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
Charles Stewart Rolls (27 August 1877 – 12 July 1910) was a British motoring and aviation pioneer. With Henry Royce, he co-founded the Rolls-Royce car manufacturing firm. He was the first Briton to be killed in an aeronautical accident wit ...
and
Henry Royce
Sir Frederick Henry Royce, 1st Baronet, (27 March 1863 – 22 April 1933) was an English engineer famous for his designs of car and aeroplane engines with a reputation for reliability and longevity. With Charles Rolls (1877–1910) and Claude ...
. Badged as a Rolls-Royce, the 30
hp was produced during 1905 and 1906 by Royce's company, Royce Ltd. at its factory in Cooke Street, Hulme,
Manchester
Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...
. It was sold exclusively by Rolls' motor dealership, C.S.Rolls & Co., at a price of GBP 890. The engine was exhibited at the
Paris Salon in December 1904, along with the
10 hp,
15 hp and
20 hp models.
Claude Johnson was keen that a
six-cylinder
The straight-six engine (also referred to as an inline-six engine; abbreviated I6 or L6) is a piston engine with six cylinders arranged in a straight line along the crankshaft. A straight-six engine has perfect primary and secondary engine balan ...
model was included in the Rolls-Royce line-up as other "quality" makers, especially
Napier, were adding them to their ranges. The 30 hp was discontinued when the company changed to a single model policy and launched the
40/50 (Silver Ghost).
Engine
The engine is made of three
separately-cast two-cylinder units with
monobloc head
A ''monobloc'' or ''en bloc'' engine is an internal-combustion piston engine some of whose major components (such as cylinder head, cylinder block, or crankcase) are formed, usually by casting, as a single integral unit, rather than being assembled ...
s which are common with the
two-cylinder 10 hp and
four-cylinder 20 hp types sharing their bore of and stroke of . It is water-cooled and of 6,000 cc capacity with
overhead inlet and side exhaust valves.
A single Royce
carburettor is fitted. Early cars have a high-tension ignition system using pre-charged accumulators, a
trembler
Tremblers are a New World group of passerine birds related to mockingbirds and New World catbirds. Like these, they are in the family Mimidae. There are 2-4 species in one genus, ''Cinclocerthia'', which is endemic to the Lesser Antilles:
* Gr ...
and a
coil ignition system; on later cars this is supplemented by a
magneto
A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, ...
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 at 1000 rpm.
[Rolls-Royce Motor Cars website]
/ref> The engine speed is controlled by a governor that can be over-ridden by the pedal-controlled accelerator.
A four-speed transmission carried over from the "Light" 20 hp model is connected to the engine via a short shaft. On this transmission, third gear is direct and fourth speed an overdrive ratio. A leather-faced cone clutch is used.
Crankshaft
The crankshaft is carried in seven main bearing
Main may refer to:
Geography
* Main River (disambiguation)
**Most commonly the Main (river) in Germany
* Main, Iran, a village in Fars Province
*"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries
...
s in an attempt to keep vibration to a minimum, a problem on many early six-cylinder engines, as the dynamics of the layout were still not fully understood. Flywheels are fitted at both the front and rear of the crankshaft. After some early cars suffered broken crankshafts Royce modified the front flywheel to incorporate a harmonic damper
A harmonic damper is a device fitted to the free (accessory drive) end of the crankshaft of an internal combustion engine to counter torsional and resonance vibrations from the crankshaft. This device must be interference fit to the crankshaft in ...
which overcame the problem.
Car
The car has a top speed of . 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. The axle is located by a triangular strut linking axle and chassis and the main drive thrust is transmitted to the car by links between the ends of the axle and forward spring brackets. By this means the springs are only responsible for suspension. Artillery
Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during siege ...
type wheels with wooden spokes were fitted.
Two chassis lengths were made, the short is in length and the long . The track is the same on both lengths at . Rolls-Royce did not provide the coachwork. Instead, the cars were sold in chassis form for the customer to arrange their own body supplier. Both closed and open cars were made. Of the 37 or possibly 38 cars made, three were exported to the US, one to Canada and one to Germany.
Only one car, a short wheelbase model with chassis number 26355 is known to survive.
References
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{{Rolls-Royce
30 hp
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious or cultural significance in many societie ...
Cars introduced in 1905
1900s cars
Brass Era vehicles