MOTOR SPORT
THE NEW 3); LITRE BENTLEY
ATTRACTIVE COACHWORK ON SUPERB CHASSIS.
ALL lovers of the sport and connoisseurs of fine cars regretted the passing of the old range of Bentley cars, but when the company was taken over by Messrs. Rolls Royce in 1921, it was certain that a worthy successor would presently appear on the market. We are privileged to give the first description of the new car, which embodies the sporting lines and the familiar bold radiator with the ” winged B” and the engineering genius and workmanship which is the hall mark of the craftsmen of Derby.
The aim of the designers has been to produce a car which is capable of high speeds and fast cornering, and to provide comfort for up to four people, without having recourse to a harsh and noisy engine or one running on special fuels. Great attention has therefore been paid to reduction of unnecessary weight, and this in conjunction with research in smooth production of high power from the 31 litre engine has given the car a powerweight ratio which fulfils the conditions set out.
The chassis follows orthodox lines, but s swept up at the back and front to give a low centre of gravity.
‘rhe six cylinder engine has a bore and stroke of 82.5 and 114 mm. (3i. inches by 44 inches) giving a capacity of 3,669 c.c.
and an R.A.C. rating of 25.3 h.p. A detachable cast-iron cylinder head is used and there are two valves per cylinder. These are operated by push rods. The shape of combustion chambers has been evolved after much research and the engine, though exceptionally smooth and flexible at the lower end of its range develops 120 h.p. It is supported in the frame by a pivoted mounting with clamped rubber supports.
The pistons are made of aluminium alloy and the monobloc cylinder casting is separate from the crankcase. 1 he crankshaft is supported in seven bearings.
Coil ignition is used, with a centrifugal control, and an additional hand lever on the steering column. Two S.17. carburetters are fitted, with the usual mixture control. An engine-driven petrol pump supplies fuel from an 18 gallon tank at the back, the last two gallons being kept as a reserve.
The engine is pressure-lubricated by a gear-pump, with a spring-loaded by-pass, and surplus oil is conveyed to the cylinder head for lubricating the valve gear.
The cooling water is circulated by a pump and the temperature is maintained constant by thermostatically controlled shutters. The clutch is of the single plate type and the four-speed gear box is operated by a lever on the off-Aide. Synchro-mesh mechanism is used for top and third gears, and second is a silent ratio. The power is transmitted to the back axle by an
open propellor shaft with two metal universal joints and the final drive is through spiral bevel gears.
Worm and nut steering is used. The car is suspended on particularly long. semi-elliptic springs and they are damped fore and aft by hydraulic shock-absorbers. A servo-motor assists the braking effort, without the possibility of loss of
control should it fail to function, The pedal applies the rear brakes and also brings the servo into operation. This applies the front brakes and adds to the pressure on the rear ones. The hand brake applies separate shoes in the rear drums.
The wheels are fitted and are shod with 18 in. by 5.50 in. India tyres.
All parts of the Chassis including the road springs are lubricated from a footoperated pump on the chassis. The 12 volt, electrical equipment is supplied by one of the new constant voltage dynamos, which automatically reduce their charging rate as the battery” collies up.” Special attention has been paid to the design of the starter, and the pinion
engages slowly, so that it should remain reliable and quiet for long periods.
The chassis dimentions are :–Wheelbase 10ft. 6 in., track 4 ft. 8 in., while the ground clearance is 6 inches. The overall length and width is 14 ft. 6 in. and 5ft. 9 in. The chassis price is £1,100.
Three different styles of bodywork have been standardised on the 34 litre Bentley, an open four-Seater, a drop-head coupe, and a two-door saloon. The open car is a two-door design With a bold and well-louvred bonnet, a folding windscreen, cut-away doors and a straight run back to the hood. A sloping tail on which the spare wheel is mounted completes its trim lines. The unusual treatment of the wings, with their sweeping turves and valances partly following the wings is notable.
The coupe is a particularly practical vehicle in our English climate, and as great care has been shown in making the hood fit down flush with the sides of the car, the appearance of the body with the head down is as sleek as that of the open car while it is completely draftproof when the top is erected. The hoodsticks and joints are so proportioned that the head can be erected with the minimum of effort. A trunk at the back is fitted with two suitcases. The two-door saloon has the sloping windscreen, the peakless front and the sweeping-down back which modern carfashion demands, and which also offer the minimum of wind-resistance and backsuction. A particularly striking colour
scheme can be had in which the bonnet is of a (lark colour. This is carried back past the door in a sweeping curve to the front of the rear wing, the top and the rest of the car being in a contrasting light shade. The wing valances closely follow the shape of the tyres and the back of the rear wing carries out the streamline layout of the rest of the car.
The saloons are fitted with sliding roofs, and the luggage container is either built into the body or carried at the back in the form of a trunk, with two suitcases.
These three bodies are built by Messrs. Park Ward, who have been responsible for so many magnificent designs on Rolls Royce chassis. The open car costs £1,380, the drop-head coupe £1,485, while the Special Sports two-door saloon is listed at £1,635. A four-door saloon of more conservative line may be had for £1,460. The 34 litre Bentley is being built at Derby, and the new showrooms are situ
«tcd at 16, Conduit Street, London, W.1, next to those• of Messrs. Rolls Rcyce.
tt on Stand No. 117 at the forthcoming Motor Show will be displayed a full range of coachwork, and the Bentley exhibits will undoubtedly be the centre of attraction at Olympia. Students of design will there be able to examine the mediumpowered motor car developed to its utmost extent in engine, chassis and coachwork.
It is a comforting thought that in these times of universal trade-depression, a car of such modern design and meticulous construction can still be produced in England. It is not too much to say that the re-introduction of the Bentley will have a world-wide effect in enhancing British motoring prestige. On the Continent and in the U.S.A. the name Bentley used to typify Britain’s contribution to the high-efficiency automobile market, in which it held a place second to none. Now the name goes on.