Not surprisingly, this caught my attention as soon as I paid a visit to the Cohort. The superb Bentley Continental S2 Flying Spur 4-Door Saloon by H.J. Mulliner was shot and posted by J.C. And although there’s plenty to admire about this elegant Bentley, it’s also an opportunity to pay tribute to its new engine under the hood, the Rolls-Royce—Bentley L-series V8, which was built and installed in various Bentleys continuously until June 2020, or 61 years, a record for any V8 engine.
That’s really worth a moment of admiration, or even veneration.
There was also a two-door version of the Flying Spur, both of which were of course sportier alternatives to the staid “regular” S2 sedan shared with Rolls-Royce. At the risk of incurring the wrath of linguistic purists, the four door might well be considered a four-door coupe, given that it has a decidedly lower and different roof than the standard sedan. But either way is fine with me.
Let’s consider what’s under the hood. But before we do that, we’d better address those that might protest about the L-Series being the longest running installed production V8: what about the Chevy small block? Although it’s still being made as a crate engine, it has been some time since (2003) it was installed in a production vehicle. Hence the Bentley V8 gets the honors.
The RR-Bentley V8 was developed during the 1950s as a rather long-overdue successor to the 4.56 L F-head six, deemed to be increasingly insufficient in its power output. It arrived in 1959 in 6.23 L form, and it has been determined that it had some 172 (real) hp and 295 lb.ft. of torque, even though such vulgar numbers were never publicized. “Sufficient” is what was used. Which is a lovely term, one I’d like to see used more often.
Contrary to what some might assume, the L-410 (named after its 4.10″ bore) was not an imitation of American V8s. RR had a deep history in engine design and building, and had actually built the world’s second V8 engine back in 1905. Although the L-410 shares certain inevitable similarities to American V8s, there are a number of differences too, that reflect RR tradition. Its block is aluminum with wet cylinder liners, for starters, something never seen in the US V8s. Even its firing order of 1-5-4-8-6-3-7-2 is a bit out of the ordinary, although the Ford flathead, Y-Block and Coyote V8s also share that. And obviously, no American V8 ever had a twin SU carburetors feeding its intakes.
Fast forward to 2020 (sorry, I’m a bit too swamped to do a full history of this engine tonight), and the same basic engine in 6.75 L form was making 530 hp and 811 lb.ft. of torque in the Bentley Mulsanne Speed. Of course, there was a bit of development over the centuries, but it really is fundamentally the same engine, fed by twin turbochargers and sanitized thanks to the usual technological solutions.
But no more; all things must end.
The Mulsanne has been replaced by the latest generation (3) of the Flying Spur, which is powered by VW-based engines, either a twin-turbo 4.0 L V8, or the 6.0 L W12, also with twin turbos.
Who could have imagined a VW powered Flying Spur back in 1959, when a VW made all of 30 (net) hp?
And of course, the VW-engined Bentleys are not long for this world either, having been deemed “insufficient” in their environmental compatibility. Bentley’s first EV is due in 2025, and the last gas-powered Bentley will be gone before 2030. All things must change…
The bottom one is losing its exhaust.
Not an especially beautiful engine, compared to a Jaguar V12. The dashpots mark it as British, but otherwise it could be a Buick.
“…it could be a Buick.”
It was developed with Buick hydraulic lifters.
There was/is a short history of the engine’s development authored by Jack Phillips, hosted on an English RR/Bentley owner’s club web site. The link I bookmarked in 2015 is now dead.
A vastly condensed version, also without the wonderful photos, is here:
https://rroc.org.au/wiki/index.php?title=History:RR-V8_Designer
A quote from that essay:
“I had been to Detroit to see General Motors about hydraulic tappets, and had bought several engine sets of Buick tappets which were the right diameter. Coupled with this, the crankcases were modified to accept cast iron tappet blocks (as now) and steel push rods were substituted for the light alloy ones.”
After this, the prototype cylinder head was changed from a “Chrysler Hemi” style, to a more-common “wedge” design, saving weight, bulk, and improving the burn.
Another similarity with (later) Buicks was the problem they had with their aluminum-housing oil pump. Of course, when hot, the aluminum housing grew more than the steel gears within. This increased clearance and reduced pumping efficiency. RR changed the pump housing to iron; Buick merely accepted crappy idle oil pressure problems in both their “small block” and “big block” engines.
A different article, dated 2012, says the original Jack Phillips design ended production around 2010–2011, replaced by an “all new” design using the same bore and stroke, and still a pushrod V-8.
https://www.rrocwa.com/Articles/LetstalkV8/LetstalkV8.htm
“It was not until a year or so ago that the original Jack Phillips design was finally replaced with an all-new engine. Rolls-Royce and Bentley had by then seperated again, and now it is a Bentley engine. But it is still an aluminum pushrod V8. It has the same bore and stroke as the Phillips design, but is produced using the latest in block and head design and casting technology, which makes it physically a lot smaller and lighter than before. And still more powerful. “
That first article link is a bit of a gem, and in a bigger context, a tad dispiriting. The stated belief that this engineering team was the best in the entire country and Rolls generally the best in the world, it just wasn’t borne out by what they were making, which was largely fairly antiquated stuff. (First car this motor was fitted to still had had half-mechanical brakes, FFS, and the next Shadow had a loopily-unnecessary double hydro brake system all its life. Note to Rolls dudes, hydraulics was all good once the split system was invented – in about 1960!)
In the result, the V8 they made was a perfectly good engine, but far from best in world by any measure. This sort of foolish insularity is part of what killed off what was the second-biggest car industry in the world when this engine was new.
In relation to your second link, I too have read that pretty much only the bore-stroke remained after about 2010, so I wonder if 60 years isn’t a bit more like a still-remarkable 50.
Lovely—the car(s), and the engine. Paul, do we have the displacement of the L-series V8 in its initial form ?
6.23 L.
Check out the TH-400 Hydramatic and “1970 Cadillac” belt-driven accessories.
This might be the longevity champ. First I’d want to make sure that India isn’t still building something like the ’32 Ford V8. Lol
I believe the flattie went on in French military applications into the ’80s, maybe ’93? So maybe about 60 years? But, that wouldn’t be John Q Public’s passenger car.
Paul,
I’d always heard that this V8 was very similar to the Packard V8. Any truth to that found in your research?
I didn’t have time to research this one.
Obviously R-R had plenty of time to look at all of the American V8s, and could pick elements that they wanted for theirs. But I’m not knowledgeable as to the details.
Maybe another time.
Describing this as a four door coupe is new to me, but not inappropriate for the style of this car and the saloon. Seeing this as a proto Rover P5 Coupe is plausible.
Still stunningly graceful though.
I did that mainly to annoy the purists. 🙂
But I do think it’s a perfectly appropriate term. And it does rather apply here.
It don’t mean a coupe if it ain’t got that stoop – on entry, you see – so with max headroom for all, I take a purified offense to naming it such (though that would be to mistake I for one who gave a flying copulatory engagement about the issue).
It IS stunning in its grace, Mr Rog, but I’ll quibble that the coupe – shit, the 2-door! – is yet better again.
Can’t easily find who penned this lovely, anyone know?
Coupe
Coupe ?
Koop
Kia Forte Koup.