1955 Autocar review of Citroën DS19

THE 11 c.v. Citroen has been in production for twenty-one years without any basic changes. It was a fairly short-odds bet, therefore, that when it was replaced the new car would be equally advanced in its conception, and the impact which the new D l9 made at its presentation the night before the Paris Salon was opened was quite staggering. It will take some time to prove whether the innovations offered will be acceptable to the buying public.

There is a complicated system of hydraulics, controlled from a master pressure pump and accumulator. The system is ingenious, but there is a complementary degree of complication which may present problems in maintenance.

The new model retains the same basic layout as previously, with reversed engine and front wheel drive. A constant-layshaft type of gear box is used, as hitherto, in which the drive shaft £rom the clutch passes over the differential assembly mounted on the end of the second motion shaft. The drive shaft to the wheels uses a double Hooke type universal joint, placed back to back also as hitherto.

Hydraulic Circuits

A belt-driven hydraulic pump and reservoir feeds an elaborate hydraulic system used for the four-wheel oleopneumatic independent suspension, which is similar to that fitted to the rear end only of the six-cylinder 15H model, now taken out of production. A full description of this system was given in The Autocar of August l9, 1955. Other circuits supply hydraulic power for operation of the four-speed gear box and clutch, which are controlled by a single change-speed lever on the dash. The clutch pedal has, therefore, disappeared and clutch action begins automatically at the moment of gear change.

Another circuit operates the brakes. These are inboard discs at the front, and normal drums with leading and trailing shoes at the rear. Finally the rack and pinion steering is hydraulically assisted by a booster cylinder on the end of the rack, controlled by a two-way valve on the steering column.

The four-cylinder power unit incorporates a new aluminium cylinder head on the previous D-model cylinder block and crankcase. It has a bore of 78 mm and stroke of 100 mm (1,911 c.c.) and develops 75 b.h.p. at 4,500 r.p.m. with a compression ratio of 7.5 to 1. The combustion chamber is hemispherical and the valves, with an included angle of 60 degrees, are operated by long and short rockers actuated by push rods from the single camshaft mounted in the crankcase. The layout is similar to that used on the Peugeot and the Armstrong Siddeley Sapphire.

A double-choke downdraught Weber carburettor is used and the induction manifold is water-jacketed for induction pre-heating. A twin V belt takes the drive from a pulley on the end of the camshaft to the dynamo and water pump, on the end of which is an eight-bladed fan moulded in nylon and running in a ducted cowl behind the radiator. The hydraulic Pressure pump is driven by a single belt from the same camshaft pulley.

Trailing arms are used for the rear suspension, with a drop arm lever at their pivot points connecting to the suspension cylinders. There is an anti-roll bar connected between the two pivot bearings. At the centre of the anti-roll bar, on the point of neutral twist, is a rod which connects to the control valve of the height corrector. This valve controls the flow of oil into the strut of the suspension cylinders so that the static height of the car remains the same irrespective of load.

Oleo-pneumatic cylinders are also used for the front suspension. There are two L-shaped arms top and bottom which, in effect, are each one half of an orthodox wishbone system. They extend forward from two longitudinal bearings which are bolted in one assembly to the frame side members at the scuttle structure. At their outer ends they swivel on balls for wheel movement.

At the rear end of the top arm bearing is a lever attached to the end of the arm. It connects to the lower end of the oleopneumatic strut and also carries a drop link which is connected to the ends of a transverse anti-roll bar. From the neutral point of this torsion bar is a rod connecting to the static height corrector valve, in the same way as in the rear suspension.

The wheels are fixed to the hubs by one central bolt retained in the wheel by a circlip. The drive is taken through a hexagonal member on the outside of the wheel hub, mating with a corresponding ferrule depression formed in the wheel hub. The front tyres are larger in section than the rear since the loads are considerably higher, an estimate of the ratio being 65 per cent front and 35 per cent rear. Front tyre size is 165 x 400 mm (approx. 6.50—-16in) and at the rear 155 x 400 mm (approx. 6.00—16in). The spare wheel, which is mounted in front of the radiator, is 165-400 mm — the same size as the front - but it could be used on the rear in an emergency.

Disc brakes are used at the front and are mounted inboard at the final drive unit in a similar manner to those of the 2 c.v. Normal leading and trailing shoe brakes with their drums mounted at the wheels are used at the rear. Both are operated hydraulically from the main servo system, the operating pedal being a plunger with a circular pad of only about 1 ¾ in diameter. The operational travel is very small as it is required only to open the distribution valves, which are actuated by a balance bar attached to the pedal.

There is one distribution valve for each of the front and rear brake circuits, and similarly one small accumulator for each, taken off the main accumulator circuit. Depression of the pedal opens the valves and oil under pressure is fed from the accumulators to each circuit. The brake pedal load will be almost negligible under these conditions and would be expected to lack feel.

The front disc brakes are cooled by air inlets for the front, and have automatic adjustment for wear. The braking system allows for varying load conditions, which means that, irrespective of the load carried and transference to the front resulting from it, the braking will be compensated for this condition.

No parking brake lever is provided; instead a large pedal on the driver's extreme left doubles as parking and emergency brake. It is connected to the front brakes by a mechanical linkage and is thus available for emergency use in the event of failure of the main hydraulic system. For parking the pedal is depressed and then locked down with the aid of a knob below the facia. The knob itself has a safety catch.

