Motor Sport Tests -- The Bristol 401

A High-Efficiency 2-litre Saloon Possessing Outstanding Qualities of Performance, Comfort and Control. Driving an Epicurean Pleasure in this Near-Perfect Car for the Connoisseur.

Under wintry conditions at November we realised a patiently-awaited experience, that of road-testing the Bristol 401. We have always held the Bristol in high esteem, approving of the famous aeroplane company’s decision to make a beautifully-appointed, extremely comfortable, fast car of only 2-litres capacity and, consequently, a car which pays dividends to a keen driver and which is essentially a high-efficiency sports saloon and not an over-engined luxury carriage. It would have been easy for the Bristol engineers car division having got a firm footing in the luxury-car market to have followed the Bristol 400 with a car having an engine of twice its captivity which would have done all its work in top gear or even hydramatically. But such a temptation, if indeed it ever arose, was resisted, and the Bristol 401 retains its high-efficiency 85-b.h.p. 2-litre engine, compact dimensions and a gear-change that needs to be used and is a delight to handle.

Our test of the 401 extended to a four-figure mileage and the present writer completed 633 miles in the car. Incorporated in this mileage was a journey from Hartley Wintney in Hampshire to Land’s End accomplished at an average speed of over 50 mph. The entire out and home run, a distance of 502 miles, with only 20 minutes’  rest, was accomplished in a running time of 11 hours, although much of the return journey was done after dark, some of it restricted to 10  m.p.h over icy surfaces, and all of it made between the hours of 9.30 a.m. and 9.30 p.m. when the roads carried normal traffic. The extreme effortlessness of Bristol-fashion travel was nicely emphasised by this journey, undertaken with no thought of ultra-fast driving or “dicing” but as any other driver used to fast cars would have made it. On this run the overall fuel consumption was 20 m.p.g., a remarkable economy at these speeds, and after over 500 almost continuous miles the driver felt only moderately tired, and mentally alert for many more hours behind the wheel.

Thus, although it is true that a 2-litre engine in a car weighing over 24 cwt. and pulling a 3.9 to 1 top gear calls for considerable frequency a gear-changing, this does not tire the driver, but contributes, if anything, to the joi de vivre of his motoring.

A number of good qualities combine in the Bristol to make possible, safe, effortless, very comfortable average speeds in the 50-60 m.p.h. range. The view of the unornate bonnet, uncluttered by mascot or dummy filler cap, pleases, and although the near-side wing is invisible, a driver unfamiliar with the 401 is immediately happy cleaving a way through narrow traffic gaps. The deep front seat, with its firm yet comfortable upholstery and high curved squab adjustable for rake, leaves the elbows free and provides the utmost comfort. The pedals are well placed and solid. Above the walnut facia is a decked-ledge to keep reflections from the windscreen. The facia itself, as will be seen later, is very fully equipped with neat pull-out or push-in knobs as minor controls.

In this luxuriously-appointed “office” the driver is able to enjoy the epicurean pleasure afforded by the Bristol’s performance and handling characteristics. The six-cylinder, three-carburetter engine is smooth but is an engine which demands asistance from the driver, who will thus use third gear frequently in traffic and up main road hills, and will almost as frequently drop into second gear. If speed falls really low second gear will give only mediocre acceleration at first, but a drop into bottom will provide a very vivid “step-off.”

The gearbox, then, is there to be used but as the long central lever is absolutely rigid, has a delightful  “grip”,  and can be whipped rapidly from ratio to ratio without effort, helped if need be by excellent synchromesh, anyone who professes to like driving will respond with pleasure to this call for the lower ratios. Even the change out of second into bottom gear is rendered a lightning operation by the employment of a free-wheel, on the lowest ratio only. This first gear free-wheel can be usefully employed for inching forward in thick traffic. The indirect gears are completely unobtrusive and so can be used for as long as the driver desires; they provide maxima of 25, 50 and 70  m.p.h. without hurrying the engine unduly.

Acceleration is very smooth and purposeful once the engine speed builds up in any gear, and a cruising speed of 80 m.p.h. (4,000 r.p.m.) becomes habitual on ordinary main roads, maintained up hill and after passing obstructions by free use of those delightfully spaced and easily engaged indirect gears.

