Towards the end of last month, by courtesy of Mr. H. M. Johnson, we took an evening drive in his Citroën Six saloon with Wade-Ventor supercharger installation. The appearance of the car intrigues, even seems mildly aggressive in a purposeful sort of way. As the unusually long wheelbase forecasts, there is ample room inside for five grown-ups. This, then, is a comfortable family car, but after driving out of London as far as Maidstone, during the evening traffic peak, we realised that not only are all the splendid qualities of the “Light Fifteen” reproduced in this latest front-drive car from the Citroën factory but that in spite of its capaciousness it is able to shame many so-called sports cars in the matter of performance.
Mr. Johnson, who formerly owned, Darracq, Rolls-Bentley and Studebaker cars, bought this Citroën and drove it about 1,000 miles in standard form. He decided that he liked it and took it along to Pat Whittet & Co., Ltd., to have some additional urge instilled. The Ventor blower installation fits in very neatly with the under-bonnet scheme. A Type R 020 four-lobe supercharger is mounted high up on the near side and driven from the front of the camshaft in two stages, first by chain enclosed in a neat alloy casing and thence by short triple belts running over spring-loaded jockey pulleys. An S.U. carburetter behind the blower feeds via a curved inlet pipe and a large-bore delivery pipe passes from the blower, behind the engine, to the centre of the six-branch inlet manifold on the off side, where a blow-off valve is hidden beneath the delivery-pipe/manifold junction. At the back of the engine the main oil feed is tapped to provide drip-feed lubrication of the rotor gears and the driving chain. Ki-gass injectors enter the delivery pipe on the off side and here also it is tapped for the boost-gauge line. The pulley on the camshaft having been sacrificed for the chain sprocket, a new belt drive has been devised for fan and dynamo. The supercharger blows at 4 to 4½ lb./sq. in. at maximum speed; the compression-ratio of the engine has been lowered from 6.7 to 6.4-to-1. To obviate valve bounce 1/16-in. packings have been inserted beneath the valve springs and a Fram filter and Runbaken Oil Coil are fitted. The engine is otherwise the standard 8-litre Citroën unit evolved some years ago for lorry propulsion. The bonnet has been felt-lined to absorb noise and a boost gauge and oil and water thermometers have been added to the unobtrusive square-dial instruments on the right of the standard facia panel. Hand ignition control is a standard fitting. As a result of adding a Wade-Ventor installation to the Citroën Six a very good motor car has been rendered outstanding to a point of being unique. The engine responds instantly to the throttle and acceleration is most impressive both by reason of its degree and its continuity. As soon as possible you get out of the 13.24-to-1 bottom gear and in the 5.62-to-1 middle ratio of the facia-controlled three-speed box, the car surges cleanly forward up to an easy speedometer 60 m.p.h. Although top gear is as high as 8.87-to-1 and the car weighs 26 cwt. unladen, speed continues to build up just as rapidly as in second gear, the engine as smooth as a turbine and inaudible except for a faint hum from the blower. On the over-run things are just as smooth and unobtrusive.
The true maximum speed is probably in excess of 90 m.p.h., and on traffic-infested roads 70 to 75 m.p.h. was the usual gait. The feeling of absolute security up to maximum speed is most pronounced. As with the “Light Fifteen,” however, so in this “Six” speed as such is subordinate to the delightful manner in which the car gets on with its job. The steering is so obviously connected to the front wheels and so pleasantly high-geared that its heaviness is no disadvantage. The Lockheed brakes require fairly heavy pressure but are free from fade. The ride is so level-keel that it ensures complete confidence when cornering or standing on the brakes in an emergency, and the suspension so effectively absorbs road shocks that to ride in any seat in this car is to realise how much the French knew about motor car design fifteen years ago and how sadly our designers lag behind. For the Citroën Six derives its delightful riding and handling qualities from front-wheel-drive, low build, torsional suspension, and rigid one-piece construction, features which caused English eyes to goggle at the Citroën Twelve away back in 1934 and have enabled Citroën cars to serve ordinary Frenchmen as such satisfactory utility motor-cars ever since. It may even be said that the “Six” has more refinement of running than its famous contemporary the “Light Fifteen.”
Moreover, as it has been naturalised, the car we tried has r.h. drive and spares and service were available from Staines.
In his blown Citroën Six Mr. Johnson has a profoundly inspiring car. The supercharger, now that its bronze and steel rotor gears are bedded in, imparts merely a low hum to the under-bonnet silence and apart from that only a little resonance and wind-roar, more noticeable in the back than in the front seats, proclaim the sort of performance that is being delivered. After the wire-mesh was removed from the radiator grille no serious overheating has been experienced, and during our drive the water temperature did not exceed 75°C. The blower belts have lasted about 5,000 miles. Castrol XL oil and the plugs supplied with the car are used, and a double S.U. pump now looks after the fuel feed. Fuel consumption has scarcely increased since the engine was blown, 16 to 17 m.p.g. being normally obtained; 10 per cent. benzole is added when available. The only serious trouble in 5,000 supercharged miles was clutch slip, which Monaco of Watford cured by fitting different linings, which sweetened the action. Oil pressure, when hot, is 80 lb./sq. in. at 70 m.p.h.
In spite of its 10 ft. 1½ in. wheelbase the car can be thrown about with impunity. An American Bosch radio is fitted and tyres are 185/400 Michelins.
No car is perfect, as Mr. Johnson is the first to admit, but the snag-sheet relating to his present car is a very short one. Bottom gear is too low, and an additional gear between middle and top, with the latter a still higher ratio, would be an improvement, as at present the Citroën is a top-gear car. Hunting at idling speeds is evident to a slight degree due to supercharger surge, which is common to many blown engines, and the car sometimes suffers from a very slight “flatspot,” noticeable when opening-up from low speeds. The accelerator pedal has rather a long movement, and clutch engagement is rather difficult.
After which you return to the opinion that here is one of the few truly-great quantity-production cars of the present day. That such a bold statement is no exaggeration can be appreciated when to the foregoing remarks are added the facts that Citroën still refuses to streamstyle or aerodyne his cars, and that the doors of the all-steel body swing easily on their hinges and allow entry and egress with a minimum of contortion.
This Citroën is a roomy family saloon, endowed with additional speed and acceleration by reason of a mild boost, and it would do some of our designers a power of good to drive it. — W. B.