Talk:Bentley 4½ Litre

July 2009
how many cylinders? —Preceding unsigned comment added by 89.100.101.40 (talk) 20:26, 13 July 2009 (UTC)
 * Read the article. The information is there. No signature (talk) 01:33, 14 July 2009 (UTC)

Is this the Bond Bentley?
I don't think so. In Casino Royale the car Bond drives is said to have 25 horsepower. The models described here all have far more than that.Tirailleur (talk) 15:04, 18 January 2010 (UTC)
 * Which Casino Royale, the book, or the movie? If it's the movie, then Bond, more used to current cars, might be exaggerating its relative lack of power.  In the first three books (Casino Royale, Live And Let Die, and Moonraker) Bond owned a 4 1/2 Litre Bentley with an aftermarket Amherst-Villiers supercharger. He didn't drive his own car in Live And let Die because he was in the USA and Jamaica. Sincerely, SamBlob (talk) 17:06, 18 January 2010 (UTC)


 * Hi SamBlob.
 * I am referring here to the Fleming book(s). It is unclear from these exactly which model of Bentley Bond owns, since little detail is given. We are told that Bond bought it nearly new in 1933 and consequently it's been suggested that the 1930 4.5-litre supercharged Bentley fits the bill. There are some problems with this, however. First, looking back from the 1950s, could a 1930 car bought in 1933 reasonably be described as having been "nearly new" in 1933? I don't think you'd do so today, although in the 1950s, perhaps you might. If you expected a car to last 25 years (as Bond's Bentley in fact does), or if it had very low mileage, then buying it with 22 of an expected 25 years' life is, I suppose, "nearly new". From the age point of view, though, the fit of the 1930 car against the description given is at least debatable.


 * The next problem is that Fleming says nothing about the car's mechanicals. All he says is that it has a supercharger, 25hp, and can do over 100mph. He doesn't say it was a 4.5-litre, and the claimed power output and top speed appear modest compared to the 4.5-litre's actual figures.


 * The only other details we are given are that the car is a convertible and that the front screen can be folded flat (Bond does so in Moonraker). Both features would appear to be consistent with the 1930 candidate.


 * So essentially the question is whether the details of the car given could describe a different model of Bentley, or whether there was in fact only one model of Bentley at the time, but Fleming's description of it is inaccurate. If the latter, then the 4.5 must be the car, the issue being that it must have produced a lot more than Fleming's 25hp. It is possible, just about, to read this as the incremental power produced by the supercharger, I suppose. The sentence in question is something like "The Bentley's supercharger whined as Bond dug deep into its 25hp", or words much to that effect, leaving it slightly ambiguous as to whether it's the just the supercharger that provides the 25hp on tope of whatever else the car has. But I've never heard of anyone separating the effect of a supercharger out in this way, and it implies that the supercharger could be switched on and off at will, which I don't think is correct.Tirailleur (talk) 11:46, 21 January 2010 (UTC)


 * Could it be a misprint which should read 250 hp?  No Bentley ever built had as little as 25 bhp.Mr Larrington (talk) 13:19, 30 March 2010 (UTC)


 * A quote from Casino Royale:

"Bond's car was his only personal hobby. One of the last of the 4½-litre Bentleys with the supercharger by Amherst Villiers, he had bought it almost new in 1933 and had kept it in careful storage through the war.  It was still serviced every year and, in London, a former Bentley mechanic, who worked in a garage near Bond's Chelsea flat, tended it with jealous care.  It was a battleship-grey convertible coupé, which really did convert, and it was capable of touring at ninety with thirty miles an hour in reserve." -


 * This, I suppose, puts an end to the speculation. Sincerely, SamBlob (talk) 22:54, 9 July 2010 (UTC)

The 25 HP referred to in the Bond books most likely refers to the "RAC formula" - a system devised for taxation purposes and was commonly used to describe a motorcar. It however had nothing whatever to do with the actual output of the engine. The formula used was something like P = n d^2/k were n is the number of cylinders, d is the diameter of the cylinders and k is some arbitrary constant.

Before the war nearly all models were described like this for example Austin 12, rated at 12 HP for tax purposes but produced around 40 hp in actual mechanical output from its 1500cc side valve engine.

