play, and check the oil filler and dipstick for signs of oil and water mixing.
• Many cars have been uprated with larger B-series engines, often to MGA or MGB specification, or converted from Zenith to SU carburettors. Note what is fitted against what the car is described as.

Gearbox and drivetrain

• The column change can wear in its linkage, making selection vague. Synchromesh and bearings also wear.
• If overdrive or Manumatic is fitted, ask whether it works; Manumatic was unpopular when new and is unusual today.
• Check the propshaft universal joints for play by hand, and look for oil leaks from the rear axle.
• A clutch that will not free off may be hydraulic or wear related; establish which.

Suspension, steering and brakes

• Front suspension is double wishbones and coil springs with lever-arm dampers; the rear is a live axle on leaf springs.
• With the front wheel off the ground, rock it to check for play. Play at the inner end of the top wishbone points to failing splines, a job that means replacement with hard-to-find parts.
• The cam-and-peg steering box often weeps oil. Oil-soaked rubber bushes fail early.
• A soft, wallowy ride may simply mean the lever-arm dampers need topping up.
• There are many grease points (around 18) that originally needed attention every 1,000 miles. Dry nipples suggest neglect and accelerated wear.
• Brakes are Girling drums. Look behind the wheels for fluid from failed wheel cylinders and inspect the steel lines for corrosion.

Electrics and interior

• Check the indicators work, and on very early cars whether the semaphore trafficators are still fitted and operate.
• Inspect the distributor, leads and plugs for age; tired ignition is a common cause of poor running.
• Leather was fitted to De Luxe cars. A good original interior is valuable because trim is hard to source, although a competent trimmer can repair leather.
• Check the heater and fresh-air system, the sloping dashboard and its instruments for completeness.

Identity and paperwork

• Make sure the V5C, chassis plate and engine number tell a consistent story, especially where a larger engine has been fitted.
• Confirm whether the car is a true A40 or an A50 fitted with a different engine, as the bodies are identical.
• Look for a service record showing regular greasing and oil changes.

Mechanical parts are the easy part. The B-series engine, Zenith and SU carburettors and many service items are shared with other BMC cars, and general BMC specialists can support them. Body panels and interior trim are the difficult areas, and secondhand parts through the clubs are often the best route. Two UK clubs cover these cars: the Austin Cambridge Westminster Car Club (acwcc.co.uk (opens in a new tab)), which caters for the pre-Farina A40, A50 and A55 Mk I as well as later models, and the Cambridge-Oxford Owners Club (co-oc.org (opens in a new tab)), whose site has model histories including the A50.

• Is the engine the original 1.2-litre unit, and has it been converted for unleaded fuel?
• What structural welding has been done, where, and are there photographs of the work?
• Has the car been laid up recently, and if so what was done to recommission it?
• Does the car have 13in or 15in wheels, and does that match its build date?
• When were the brake hydraulics last overhauled and the front suspension greased and checked?