Shopping for a Derby Bentley

Advice on how to buy, restore and enjoy one of these post-vintage thoroughbreds in the £150 to £600 price span

The advantages of the Derby-built Bentley may be summarised thus:

(1) It is not so slow as to make long journeys painful.
(2) It is extremely durable.
(3) The majority of parts are still available new from the makers and
(4) A sufficiently large number were made for there to be at any given time a good float of second-hand parts.
(5) It is pleasant to work on.
(6) People don’t laugh when you go by.

These are all incontestable virtues (unless you like being laughed at) and to them are added qualities less definable but which every vintage enthusiast will recognise—the thrill of driving a long bonnet and P100s into the night or across the downs on a summer’s morning; the extreme precision and solidity of the secondary controls; the evocations of an epoch, now remote and nostalgic.

Of course, like most vintage cars passing through a “cheap” phase, the majority of Derby Bentleys on the market are somewhat down in the mouth—at least in appearance. But take heart, a little patience and discrimination can still unearth what is, at present price-levels, a really desirable purchase.

First, background reading. There is an excellent paper-back digest of contemporary road tests and articles—”Bentley in the Thirties”—available from Autobooks. You should also study the relevant passages in the definitive Bird and Hallows. Having absorbed all this information, you can sally into the market.

There is a very wide differential of something like 12:1 between top and bottom prices. In the past twelve months £2,500 has been paid at an auction for a Barker two-door saloon with a genuine mileage of 27,000 and also (by repute) for a Vanden Plas tourer with an excellent racing history in recent Club handicaps. Both these cars were 3½-litres, but there are several 4¼s featuring regularly in Concours d’Elegance which would probably match these figures, if they came on the market. I propose, however, to confine myself to the £150 to £600 price-range—itself a differential of 4:1 and offering ample opportunity for the intelligent buyer to “beat the market”.

Generally speaking you can either go for condition or for attractiveness of coachwork—in its widest sense—and to get both together at a reasonable figure would be a stroke of luck. For example, drop-heads are invariably worth twice as much as saloons in equivalent mechanical condition; “modern” looking saloons tend in fetch less than the more vintage styles with trouser-crease wings and exposed front brakes; the lighter aluminium bodies are nearly always preferable to steel ones.

In this connection, it is worth remembering that Rolls-Royce originally stipulated that no body to be fitted on the new Bentley (in 1938) was to weigh more than 6½ cwt. But only three coachbuilders managed to achieve this, Vanden Plas with the tourer; Mann Egerton with a “lightweight” four-door saloon, and Park Ward with a two-door. The limit was very soon dropped and thereafter, as in the case with every good car since the beginning of time, weights went up, performance went down, and engine capacity and output had to be increased.

The following table, culled from contemporary road-test reports, illustrates this:—

3½-litre
Weight – 29¼ cwt. (A) – 30½ cwt. (B) – 32½ cwt. (C)
Standing ¼-mile time – 19.2 sec. (A) – — (B) – 20.8 sec. (C)
Maximum Speed (best) – 91 m.p.h. (A) – 92 m.p.h. (B) – 90 m.p.h. (C)

4¼-litre
Weight – 30½ cwt. (D) – 35 cwt. (E) – 35¾ cwt. (F)
Standing ¼-mile time – 19.4 sec. (D) – — (E) – 20.2 sec. (F)
Maximum Speed (best) – 94 m.p.h. (D) – 93 m.p.h. (E) – 88 m.p.h. (F)
A : 1934 Vanden Plas tourer.
B : 1934 Park Ward saloon.
C : 1935 Park Ward drophead.
D : 1936 Park Ward saloon.
E : 1939 Park Ward saloon.
F : 1939 Park Ward drophead.

