Rolls-Royce 15 hp
|Engine(s)||3000cc 3 cylinder.|
|Wheelbase||103 in (2616 mm)|
|Designer||Sir Henry Royce|
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 15hp was produced 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 GBP500. The 15hp was exhibited at the Paris Salon in December 1904, along with the 10hp, 20hp and engine for the 30hp models, but as the new three cylinder engine was not ready the chassis was incomplete.
Three cylinder engines were quite popular in the early years of motoring and one was part of the ambitious programme of the new company. The layout produced less vibration than 2 cylinder engines and was much simpler to make than a six cylinder with its long crankshaft. However, Royce was making his range of engines using a standard two cylinder block, putting two together for the four cylinder and three for the six. The three cylinder engine did not fit in with this production having each of its cylinders cast separately and this is thought to be the reason why only six were made. The engine, which has a bore of 4 in (102 mm) and stroke of 5 in (127 mm) is water-cooled and of 3000 cc capacity with overhead inlet and side exhaust valves. A high tension ignition system using pre-charged accumulators, a trembler and a coil provides the ignition spark. As the lighting supplied uses oil, there is no other drain on the accumulators.The power output is 15 bhp (11 kW) 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 is used, connected to the engine via a short shaft and a leather cone clutch is used.
The car has a top speed of 39 mph (63 km/h). There is a transmission brake fitted behind the gearbox operated by foot pedal and internal expanding drum brakes on the back axle operated by the handbrake lever. Springing is by semi-elliptic leaf springs on both front and rear axles with an additional crossways helper spring on the rear of some of the cars. Artillery type wheels were fitted.
Rolls-Royce did not provide the coachwork. Instead, the cars were sold in chassis form for the customer to arrange his own body supplier, with Barker recommended.
Only one car, registered SD 661 is known to survive.
Notes and references
- The Rolls-Royce Motor Car. Anthony Bird and Ian Hallows. Batsford Books. 2002 ISBN 07134 8749 6
- Pugh, Peter (2001). The Magic of a Name - The Rolls-Royce Story: The First 40 Years. Icon Books. ISBN 1840461519.
- Rolls-Royce was not formed as a company until 1906.
- In chassis only form.
- Rolls-Royce Motor Cars website http://www.rolls-roycemotorcars.com
Rolls-Royce Motor Cars road car timeline
|Independent||Vickers plc||VW Group||BMW|
|WWII||Silver Dawn||Silver Cloud||Silver Shadow/Silver Wraith II||Silver Spirit/Spur/Dawn|
|Premium||30 hp||40/50 hp (Silver Ghost)||Phantom I/II/III||Silver Wraith||Camargue||Silver Seraph||Phantom|
|Convertible||Corniche/II/III/IV||Corniche V||Phantom Drophead|