0 Austin 7
The Austin 7 was an economy car produced from 1922 until 1939 in the United Kingdom by the Austin Motor Company. Nicknamed the "Baby Austin", it was one of the most popular cars ever produced for the British market, and sold well abroad. It wiped out most other British small cars and cyclecars of the early 1920s; its effect on the British market was similar to that of the Model T Ford in the USA. It was also licensed and copied by companies all over the world. The very first BMW car, the BMW Dixi, was a licensed Austin 7, as were the original American Austins. In France they were made and sold as Rosengarts. In Japan Nissan also used the 7 design as the basis for their first cars, although not under licence. Many Austin 7s were rebuilt as "specials" after the Second World War, including the first race car built by Bruce McLaren, and the first Lotus, the Mk1.
The Austin 7 was considerably smaller than the Ford Model T. The wheelbase was only 6 ft 3 inches (1.905 m), and the track only 40 inches (1.016 m). Equally it was lighter – less than half the Ford's weight at 794 pounds (360 kg). The engine required for adequate performance was therefore equally reduced and the 747 cc sidevalve was quite capable with a modest 10 hp output.
The chassis took the form of an "A" with the engine mounted between the channel sections at the narrow front end. The rear suspension was by quarter elliptic springs cantilevered from the rear of the chassis while at the front the beam axle had a centrally mounted half elliptic transverse spring. Early cars did not have any shock absorbers. Brakes were on all wheels but at first the front brakes were operated by the handbrake and the rear by the footbrake, becoming fully coupled in 1930. In late 1931 the chassis was lengthened by 6" with a corresponding increase in the rear track. Steering is by worm and wheel mechanism.
The original 1922 four-cylinder Austin Seven engine had a bore of 2.125" (54mm) and stroke of 3" (76mm), giving a capacity of 696 cc and RAC rating of 7.2 hp. From March 1923 the bore was increased to 2.2" (56mm) giving 747 cc and 10.5 hp. The side-valve engine was composed of an aluminium crankcase, cast iron cylinder block and cast iron cylinder head. Cooling was by thermosiphon, without a water pump, and the dynamo was driven from the timing gears.
The big end bearings were lubricated by jets from an oil gallery in the crankcase, the oil striking the crankshaft webs which were drilled accordingly. Originally the journal diameter was 1.125"; this was later increased to 1.3125". The three bearing engine (from 1936) used a white metal centre bearing. The splash-lubricated crankshaft (pressure fed on some sports models) at first ran in two bearings (two ball bearings at the front, roller at the back) changing to three in 1936. An electric starter was fitted from November 1923. The early cars used magneto ignition, but this was changed to coil in 1928.
The 3-speed and reverse gearbox was integral with the engine, and had a variety of ratios depending on application. A four-speed gearbox was introduced in 1932 and in 1933 synchromesh was added to third and top ratios extending to second gear in 1934. The back axle was of spiral bevel type with ratios between 4.4:1 and 5.6:1. A short torque tube ran forward from the differential housing to a bearing and bracket on the rear axle cross member.
The Austin 7 was considerably smaller than the Ford Model T. The wheelbase was only 6 ft 3 inches (1.905 m), and the track only 40 inches (1.016 m). Equally it was lighter – less than half the Ford's weight at 794 pounds (360 kg). The engine required for adequate performance was therefore equally reduced and the 747 cc sidevalve was quite capable with a modest 10 hp output.
The chassis took the form of an "A" with the engine mounted between the channel sections at the narrow front end. The rear suspension was by quarter elliptic springs cantilevered from the rear of the chassis while at the front the beam axle had a centrally mounted half elliptic transverse spring. Early cars did not have any shock absorbers. Brakes were on all wheels but at first the front brakes were operated by the handbrake and the rear by the footbrake, becoming fully coupled in 1930. In late 1931 the chassis was lengthened by 6" with a corresponding increase in the rear track. Steering is by worm and wheel mechanism.
The original 1922 four-cylinder Austin Seven engine had a bore of 2.125" (54mm) and stroke of 3" (76mm), giving a capacity of 696 cc and RAC rating of 7.2 hp. From March 1923 the bore was increased to 2.2" (56mm) giving 747 cc and 10.5 hp. The side-valve engine was composed of an aluminium crankcase, cast iron cylinder block and cast iron cylinder head. Cooling was by thermosiphon, without a water pump, and the dynamo was driven from the timing gears.
The big end bearings were lubricated by jets from an oil gallery in the crankcase, the oil striking the crankshaft webs which were drilled accordingly. Originally the journal diameter was 1.125"; this was later increased to 1.3125". The three bearing engine (from 1936) used a white metal centre bearing. The splash-lubricated crankshaft (pressure fed on some sports models) at first ran in two bearings (two ball bearings at the front, roller at the back) changing to three in 1936. An electric starter was fitted from November 1923. The early cars used magneto ignition, but this was changed to coil in 1928.
The 3-speed and reverse gearbox was integral with the engine, and had a variety of ratios depending on application. A four-speed gearbox was introduced in 1932 and in 1933 synchromesh was added to third and top ratios extending to second gear in 1934. The back axle was of spiral bevel type with ratios between 4.4:1 and 5.6:1. A short torque tube ran forward from the differential housing to a bearing and bracket on the rear axle cross member.
