The Bentley 3 litre, introduced in 1921, was replaced with a more powerful car in 1927, by increasing its engine displacement to 4.4 litres. Mostly Tourers and Saloons were built. A total of 720 4½ litre cars were produced between 1927 and 1931, including 55 cars with a supercharged engine popularly known as the Blower Bentley, these Blower Bentleys were introduced in 1929. The Blower Bentley got a Roots type supercharger placed at the end of the crankshaft, in front of the radiator giving it an easily recognisable appearance. Street versions produced 175hp whereas the race version, 240hp At the time, noted car manufacturers such as Bugatti and Lorraine-Dietrich focused on designing cars to compete in the 24 Hours of Le Mans, a popular automotive endurance course established only a few years earlier. Bentleys had four consecutive wins at the 24 Hours of Le Mans, and forged the brand's reputation