The Park Ward saloon was an elegant creature in its early days, with a stylish sawn-off tail, but it gradually increased in bulk and weight so that the 1937-39 examples are today probably the least valuable of all the pre-war Bentleys. Yet paradoxically the 1936s, the very first 4¼s, were the fastest cars that Bentley Motors built before the war (after the “J” chassis series, they were fitted with a “deturbulated” cylinder head, and slower), and anyone who doubts their performance should read Raymond Mays’ account of his tremendous drives in one between the various Continental race circuits before the war, and how he set up the record, on unmade roads, between Cape Town and East London. A 1936 4¼-litre in original condition would be nice!

While on the subject of performance, it is probably true to say that the evolution of engine output and suspension design has now progressed to a point where the Derby Bentley stands in the same relation to the modern car as the vintage Bentley did to the cars of the 1940s and early ’50s. This fact is somewhat obscured because good vintage Bentleys at present greatly outnumber good Derby ones and the beautifully-cared-for 3/4½-litre W. O. car will—may—out-perform a raddled Derby specimen which hasn’t had a spanner on it for 50,000 miles. But car for car, a 3½-litre will run away and hide from most of the W. O. models—anyone doubting this could turn to The Autocar of March 30th, 1934, for a comparative test with a 3-litre Speed model; the 3½-litre did 0-60 m.p.h. in 13 sec, the 3-litre took 23 sec.! In addition, any good Derby car is susceptible to some mild Stage 1 tuning of a “do-it-yourself” nature; the three easiest steps are (1) taking up to 60 thou. from the head, (2) substituting a single straight-through expansion chamber for the existing exhaust system (which is probably rotten anyhow), and (3) removing the fan and fitting an electric unit (Wood-Jefferies is the best). There are many further stages of tuning, but before embarking on them be sure of the bottom-end’s soundness, and fit a full-flow oil filter.

First, though, one must find as good a specimen as possible. In the late ‘fifties p.v.t. Bentleys were worth very little and went through that phase (which nearly every vintage machine has been through at some stage in its life) of being “driven into the ground”, i.e., where the cost of servicing—much less of repairing or replacing defective components—was equivalent to, or exceeded, the value of the car. So why not go on until the thing literally dropped dead? They took an awful lot of killing, but during this period many suffered internal damage so extensive that only a full strip and overhaul would put it right. There are few dealers who will put their money into an “invisible” restoration of this kind (SAP 60 oil, and a restricted duration demonstration run is a cheaper solution), so the only hope is that it should have been done either by the original owner as part of the car’s maintenance, or by another enthusiast who was fond of it.

When you examine one of these cars the vendor will nearly always produce bills. Scrutinise them carefully. Invoices from Bentleys for parts (quoting the car’s chassis number) are worth three times as much as a long job-card from Oliver Bash Ltd. Ideally, one is looking for a car with documentary evidence (preferably the log-book) showing that it has led a sheltered life. It is worth remembering that up to about 1952 p.v.t. Bentleys were worth over four figures and were correspondingly well looked after. You will have to form your own assessment of the car’s history, which may range from peaceful storage in the heated garage of a country house, to a hectic turnover of owners with suspiciously student-like addresses.

Having examined the documents, next make the static inspection. Coachwork first; open and shut all the doors, windows, bonnet, boot, observing. look for overspray, cracking, rust and aluminium oxidisation lifting the paint (unimportant, but useful for “knocking” the price). Put all your weight on the front wings where the sidelight is mounted and press down suddenly. If the car rock’s on its springs solidly as if in one piece, that’s a good sign. Try the sliding roof, and inspect the channels and corners. (In fact, most cars now have their sliding roofs sealed over, but rehabilitating them is one of the pleasanter and least arduous phases of the restoration.)

The Condition of the internal chrome and woodwork is always a good indication of the way in which the car has been cherished. Naturally the veneers lift and chafe away at the corners and along the top sills, but original veneers are nearly always preferable to a quick restain and plastic finish. Some of the very early 3½-litres had solid mahogany or cedarwood fillers, which can be sanded off pale in your workshop and look extremely smart.

