Rolls Royce SC Convertible

Construction was body-on-frame, which permitted special bodied versions, though the overwhelming majority were built with the standard Pressed Steel Company manufactured steel body shell. A light-weight aluminium-based alloy was used for doors, bonnet/hood and boot/trunk lid. The chassis was a simple steel box section, welded together and very rigid. The car was 5.38 m (212 in) long, 1.90 m (75 in) wide, and massed 1.95 tonnes. The engine was a 155 hp / 4000 rpm 4.9 L six-cylinder unit with inlet over exhaust valves: twin SU carburetors were added in September 1957. The standard transmission was a four-speed automatic, the General Motors sourced Hydramatic transmission. The turning circle was 41 feet 8 inches.
The Silver Cloud II was introduced in 1959. Little changed externally but it now had a 6.2 L V8 engine, which pushed the weight to 2.11 tonnes. Performance was greatly improved and top speed was raised to 183 km/h (114 mph), but the main improvements were in acceleration and torque. Power steering became standard. Electrically operated windows were now available as an option.
The Silver Cloud III arrived in 1963. External dimensions were slightly altered, the interior remodeled, the weight reduced by a little over 100 kg (220 lb) and improvements made to the engine which included fitting 2-inch (51 mm) SU carburetors in place of the 1¾ inch units used on the Series II Silver Cloud.
The compression ratio was increased to 9:1, reflecting the higher octane levels of premium fuel in major markets, although the option of a lower 8:1 compression ratio was still offered in markets where non-availability of higher octane fuels might be an issue. Rolls-Royce, as before, refused to disclose overall engine power output, but indicated that there had been an improvement of “perhaps 7%”.