The steering wheel is of very unusual design in that it has only one spoke, formed by bending the steering column over into the wheel rim. Towards the rack end, the steering column is split and provided with a flattened face on each of the halves. These two faces overlap. In the lower half are two distributor valves, one for each direction of turn, which circuit the main oil pressure to either side of a booster cylinder attached to the end of the rack. In the event of hydraulic failure mechanical connection is effected by the two_ flattened faces of each half in the steering column joint. Hydraulic assistance will considerably lighten the steering loads, which are otherwise heavy owing to the disproportionate weight distribution of a front-wheel-drive layout.

Synchromesh is provided on the top three ratios of the four speed box. Operation is hydraulic, in conjunction with the clutch release, which is incorporated in the change-speed lever. The gear lever is merely moved into the required gear and clutch operation is automatically combined with this movement. It has not been possible to analyse this circuit, but there is some sort of override mechanism on the throttle linkage as there are two slip links incorporated in it.

Thus the foot throttle is overridden, irrespective of its position, and the throttle setting automatically adjusted to give the required engine speed for the gear change. It is necessary to move through the gears progressively, i.e., a change cannot be made direct from top to second without going through third.

The clutch is of the normal single dry plate type without centrifugal action, which is common practice when the clutch pedal is discarded. The clutch plates are held in the drive position by springs, released by hydraulic actuation from gear lever. There is a control sensitive to engine speed to release the clutch below a set minimum speed when idling. It is a hydraulic governor in tandem with the water pump and connected to the selector mechanism. There is a manual override control on the facia to put the automatic clutch out of action when the engine is stationary. By this means the engine can be tow started.

Integral construction is used on the same lines as the previous cars, with deep side members formed by the body sills and front suspension. Power unit loads are carried on the forward bearer arms and braced into the scuttle structure.

The outline of the car is long and low, with very little overhang at the rear; the Italian firm of Bertone (incorrect – Flaminio Bertoni – unrelated to Bertone - was employed by Citroën) were enlisted on the design side. The windscreen is curved well round to provide excellent vision and the screen pillars are very thin, a thinness which is helped by the fact that the doors have no window frames. The glass of the door windows seals against flexible rubber strips attached to the body. The new model has winking indicators in the belled-out rear ends of the chrome mouldings which extend rearward, above the frameless windows, from the top of the curved screen. The roof panel is plastic.

The rear track is narrower than the front by 7 3/4in, and the body form follows its general shape with the noticeably greater width at the front. For its size the wheelbase is exceptionally long at 10ft 3in, which is l 1/2in more than the present range. Although the overhang at the rear is short the overall length is 15ft 9in. Similarly, the front track is 1/2in wider at 4ft llin, but - which is more important-—-the turning circle has been reduced to 36ft lin (as opposed to 45ft 6in), which considerably improves manoeuvrability, which was always a point of criticism on the Citroen.

It is difficult to assess at the moment what sort of reception the car will receive. It moves into a higher price bracket than previous Citroen models by approximately £150. It is bristling with ingenious features, but they are, of necessity, rather complex, and the maze of hydraulic pipes with their circuits, dependent upon one belt-driven hydraulic pump, may result in some apprehension on the part of would-be purchasers, and this might affect its initial commercial success.

Engine.—4-cyl, 78 mm bore X 100 mm stroke (3.1 ><'3.9in), 1,911 c.c. (116.5 cu in).
Compression ratio, 7.5 to 1. 75 b.h.p. at 4,500 r.p.m. Maximum torque, 101 lb/ft. Double-bodied Weber downdraught carburettor. Pump and thermostat, nylon fan, cooling.

Clutch.—Single dry plate. Automatic hydraulic control.

Transmission.—Four-speed with synchromesh on second, third and top. Hydraulic control. Front wheel drive, spiral bevel final drive. Gear change lever under steering wheel (this is incorrect, it is above the steering wheel).

Suspension.—Front, independent, oleopneumatic with anti-roll bar and static height corrector. Rear, independent, oleopneumatic with anti-roll bar and static height corrector.

Brakes.—Disc brakes for the front wheels, drum brakes for the rear wheels. Pressure distributed according to axle loading. Automatic adjustment on front brakes. Total brake lining area, 80.6 sq in.

Steering.—Rack and pinion. Hydraulically assisted.

Wheels and Tyres.—Central fixing for wheels. Michelin 155-400 tyres rear, 165-400 front and on spare wheel. English models have 165x400 tyres all round.

Fuel System.—14-gallon fuel tank. Mechanical feed pump. Oil capacity 7 pints.

Electrical System.—l2-volt S7 ampere-hour battery (6-volt system in France).

Main Dimensions.—Wheelbase, 10ft 3in. Track, front, 4ft llin; rear, 4ft 3 1/4in. Overall length, 15ft 9in. Width, 5ft 10 1/2in. Height, 4ft 10in. Turning circle, 36ft 1in. Dry weight, 2,464lb (22cwt).

Performance.—Top speed on level, 87 m.p.h.; maximum speed in third, 72 m.p.h.; maximum speed in second, 50 m.p.h.; maximum speed in first, 25 m.p.h.

Price.—Basic, £990, plus £413 12s 6d U.K. purchase tax; total, £1,403 12: 6d.