Citroën 2CV Technical info

Construction

The level of technology in the 1948 2CV was remarkable for a car of any price in that era, let alone one of the cheapest cars on the planet. While colours and detail specifications were modified in the ensuing 42 years, the biggest mechanical change was the addition of front disc brakes in 1981 (from the discontinued Citroën Dyane), for the 1982 model year.

CHASSIS: platform with long members; front and rear suspension: independent,

Features of the 1948 2CV

• unusual four-wheel independent suspension, front and rear wheels which connected the front and rear suspension on each side
• leading arm front suspension
• trailing arm rear suspension
• rear fender skirts, but the suspension design allowed wheel change without removing the skirts / rear wings
• front-wheel drive
• inboard front brakes, in order to help lower unsprung weight thus making ride even softer
• Four-wheel hydraulic brakes, (British Austin economy cars of the time only had hydraulic front brakes, the rears were by mechanical linkage)
• small, lightweight, 9HP air-cooled flat twin engine, (with overhead valves when side valves were still common), mounted very low in front of the front wheels for stability
• 4-speed manual transmission, (when three speeds were common) with an unusual dashboard push/pull/twist linkage
• bolt-on detachable front and rear wings/fenders
• detachable doors, bonnet (and boot lid after 1960), by "slide out" P profile sheet metal hinges
• front rear-hinged "suicide doors"
• flap-up windows, as roll up windows were considered too heavy and expensive.
• detachable full length fabric sunroof and boot lid, for almost pickup-truck-like load carrying versatility
• ventilation in addition to the sunroof and front flap windows was provided by an opening flap situated underneath the windscreen.
• rack and pinion steering mounted inside the front suspension cross-tube, well behind the front wheels, away from a frontal impact
• load adjustable headlights.
• a heater (heaters were standardised on British economy cars in the 1960s)

Body

The body was constructed of a dual H-frame platform chassis and aircraft-style tube framework, and a very thin steel shell that was bolted to the chassis. Because the original design brief called for a low speed car, little or no attention was paid to aerodynamics. The result was that the body had a drag coefficient (Cd) of a high 0.51.

Suspension

front swinging leading arms, rear swinging trailing arms linked by longitudinal coil springs, 4 frictional damping, 4 inertia type patter dampers.

STEERING: rack-and-pinion; turns of steering wheel lock to lock: 2.25.

The suspension of the 2CV was almost comically soft; a person could easily rock the car side to side dramatically (back and forth was quite a bit more resistant). The leading arm / trailing arm swinging arm, fore-aft linked suspension system together with inboard front brakes had a much smaller unsprung weight than existing coil spring or leaf spring designs. It was designed by Marcel Chinon.

• The system comprises two suspension cylinders mounted horizontally on each side of the platform chassis. Inside the cylinders are two springs, one for each wheel, mounted at each end of the cylinder. The springs are connected to the front leading swinging arm and rear trailing swinging arm, that act like bellcranks by pull rods (tie rods). These are connected to spring seating cups in the middle of the cylinder, each spring being compressed independently, against the ends of the cylinder.
• If each cylinder was rigidly mounted to the chassis, it would provide fully independent suspension, but it is not rigidly mounted. It is mounted using an additional set of springs, originally made from steel, called "volute" springs (that are visible on the ends of cylinder in the external linked drawing above), but on later models made from rubber. These springs allow the front and rear suspension to interconnect.

• When the front wheel is deflected up over a bump, the front pull rod compresses the front spring inside the cylinder, against the front of the cylinder. This also compresses the front "volute" spring pulling the whole cylinder forwards. That action pushes the rear wheel down on the same side via the rear spring assembly and pull rod. When the rear wheel meets that bump a moment later, it does the same in reverse, keeping the car level front to rear. When both springs are compressed on one side when travelling around a bend, or front and rear wheels hit bumps simultaneously, the equal and opposite forces applied to the front and rear spring assemblies reduce the interconnection significantly, or even completely. This stiffens the suspension after a certain amount of body roll has been achieved. It allows the 2CV to have very soft "bump mode" absorption, without wallow or uncontrolled float.
• It reduces pitching, which is a particular problem of soft car suspension.
• At high angles of body roll, the swinging arms that are mounted with large bearings to "cross tubes" that run side to side across the chassis; combined with the effects of all-independent soft springing and excellent damping, keeps the road wheels in contact with the road surface and parallel to each other across the axles. A larger than conventional steering castor angle, ensures that the front wheels are closer to vertical than the rears, when cornering hard with a lot of body roll. All this provides excellent road holding, while appearing to look like a softly sprung American car with poor handling and road holding because of poor body control.

