Rolls-Royce 20 hp (1905)
Encyclopedia
The Rolls-Royce 20 hp
was one of four cars to be produced as a result of an agreement of 23 December 1904 between Charles Rolls
and Henry Royce
. Badged as a Rolls-Royce, the 20 hp was produced during 1905 and 1906 by Royce's company, Royce Ltd. at its factory in Trafford Park
, Manchester
. It was sold exclusively by Rolls' motor dealership, C.S.Rolls & Co., at a price of GBP650. The 20 hp was exhibited at the Paris Salon in December 1904, along with the 10 hp
, 15 hp
and engine for the 30 hp
models.
The engine was made of two separately cast two-cylinder units which were common with the two-cylinder
10 hp and six-cylinder
30 hp types sharing their bore of 4 in (102 mm) and stroke of 5 in (127 mm). It is water-cooled and of 4118 cc capacity with overhead inlet and side exhaust valves Early cars had a high-tension ignition system using pre-charged accumulators, a trembler and a coil ignition system; on later cars this was supplemented by a magneto
which could be used as an alternative. As the lighting supplied uses oil for the side and tail and acetylene
for the headlights, there is no other drain on the accumulators, which need to be recharged between outings. The power output is 20 bhp at 1000 rpm. The engine speed is controlled by a governor
that can be over-ridden by the pedal-controlled accelerator. A three-speed gearbox was fitted at first, later changed to four-speed with the introduction of the Light 20 and subsequently fitted to all cars, connected to the engine via a short shaft and a leather-lined cone clutch
was used. On the four-speed type, third gear is direct and fourth speed an overdrive
ratio.
Two of the cars ran in the 1905 Isle of Man
TT race and one driven by Percy Northey came second overall, the other driven by C.S. Rolls failed to finish after gearbox problems. Rolls tried again in 1906 and won. In December 1906 he took a car to the United States and won a race at Yonkers.
The first cars had a chassis length of 114 in (2,896 mm) but following the special lightweight cars made for the TT Race a shorter 106 in (2,692 mm) version became available. These would become known as the Heavy 20 and Light 20. The track on the Light 20 was also narrower at 52 in (1,321 mm) compared with the Heavy 20's 56 in (1,422 mm). Rolls-Royce did not provide the coachwork. Instead, the cars were sold in chassis form for the customer to arrange his own body supplier. Both closed and open cars were made.
The Light 20 has a top speed of 50 mph (80 km/h) (52 mph (84 km/h) on the TT versions) and the Heavy 20 47 mph (76 km/h) . This speed would be reduced if a heavy body was fitted. There is a transmission brake operating on a drum fitted behind the gearbox operated by foot pedal and internal expanding drum brakes on the back axle operated by the handbrake lever. Suspension is by semi-elliptic leaf springs on both front and rear axles with an additional crossways helper spring on the rear. Artillery
type wheels with wooden spokes were fitted.
Three cars, chassis number 26350, 40509 and 40520 are known to survive.
Tax horsepower
The tax horsepower or taxable horsepower was an early system by which taxation rates for automobiles were reckoned in some European countries, such as Britain, Belgium, Germany, France, and Italy; some US states like Illinois charged license plate purchase and renewal fees for passenger...
was one of four cars to be produced as a result of an agreement of 23 December 1904 between Charles Rolls
Charles Rolls
Charles Stewart Rolls was a motoring and aviation pioneer. Together with Frederick Henry Royce he co-founded the Rolls-Royce car manufacturing firm. He was the first Briton to be killed in a flying accident, when the tail of his Wright Flyer broke off during a flying display near Bournemouth,...
and Henry Royce
Henry Royce
Sir Frederick Henry Royce, 1st Baronet, OBE was a pioneering car manufacturer, who with Charles Stewart Rolls founded the Rolls-Royce company.-Early life:...
. Badged as a Rolls-Royce, the 20 hp was produced during 1905 and 1906 by Royce's company, Royce Ltd. at its factory in Trafford Park
Trafford Park
Trafford Park is an area of the Metropolitan Borough of Trafford, in Greater Manchester, England. Located opposite Salford Quays, on the southern side of the Manchester Ship Canal, it is west-southwest of Manchester city centre, and north of Stretford. Until the late 19th century it was the...
, Manchester
Manchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
. It was sold exclusively by Rolls' motor dealership, C.S.Rolls & Co., at a price of GBP650. The 20 hp was exhibited at the Paris Salon in December 1904, along with the 10 hp
Rolls-Royce 10 hp
The Rolls-Royce 10 hp was the first car to be produced as a result of an agreement of 23 December 1904 between Charles Rolls and Henry Royce, and badged as a Rolls-Royce. The 10 hp was produced by Royce's company, Royce Ltd., at its factory in Trafford Park, Manchester, and was sold...
