The Bentley 4.5 Litre was a supercharged variant, also known as the Blower Bentley. Famous for his statement 'there's no replacement for displacement', Walter Owen Bentley upped the displacement of the Bentley 3 Litre in 1926 to produce the 4.5 Litre. Upon taking control of the company, the 'Bentley Boys' went in search of even more power and developed the supercharged model in 1929 at Henry Birkin's racing workshops in Welwyn Garden City.
The total production of the 4.5 Litre was 720 between 1927 and 1931. Of these, 55 were fitted with superchargers.