Armstrong Siddeley Sapphire 346

From 1953 to 1958

Production	1953–1958 7,697 made
Body style	FR layout 4-door saloon limousine
Engine	3,435 cc Straight-6
Wheelbase	114 in (2,896 mm) 133 inches (3,378 mm) (limousine)
Length	193 in (4,902 mm) 212 in (5,385 mm) (limousine)
Width	72 in (1,829 mm)
Height	63 in (1,600 mm)

The 346 was the first of the Sapphires introduced late in 1952 for sale in 1953 and continuing until 1958. The six-cylinder 3,435 cc engine had hemi-spherical combustion chambers and could have optional twin Stromberg carburettors (£25 extra) which increased the output from 125 to 150 bhp (93 to 112 kW) giving a top speed in excess of 100 mph (161 km/h). The front suspension was independent coil springs with a rigid axle and leaf springs at the rear. The Girling hydraulic brakes used 11 in (279 mm) drums all round.

The body was available as a four- or six-light (two or three windows on each side) at the same cost and with either a bench or individual front seats. The seats were finished in leather, with the dashboard and door-cappings in walnut veneer. A heater was standard.

It was introduced with the choice of a Wilson electrically-controlled finger-tip four-speed pre-selector gearbox as a £30 option, or four-speed synchromesh gearbox. It became available with automatic transmission (Rolls Royce four-speed) with the introduction of the Mark II in 1954.

A long-wheelbase model was launched in 1955 as a limousine version which had the pre-selector gearbox as standard, however, there was an optional four-speed manual column-change gearbox available.

1958 Armstrong Siddeley Sapphire 346 limousine

Models for export to the U.S. were always delivered with twin caburettors.

A saloon with the optional twin-carburettors and synchromesh transmission tested by the British magazine The Motor in 1953 had a top speed of 100.1 mph (161.1 km/h) and could accelerate from 0–60 mph (97 km/h) in 13.0 seconds. A fuel consumption of 18.7 miles per imperial gallon (15.1 L/100 km; 15.6 mpg_-US) was recorded. The test car cost £1,757 including taxes.

7,697 were produced.