Rover 20

Rover 20
Tourer first registered December 1907
Overview
Manufacturer	Rover
Production	1907–1910
Model years	1908–1910
Body and chassis
Body style	open tourer landaulet chassis only
Layout	FR
Powertrain
Engine	3,251 cc (198.4 cu in) Straight-4
Dimensions
Wheelbase	114 in (2,896 mm) tourer 120 in (3,048 mm) landaulet Track 53 in (1,346 mm) wood Track 55 in (1,397 mm) wire
Length	156 in (3,962 mm)
Width	63 in (1,600 mm)
Kerb weight	Chassis 17 cwt, 1,904 lb (864 kg)

Rover 20hp
engine's near side
Overview
Manufacturer	Rover
Combustion chamber
Configuration	straight 4-cylinder
Displacement	3,251 cc (198.4 cu in)
Cylinder bore	97 mm (3.8 in)
Piston stroke	110 mm (4.3 in)
Cylinder block alloy	cast iron, en bloc, four separately cast cylinders
Cylinder head alloy	in unit with blocks
Valvetrain	side valves
Combustion
Fuel system	Rover (pat.) carburettor gravity fed from fuel tank in scuttle
Management	Bosch H T magneto or accumulator
Fuel type	petrol
Oil system	splash
Cooling system	water: flattened tube radiator, water pump, fan
Output
Power output	2 bhp (1.5 kW; 2.0 PS) @2,400 rpm Tax horsepower 23.33
Chronology
Predecessor	Rover 16 but 20 has been bored out by 2mm

The Rover 20 was a new medium sized car announced by Rover in June 1907. It was a production version of the car which won the Isle of Man Tourist Trophy Race in 1906. However artillery wood wheels were fitted instead of the (still recommended) wire wheels used in the race and the longer wheelbase allowed the engine to be kept out of the passenger area. The prototype's engine came back beneath the petrol tank.

With a few breaks Rover kept a premium 20 tax horsepower car in their catalogue until the outbreak of war in 1939. In the early 1950s an equivalent model returned to the market, the 2.6-litre Rover 90 and later Rover's 3-litre.

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.

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.