It is after holding this speed for a while that the occupants become aware of a remarkable and very desirable aspect of the Bristol saloon. Eighty miles per hour gives the impression of little increase over 50 m.p.h. and it dawns on the fortunate owner that the aerodynamic lines of the handsome two-door closed body are really and truly aerodynamic,  i.e. that the wind-tunnel tests made on the Bristol have resulted in a car which, so far as wind-noise is concerned, is all but completely silent at all speeds up to 90 m.p.h. As the speedometer needle creeps from 90 to over 100 m.p.h. a slight increase in sound is perceptible, but it is very slight. Complete silence in this respect is marred only by a slight whistle of air round the area of the front screen pillars and even this is inaudible in the back compartment.

This lack of wind-noise is one of the main factors in the Bristol’s effortless running, leaving the occupants fresh after many hundreds of miles at high cruising, speeds, as our winter-day’s drive to Land’s End  and back so nicely emphasised.

This clean aerodynamic form gives rise to the impression, even at low speeds, that the car has a free-wheel (which is actually operative in first gear only), so that the driver feels he must rely on his brakes more than usual. It also permits engine noise, which is to be expected from a high-efficiency 2-litre unit, to be heard in the lower gears to a greater extent than would  be the case in square-rigged cars; in any case, the engine note is not in any way excessive and is not accompanied by so much as a trace of exhaust noise, while the aerodynamically-efficient form undoubtedly contributes to a fuel consumption of a genuine 20 m.p.g. under conditions when we would have been well content with 5 m.p.g. less.

In top gear the Bristol runs with the smoothness and silence of the true luxury car. As the engine idles at 600 r.p.m. in neutral it is virtually inaudible.

The cornering and roadholding qualities are fully in keeping with the Bristol’s easy, vivid performance.

The steering, which on the car tested showed about 1-16th  free movement in the rack-and-pinion mechanism, is smooth and quite light, but acts against a strong castor action which not only spins the wheel straight after corners, but renders control a taut, positive action. The front wheels can be “felt” almost unconsciously by the driver and on some surfaces cause the wheel to rock but not kick through his hands — good, sensitive steeering. It feels extremely high-geared although, in fact, calling for three turns from one generous lock to the other. No vibration is conveyed to the pleasant thick-rimmed wheel and, to sum up, this is steering which enables the Bristol to be taken down the camber at 70 m.p.h. and past a lorry with only inches to spare with complete nonchalance and no conscious effort, while it gives great confidence when the sheen of sheet-ice is mistaken for the glint of rain-soaked tarmac.

The Bristol goes round corners fast with neither over- nor under-steer characteristics and with a minimum of roll. Such roll as there is takes the form of a slight lurch, killed at the outset before the back end breaks away. Rain has little effect on the splendid roadholding, but if the back wheels do break away, a flick of the sensitive steering wheel corrects the incipient slide. The tyres make practically no sounds of anguish during fast cornering or brisk negotiation of traffic roundabouts. The nose of the car can be made to dip slightly under heavy braking, but this is particularly firm suspension yet one which gives a luxurious ride —  there is no other term for it — over the  vilest surfaces. The wheels are also very well damped, and a sudden excursion onto an unmade road verge has no effect on the accuracy of control, which is another feature of the Bristol’s seven-league boots. Before we dismiss the transverse leaf-spring  i.f.s., and the torsion-bar rear suspension, it must be remarked that no noise from the Michelin-shod wheels over varying road surfaces was transmitted to the occupants’ ears.

To this general picture of the 401, difficult to set down but adding up to an ability to go far, fast, with a maximum of pleasure to those travelling in it, can be coupled some more detailed observations on performance.

The Bristol is not intended as a top-gear car, although the lazy need have no qualms: it will accelerate smoothly from 20 m.p.h. in top gear. Use that delightful gearbox and cruising speeds that would not disgrace a car of twice the engine size come up like magic.

The body is substantially made and completely rain and draughtproof. The doors,  for example, possess that solid construction which denotes the luxury car, while the equipment is truly generous. Yet  60 m.p.h. from rest comes up in under 17 seconds, 70  m.p.h. in 23 seconds or less. Some performance figures are included in the data panel but we must emphasise that they were taken on a wet road, and on Pool petrol, so that the engine would take very little ignition advance; the clutch was also prone to slip. Incidentally, there was noticeable free-play in the transmission.

The poor weather conditions precluded a maximum speed check, but this can be put at about 97-98 m.p.h. Twice the speedometer indicated well over 100 m.p.h and, what pleased us more was to see it at over 90 m.p.h. up an appreciable main-road hill ! The Bristol 401, for all its refined manners, does not lack real performance. (It is a stimulating mental exercise to visualise a short-chassis ” Gran Sport ” version, with alloy-shell saloon body and the 132-b.h.p. Bristol engine used in the Le Mans Replica Frazer Nash !)

