Bentley Blower

The Bentley 4½ Litre is a British sports car built by Bentley Motors. Replacing the Bentley 3 Litre, it is famous for epitomizing prewar British motor racing and for its popular slogan "there's no replacement for displacement", created by the founder of Bentley, Walter Owen Bentley. Bentley sought to produce a more powerful race car by increasing engine displacement.

At the time, noted car manufacturers like 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. A victory in this competition quickly elevated any car maker's reputation.

A total of 720 4½ Litre were produced between 1927 and 1931, including 55 models with a supercharged engine known as the Blower Bentley. Some of these Bentleys did win a few competitions, including the 24 Hours of Le Mans. Though its overall competitive performance was not particularly outstanding, the 4½ Litre Bentley managed to beat several speed records, most famously in 1932 at Brooklands with a recorded speed of 222.03 km/h.

The most significant difference between the Bentley 4½ Litre and the Blower is the engine. The Blower engine is supercharged by a mechanical compressor designed by engineer Charles Amherst Villiers. W.O. Bentley, being hostile to forced induction, believed that "to supercharge a Bentley engine was to pervert its design and corrupt its performance." He refused to allow the engine to be modified to incorporate the compressor; the latter is therefore placed at the end of the crankshaft, in front of the radiator, giving the Blower Bentley a unique and easily recognizable profile and exacerbating its understeer.

A guard protects the carburetor, now located near the compressor, and the headlights are exposed to shocks.[12] Similar protection is used (both in the 4½ Litre and the Blower) for the gas tank at the rear, because a flying stone punctured the 3 Litre of Frank Clement and John Duff during the first 24 Hours of Le Mans, possibly depriving them of victory.[14][15]

Villiers chose a Roots type supercharger. The weight of the crankshaft, another set of pistons and a piston lubrication dry sump, nevertheless, are adapted to the engine.[8] Supercharged, the Blower Bentley produces 175 hp (130 kW) at 3,500 rpm for the Touring model and 240 hp (177 kW) at 2,400 rpm for the racing version--more powerful than the Bentley 6½ Litre despite lacking the two additional cylinders

Gallery: Bentley Blower