Slow, incremental change could be said to represent one of the hallmarks of the Rolls Royce marque. Something similar could be said of its engine.
The L410 V8 engine was born in the early 50s with the role of powering Bentleys and Rolls-Royce cars. From the 50s to 1998 the engine found homes in cars of both brands. After BMW acquired Rolls-Royce (the name and nothing else), the engine then became the sole preserve of Bentley where it is still in use, very highly modified, in the Mulsanne.
This engine has a rough parallel with the Buick V8 talked about recently, in that it is simply a very long lived V8. The differences are that the L410 is still in production and that nobody seems to have tried to use the engine in other commercial applications.
The main steps of the history of the L410 are well-documented so I won’t try to recapitulate them in their entirety. What any informed person might remember is that the engine has had one increase in capacity, from 6.25 litres to 6.75 litres in 1968. In 1982 a turbo-charger was added to give the Bentley Mulsanne a more sporting character.
That particular step is of significance because it was the germ of Bentley’s eventual independence. The more aggressive engine made people wake up to Bentley’s sporting heritage and gradually at first more and more customers were opting for a winged “B” on their bonnet instead of the Spirit of Babycham.
For me the relative simplicity of the engine’s development is fascinating. First, that a design conceived in the mid 1950s has such flexibility that it can be made to run to the expected performance standards of the 21st century is quite remarkable.
Second, the fact that one basic engine format was sufficient for four or six decades of production of various models shows how focused Rolls-Royce were. They made what was essentially variants of one car. Not three with three different engines but one simple saloon or coupe with one powerful motor.
The L410 is also an interesting metaphor for conservatism, if you feel inclined to view it that way. Conservatism historically has favoured slow, organic change rather than revolutions and sudden disruptions. The L410 is surely perhaps the best example of this approach (which is not so successful in other applications).
This bit of the Wikipedia entry is worth repeating here: “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 emissions. In the current Brooklands and Mulsanne, the 6.75-litre engine produces 395 kilowatts (537 PS; 530 bhp) and 1,050 newton metres (774 lb ft) of torque.”
So, what remains? Which parts are common to the 1959 engine? Yet there is continuity, meaning the engine could be gently altered from one year to the next which avoided making costly mistakes or building-in untested features. This doesn’t work for everyone, of course, which is why the L410 is a metaphor. Given the cars it sits in, that’s rather appropriate.