By on April 9, 2021

Today we bid a belated farewell to a legend of an engine, the Six and Three-Quarter Litre V8. In production since 1959 at the factory in Crewe, The L-series V8 had several different displacements and powered many different luxury vehicles. And some boats.

Your author only realized this engine had met its end because of the Rolls-Royce Ghost review Mr. Tim Healey (That’s Mr. Editor Tim Healey, to you, Buster) posted the other day. Upon dismissing the Ghost as my large luxury car choice, I went to check on what Bentley’s current sedan offerings looked like. Turned out the flagship Mulsanne saw its final model year in 2020, as Bentley continued with the Flying Spur as its only sedan in 2021. Ten inches shorter and $100,000 less expensive in its base form, it looks almost exactly like the Mulsanne but is obviously for the middle class. Above, dark blue is the Flying Spur, and light blue the Mulsanne. By the way, here’s an exquisite final run Mulsanne for your perusal. The marquetry on the wood is especially impressive.

And with the Mulsanne’s end came the end of the L-series Rolls-Royce-Bentley V8. A 90-degree configuration, it was introduced in 1959 to power Rolls-Royce and Bentley cars (both companies were under the same ownership at the time). The engine’s initial displacement was 5.2-liters during development but reached 6.25 liters by the time it entered production. Developed in-house by the Rolls-Royce and Bentley engineering teams, the basic 6.25-liter version was in use from inception through 1982, though most of its usage was prior to 1970. Circa 1963 the L-series spawned a marine version that was 6.2-liters in displacement and sold as a complete marine power package that included a BorgWarner-supplied transmission.

For 1971, Rolls-Bentley increased the stroke of the engine, and the Six and Three-Quarter Litre version was created. The main advantage emphasized on the new engine versus the outgoing was an increase in torque, as power was similar initially. Over the years many revisions were applied to the engine, often driven by tightening emissions regulation. Carburetors of course gave way to fuel injection. In 1987 a new cylinder firing order was introduced, and around the same time some turbochargers were attached on the sportier Bentley versions. At the time, the Turbo R was one of the most powerful sedans available, and the power and character of the V8 reinvigorated Bentley’s fusty image.

In the Nineties, BMW purchased Rolls-Royce, while Bentley went to Volkswagen. It was a complicated and contentious sale. On the production side, starting in 1998 BMW forced its engines upon Rolls and Bentley in the Silver Seraph and Arnage, respectively. From 1998 to 2000, you could only purchase an Arnage with a BMW engine. Eventually, the pieces fell into place. Post-2003, BMW was not allowed to produce any Rolls or Bentley engines from prior to 2003. It used its own engines in Rolls-Royce, and Volkswagen could resume use of the Six and Three-Quarter Litre in Bentleys.

Improvements continued over the years, and circa the 2000s, nearly all engine components from 1959 had been changed or upgraded in some way. In its initial guise, the engine produced around 172 horsepower, but with modernization and twin-turbo action, that figure jumped to a much more impressive 530 horses. The engine was utilized in more expensive “pure” Bentley products like the Brooklands and Mulsanne, where lesser offerings like the Continental GT used VW’s W-12 engine shared with the Phaeton.

Mulsanne would be the final user of the Bentley 6.75-liter engine. In use since Mulsanne’s arrival in 2010, the only other Bentley to use it in the past decade was the superb Brooklands, and only through 2011. The V8 was so long-lived, only the Chevrolet small-block V8 has a longer production history. Requiescat in pace.

[Images: Bentley]

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25 Comments on “In Memoriam: The Rolls-Royce-Bentley Six and Three-Quarter Litre V8...”

  • avatar
    SCE to AUX

    My, what big eyes you have.

  • avatar

    The Brits need to leave the V8 making to the ‘Mericans (or “Yanks” as they like to say). Same goes for the Euros. OK everybody else too.

    • 0 avatar
      Kyree S. Williams

      I like the V8 in my new 2021 GX 460. It’s relatively simple, smooth, and it makes trucky noises.