The RAC formula influence design, since in order to have a low taxation class, the bores were made narrow with a long stroke and the number of cylinders kept to four. — Preceding unsigned comment added by 109.170.131.21 (talk) 12:11, 22 June 2011 (UTC)


 * That's all good but the comment about the number of cylinders. Bentleys have always been expensive cars and tax would have been the last thing on original purchasers' minds. Here's the Wikipedia article for more info on Tax horsepower. Eddaido (talk) 13:15, 22 June 2011 (UTC)


 * Depends just *how* much each year's road tax (as it was a repeating annual charge) would have been. These days its based on CO2/km output and the upper levels can be quite punitive, and they apply whether you drive 1 mile on the public road or 100,000... and they also affect an additional environmental levy at the original point of sale, so there's still an incentive for manufacturers to keep the total cylinder cross-section / CO2 output / whatever just under some abitrary figure even on supercars, including the AM Vanquish et al which 007 drives now (after all, one does not stay rich by throwing ALL of one's money away, especially on things that are neither bankable possessions nor valuable experiences)... whether that be 25.0 "RAC horsepower" (on a car that, with a supercharger, might actually be producing closer to 200), 300.0g/km, etc. A car that has 24.95hp's worth of cross-section / 299.5g/km might actually be, for bureaucratic reasons, surprisingly cheap to tax vs one with 25.05hp's worth or emits 300.5g/km. Besides, James Bond's Bentley was, at the time, more of a "sleeper" than a luxury vehicle ... something that looks like an old wreck (and was, at the time of the book's publication, knocking on for 20 years old in an age where classic cars didn't get anywhere near the respect they do now) but is meticulously maintained under its tatty exterior and, thanks to at one point being one of the fastest cars in the world, is still more than capable of blowing away almost any more fully road-bred vehicle when 007 puts his mind to it. 87.113.106.0 (talk) 00:12, 6 June 2014 (UTC)


 * Some original research: The article states that the bore (D) was 3.9 inches and that the engine had four cylinders.  Therefore, RAC hp = (3.9)2 * 4 / 2.5 = 15.21 * 1.6 = 24.336, which rounds up to 25, hence 25 HP.


 * You might say it should round down to 24, but you wouldn't be from a tax collection agency. ;)


 * Sincerely, SamBlob (talk) 14:51, 22 June 2011 (UTC)


 * Don't be too hard on the poor taxman: the bore was 100 millimetres, so the RAC hp was 24.8! 86.181.177.63 (talk) 23:57, 26 February 2012 (UTC)

The Treasury horsepower tax was devised in 1910 specifically to penalise the imported American Model T Ford, which, though you wouldn't think it, had a big 3-litre engine (just a rather inefficient one). The Ford's four cylinders were large-bore and short-stroke, and the tax discouraged this pattern. (Ford were then building a British factory in Manchester, but the profits would go overseas.) As a result, the Tin Lizzie was about the only car correctly taxed, with an actual 22bhp incurring £22 annual tax. This was a lot of money at the time and you need to multiply pre-1914 figures by about 110 for current values. British designers therefore favoured small-bore long-stroke engines, with the result that, in the 1920s, the fast and glamorous Bentley 3 Litre had more than three times the bhp of the slow and unglamorous Ford but only cost £15 annual tax. (Multiply by about 60 for current values.) You were a mug to buy the Ford by then, but some people still did. Khamba Tendal (talk) 17:41, 22 September 2023 (UTC)

Image mistake
The vehicle in this image is very clearly not one of the subjects of this article.

In any case the same photographer describes it as "A Derby Special" in the supporting documentation for this image here:

The replacement image of the real thing is good because while the car may not be in flight it is on the road (it is attending a Formula One Grand Prix not wheeled out of a museum) and in use and best of all for this article it is surrounded with people who give an idea of the sheer size of the vehicle which all the other images do not - which is just one of the things wrong with that awful Derby bitza. That is why I chose it but so long as it is not the bitza I leave alternative images to the choice of other editors but at least make it of the right subject!

Eddaido (talk) 21:59, 18 October 2011 (UTC)

Even slow lorries (well, most of them) have sprung front axles!
The article says that:

< The front axle is held rigid and the rear drive axle is supported by semi-elliptic leaf springs. >

which doesn't read at all well. I don't believe that the front axle was attached immovably to the chassis, though none of the pictures show front springs very clearly: frictional shock absorbers are evident, however, which at least implies the presence of springs!

