The Crewe built Rolls-Royce - Bentley L Series V8 engine was used on many Rolls-Royce and Bentley motor cars in the four decades after its introduction in 1959. With BMW’s acquisition of the rights to use the Rolls Royce name in 1998, Rolls-Royce Motor Cars began using BMW supplied V12 engines but Bentley Motors Limited under Volkswagen ownership continued to use highly modified versions of the L Series on its Bentley Arnage, Bentley Brooklands and Bentley Mulsanne models, with VAG W-12 engines being used in its Bentley Flying Spur and Bentley Continental models.
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United States firm Marmon developed the first engine of V8 configuration in 1904, though it was experimental and did not find its way into a passenger vehicle. Rolls-Royce premiered the world's second V8 engine in 1905 for their eponymous Rolls-Royce V-8. Production of this engine predated by a decade Cadillac's first mass production of a V8 engined automobile. The 1905 Rolls-Royce V8 was not a success, with only three made and just one sold, which was soon returned to the factory to be scrapped[1].
Rolls-Royce acquired Bentley in 1931 and continued to use Bentley engines alongside their own for a time, although none was a V8. Prior to World War 2, Rolls-Royce had developed a 7.3 litre V-12 for the Phantom III, which was succeeded by the F-head B60 straight-6 and B80 straight-8 series of engines. The B80 powered the Phantom IV limousine, whilst the 4.3 litre B60 was used until 1955 to power the Rolls-Royce Silver Wraith and Silver Dawn and the Bentley Mark VI. The B60's bore was enlarged in 1955, increasing the displacement to 4.9 litres, that engine being known as the B61.
The need for a new engine was recognised by Rolls Royce in the early 1950s and its development began in 1952, bearing no relation to the 1905 Rolls-Royce V8. The result was a series of V8 engines known as the L series, more specifically the "L410" for its bore size of 4.10 inches (104 mm), in keeping with company practice.
Developments of the L410 continued in production powering Rolls-Royces up to 1998 and Bentleys into the 21st century. Bentley, under Volkswagen ownership since 1998, continues to develop the L410 for its range of cars. Roll-Royce ceased using the L410 with the switch to BMW ownership of that brand in March 1998 and introduction of a BMW sourced V12 engine in the Rolls Royce Silver Seraph.
Since 1998 therefore, development and use of the L410 engine can be said to have been exclusively a Bentley enterprise.
The factory nomenclature for the L Series V8 engines, in chronological order, is as follows:
The engine was of an overhead valve (OHV) design, angled at 90 degrees, and featured a central camshaft and wedge-shaped combustion chambers. As initially released, the bore x stroke was 104.14 by 91.44 millimetres (4.10 in × 3.60 in) and displaced 6,230 cubic centimetres (380.2 cu in), which is rounded up to describe it as the six and a quarter litre engine.
When new, the Rolls-Royce/Bentley V8 was rumoured to be an American license-built engine but it was developed in-house by Rolls-Royce and Bentley engineers. This can be seen in its design characteristics, with features like an aluminium alloy cylinder block with wet liners, gear-driven camshaft, (initially) outboard spark plugs and porting inspired by the Rolls-Royce Merlin aircraft engine. Rolls-Royce did use General Motors transmissions in their vehicles, notably the Turbo-Hydramatic in the Silver Shadow.
Starting in 1968 for the 1971 model year, the stroke of the V8 engine was increased from 3.6 inches (91 mm) to 3.9 inches (99 mm), thereby increasing the engine capacity to 6.75 litres - 6,752 cubic centimetres (412.0 cu in). Known as the Six and Three-Quarter Litre or simply the Six and Three-Quarter, it is the most widely used and well known of all the versions and possibly the most famous British V8 engine of all time, save for the Rover V8 engine, which was actually an American Buick design purchased from General Motors.
Except for the Chevrolet Small-block V8 and Lamborghini V12, the Rolls-Royce/Bentley V8 is the longest-lived engine currently in production. From a standpoint of usage in currently sold vehicles, the 6.75 litre engine is the second longest lived engine produced (after the Lamborghini V12, 1963-2010). Production of the Chevrolet small-block engine has been relegated to sale as a crate engine and the replacement GM LS engine is dynamically unrelated to the classic Chevrolet V8 engine, (though the Chevrolet 90-Degree V6 engine is directly related to the original small block and is still in production).
The power output of the 6.75-litre over the 6.25-litre version was not very significant at the outset, the emphasis being on increased torque. However, with improved tuning and the addition of turbochargers, the 6.75-litre became one of the world's powerful automobile engines and enormously enhanced the image of Bentley as a sporting car maker.
The process of evolving the engine has been gradual and continuous; by 2006 almost all the 1959-specification engine components had been upgraded, so that the current twin-turbo 6.75-litre engine produces over 150% more motive power and torque than at the beginning of its life, has 40% better fuel economy, and produces 99.5% less exhaust emission.[2] In the current Brooklands and Mulsanne, the 6.75-litre engine produces 395 kilowatts (537 PS; 530 bhp) and 1,050 newton metres (774 ft·lbf) of torque.[3]
BMW obtained an interest in Rolls-Royce and Bentley in the 1990s and began supplying them with engines in 1998, specifically a V12 engine for the Rolls-Royce Silver Seraph and a twin-turbo 4.4 litre V8 engine to replace the 6.75 litre for the Bentley Arnage. BMW V8 engines were used exclusively in the Arnage from 1998 to 2000.
In 1998, Volkswagen Group outbid BMW to acquire Rolls Royce and Bentley Motor Cars. BMW reached agreement with Rolls Royce plc to secure usage of the Rolls Royce brand, the badge and the Flying Lady mascot—the aero engine company having retained control of the brand when it split from the car manufacturing business. A deal was finally reached whereby Volkswagen Group retained use of the Rolls Royce brand until the end of 2002, when Rolls-Royce Motors transferred to BMW control, leaving VW with the Bentley marque, the factory, and ownership of all current models (although production of the Rolls Royce Silver Seraph was discontinued).
BMW no longer owns the rights to produce any pre-2003 Rolls-Royce or Bentley engines. The current Rolls-Royce Phantom and its derivatives use a normally aspirated BMW V12 engine, which has no technical similarities with the L410 engine. The Rolls Royce Ghost introduced in 2010 uses a 6.6 litre twin-turbo V12.
Under Volkswagen Group, the Bentley Arnage's BMW engine was phased out from 2000 to 2002 and the L410 engine was reintroduced in highly redeveloped form. The Arnage-derived Brooklands uses the most powerful version of the engine yet. Those models and the convertible Bentley Azure are produced alongside the Bentley Mulsanne and smaller Bentleys based on the Continental GT, which use the VAG W-12 engine.