1929 Bentley Speed Six Cadogan 4-Seater

by Diane Brandon

At the end of World War I, Walter Owen Bentley gathered a small group of dedicated and skilled artisans to create Bentley Motors. The first Bentleys appeared in 1919, a group of three experimental 3-liter cars. In the following decade, the 3-liter gave way to the 4 1/2-liter, the 6 1/2-liter, the Speed Six, the 8-liter, the supercharged 4 1/2, and finally the subdued 4-liter.

The 6 1/2-liter Bentley was introduced in 1926, but work soon began on an upgraded version with increased horsepower to handle heavier coachwork, and to become more competitive on the racing circuit. The original 6 1/2-liter Bentley was powered by a 6,597-cc engine with a single Smith’s five-jet carburetor.

The upgraded 6 1/2 became known as the “Speed Six,” with a higher compression ratio. The OHC inline six had four-valve heads, twin S.U. carburetors, Bosch magneto, Delco coil dual ignition, and a four-speed transmission. The front of the chassis was supported by a solid...