• The other key factor in the quality of its road holding is the very low and forward centre of gravity, provided by the position of the engine and transmission.

• The suspension also automatically accommodates differing payloads in the car- with four people and cargo on board the wheelbase increases by around 4 cm (2 in) as the suspension deflects, and the castor angle of the front wheels increases by as much as 8 degrees thus ensuring that ride quality, handling and road holding is almost unaffected by the additional weight.

• On early cars friction dampers (like a dry version of a multi-plate clutch design) were fitted at the mountings of the front and rear swinging arms to the cross-tubes. Because the rear brakes were outboard, they had extra tuned mass dampers to damp wheel bounce from the extra unsprung mass. Later models had tuned mass dampers at the front (because the leading arm had more inertia and "bump/thump" than the trailing arm), with hydraulic telescopic dampers / shock absorbers front and rear. The uprated hydraulic damping obviated the need for the rear inertia dampers. (It should be noted that only dampers designed to be able to work horizontally should be used as replacements. Some that will physically fit do not work properly horizontally.)

• It was designed to be a comfortable ride by matching the frequencies encountered in human bipedal motion.

This sophisticated suspension design ensured the road wheels followed ground contours underneath them closely, while insulating the vehicle from shocks, enabling the 2CV to be driven over a ploughed field without breaking any eggs, as its design brief required. More importantly it could comfortably and safely drive at reasonable speed, along the ill-maintained and war-damaged post-war French Routes Nationales. It was commonly driven "Pied au Plancher"—"foot to the floor" by their peasant owners.

The 2CV suspension and vehicle dynamics was assessed by Alec Issigonis and Alex Moulton in the mid-1950s (according to an interview by Moulton with CAR magazine in the late 1990s); this inspired them to design the Hydrolastic suspension system for the Mini and Austin 1100, to try to keep the benefits of the 2CV system but with added roll stiffness in a simplified design.

Front-wheel drive

Front-wheel drive made the car easy and safe to drive and Citroën had developed expertise with it due to the pioneering Traction Avant, which was the first mass-produced steel monocoque front-wheel-drive car in the world. The 2CV was originally equipped with a sliding splined joint, and twin Hookes type universal joints on its driveshafts; later models used constant velocity joints and a sliding splined joint.

Gearbox

The gearbox was a 4-speed manual transmission, an advanced feature on an inexpensive car at the time. Boulanger had originally insisted on no more than three gears, because he believed that with four ratios the car would be perceived as complex to drive by customers. Thus, the fourth gear was marketed as an overdrive, this is why on the early cars the "4" was replaced by "S" for surmultipliée. The gear shifter came horizontally out of the dashboard with the handle curved upwards. It had a strange shift pattern: the first was back on the left, the second and third were inline, and the fourth (or the S) could be engaged only by turning the lever to the right from the third. Reverse was opposite first. Although this may seem an odd layout, it is in fact logical. The idea is to put most used gears opposite each other: for parking, first and reverse; for normal driving, second and third. This layout was adopted from the H-van's 3-speed gearbox.

TRANSMISSION: driving wheels: front: clutch: single dry plate; gear box  mechanical; gears: 4 + reverse; synchromesh gears: ratios: (1st) 6.71, (2nd) 3.24, (3rd) 1.93, (4th) 1.47, (Rev) 7.24; gear lever: on facia; final drive: hypoid bevel; ratio: 3.875 : 1.

The windscreen wipers were powered by a purely mechanical system: a cable connected to the transmission; to reduce cost, this cable also powered the speedometer. The wipers' speed was therefore dependent on car speed. When the car was waiting at a crossroad, the wipers were not powered; thus, a handle under the speedometer allowed them to be operated by hand. Although this system was far from perfect, it was better than some 1950s British Ford economy cars that had wipers powered by inlet manifold vacuum that ran at full speed at engine idle but slowed down to a crawl when cruising at speed. From 1962, the wipers were powered by a single-speed electric motor. The car came with only a speedometer and an ammeter.

The reliability of the car was increased by the fact that, being air-cooled (with an oil cooler), it had no coolant, radiator, water pump or thermostat. It had no distributor either, just a contact breaker system. Except for the all hydraulic brakes, there were no hydraulic parts on original models as damping was by tuned mass dampers and friction dampers. On later models the mass dampers and friction dampers were replaced by conventional shock absorbers.

Early models used a combination of steel pipes and flexible rubber hoses in the braking system. Later 2CV used only steel pipe in the hydraulic braking system; no flexible rubber hoses were used. The front inboard brakes were fixed to the gearbox and did not move with the wheels, while the rear brake pipe was coiled multiple times around the rear trailing-arm mounting tube to absorb suspension movement. This allowed cheaper and lighter assembly, greater reliability and a solid feel at the brake pedal.