      • 0 avatar

        Lots of outfits manage to make nice V8s. As Long As they keep them normally aspirated. Turbos are fine enough for small, cylindrically challeged engines. But once you get to 4+liter V8s, If you need even more power, the solution is bigger V8s (or V12s). Not turbos.

        Toyota’s NA V8s are nice. As was, perhaps even more so, the late, great 6.3 AMG one. What an engine! The turbodullery the Euros are hawking these days, aren’t even in the same zipcode.

        • 0 avatar
          Kyree S. Williams

          Or hybrids. The LS 600hL, which mated the 5.0-liter V8 with some electric propulsion for a V12-like experience was the smoothest thing I’ve ever driven.

          Indeed Toyota now uses that same powertrain combination for its Century, which is the culmination of Toyota’s very best engineering.

          That said, the Bentley/Rolls-Royce 6.75-liter with the twin turbos is also an especially smooth powertrain, and the turbos in no way detract from the experience. I do agree that the more mainstream twin-turbo stuff (such as in BMW, Audi and Mercedes-Benz products) seems sort of bipolar.

  • avatar
    Kyree S. Williams

    You have it a bit wrong.

    The relationship between Crewe (the nickname for the combined entity of Bentley and Rolls-Royce until 1998 or so) and BMW started in the early nineties, when Crewe explored the idea of building a smaller, more-sporting Bentley. Its SZ platform, which underpinned all of its then-current cars, was much too large for this purpose. So Crewe–which had a shoestring budget–began exploring the use of building a smaller car using someone else’s engineering.

    The eventual result of this, a convertible called the Concept Java, debuted in 1994. It was, in essence, a heavily modified E34-generation BMW 5 Series.

    BMW caught wind of the fact that the concept used 5 Series underpinnings and sparked up a relationship with Crewe. Two things came of this: one was that the Concept Java was approved to become an actual product. It was to use the engineering from the subsequent-generation (E39) 5 Series, specifically the M5, and both BMW and Crewe immediately began development work on it.

    For whatever reasons, the Concept Java production car fizzled out. But the second thing that came of it was that the upcoming Bentley and Rolls-Royce sedans, the Arnage and Silver Seraph, respectively, would use BMW engines. The 6.75-liter L-Series V8 had become Crewe’s go-to powertrain, and was used in just about every one of its production cars at the time, along with a GM 4-speed automatic transmission. But Crewe was having some trouble getting the engine to meet the latest round of European emissions regulations, plus it was extremely heavy. So, it was a twin-turbocharged BMW V8 for the Bentley and a N/A BMW V12 for the Rolls-Royce.

    And indeed, the Arnage and Silver Seraph debuted with those engines. They also debuted with some other BMW electronics, such as the steering wheel controls and HVAC panels.

    At that same time…Vickers was looking to sell Crewe, and both BMW and Volkswagen were interested suitors. It was Volkswagen that effectively purchased Crewe. That included the engineering, the factory *in* Crewe, the Bentley brand, the IP and the employees. And yes, it included the heritage L-series V8.

    It did *not* include Rolls-Royce.

    Volkswagen thought it won Rolls-Royce, which was arguably the most valuable part of the deal…but it didn’t. Vickers (the former parent company of Crewe) had never owned Rolls-Royce; the name and logo were merely licensed from Rolls-Royce Aerospace, and thus were not part of the Crewe deal.

    BMW swooped in and licensed Rolls-Royce’s name and logo for less than a tenth of what Volkswagen paid for everything else. And at that point, there were two problems:

    1. BMW was a key supplier for Crewe. And BMW had a provision in its contract that said it could stop being a supplier for any reason with a year’s notice. And BMW threatened to do just that.

    2. Crewe no longer held the rights to manufacture cars called “Rolls-Royce.”

    Volkswagen, fearing the worst, immediately set about an early facelift for the Bentley Arnage. There was an interior overhaul to remove the BMW components, and Volkswagen dusted off the 6.75-liter. Backed by the financial and engineering might of the German automaker, Cosworth (another new Volkswagen subsidiary that was part of the deal) massaged the L-Series to meet emissions and bolted a single turbocharger to it, and it debuted in the 2000 Arnage. This engine was close to what Bentley used in the Turbo R several years prior. That year, you could buy the Arnage as a Green Label (which had the BMW engine) or a Red Label (which had the L-Series engine). These cars were, predictably, distinguishable by literally having either red or green Bentley badges.