86.181.177.63 (talk) 00:02, 2 February 2012 (UTC)


 * Congratulations! You may be the first person to have read the whole article since the very special revisions of 22 May 2011! Well, its the French again you see ;) There is no sign that Andy85719 has returned for another try. A total revert seemed to me to be offensive (I know very little about the subject of the article) and I elected to wait for others to pick up the solecisms and barbarisms I chose to leave untouched. I suspect the rigid front axle was firmly held and with the rear drive axle supported the car by semi-elliptic springs though I would not put any of it quite like that myself. I also enjoy "The steering wheel, measuring about 45 cm (18 in) in diameter, is itself a solid braided rope held tight for optimal operation.[clarification needed]" and the concept of serrated brake drums (er, finned?). As you are clearly of sufficient intelligence to recognize a friction damper when you see it please would you revise the entire article. Please. Regards, Eddaido (talk) 00:54, 2 February 2012 (UTC)


 * You're too kind. (You might like to glance at the talk page in the Speed Six article, too). 86.181.177.63 (talk) 10:53, 2 February 2012 (UTC)

Ian Fleming and the Blower Bentley
Surely the moment to mention ownership. Life 10 August 1962 Eddaido (talk) 23:49, 21 February 2012 (UTC)


 * Quote from the article: "...and the Bentley is not his." There is nothing in the article that suggests that he ever owned a Bentley. Sincerely, SamBlob (talk) 03:34, 22 February 2012 (UTC)

Can anyone verify or dispel this?
The first supercharged Bentley had been a 3 litre FR5189 which had been supercharged at the Cricklewood factory in the winter of 1926/7.

The editor who introduced this information has suggested, in a rather unwieldy manner, that the book "Blower Bentley: Bentley 4 1/2 Litre Supercharged" by Michael Hay should have this information. I have found a review for a different Michael Hay book, "Bentley 'Old Number One'", that mentions FR5189 as a factory supercharged 3 Litre Bentley, but I do not know if it can be considered a reliable source: http://speedreaders.info/2642-bentley-%E2%80%9Cold-number-one%E2%80%9D

Does anyone have access to either of these Michael Hay books and, if so, do these books confirm the existence at any time of such a vehicle?

Sincerely, SamBlob (talk) 22:53, 16 January 2013 (UTC)

Chaotic layout changes
Up until recently, the structure of the article was as follows:


 * 1) Lead section - summarizing article as per MOS:LEAD.
 * 2) Background and Development, subsection 1: Bentley at the 24 Hours of Le Mans - stating the reason why the $4 1⁄2$ Litre engine/chassis was developed and some of the method behind its development.
 * 3) Background and Development, subsection 2: Tim Birkin and the Blower Bentley - stating why and how the Supercharged version was developed.
 * 4) Specifications, subsection 1: Bentley 4½ Litre - giving more detailed specifications of the $4 1⁄2$ Litre engine/chassis
 * 5) Specifications, subsection 2: Blower Bentley - giving more detailed specifications of the Supercharged version where they differ from the original
 * 6) Competition performance - how the cars performed in competition
 * 7) End of production - about the end of the $4 1⁄2$ Litre engine/chassis in particular (and Bentley's enterprise in general)
 * 8) Current status - How the cars are regarded at present.

However, an editor has decided to put the Background and Development subsections after the Specifications subsection and to remove the Specifications heading to have them all under the heading "Background and Development".

This has had the following effects:
 * 1) The detailed specifications now appear before the reasons for creating the car, which reverses the natural order of things where the background is given before the specific details, and
 * 2) The order of the new, larger "Background and Development" section is now:
 * a: specifications of the $4 1⁄2$ Litre,
 * b: specifications of the Supercharged version
 * c: rationale for the development of the $4 1⁄2$ Litre,
 * d: rationale for the development of the Supercharged version

The result is particularly chaotic. What was the intended purpose of this? How is this supposed to appear when it is finished?

Sincerely, SamBlob (talk) 14:02, 8 August 2013 (UTC)

Race cars
I think it would be best for a new separate article to be set up to cover the cars raced by Bentley.

Some imagine—and this article until recently made them no wiser— that (racing) is all Bentley's business did and it might be best to satisfy this approach to the Bentley cars subject in - of course - an appropriate manner. Thoughts? Eddaido (talk) 01:10, 9 August 2013 (UTC)


 * Show us some sources that show the Bentley $4 1⁄2$ Litre to be notable outside of racing and we have no reason not to include material based on it. Wikipedia runs on verifiability, not supposedly "self-evident truths".


 * I am particularly skeptical about the idea that the $4 1⁄2$ Litre was built for the high-end non-sporting market. It would be more for one wanting some sporting pretention who would otherwise go for a Bugatti or an Alfa Romeo; one considering a Rolls-Royce or Hispano-Suiza (or trying to replace his Leyland Eight) would be more likely to consider a $6 1⁄2$ Litre.