Engines

The engine was designed by Walter Becchia and Lucien Gerard, with a nod to the classic "boxer" BMW motorcycle engine (it is reported that Becchia dismantled the engine of the BMW motorcycle of Flaminio Bertoni before designing the 2CV engine). It was an air-cooled, flat-twin, four-stroke, 375 cc engine with pushrod operated overhead valves and a hemispherical combustion chamber. The notoriously underpowered earliest model developed only 9 bhp DIN (6.5 kW). A 425 cc engine was introduced in 1955, followed in 1968 by a 602 cc one giving 28 bhp (21 kW) at 7,000 rpm. With the 602 cc engine, the tax classification of the car changed so that it became in fact a 3CV, but the commercial name remained unchanged. A 435 cc engine was introduced at the same time in replacement of the 425 cc; the 435 cc engine car was christened 2CV 4 while the 602 cc took the name 2CV 6 (although a variant did take the name 3CV in Argentina).

• ENGINE: front. 4 stroke; cylinders: 2, opposed, horizontal;
  
• Bore and stroke 2.60 x 2.44 in, 66 x 62 mm
  
• Engine capacity: 25.99 cu in, 425 cu cm
  
• Compression ratio: 7.5 : 1; max power (SAE): 13.5 hp at 4200 rpm; max torque (SAE): 20 1b ft, 2.7 kgm at 2500 rpm; max number of engine rpm: 4500; specific power: 31.8 hp/l;
  
• Cylinder block: cast iron, dry liners; cylinder head: light alloy,hemispherical combustion chambers; crankshaft bearings: 2; valves: 2 per cylinder, overhead, Vee-slanted at 700; camshaft: 1, central; lubrication: gear pump.filter in sump; lubricating system capacity: 1.8 imp qt, 2.1 US qt, 2 1: 
• Carburation: 1 Solex 26 CBI downdraft carburettor with minimum retarder; fuel feed: mechanical pump; cooling system: air-cooled.

The 602 cc engine evolved to the M28 33 bhp (25 kW) in 1970; this was the most powerful engine fitted to the 2CV. A new 602 cc giving only 29 bhp (22 kW) at a slower 5,750 rpm was introduced in 1979. Despite being less powerful, this engine was more efficient, allowing lower fuel consumption and better top speed, at the price of decreased acceleration. All 2CVs with the M28 engine can run on unleaded petrol, but attention is needed to ensure that valve clearances are maintained. Although there were not any more powerful engines for this model, Citroen used the same engine design on other cars, like the AMI, the LN, the Dyane. The slightly increased capacity 652cc mapped electronic ignition version in the Visa was significantly different. They had a bit more power, and many 2CV owners installed those engines in their car for more flexibility. The final development of the engine was within the PSA Peugeot-Citroën / Renault / French government ECO 2000 project, first prototype SA103 of March 1982. It was watercooled and increased to 704cc. Later prototypes used a three cylinder Fiat FIRE engine instead, which was then being developed in conjunction with PSA.

The 2CV used the wasted spark ignition system for both simplicity and reliability and had only speed-controlled ignition timing, no vacuum advance taking account of engine load.

Unlike other air-cooled cars (such as the Volkswagen Beetle and the Fiat 500) the 2CV's engine had (for simplicity and reliability) no thermostat valve fitted to its oil system to allow the oil to reach normal operating temperature quickly in cold weather. All the oil in the system passed through an oil cooler mounted behind the fan and received the full cooling effect regardless of the ambient temperature. This removes the risk of overheating from a jammed thermostat that can afflict water- and air-cooled engines and the engine can withstand many hours of running under heavy load at high engine speeds even in hot weather. To prevent the engine running cool in cold weather (and to improve the output of the cabin heater) all 2CVs were supplied with a grille blinds (canvas on early cars and a clip-on plastic item called a 'muff' in the owner's handbook, on later ones) which blocked around half the grille aperture to reduce the flow of cool air to the engine.

The engine's design concentrated on the reduction of moving parts. The cooling fan and dynamo were built integrally with the one-piece crankshaft, removing the need for drive belts. (Late models (shown in photo) used an alternator mounted high above the engine, to keep it dry, run with a drive belt). The crankshaft was a "built-up" design similar to that used in many motorcycle engines. In place of the split big ends and two-piece big-end bearings commonly used in car engines, the 2CV engine used connecting rods with one-piece big-ends and bearings, which were fitted to the crankpins before the crank was assembled. The crankpins were then hydraulically pressed into the webs after being chilled with liquid nitrogen to cause them to contract. The entire unit (crank, big-end bearings and connecting rods was then fitted to the engine. The camshaft drive gears incorporate a spring-loaded split gear, to reduce the effects of gear wear and backlash on valve timing and ignition timing. With the contact breaker in a housing on the end of the crankshaft there was no separate jackshaft to be affected by chain or gear wear and associated backlash.The use of gaskets, seen as another potential weak point for failure and leaks, was also kept to a minimum. The cylinder heads are mated to the cylinder barrels by a lapped joints with extremely fine tolerances as are the two halves of the crankcase and other surface-to-surface joints.

