Bentley 4½ Litre
1927–1931 · Bentley 4½ Litre — Sports Car, Inline-4, designed by W.O. Bentley.
The Story
The 4½ Litre was W.O. Bentley’s idea of how to go racing: not cleverness, but cubic capacity — a bigger, brawnier four-cylinder built to outlast everything else at Le Mans. It worked. In 1928 Woolf Barnato and Bernard Rubin won the 24 Hours in a 4½ nicknamed ‘Old Mother Gun,’ a car that had been wrecked in the previous year’s infamous White House crash and rebuilt.
That win was pure Bentley drama: on the very last lap the top water hose pulled out, and Barnato nursed the overheating car across the line just after 4pm, beating the Stutz by a whisker. It was the second of Bentley’s run of Le Mans victories — and the foundation on which the legendary Blower would later be built.
The Numbers
Benchmarked against its class
Each dial ranks this car within its Sports Car class — fuller means higher, and the tick marks the class midpoint.
Signature Colors
The Designer
W.O. Bentley
Walter Owen Bentley founded Bentley Motors in 1919; his OHC 4-valve engines and the ‘Bentley Boys’ won Le Mans five times (1924, 1927–30). After Rolls-Royce bought Bentley in 1931 he moved to Lagonda, designing its V12.
Studio Motors POV
W.O.’s definition of a racing Bentley — big, brawny, naturally aspirated — and a Le Mans winner. A genuine 4½ is vintage motorsport history you can still drive hard.
The Engine
W.O. Bentley Vintage Four
Market & Value
Values on cars like this move monthly. Our brokers price from real transactions.
What Reviewers Said About 4½ Litre
Worth Knowing About the 4½ Litre
3 Things You Didn’t Know
- 1. The 1928 Le Mans-winning 4½, 'Old Mother Gun,' had been wrecked in the previous year's 'White House crash' and rebuilt.
- 2. On the final lap its top water hose pulled out — Barnato timed the overheating run to cross the line just after 4pm and win.
- 3. W.O. Bentley believed in a bigger naturally-aspirated engine over supercharging — the philosophy that split the 4½ from the Blower.
5 Fast Facts
- 1. 4,398 cc OHC four, 110 hp; 720 built 1927–1931 (665 NA + 55 supercharged Blower).
- 2. Le Mans winner 1928 (Barnato/Rubin, 'Old Mother Gun').
- 3. Won the inaugural Le Mans overall-distance prize.
- 4. The basis for the supercharged 'Blower' Bentley.
- 5. Part of Woolf Barnato's 3-for-3 Le Mans win streak (1928–30).
Provenance
Owners & what to look for
Famous Owners
Woolf Barnato & Bernard Rubin — won Le Mans 1928 in the 4½ ‘Old Mother Gun.’ The ‘Bentley Boys’ campaigned 4½ Litres at Le Mans and Brooklands. (Documented; Wikipedia / Bonhams.)
Studio Buyer’s Brief
Works or Le Mans provenance is blue-chip (‘Old Mother Gun’ is the car); demand matching numbers and authenticate rigorously. A period-correct 4½ is among the most usable of the vintage grails.
Full Specifications
- Make / Model
- Bentley 4½ Litre
- Class
- Sports Car
- Production years
- 1927–1931
- Units built
- 665 naturally-aspirated (720 total incl. 55 Blower)
- Variants
- Open tourer & saloon coachwork; works racing cars
- Engine layout
- Front
- Engine
- Inline-4
- Engine family
- W.O. Bentley Vintage Four
- Displacement
- 4,398 cc (4.5 L)
- Power
- 110 hp
- Torque
- lb-ft
- 0–60 mph
- s
- Top speed
- 92 mph
- Power-to-weight
- 65 hp/tonne · 34.1 lb/hp
- Transmission
- 4-speed manual
- Drivetrain
- RWD · Petrol
- Curb weight
- 3750 lb
Questions
4½ Litre FAQ
Did the Bentley 4½ Litre win Le Mans?
Yes. In 1928, Woolf Barnato and Bernard Rubin won the 24 Hours of Le Mans in a 4½ Litre nicknamed ‘Old Mother Gun,’ a car that had been wrecked in the previous year’s White House crash and rebuilt for the race.
What happened on the final lap of the 1928 Bentley Le Mans win?
On the final lap, Old Mother Gun’s top water hose failed, leaving the engine to overheat. Barnato timed the remaining distance precisely, crossing the finish line just as the engine reached its limit — winning the race through careful management of a failing car.
What engine does the Bentley 4½ Litre have?
The Bentley 4½ Litre is powered by a 4,398 cc overhead-camshaft four-cylinder engine producing approximately 110 horsepower in naturally-aspirated form, driving through a four-speed manual gearbox with a top speed of around 92 mph.
Can you lease a Bentley 4½ Litre?
Yes, specialty lenders structure collector-car leases regardless of model year.
What is the difference between the Bentley 4½ Litre and the Blower?
The standard 4½ Litre produces approximately 110 horsepower from its naturally-aspirated engine, while the supercharged Blower uses an Amherst Villiers Roots blower to develop approximately 175 horsepower in road-going form. W.O. Bentley disapproved of the Blower and only built the road cars for Le Mans homologation.
The Bentley Lineup
Explore every Bentley
3 Litre ’216½ Litre / Speed Six ’264½ Litre ’27Blower 4½ Litre ’29
R-Type Continental ’52S1 Continental ’55S-Type Saloon (S1/S2/S3) ’55S2/S3 Continental ’59
Mulsanne (1980) ’80Turbo R ’85
Continental R ’91Azure ’95Arnage ’98
Continental GT (1st gen) ’03Continental Flying Spur ’05Azure (2nd gen) ’06Brooklands (Coupé) ’08
Mulsanne (2010) ’10Continental GT (2nd gen) ’11Flying Spur (2nd gen) ’13Bentayga ’15Continental GT (3rd gen) ’18Flying Spur (3rd gen) ’19
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