, 15 hp
Rolls-Royce 15 hp
The Rolls-Royce 15 hp was one of four cars to be produced as a result of an agreement of 23 December 1904 between Charles Rolls and Henry Royce. Badged as a Rolls-Royce, the 15 hp was produced by Royce's company, Royce Ltd., at its factory in Trafford Park, Manchester. It was sold exclusively...
and engine for the 30 hp
Rolls-Royce 30 hp
The Rolls-Royce 30 hp was one of four cars to be produced as a result of an agreement of 23 December 1904 between Charles Rolls and Henry Royce. Badged as a Rolls-Royce, the 30 hp was produced during 1905 and 1906 by Royce's company, Royce Ltd. at its factory in Trafford Park, Manchester. It...
models.
The engine was made of two separately cast two-cylinder units which were common with the two-cylinder
Straight-two
A straight-two engine, is a two-cylinder piston engine that has its cylinders arranged side by side....
10 hp and six-cylinder
Straight-6
The straight-six engine or inline-six engine is a six-cylinder internal combustion engine with all six cylinders mounted in a straight line along the crankcase...
30 hp types sharing their bore of 4 in (102 mm) and stroke of 5 in (127 mm). It is water-cooled and of 4118 cc capacity with overhead inlet and side exhaust valves Early cars had a high-tension ignition system using pre-charged accumulators, a trembler and a coil ignition system; on later cars this was supplemented by a magneto
Magneto
A magneto is a type of electrical generator.Magneto may also refer to:* Magneto , permanent magnetic alternating current rotary generator* ignition magneto, magnetos on internal combustion engines...
which could be used as an alternative. As the lighting supplied uses oil for the side and tail and acetylene
Carbide lamp
Carbide lamps, properly known as acetylene gas lamps, are simple lamps that produce and burn acetylene which is created by the reaction of calcium carbide with water....
for the headlights, there is no other drain on the accumulators, which need to be recharged between outings. The power output is 20 bhp at 1000 rpm. The engine speed is controlled by a governor
Governor (device)
A governor, or speed limiter, is a device used to measure and regulate the speed of a machine, such as an engine. A classic example is the centrifugal governor, also known as the Watt or fly-ball governor, which uses a rotating assembly of weights mounted on arms to determine how fast the engine...
that can be over-ridden by the pedal-controlled accelerator. A three-speed gearbox was fitted at first, later changed to four-speed with the introduction of the Light 20 and subsequently fitted to all cars, connected to the engine via a short shaft and a leather-lined cone clutch
Cone clutch
A cone clutch serves the same purpose as a disk or plate clutch. However, instead of mating two spinning disks, the cone clutch uses two conical surfaces to transmit torque by friction....
was used. On the four-speed type, third gear is direct and fourth speed an overdrive
Overdrive (mechanics)
Overdrive is a term used to describe a mechanism that allows an automobile to cruise at sustained speed with reduced engine RPM, leading to better fuel economy, lower noise and lower wear...
ratio.
Two of the cars ran in the 1905 Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
TT race and one driven by Percy Northey came second overall, the other driven by C.S. Rolls failed to finish after gearbox problems. Rolls tried again in 1906 and won. In December 1906 he took a car to the United States and won a race at Yonkers.
The first cars had a chassis length of 114 in (2,896 mm) but following the special lightweight cars made for the TT Race a shorter 106 in (2,692 mm) version became available. These would become known as the Heavy 20 and Light 20. The track on the Light 20 was also narrower at 52 in (1,321 mm) compared with the Heavy 20's 56 in (1,422 mm). Rolls-Royce did not provide the coachwork. Instead, the cars were sold in chassis form for the customer to arrange his own body supplier. Both closed and open cars were made.
The Light 20 has a top speed of 50 mph (80 km/h) (52 mph (84 km/h) on the TT versions) and the Heavy 20 47 mph (76 km/h) . This speed would be reduced if a heavy body was fitted. There is a transmission brake operating on a drum fitted behind the gearbox operated by foot pedal and internal expanding drum brakes on the back axle operated by the handbrake lever. Suspension is by semi-elliptic leaf springs on both front and rear axles with an additional crossways helper spring on the rear. Artillery
Artillery wheel
The artillery wheel was developed for use on gun carriages when it was found that the lateral forces involved in horse artillery manoeuvres caused normally-constructed cart wheels to collapse. Rather than having its spokes mortised into a wooden nave , it has them fitted together then bolted into...
type wheels with wooden spokes were fitted.
Three cars, chassis number 26350, 40509 and 40520 are known to survive.