The Bentley 4 ½ Litre, produced between 1927 and 1931, is a truly iconic car that reflects the golden age of British motoring and helped create the foundations that the Bentley name was built upon. Bentley Motors Limited had already established a reputation for creating fast and durable cars, especially with the success of the 3 Litre model, highlighted by its victories at Le Mans in 1924 and 1927.
However, due to increasing competition it was clear that in time the 3 Litre would soon be surpassed by its peers. There was a clear need for a Bentley with a more powerful engine to help maintain their competitive edge on the racetrack. The answer came in the form of the 4 ½ Litre which was introduced to replace the 3 Litre. The 4 ½ Litre was conceived to maintain Bentley’s philosophy of ruggedness over lightweight design. It was a car primarily aimed at well-heeled enthusiasts and racing drivers, often associated with the "Bentley Boys," a group of wealthy British motorists who favoured Bentley cars for their reliability and speed.
The Bentley 4 ½ Litre was powered by an inline four-cylinder engine with four valves per cylinder, twin SU carburettors and an overhead camshaft. The larger straight-four engine epitomised Bentley’s sporting image and proved to be both reliable and fast. This was mated to a four speed non-synchromesh gearbox. A standard 4 ½ Litre produced approximately 110 bhp with a top speed of over 90mph. The short chassis version of the 4 ½ Litre is widely regarded as one of the best handling vintage Bentleys, with its compact, sporty appearance.
Sir Henry “Tim” Birkin believed that a supercharged 4 ½ Litre would be superior to the Speed Six model on the racetrack. The supercharger fitted to the Blower was developed by Birkin and fitted with an Amherst Villiers Roots type unit mounted in front of the radiator. It did indeed significantly boost the engine’s power output but also increased mechanical stress and reduced reliability compared to the standard 4 ½ Litre.
Although it didn’t achieve the same level of racing success as the standard 4 ½ Litre, the Blower Bentley became one of the most iconic racing cars of its time due to its raw power and distinctive appearance. One could argue that over time, it is now recognised as one of the greatest cars from the 1920’s which now mostly reside in some of the world’s finest collections.
The 4 ½ Litre made its racing debut at the 1927 at Le Mans when driven by Clement and Callingham. The early signs were good with the fastest lap recorded whilst being driven by Clement, until crashing out later in the race. One year later things were very different when Barnato and Rubin steered their 4 ½ Litre to a famous victory at Le Mans further solidifying Bentley’s reputation in the motorsport world.
The Bentley 4 ½ Litre is celebrated for its engineering excellence, performance, and its contribution to Bentley’s storied history in motorsport, symbolizing the peak of pre-war British automotive engineering and Bentleys racing dominance. Its blend of engineering prowess, rugged construction, and racing pedigree makes it one of the most iconic pre-war cars. Immortalised by legendary accomplishments at Le Mans and brilliantly promoted by the Bentley Boys, the car is now viewed by many as the height of pre-war British motoring.
Thoughts from Frank Dale
Although the 3 Litre was the genesis of the Bentley name, achieving incredible success on the racetracks of Le Mans, one could argue that the strength of the Bentley brand and legacy today was built on the shoulders of the 4 ½ Litre and the success it achieved.
It is nothing short of legendary and the romance of the Bentley Boys only adds more colour to the background story. When you ask people to visualise a pre-war Bentley, many will pick out a 4 ½ Litre, with a Vanden Plas touring body, aero screens, union jack and number painted on the body, screaming around a racetrack at the hands of a fearless young driver with goggles and helmet.
Our grandfather Jack, now very long gone, raced at Brooklands in the late 1920’s with and against the likes of Birkin, Barnato and the other Bentley Boys. Sadly, we didn’t get to hear his tales first hand and have had them relayed to us down the generations.
To get behind the wheel of a 4 ½ Litre, either on the racetrack or on the open road, is quite an experience, transporting you back to the heady days of the late 1920’s. A truly great British icon.