The 11-in. Lockheed hydraulic brakes are so powerful that all four wheels can be locked and they are in themselves vice-free. However, they call for determined pressure on the pedal when fully arresting the car. This rather “solid” vintage-style retardation is quite pleasant but proves tiring on a long run and as the leg-muscles tire it becomes increasingly difficult to gauge the braking effect. Moreover, a lady would hardly enjoy such braking and at times we felt the car lacked sufficient stopping power although for a crash stop, given sufficient effort, the safety factor would prove ample. For mere slowing down from high speeds these are good brakes. The horizontal central hand-lever has a good hand-grip topped by a release button and works impeccably.

Clutch and accelerator are light to operate. The gear-lever is sprung away from the reverse location.

The three-carburetter engine proved difficult to start under low-temperature conditions but, once started, pulls well with minimum use of the mixture control and without falter. It ran too cool, blanking of the grille still failing to send the water temperature over 80 deg. C.; the oil temperature stayed at 50 deg. C.  The oil pressure varies somewhat with speed to a maximum of about 70 lb./sq. in . We noticed that Castrol oil was in use; only a pint was needed throughout the test and the radiator did not require topping up. The engine pinks viciously at full advance, but there is a sensitive, slide-out ignition control as an antidote, a similar control providing hand variation of engine speed from 600-2,800 r.p.m. The engine does not run-on, not a trace of fumes enters the car, and the Bristol feels as if it would do over 500 miles within 12 hours day after day without loss of engine or chassis tune.

Although the saloon has such good aerodynamic contours the interior is spacious, with plenty of leg and head room for everyone and an unusually deep luggage locker. The sloping rear window poses no problem of rear-view visibility and the rear windows, which open slightly to extract warm air, give a fine view.

The Bristol in Detail

 The 401 is such a magnificently appointed car that a brief description of those features which make it such a desirable personal possession will be of interest.

The built-in Lucas 770 headlamps give a long but not sufficiently concentrated beam; this may be because they had yellow bulbs. They are supplemented by excellent, but dazzling, fog-lamps, automatically extinguished as full headlamp beam is selected. The doors are opened internally and externally by flush push-buttons, the driver’s having a Yale lock. There are rope “pulls” on the doors, and four ash-trays. The driver’s door button was far too stiff and resulted in a sprained thumb, although it became easier to operate with use. The doors each have deep, “rigid,” very useful, two-partition wells, and there is a deep shelf behind the back seat.

The walnut facia carries large knobs which control the concealed panel lights (rheostat control of intensity), starter, mixture, throttle, ignition, de-mister, roof-light, petrol reserve, and wipers. There are neat windows for headlamp beam, fuel reserve and ignition lamps.

The horn button is part of the-steering-wheel boss and the indicator switch is on the screen sill — it works rather too lightly and the self-cancelling action is too rapid. The lamp dipper is under the clutch pedal; we prefer a steering-wheel switch.  In place of visors there are neat pull-out stiff blinds for both front-seat occupants. The sloping V-screen with central rib is free from reflected light; the wipers function well but are not self-parking. The screen sprays work splendidly; the lamps control is normal. A nice touch is the tiny “Bristol 2-litre” badge attached to the ignnition key ring

At each end of the facia is a good cubby-hole with matching walnut lid having a Yale lock. The interiors are lined to match the roof, in washable material, and the lids have leather “keeps.”

The doors stay fully open as set; the locker lid is light to lift and is released by a knob concealed beneath the rear-seat central armrest when this is stowed. After the locker has been opened the catches which release the spare-wheel tray and allow it to be opened are revealed. Another clever anti-thief device is a knob in the near-side rear-seat armrest which releases the flap covering the quick-action fuel filler. This location keeps its operating Bowden cable short but would be more convenient on the facia.

A rear-window blind with a “wire” cord within reach of the driver is provided; it did not quite eliminate dazzle from lamps close behind, but at least this warned of a closely-following vehicle. The radio is that impeccable set, His Master’s Voice, with external non-adjustable roof aerial. The heater has a stopcock within reach of the driver and volume controls (providing cool air with the heater off) for both front-seat passenger and driver. The heater took time to come into operation but was then very effective. There is rheostat control of de-mister heat and the fan is quite quiet.

