Bentley Speed Six

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
Bentley 6½ Litre & Speed Six
File:Sir Michael Kadoorie's 1930 Bentley Speed Six Mulliner Drop Head Coupe1.jpg
Speed Six Mulliner drophead coupé 1930
original body, chassis LR2766, engine KR2698, registration GH 1517. First owner a Miss Bingham
Overview
Manufacturer Bentley Motors Limited
Production 1926–1930
544 produced[1][2]
Assembly Cricklewood, London
Designer Walter Owen Bentley
Body and chassis
Class Luxury car
Body style as arranged with coachbuilder by customer[3]
Layout FR layout
Powertrain
Engine 6.5 L I6
Dimensions
Wheelbase 132 in (3,353 mm)[4][5]
138 in (3,505 mm)[6]
140.5 in (3,569 mm)[5]
144 in (3,658 mm)
145.5 in (3,696 mm)
150 in (3,810 mm)[4]
151.5 in (3,848 mm)
152.5 in (3,874 mm)[4][5]
Chronology
Successor Bentley 8 Litre

The regular Bentley 6½ Litre and the high-performance Bentley Speed Six were sports and luxury cars based on Bentley rolling chassis[3] in production from 1926 to 1930. The Speed Six, introduced in 1928, would become the most successful racing Bentley. Two Bentley Speed Sixes became known as the Blue Train Bentleys after their owner Woolf Barnato's involvement in the Blue Train Races of 1930.

Background

By 1924, Bentley decided to build a larger chassis than the 3 Litre, with a smoother, more powerful engine. The new chassis would be more suitable for the large, heavy bodies that many of his customers were then putting on his sports car chassis, and the resulting car would be more refined and better suited for comfortable general motoring.[1][7][8]

Prototype race

Bentley built a development mule with a 4¼ L straight-six engine[7][8] derived from the 3 Litre's four cylinder engine.[9] To disguise the car's origin, it had a large, wedge-shaped radiator[8][9][10] and was registered as a "Sun".[8][9] The car had a large Weymann-type[9] tourer body built by Freestone and Webb.[7]

W. O. Bentley combined one of his road tests of the Sun with a trip to see the 1924 French Grand Prix in Lyon.[7] On his return trip to the ferry at Dieppe, W. O. encountered another disguised car at a three-way junction. W. O. and the Rolls-Royce test driver recognized each other and began racing each other along the routes nationale.[7][9] This street race continued until the Rolls-Royce driver's hat blew off and he had to stop to retrieve it.[8][9] The Sun's tyres were heavily worn when W.O. got to the ferry at Dieppe.[8]

6½ Litre

1927 Bentley 6½ Litre
with H. J. Mulliner & Co. limousine body
File:1927 Bentley 6½-litre H J Mulliner Limousine 3156810435.jpg
rear view

Realizing from the impromptu race that the Sun had no performance advantage over Rolls-Royce's latest development,[7] W. O. increased the bore of his six-cylinder engine from 80 millimetres (3.1 in) to 100 millimetres (3.9 in).[8][9] With a 140 mm (5.5 in) stroke, the engine had a displacement of 6.6 L (6,597 cc (402.6 cu in))[1][9][11] Like the four-cylinder engine, Bentley's straight-6 included overhead camshaft, 4 valves per cylinder,[9] and a single-piece engine block and cylinder head cast in iron, which eliminated the need for a head gasket.[12] In base form, with a single Smiths 5-jet carburettor,[1] twin ignition magnetos,[1][8][9] and a compression ratio of 4.4:1, the Bentley 6½ Litre delivered 147 horsepower (110 kW) at 3500 revolutions per minute.[8][11]

Although based on the 3 Litre's engine, the 6½ engine incorporated many improvements. The 3 Litre's cone-type clutch[13] was replaced by a dry-plate design[5] that incorporated a clutch brake for fast gear changes,[citation needed] and the car had power-assisted[1] four-wheel brakes with finned drums. The front brakes had 4 leading shoes per drum.[citation needed] By operating a patented compensating device, the driver could adjust all four brakes to correct for wear while the car was moving, which was particularly advantageous during races.[citation needed]

A large variety of wheelbases were produced for such a low-production car, ranging from 132 to 152.5 in (3,353 to 3,874 mm). The most popular wheelbase was 150 inches.[4]

Speed Six

File:1929 Bentley Speed Six Gurney Nutting Old Number 1.jpg
Old Number One, winner of the 24 Hours of Le Mans in 1929 and 1930
File:Bentley Speed Six body by Hooper.jpg
Speed Six tourer with original body by coachbuilder Hooper

The Bentley Speed Six was introduced in 1928[5] as a more sporting version of the Bentley 6½ Litre.[12] With a single-port block, two SU carburettors,[5][8][11] a high-performance camshaft,[14] and a compression ratio of 5.3:1, the Speed Six's engine produced 180 hp (130 kW) at 3500 rpm.[5][11] The Speed Six was available to customers with wheelbases of 138 inches (3,505 mm),[6] 140.5 inches (3,569 mm), and 152.5 inches (3,874 mm),[5] with the 138 inch wheelbase being most popular.[6]