Next, occupy the driver’s seat. Some indication of the car’s total mileage can be drawn from the quality of definition in the lettering on the steering-column boss. The enamel starts to go at 60,000 miles; it virtually disappears at 100,000, leaving only the cuts of the engraving. lf the lettering has gone, let your hand drop to the gear lever and grasp it around the shaft as near to the gate as possible. Then lift it upwards. Over 100,000 miles some vertical play becomes apparent and this increases with mileage. (This is not an infallible test, of course, as the gearbox may have been rebuilt during the car’s affluent period.)

Now start the engine. It should fire at once. If it doesn’t, it may mean that all is not well in the cylinder head—a sticking valve, a broken piston-ring. If it’s simply bad tuning, carburetters or ignition out of adjustment—well, that’s a sign of poor maintenance. (Here it’s worth mentioning that a car need not be rejected out-of-hand because the engine is dead, if it appeals otherwise. But make sure it will turn over on the handle, and that the cylinder head is not cracked. A second-hand cylinder head costs upwards of £45, and every day they are getting harder to find.) Water in the sump sometimes shows itself by the oil indicator needle lying right up against the stop.

If you get the engine running, set the hand-throttle to 1,100 r.p.m. and jack up the front of the car. (The vendor is most probably getting the sulks by now.) Look at the brake cable and adjusters, and the junction points of the one-shot lubrication system. Dryness and caked dirt are ominous here. Next, remove one of the front wheels. They should slide off a treat, but seldom do. Old yellow grease caked hard on the hub splines is a sure sign of neglect.

All this time you will have been listening to the engine. Tapping and clicking doesn’t matter, but if it knocks, or rattles on a trailing throttle, you had better leave it (unless he’ll take less than £100). Switch off, and look at the water-pump greaser; it should be finger-tight and when extracted found to be full of the correct grade of Castrol grease. While the bonnet is open on the induction side (which, of course, will be at this moment) inspect the unions from fuel pump to carburetters via the filter casing, all control rods, and the block itself for cleanliness, seepage, etc.

Now comes the moment for the road test. There may be difficulties. Quite likely it will emerge that the car isn’t licensed, hasn’t got an M.o.T. certificate, or the insurance position is obscure. The probability of the vendor allowing you to drive is almost nil, and in fact there is little you would discover that vigilance during the earlier stage should not have told you already. But the road test can be of help in sealing the transaction. Most of this article is slanted against the vendor, but it is only fair to him to get the haggling over at this stage and agree a figure—subject to nothing dreadful happening on test. Then, if the back axle clunks horribly but the car still appeals, you could try and cut the earlier figure a bit lower.

I may say that you won’t get this kind of opportunity from many dealers, as the whole business is going to take at least a couple of hours and, even allowing that he will have a 75 per cent mark-up on the car, he won’t like putting himself out to this extent on a £450 deal. In fact, I’m assuming that readers of Motor Sport have enough enthusiasm and savoir-faire to “shop around”. The object is to try and find something which costs less than £400 but which a dealer could wax and vacuum and ask £675 for. On the other hand it must be said that some dealers are extremely tolerant and enthusiastic, and if you have a part-exchange problem then it is to them that you will have to go, unless you are extremely lucky, for that is what their big margin is to take care of.

Below I append a table as a very rough guide to fair prices. This is a thankless task, owing to all the variables, but equally one must have some guideline. (I am against caginess on figures, believing that every article offered for sale should be clearly marked with the price— just as every published picture of a woman under 35 should state her exact age.)

Type – Non-runner – Poor – Fair – Mint
A – £90 – £135 – £240 – £600
B – £110 – £175 – £325 – £750
C – Add proximately 25%
D – £250 – £400 – £ 575 – £1,000
A: 4½-litre Park Ward saloons, post-1936. (Add 10% for MR and MX chassis.)
B: 3½-litre coachbuilt saloons.
C: Two-door saloons, fancy closed coachwork on either chassis.
D: Dropheads, some sednaces of particular elegance.

