Sunday, 20 April 2014 04:18
Austin 7 Racing CarsWritten by Guus Docen
The original Chummy Tourer first appeared in 1922. It had 190 cm wheelbase, a 10 bhp engine and the weight of 356 kg. Its tiny side valve engine with two bearing crankshaft only 28.6 millimetres in diameter proved tough enough to win the longest and races such as Monza, Brooklands, Ulster and elsewhere, and to withstand supercharging.The Ulster Super Sports car was Austin's most serious effort in the sports car market. It had an A frame, transverse leaf spring at the front, 1/4 eliptic springs at the rear, and tiny four wheel brakes. The 747 cc side valve engine was fitted with a gear-driven Cozette supercharger, special cylinder head, valve gear and camshaft and pump-cooling. The two-bearing crank shaft was required to turn over at 5000 rpm. It was pressure-lubricated and balanced.The three speed gear box had close ratio gears. Wings, hood, windscreen and lights were quickly removable for competition work and the weights with a doorless, open, two-seater body and spidery outside exhaust system was around 435 kg. With 33 brake horsepower available, the little car could exceed 120 kilometres an hour (75 MPH) reliably. An unblown 24 bhp version could reach 100 kilometres an hour (60 mph).The blown car, raced by the factory in 1929 scored four class wins in major British races, and finished third and fourth in the Ulster Touring Trophy. In 1930 the little orange cars took three more British class wins and won the 500 miles race at Brooklands outright at 134.25 kilometres (83.42 mph).The overhead cam MG Miidget introduced intruded on Austin successes in the 750 CC racing cars but more plebeian sporting Sevens provided enthusiasts with a wide variety of fun racing at minimal cost for many years.