 * Sincerely, SamBlob (talk) 02:39, 9 August 2013 (UTC)

Something doesn't add up here...
According to the article and the photo shown in Figure 1 in this section, the supercharger and the carburettors of the supercharged version are at the front of the engine, under the radiator.

The car in Figure 2 is said to be a supercharged car, but it has an inlet manifold with carburettors on it that are open to the surroundings, and there is no tube going to the manifold from the front, where the supercharger and carburettors are supposed to be.

This suggests that the car in Figure 2 is not supercharged as claimed, but is normally aspirated.

Sincerely, SamBlob (talk) 17:25, 11 August 2013 (UTC)


 * An astute observation, but sadly one that elects to ignore how inlet manifolds and intake pipes are inherently removable items. And I know the drivers of the day might have been a bit gung-ho, but running something like that with no air filtering? Seems downright cavalier. 87.113.106.0 (talk) 00:19, 6 June 2014 (UTC)


 * Why would someone remove the supercharging from a Blower Bentley? Normally aspirated 4 1/2 Litre Bentleys are rather less expensive than Blower Bentleys, so who would take the time and effort to make a really valuable car *less* valuable? Sincerely, SamBlob (talk) 02:26, 6 June 2014 (UTC)


 * *sigh* ... as in, you can take them off for servicing, or to do repairs on the rest of the engine with them out of the way. Not that you would purposely unplug the charger and then drive off with it like that. Indeed, my POINT was that the lack of said pipework was probably a temporary situation, and that the photo was being taken out of context. Never mind the blower not being plumbed in - who runs anything other than a(n unblown) drag racer with the carb intakes completely open to the air with no filtering? (Which is what the picture seems to show) 87.112.151.166 (talk) 00:21, 16 June 2014 (UTC)


 * Consider the following:
 * The car is on grass, probably on display
 * The photograph was taken in Monterey, California
 * This would indicate that the car is on display at one of the events on the Monterey Weekend, quite possibly at the Pebble Beach Concours d'Elegance.
 * Nobody who brings cars of this caliber to the Monterey Weekend is going to bring an off-spec car. If they did, the judges would throw them out and decline any future applications for entry.
 * Besides, who would bodge up an unsupercharged manifold to a Blower Bentley just because the supercharger was in need of repair? They would simply keep the car in the garage until the repair is done, and probably stop up all the gaping holes to keep the vermin out.  A Blower Bentley is *not* going to be someone's only car! Sincerely, SamBlob (talk) 02:17, 16 June 2014 (UTC)


 * Consider 87.112.151.166 might know something the preceding editor does not. Eddaido (talk) 05:55, 16 June 2014 (UTC)


 * Thank you for your contribution to this discussion. Sincerely, SamBlob (talk) 08:18, 16 June 2014 (UTC)
 * Considering it...
 * " who runs anything other than a(n unblown) drag racer with the carb intakes completely open to the air with no filtering? "
 * That'll be a nope then.
 * This car is not simply not a blower, it's just not even GT 8771 (which is a big budget blower, last heard of being pampered in the US). (Might be YU 8477?)  It's not a blower, never was a blower, and it's in far from original condition (I see at least four major changes. If the battery is missing too, suspect Alan Clarke!). There is (thankfully) no risk of it ever being show ponied to Pebble Beach.
 * Mind you, if you want ugly and pointless, I was looking at a Mallalieu this weekend, painted a fetching shade of Turd. Now that was a car that just left me shaking my head sadly 8-( (and also wishing that my J2 was as nice as the PA at the same show.) Andy Dingley (talk) 16:53, 16 June 2014 (UTC)


 * In any case, since the setup being shown is clearly normally aspirated, it is not a good choice to illustrate the intake side of a Blower Bentley. Fortunately, another image has since been found and is in use. Sincerely, SamBlob (talk) 08:40, 16 June 2014 (UTC)

Discussion of no replacement for displacement quote
See discussion at Wikipedia talk:WikiProject Automobiles. --Dennis Bratland (talk) 02:00, 5 May 2014 (UTC)

Major victories of Bentley 4½ Litre
Why does this chart list five events only one of which a Bentley 4½ Litre won? 188.29.164.200 (talk) 04:57, 30 August 2016 (UTC)

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How were the valves driven?
Does anyone know how the valves were driven? Given its SOHC and 4 valves, there had to be something like rocker arms for at least some of the valves; they couldn't all be driven directly from tappets, as with DOHC. I would suspect roller tappets, as on later SOHC Ferrari engines. BMJ-pdx (talk) 04:26, 14 April 2020 (UTC)