Assuming you’ve clinched a private deal, and fixed the insurance, take the car to the nearest garage and change the oil. This is mandatory unless you live under five miles away; that oil could have been in the sump since 1954.

The journey home will be characterised by extremely SLOW driving. In his classic work on racing drivers Motor Sport‘s Continental Correspondent somewhere expresses the hope that none of his readers will ever be driving at less than “six-tenths”. Well, on this journey they will. Your chances of driving the car hard and enjoyably in the future may be at stake. Just listen to everything that is happening and watch the instruments.

High engine-coolant temperature may simply be a weak thermostat-shutter spring, or the shutters themselves in need of lubrication. There is provision for over-riding the thermostat and locking them fully open (a normal engine will then run very cool, but can be blanked off with a piece of aluminium plate according to the seasons). If the oil pressure falls away to below 10 lb./sq. in., stop and look at the level. 4¼-litres habitually use more oil than 3½s, but don’t assume the worst; it may be a simple leak. If the engine stops, the most likely cause will be a blockage in the fuel system from gummy deposits working free—but no matter, you are shortly going to deal with all this in a systematic fashion. In all cases of engine or other failure, first check the fuses, which are beautifully laid out and labelled in a box on the n/s of the engine bulkhead. You are going to rewire this car sooner or later; if the fuses are popping already, make it sooner.

Once the car is safely in your garage a Stage-1 restoration can be commenced. Far the best beginning is to follow, scrupulously, the directions in the R.R. service pamphlet on “Recommissioning cars after long periods of storage”—even though “a long period of storage” is probably the last thing the car has been enjoying! The procedures laid down are hard work, but rewarding, and get one familiar with every part of the car. I strongly recommend against premature dismantling of suspect components. One loses heart (and pieces) and finds reassembly difficult. Besides, you ought to keep the car on the road, to “live with it” and appreciate its foibles.

It is a good idea to alternate spells on the engine and chassis with attacks on the coachwork. First, thoroughly brush and vacuum the interior; and cut and wax the cellulose (however shabby and patchy it may first appear). This improves everyone’s morale, especially that of your wife/girl-friend. Then clean all the chrome, starting with the interior. The best substance for this is Autosolvol, at 4s. 6d. per tube. On the exterior chrome you can use this substance with 000 steel wool, and be amazed. New carpets are easily made from the old templates; about 4½ yards will do the trick, though professional trimmers claim to need 15. Slightly more skilled, but perfectly feasible, is the fitting of a new head-lining.

As for the leather, you can use Handy Andy, once—thereafter repeated applications of Connolly’s “Hide Food” works wonders. At the same time it is a good idea to remove the trim panels, blow out the rust and dust, re-open the drain holes, and check and lubricate the window-winding mechanism. These are all enjoyable, and not at all costly, tasks which will transform the interior.

To itemise every stage would carry us on and out the other side of the small advertisements. But two final recommendations should be made, to increase your enjoyment: Buy, read and digest Wheatley and Morgan’s “Restoration of Vintage Motor Cars”, every word therein is golden; and in due course, if you’re in the mood, join the Bentley Drivers Club. Some of the W. O. owners are a bit high-hat about the Derby cars, but this is certainly not true of the Secretariat, who are extremely helpful. The club is very active socially, and chats with other owners can save hours of experimentation on your own car.

Total production of Derby Bentleys was 1,191 3½-litres, and 1,241 4¼-litres. Of these, how many survive? According to the Register, there are 61 3½-litres and 119 4¼s in America; 145 and 136 in Britain. Even allowing a “float” of a further 40 per cent, the total is still less than 700 cars, compared with at least 1,000 vintage Bentleys. Derby-built cars are still being broken for spares, but those that survive are being steadily improved in condition as their value rises. Sir Henry Royce took a personal interest in the design and development of the Bentley—indeed, it was the last Rolls-Royce product where this was the case—and the impact of his personality can be traced throughout the chassis. For its intrinsic charm and quality, a car to look for now, while prices are decently low.—A. C.