    But in 1999, right before the introduction of the Red/Green Label thing, BMW and Volkswagen came to a consensus. BMW would need some time setting up its new Goodwood facility for Rolls-Royce and engineering new product. So, BMW agreed to have Volkswagen continue to build the Silver Seraph and the other Rolls-Royce product under license through the 2002 model year. The Silver Seraph continued to use the BMW V12. Meanwhile, the BMW engine was formally retired from the Arnage after 2000, and it began exclusively using the L-series again.

    In 2003, the brands formally divorced as Rolls-Royce’s Goodwood facility came online and began producing the Phantom VII, which relied entirely upon Bentley engineering and had nothing at all to do with Crewe or Volkswagen.

    In 2004, Bentley’s dream of a smaller and sportier vehicle on German bones was finally realized with the advent of the Continental GT…only it used Volkswagen engineering instead of BMW’s, had an Audi-style longitude-transaxle setup, and was a close cousin to Volkswagen’s own Phaeton. The convertible (Continental GTC) and sedan (Continental Flying Spur/Flying Spur) later followed, as did high-performance “Speed” versions of each.

    Still, even as Bentley began making serious coin with its more profitable and more volume-oriented Continental family, the larger heritage Bentleys remained in place. Volkswagen/Bentley went on to retune the L-series several times for added power and refinement, also ditching the GM 4L80E for ZF 5AT and 6AT units. The Azure (convertible) and Brooklands (coupe) were also reintroduced, lasting through 2010.

    In 2011, the Mulsanne debuted, chock-full of Audi electronics, but still possessing an L-series V8 (this time backed by a ZF 8AT) and still very much handbuilt in the traditional Crewe way. Bentley also made a number of Grand Convertible units, which were droptop versions of the Mulsanne. And, as you said, both the Mulsanne and its L-series V8 were retired in 2020.

    Still, things could have gone differently had BMW won Crewe. BMW’s philosophy seems to be about taking its own technology and reskinning it to imitate the philosophy of other storied brands. That’s evidenced by the 2003-2005 “L322” Range Rover that was very much a BMW with British coachwork, the aforementioned post-2002 Rolls-Royce brand, the modern MINI brand, and BMW’s sheer willingness to produce such projects as the 2020+ Toyota Supra.

    For better or worse, had BMW gotten its way, the traditions of Crewe would have ended 20 years earlier than they did. I’m grateful for that extra couple of decades’ worth of British motoring excellence.

  • avatar

    Because I am a man of culture, I own an entire book dedicated to this engine.

    When Bentley was designing it they took an example of basically every American V8 and then reverse engineered the best parts. The final result was something of a melange from Chrysler, Lincoln, Pontiac, and the V12 RR aero engine.

    • 0 avatar
      Kyree S. Williams

      Ordered! Thanks for the tip. I can’t wait to read about that.

    • 0 avatar

      That would be a major revelation to me. So Rolls Royce copied Detroit V8 features like an all-aluminum block, wet iron cylinder liners, aluminum heads, gear driven camshaft instead of chain, evenly spaced exhaust ports, and twin SU carburettors, did they? Evenly-spaced exhaust ports are a necessity for an aluminum head on an aluminum block, otherwise you’ll get warpage from uneven thermal expansion. See current GM V8s. Chrysler used them on their cast iron 1950s hemis, so I guess RR copied them. Got it.

      From the Merlin, RR copied themselves with the aluminum block and heads, but threw away four valves per cylinder, overhead cam, knife and fork connecting rods on crank throws to eliminate bank offsets, and the supercharger.

      Yup, the L Series V8 took Detroit’s designs all right, the parts that really did matter, wedge combustion chambers and hydraulic lifters. So other than being completely different in all other aspects, they were the same.

