Thank Frankel it’s Friday: Predicting the demise of the greatest British V8

No other engine in any other car on sale has had an innings like it and the reason I’m writing this is not just because I don’t think it’s long for this world, but because this year marks its 60^th year of continual production. Or near continual, of which more in a moment. People will say the Chevrolet small block dates back to 1954 and so it does, but so too was it replaced in its entirety by the LS-series motor in 2003, before it had hit even its 50^th, let alone 60^th birthday.

The Bentley motor’s longevity is down to many different factors, a unique confluence of circumstances that ensured it stayed in production not just for all its natural lifespan, but then stayed in production for another 30 years after that.

But first, what is it and how did it get that way? I think because people know the also long-lived Rover V8 motor started life as a US design for Buick, and because a big pushrod V8 was for years Detroit’s own calling card, that the Rolls/Bentley V8 must also owe its origins to America. Not so. The Rolls engine was a clean sheet design that owed nothing to any other.

It was needed because the engine it was replacing was itself far from in the first flush of youth. Indeed, the straight six used in the likes of the Bentley S1 up until 1959 could trace its roots all the way back to the Rolls-Royce Twenty of 1922, albeit changed in size and much modified. That engine had reached the end of the road, its curious cylinder head design – adopted post-war – limiting development potential.

So as early as 1952 the need was identified for a new engine and certain rules were applied. It must offer all the refinement and reliability the customer expected of a Rolls-Royce engine, but more power, greater torque yet – and this was the kicker – all that for no additional weight penalty.

So it was decided to up the size and cylinder count to liberate the power, allow it to spin even more lazily and therefore quietly, and keep some development potential up its sleeve for the future. The weight was saved by casting it in aluminium rather than iron. A straight eight was by then unfashionable and difficult to package, so a 90-degree Vee was clearly the way to go.

The engine took years to develop and was tried at different sizes – one as small as 5.2-litres – before a 6.25-litre capacity was chosen. And because Rolls-Royce was already hiding the rather modest outputs of its engines by pretending such talk was beneath them, there’s no official power figure available, though around 200bhp is probably about right, or no more than an 8-litre Bentley engine was producing almost 30 years earlier, though we’ll gloss over that.

I’d love to know how long it was meant to last, but probably not even the 23 years until some bright spark though that strapping a turbo to it may be just the thing required to relaunch the Bentley brand. The engine had had a 6.75-litre capacity since 1968 and the single turbo added to the Mulsanne raised power by at least 50 per cent, catapulting Bentley back into the limelight and, in time, relegating Rolls-Royce to obscurity. 

Then, in 1998, Rolls-Royce and Bentley owners, Vickers, killed it. From now on the brands would be powered by BMW engines, V12s for Rolls-Royces, small capacity V8s for Bentleys. Except that at exactly the same time, Vickers was negotiating the sale of the two brands, with BMW ending up with the rights to call a car a Rolls-Royce, VW with the Bentley name, the Crewe factory and everything in it including, incidentally, the immortal Rolls-Royce Silver Ghost which remains in Bentley ownership to this day. I’ve often wondered just how many walls got kicked the day it was realised that had been omitted from the deal.

And just about the first job mandated by VW was that the Arnage be completely re-engineered to take an engine for which it was never designed: the good old 6.75-litre V8. And with continuous development it’s been with us ever since, and now develops 530bhp in the Mulsanne Speed. I think if you told those who invented it that one day its output would have increased by 265 per cent, they’d probably have fallen off the furniture.

I took a Mulsanne Speed for one last drive the other day and revelled in its rumble, its thunder and, above all, its ability to dump 811lb ft of torque on the tarmac at just 1750rpm. I expect the engine’s imminent demise is due to the prohibitive expense of getting it through the next round of emissions test and that I understand. And I know 60 is a fine innings for an engine, one of the longest of all in fact. But I’ll still be sad to see it go.