Bentley 3 Litre

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Bentley 3 Litre
Manufacturer	Bentley
Production	1921–1929 1622 produced[1]
Successor	4½ Litre
Class	Sports car
Engine(s)	3.0 L OHC 4-valve I4
Wheelbase	108 in (2743 mm) 117.5 in (2985 mm) 130 in (3302 mm)
Designer	Walter Owen Bentley

The 3 Litre was the sports car that put Bentley on the automotive map. It was a large car compared to the tiny, lightweight Bugattis then dominating racing, but its innovative technology and strength made up for its weight. The 4000 lb (1800 kg) car won the 24 Hours of Le Mans in 1924, with drivers John Duff and Frank Clement, and again in 1927, this time in Super Sports form, with drivers S. C. H. "Sammy" Davis and Dudley Benjafield. Its weight, size, and speed prompted Ettore Bugatti to call it "the fastest lorry in the world."

Contents 1 Coachwork 2 Engineering 3 Variants 3.1 Blue label 3.2 Red label 3.3 Green label 4 Production 5 References

[edit] Coachwork

The 3 Litre was delivered as a running chassis, with Bentley referring many customers to Vanden Plas for standard bodies. Most were open touring cars, but some variety was inevitable with custom coachwork. Customers included Prince George, Duke of Kent, Gertrude Lawrence, and Beatrice Lilliewere.

[edit] Engineering

The 3.0 L (2996 cc/182 in³) straight-4 engine was large for its day, but it was its technical innovations that were most noticed. It was one of the first production engines with 4 valves per cylinder, and these were driven by an overhead camshaft. It was also among the first with two spark plugs per cylinder, pent-roof combustion chambers, and twin carburetors. It was extremely undersquare, optimized for low-end torque, with a bore of 80 mm (3.1 in) and a stroke of 149 mm (5.9 in). To increase durability, the iron engine block and cylinder head were cast as a single unit.

Power output was roughly 70 hp (52 kW), allowing the 3 Litre to hit 80 mph (129 km/h). The Speed Model could reach 90 mph (145 km/h), while the Super Sports passed 100 mph (161 km/h).

A four speed gearbox was fitted.

On the early cars the brakes only operated on the rear wheels but from 1924 four wheel brakes were used.^[2]

[edit] Variants

There were three main variants of the 3 litre and they became known by the colours commonly used on the radiator badge. There is, however, no definitive rule controlling badge colours and the factory would suppl;y any colour requested.

[edit] Blue label

This was the standard model with 117.5 in (2985 mm) wheelbase from 1921 to 1929 or long 130.0 in (3302 mm) wheelbase from 1923 to 1929.^[2]

[edit] Red label

This used a 5.3:1 high compression engine in the 117.5 in (2985 mm) wheelbase chassis and was made from 1924 to 1929.^[2]

[edit] Green label

Made between 1924 and 1929 this was the high performance model with 6.3:1 compression ratio and short 108 in (2743 mm) wheelbase chassis. 100 mph performance was guaranteed.^[2]

[edit] Production

The 3 Litre car was shown at the 1919 London Motor Show, but the engine had not yet been finished. It took two years to get the engine right, with the first customer delivery in September of 1921. Production lasted through 1929, by which time the car had been surpassed by Bentley's own 4½ Litre car.

• Experimental: 3
• 3 Litre: 1088
• Speed Model: 513
• Super Sports: 18

[edit] References

Preceded by Mercedes 60hp

Fastest street-legal production car 160 km/h

Succeeded by Bentley 4½ Litre

v • d • e Bentley ownership and road car timeline, 1920s–present – now a marque of the Volkswagen Group (Volkswagen AG) (VWAG)
Type	1920s		1930s		1940s		1950s		1960s		1970s		1980s		1990s				2000s
	Independent		Rolls-Royce															Volkswagen Group
Sports car	3 L	4½ L			WWII
Saloon		6½/Six	4L/3½ 4¼L/V			VI	R	S1/S2/S3		T1		T2	Mulsanne								CFS
Premium		8 L										Camargue						Arnage
Coupé											Corniche			Continental & C Turbo		Continental R/S/T				C GT
Convertible																	Azure				C GTC
Founder: Walter Owen Bentley • Bentley Motors corporate website • A marque of the VWAG group • Bentley Boys