There were a total of about 50 production supercharged Bentleys
and another five were developed for racing.
Harry Rose is at the wheel of a genuine ex-Paget team car and Russ Turner’s
is a modified production car. Both cars were capable of about a 100 mph and
remained smooth and flexible to drive at high speed.
The idea of supercharging the big 4½ litre 4-cylinder Bentley
was that of Sir Henry ‘Tim' Birkin and, although W.O. Bentley did
not approve of superchargers, it became a production car.
Birkin formed his own racing team, to race the supercharged cars, but these
were not as reliable as the standard Bentley team cars.
Bentley 4½ litre Supercharged
Specification (1930-31)
Engine: 4-cylinder single overhead camshaft 4398 CC (100
x 140 mm) with Roots-type supercharger developing 240 bhp at 4200 rpm.
Gearbox: 4-speed. Chassis: Channel-section with
front and rear suspension by rigid axles suspended on semi-elliptic leaf springs.
Wheelbase: 10 feet 10 inches. Front and Rear Track:
4 feet 8 inches Unladen weight: 36 cwt.