      It wasn’t as if prewar Rollers hadn’t used straight pushrod OHV engines. The postwar B series F-heads were a step back from that and never wonderful, barely average, just as Rover’s F-head engine was a lard, like Willys’ attempts. A dead end.

      Maybe it makes Americans feel better thinking Rolls copied Detroit. Karl Ludvigsen was always a bit of a waffler. The company that really did rip off Chrysler V8 engines was Daimler, the British company, not the German Mercedes Benz outfit. In 1960 when introduced, their new 2.5 and 4.5 litre hemi V8s were as much of a copy of Chryslers as can be imagined. Of course, Chrysler had by then moved on from the hemis to the wedge head V8s. It’s hard to get high compression ratios in hemi heads unless the pistons are domed, the combustion chamber then no longer a hemi, but a bit like a piece of grapefruit rind, with terrible combustion characteristics — like present day Chrysler hemis, which need two spark plugs per cylinder to work properly.

  • avatar
    MRF 95 T-Bird

    Since Prince Philip was kind of a car geek, a couple of years ago they actually had to pry the keys from him after a jaunt in his Range Rover I’m sure that he was a fan of the Bentley 6.75-liter.
    As a kid every year I would get the Encyclopedia Brittanica year in review. In one of the early 60’s issues there’s a picture of the prince behind the wheel of the all new Hillman Imp. He had a grin on his face while the Coventry Climax motored along.

    • 0 avatar
      Kyree S. Williams

      I believe he was actually driving a Land Rover Freelander 2, known here in the ‘States as the LR2…not a Range Rover. But yes, that’s a timely story given his passing earlier today.

      The Queen herself is known to putt around the estates in one of several Land Rovers, including a 2006-era Range Rover Supercharged and a later Land Rover Defender, both painted a brilliant green.

  • avatar

    I have traveled a lot more miles with these engines:

    (Significantly more power, but also more expensive – and much louder.)

    • 0 avatar

      Widebody power, and widebody maintenance expense, in a narrowbody.

      Once Airbus figured out how to make a proper narrowbody engine carry the same number of people across North America, the RB211’s goose was cooked (along with that of the 757 it was affixed to).

  • avatar

    Why would I want to pay this much for an vehicle, which is not even as good looking as a 2020 Lincoln Continental. This sedan is a stylistic mess.

    • 0 avatar

      @akear: There’s a 1985 L-39 Albatros for sale in Florida for slightly less money and it comes complete with fake missiles and ejection seats. A lot more fun for a little less money and it won’t be confused with a lincoln. Fuel economy is probably the same.

      Ya gotta have your priorities in life.

      • 0 avatar

        Sure mcs, but if you are pointing at an L-39 then you know that the true cost of warbird ownership, especially jets, is operational and maintenance costs! Acquisition just gets you in the door. As a pilot from a family of pilots with warbirds in the mix, I can speak to the reality. For example, the fuel burn on take-off of an L-39 is ~400 GPH, and half that or less at high speed cruise around FL180+. However, you don’t buy an L-29 to cruise. You buy it to fly low and fast at an airshow or for a fun jaunt. So, the FL180 cruise is just to get you to the airshow a handful of states away, and you might burn 2600 lbs of fuel just getting there with reserve. In the 1970’s, if you brought your warbird to the EAA Convention at Oshkosh, they would pay for your fuel. Those days are gone…

  • avatar

    Didnt the same issue crop when Ford bought Jaguar , they found they didnt have the rights to the Daimler ( UK ) name outside of Britain

  • avatar

    VW group have ceased all ICE engine development – probably apart from regulatory requirements. We will be seeing a lot of articles like this over the next 10 years as they are phased out. I have loved my ICE vehicles (mostly) but the time is right.

  • avatar
    el scotto

    Hmmm, jingoistic in announcing their Britishness, yet not so secretly German? Kinda sounds like the Royal Family.

  • avatar

    Meh throw a turbo on an an otherwise anemic 3 cylinder, the owner will never notice

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