1926→1928 Bentley 6½ Litre
Often confused with the Speed 6, the 6½ Litre was Bentley’s first large-displacement, six-cylinder car. The new engine was necessary to bolster the image of Bentley beyond rivals of Rolls-Royce and Mercedes-Benz. Furthermore, the six-cylinder unit ran much smoother than the 6½.
The new engine was very advanced, using aluminum pistons and a unique valvetrain that employed the use of three crankshafts. While complex, this system was much quieter than the outgoing 6½ Litre.
Although intended for luxury, the advanced engine was raced with great success in the Speed 6.
To keep pace with the larger engine, the chassis was upgraded. Larger disc brakes were fitted with finned aluminum drums.
The first 6½ appeared as a bare chassis at the 1925 Olympia Motor Show, but it would take over a year to launch the car. During this period the engine was thorougly tested and bored out to 6,597cc before market launch.
In Detail
| type | Series Production Car |
| production years | 1926 – 1928 |
| released at | 1925 Olympia Show |
| built at | England |
| engineers | Walter Owen Bentley |
| production | 545 |
| engine | Inline-6 |
| position | Front Longitudinal |
| aspiration | Natural |
| valvetrain | 4 Valves / Cyl |
| fuel feed | Dual SU Carburetors |
| displacement | 6597 cc / 402.6 in³ |
| bore | 100 mm / 3.94 in |
| stroke | 140 mm / 5.51 in |
| compression | 5.1:1 |
| power | 119.3 kw / 160.0 bhp @ 3500 rpm |
| specific output | 24.25 bhp per litre |
| body / frame | Body over Steel Chassis |
| front brakes | Drums w/Servo Assist |
| rear brakes | Drums w/Servo Assist |
| f suspension | Solid Axle w/Semi-Elliptic Leaf Springs |
| r suspension | Live Axle w/Semi-Elliptic Leaf Springs |
| wheelbase | 3568 mm / 140.5 in |
| transmission | 4-Speed Manual |
| top speed | ~148 kph / 92.0 mph |
Auction Sales History
1927 Bentley 6 1/2 Litre Tourer BX 2416 – sold for $1,210,000 Originally fitted with saloon coachwork by Gurney Nutting in the Weymann style. Fitted with Le Mans style bodywork in 2008 by David Ayre.
Auction Source: The Pebble Beach Auctions 2015 by Gooding and Company
1929 Bentley 6½-Litre Sedanca de Ville by H.J. Mulliner KR2687 – did not sell for €540,000 The 1929 Olympia Motor Show car. One of about 20 surviving 6½-Litre Bentleys, with original coachwork and engine. Engine rebuilt and equipped to Speed Six specification. Recently displayed at the Bentley factory.
Auction Source: 2013 Villa d’Erba Auction by RM
1929 Bentley 6½/8-Litre Tourer FA2510 – sold for €615,250
This 6½-Litre Le Mans-style tourer offered here was constructed from parts by well known Bentley collector/racer and VSCC competitor, David Llewellyn, and has been upgraded with the engine block of an 8-Litre model. Off test on 19th January 1929, chassis number ‘FA2510′ is one of only 97 Bentley 6½-Litre models completed on the 12′ wheelbase chassis, the majority being erected on the 12’ 6″ frame. The car started life fitted with Weymann-type saloon coachwork by H J Mulliner and was first owned by Mr R H R Palmer, of Messrs Huntley & Palmer, the Reading-based biscuit manufacturers. It was first registered in the UK on 30th June 1929 as ‘RX 3612’, a Berkshire mark. The car is described in ‘Bentley, The Vintage Years’ by Michael Hay (page 465).
David Llewellyn built the car as a copy of a Le Mans Speed Six, with replica Vanden Plas-type coachwork and to high-performance specification, its 8-Litre engine delivering tremendous torque. The 8-Litre block is mounted in reverse on the 6½-Litre crankcase so that the engine retains the appearance of a ‘6½’ while the gearbox is an original Bentley D-type and the axles, steering box, etc are likewise genuine Bentley. After completion the car was bought from David Llewellyn by David Ayre, the Berkshire-based Bentley and Invicta specialist, who further improved it by fitting a servo to the braking system. At some stage the Bentley was loaned to a client to participate in a rally in South Africa. When the car returned it was discovered that the top had come off one of the pistons, so rather than risk further damage David dismantled the entire car and was in the process of reassembling it when a Dutch client, Dirk Lindenberg, persuaded him to part with it. The restoration was completed in time for the 2007 Paris-Peking Rally.
Auction Source: The Paris Sale 2012 by Bonhams
1926 Bentley 6½ Litre Motor Bodies Coupe WT2271 – did not sell for $600,000
Supreme Champion Award Winner. A Remarkably Original 6 1/2-Litre Bentley, Fully Upgraded to Speed Six Specifications by the Factory and Still Wearing Its Original Coachwork. Part of the Highly Regarded Reg Parker Collection for Almost 20 Years. Beautiful Presentation of a Most Significant Bentley Motorcar.
Remarkably, this car retains its original Coupe body by Motor Bodies of Newcastle and is one of only a handful of 6 1/2-litre models still retaining their original bodywork, as most have been converted into Le Mans-style Tourers over the years. As such, it is quite a pleasure to encounter such an original, well- maintained 6 1/2 litre. This example is one of a select few 6 1/2-litre models still wearing their original bodywork and this is the only example to feature Motor Bodies coachwork. The coach- work is truly splendid, sporting twin side-mount spares, a number of bespoke details and a unique sliding roof. With its large sunroof and disappearing windows, the handsome Coupe is an ideal configuration for touring. The car is an absolute joy in any weather condition, offering a comfortable and secure cockpit in adverse conditions while the roof can easily slide back, allowing sunlight to pour into the front seats on more idyllic days. It is finished in a handsome and most fitting black livery, the ideal presentation for a vintage Bentley.
Auction Source: 2011 Amelia Island Auction by Gooding & Company
1927 Bentley 6½ Litre Surbiton Sport Coupé TW2713 – sold for $781,000 Originally built to standard six and a half liter specifications, TW2713 has been updated to Speed Six configuration, including the proper cylinder blocks and twin carburetor setup as designed by porting expert Harry Weslake. While such updates were often performed by the factory, there are no records to indicate when the work was done, or who was responsible for it.
Auction Source: 2006 Monterey Preview