The model was available as a road car for everyday use. Barnato 's personal Speed Sixes had bespoke bodywork by various coachbuilders, and the Criminal Investigation Department of the Western Australia Police operated two saloon-bodied examples as patrol cars.[4]

In March 1930, Barnato raced against the Blue Train in a Speed Six with H. J. Mulliner saloon coachwork, reaching his club in London before the train was due in the station at Calais. It had generally been believed that the car in the race was a Gurney Nutting Sportsman Coupé, but the coupé had been delivered to Barnato in May 1930, more than a month after the race.[15][16]

Factory racing cars

The racing version of the Speed Six had a wheelbase of 11 feet (132 in; 3,353 mm)[5] and an engine with a compression ratio of 6.1:1 that produced 200 hp (150 kW) at 3500 rpm.[17] Successful in racing, these cars won the 24 Hours of Le Mans in 1929 and 1930[18][19] with Bentley Boys drivers "Tim" Birkin, Glen Kidston, and Woolf Barnato, the Chairman of Bentley Motors.[19]

Production

  • 6½ Litre: 362[1]
  • Speed Six: 182[20]

Gallery

  • Blue Train Bentley 6½-litre saloon.jpg

    Woolf Barnato's Speed Six H. J. Mulliner saloon, in which he raced against the Blue Train

  • 1930 Bentley Speed Six Nutting Coupe (3828597253).jpg

    1930 Gurney Nutting Sportsman Coupé, often believed to be the car that raced the Blue Train despite being delivered to Barnato weeks after the race. Photo from 2009 Concours.

  • 1930 Bentley Speed Six Nutting Coupe (3828596647).jpg

    ...Another view

  • 1928 Bentley 6½ Litre Tourer KD2111, VandenPlas lhs.jpg

    Bentley 6½ Litre Tourer

  • 1929 Bentley "Speed Six" IMG 9625 - Flickr - nemor2.jpg

    Bentley Speed Six drophead coupé

  • Bentley Speed Six.JPG

    Bentley Speed Six prepared for racing

  • Bentley 6,5-Litre Tourer.jpg

    Bentley 6½-Litre Tourer

  • Bentley 6,5-Litre Speed Six Tourer 1930.jpg

    Bentley 6½-Litre Speed Six Tourer 1930

Notes

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Brooks 2009, p. 27.
  2. ↑ Johnson 2011, p. 9.
  3. ↑ 3.0 3.1 History By Chassis – List of all W. O. Bentleys with original chassis nos. 6 1/2 Litre (Page 1)
  4. ↑ 4.0 4.1 4.2 4.3 4.4 Brooks 2009, p. 28.
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Robson 2001, p. 66
  6. ↑ 6.0 6.1 6.2 Brooks 2009, p. 31.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Feast 2004, p. 44
  8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 Johnson 2011, p. 8.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 Posthumus 1977, p. 102.
  10. ↑ Brooks 2009, p. 26.
  11. ↑ 11.0 11.1 11.2 11.3 Culshaw & Horribin 2013, p. 81.
  12. ↑ 12.0 12.1 Robson 2001, p. 68
  13. ↑ Robson 2001, p. 60
  14. ↑ Feast 2004, p. 46
  15. ↑ "Special Edition: Bentley Arnage Blue Train", The Car Experience
  16. ↑ Young 2010.
  17. ↑ Johnson 2011, pp. 8-9.
  18. ↑ Culshaw & Horrobin 2013, p. 82.
  19. ↑ 19.0 19.1 Feast 2004, p. 55
  20. ↑ Brooks 2009, pp. 27-28.

References

Print
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
Online
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
  • Lua error in package.lua at line 80: module 'strict' not found.
Bentley timeline, 1920s–present
Type 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s
Ownership Bentley Motors Limited
(1919–1931)		 Rolls-Royce
Bentley Motors (1931) Limited
(1931–1980)		 Vickers plc
Rolls-Royce
Bentley Motors (1931) Limited
(1980–1998)		 Volkswagen Group
(1998–)
Coachbuilder's
open
2/4 seater		 3 L 4½ L
6½ L
Speed Six
Coachbuilder's
large saloon
coupé or
convertible		 6½ L
Speed Six
8 L		 4L
3½ 
4¼L
Mark V		 Mark VI R S1
S2
S3		 T
C
o
n
t		 Continental S1
Continental S2
Continental S3
Cars with Bentley own-factory coachwork
Large
saloon
 Mark VI R S1
S2
S3		 T1 T2 Mulsanne Brooklands Arnage Mulsanne
Turbo R
Coupé Corniche Continental R/S/T Br.
Convertible Corniche Continental Azure
Bentleys on the Volkswagen platform
Large
saloon		 Continental
Flying Spur
Coupé Continental GT
Convertible Continental GTC
Bentley timeline, 1921–1931
type /class 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931
Sports car 3 L
4½ L & Blower
Grand tourer 6½ L & Speed Six 4L
Luxury vehicle 8 L
Retrieved from "https://infogalactic.com/w/index.php?title=Bentley_Speed_Six&oldid=3500874"