Rover 20

The engine was very much based on the Rover 16's but the bore had been increased 2mm. There were a number of minor improvements. The water inlet pipe was now to the other side of the engine to provide better access to the valves and tappets. The oil box (reservoir) was now at the left rear of the engine so a catcher for oil thrown up by the flywheel is no longer necessary. Lubrication pipes had been mounted lower. There was a new partition between sump and clutch housing so oil was not thrown to the clutch. Rover's engine braking system was fitted, it has the ability to close the engine's valves.

engine's off side showing ignition etc The petrol tank was above the driver's knees with its filler in front of the centre of the windscreen and the tank shaped to form the car's dashboard and scuttle. It was high enough to always provide sufficient head of petrol and no pressure feed was needed. The coil is mounted on a board which slides in grooves on the front of the petrol tank. The coil is used with either an accumulator or the Eisemann ignition magneto and provides both ignition systems. At the forward right hand end of the engine a shaft spur-driven from the crankshaft powers the water circulation pump, the magneto and the contact maker. The magneto and contact maker are linked so one lever controls the advance or retard of the ignition timing.[1] Crankcase, clutch case and gearbox case are all aluminium castings. They are assembled to form one unit.[3]

Rover's system of front suspension

The chassis was suspended from the front axle at just one point by a pivoted transverse leaf spring which made no contribution to transverse stability and the whole car rested on just three points. Radius rods from the gearbox take up braking strains and act as distance stays for the back axle. The front end of these stays have buffer springs The foot brake is the contracting band type, the hand brake is of the pull-on internal expanding type. Both sets of brake are metal to metal. The action of the engine brake avoids much use of the conventional braking system.[1] The rear springs attach by means of a spherical case clipping over a spherical turned part of the axle casing thus allowing a little motion due to bumps.[3]

The chassis is built up from steel flitch plates over ash to give the necessary strength with flexibility.[3]

A pair of Autoloc levers move over the top of the steering wheel. They operate the throttle and ignition. A pedal controls the engine braking system.[3] Road tests as late as 1911 noted how Rover cars lacked accelerator pedals.[4]

Winning the RAC Tourist Trophy 1907