The door windows wind easily and their handles have rotating finger-knobs, but the action is opposite from conventional, tending to a locked car with open windows! The back windows hinge slightly open to give an extractor effect.

The instruments comprise an accurate fuel gauge, Smith’s speedometer with trip and total mileometers, Smith’s rev-counter, combined oil and water thermometers, clock, ammeter, and oil gauge.  All are steady-reading, high-grade “square-dial” instruments with white needles. The speedometer suffered only slight needle-float but the rev.-counter took some time to “settle”; the former was virtually accurate at 30 and 60 m.p.h. The petrol gauge reads zero before the two reserve gallons have been consumed.

Above the accelerator is the pedal for working the useful Enoto one-shot chassis lubricator, to be used rather frequently every 70 miles. The bumpers provide excellent protection of wings and tail. The light bonnet top panel opens on either side by operation of the appropriate pull-out knob, or can be removed entirely. It can be propped open with a crude but effective stay. There is no screen de-froster. A reversing lamp is selected automatically as the gear-lever engages reverse.

The front seats have slides which give a wide choice of positions, while four-lobe cams enable the angle of the squabs to be pre-set to any one of four positions before the occupants enter. As these cams are not interconnected some delay can result in getting them synchronised. These seats also slide forward to give very reasonable access to the comfortable back seat. The bucket-type front seats with their curved-back squabs are a commendable feature of a fast-cornering car. The upholstery is of the finest crushed-grain leather over Dunlopillo and the head-lining is of soft, washable material, while the floor is covered with a deep carpet over a felt underlay.

Battery, dip-stick, etc. are decently accessible when the bonnet is raised. The coachbuilt, aluminium-panelled body is free from rattles, and its fine construction is complementary to the Bristol’s refined manner of running.

Conclusion

In conclusion, the Bristol 401 appeals not on account of a single outstanding characteristic, but because a combination of good qualities renders it an outstandingly pleasant car on long runs when time presses or the driver seeks to go fast for the sheer pleasure of driving. Responsiveness of control and the high degree of aero-dynamic silence stamp the 401 as a fine car, perhaps to a greater degree than its acceleration and speed abilities, excellent as these are.  The fascinatingly complete equipment and the craftsmanship evident in the specification and construction are truly refreshing in this age of standardisation and chromiumed tin shrouds. This, indeed, is the car for the true connoisseur. It can only be modesty on the part of the Bristol publicity boys which has prevented them from quoting as the 401’s slogan “The Best Car in Britain”. —  W.B.

***

THE BRISTOL 401 SALOON

Engine:  Six-cylinder, 66 mm by 96 mm (1,971 c.c.);  Push-rod o.h.v.;  7.5 to 1 compression ratio; 85 b.h.p at 4,500 r.p.m.

Gear ratios: 1st, 14.08 to 1;   2nd, 7.12 to 1; 3rd, 5.04 to 1; top, 3.0 to 1

Tyres:  5.75 by 16 Michelin on bolt-on steel disc wheels.

Weight:  21 cwt. 1 qtr. (less occupants but with one gallon of petrol).

Steering ratio: Three turns, lock to lock.

Fuel capacity: 17 gallons (including 2 gall. in reserve).

Range approx: 310 miles.

Wheelbase: 9 ft. 6 in.

Track:  Front, 4 ft. 3-3/4 in;  Rear, 4 ft. 6 in.

Overall dimensions: 15 ft. 11-1/2 in.  by  5 ft. 7 in. (wide)  by 5 ft. (high).

Price:  £2,000  (£3,112  12s  3d  with p.t.)

PERFORMANCE DATA:

Speeds in gears (m.p.h.): 1st … 25;  2nd … 50;  3rd… 70;   Top … 98

Acceleration (on wet road) through gears: 0-30 m.p.h. in 5.0 sec;  0-40 m.p.h. in 7.6 sec;  0-50 m.p.h in 11.2 sec;  0-60 m.p.h. in 16.1 sec; 0-70 m.p.h. in 23.0 sec;  0-80 m.p.h. in 33 sec.

s.s 1/4 mile: 20.7 sec 

Second gear:  10-30 m.p.h in 5.8 sec;  20-40 m.p.h in 5.6 sec;  30-50 m.p.h in 5.4 sec

Third gear:  20-40 m.p.h in 7.4 sec;  40-60 m.p.h in 8.0 sec

Top gear:  30-50 m.p.h in 11.0 sec

Makers: The Bristol Aeroplane Co., Ltd., Filton, Bristol.