As well as the close tolerances between parts the engine's lack of gaskets was made possible by a unique crankcase ventilation system. On any 2-cylinder boxer engine such as the 2CV's, the volume of the crankcase reduces by the cubic capacity of the engine (375 to 602cc in the Citroen's case) when the pistons move together. This, combined with the inevitable small amount of 'leakage' of combustion gases past the pistons leads to a positive pressure in the crankcase which must be removed in the interests of engine efficiency and to prevent oil and gas leaks as the pressure tries to escape. The 2CV's engine has a combined engine 'breather' and oil filler assembly which contains a series of rubber reed valves. These allow positive pressure to escape the crankcase (to the engine air intake to be recirculated) but which close when the pressure in the crankcase drops as the pistons move apart. Because gases are expelled but not admitted this creates a slight vacuum in the crankcase so that any weak joint or failed seal causes air to be sucked in rather than allowing oil to leak out. Since the oil serves both as the engine's lubricant and forms a vital part of the cooling system this 'anti leak' system was especially important.

These design features made the 2CV engine highly reliable; test engines were run at full speed for 1000 hours at a time, equivalent to driving 80,000 km (50,000 mi) at full throttle. They also meant that the engine was very much "sealed for life"—for example, replacing the big-end bearings required specialised equipment to dismantle and reassemble the built-up crankshaft, and as this was often not available the entire crankshaft had to be replaced. However, the engine is very under-stressed and long-lived, so this is not a major issue. Until the 1960s it was common for other car manufacturers' engines to need full strip downs and rebuilds at as little as 80,000 km (50,000 mi) intervals; un-rebuilt 2CV engines are still running that are passing 400,000 km (250,000 mi).

If the starter motor or battery failed, the 2CV had the option of hand-cranking, the jack handle serving as starting handle through dogs on the front of the crankshaft at the centre of the fan. This feature, once universal on cars and still common in 1948 when the 2CV was introduced, was kept until the end of production in 1990. The jack handle also served as the wheelbrace (lug wrench) and could be used to remove the nuts that held the front wings (fenders) on—part of the car's design to facilitate easy maintenance.
When asked about the 2CVs performance and acceleration, many owners said it went "from 0–60 in one day". Others jokingly said they "had to make an appointment to merge onto an interstate highway system".Performance

The original 1948 model that produced only 9 hp had a 0-40 time of 42.4 seconds and a top speed of just 64 km/h (40 mph), far below the speeds necessary for North American highways or the German Autobahns of the day. The top speed increased with engine size to 80 km/h (49 mph) in 1955, 84 km/h (52 mph) in 1962, 100 km/h (63 mph) in 1970, but was finally not capable of US freeway speeds of 115 km/h (71 mph) until 1981.The last evolution of the 2CV engine was the Citroën Visa flat-2, a 652 cc featuring electronic ignition. Citroën never sold this engine in the 2CV, but some enthusiasts have converted their 2CVs to 652 engines, or even transplanted Citroën GS or GSA flat 4 engines and gearboxes. Cars with the flat-4 engines and subtle bodywork changes so they appear to be standard are known as "Sidewinders" in the UK.

In the mid-1980s CAR magazine editor Steve Cropley ran and reported on a turbocharged 602 cc 2CV that was developed by engineer Richard Wilsher.

History

The Citroën 2CV  was an economy car produced by the French car manufacturer Citroën between 1948 and 1990.It was technologically advanced and innovative, but with uncompromisingly utilitarian unconventional looks, and deceptively simple Bauhaus and Junkers early all metal aircraft inspired bodywork (corrugated for added strength without added weight) that belied the sheer quality of its underlying engineering. It was designed to motorise the large number of small-holder farmers in 1930s France, who were still using horses and carts. It is considered one of Citroën's most iconic cars. In 1953 Autocar in a technical review of the car wrote of "the extraordinary ingenuity of this design, which is undoubtedly the most original since the Model T Ford" It was described by Car Magazine journalist and author L. J. K. Setright as "the most intelligent application of minimalism ever to succeed as a car".It was designed for low cost, simplicity of use and maintenance, versatility, reliability, low fuel consumption and off-road driving. For this it had a light, easily serviceable engine, extremely soft long travel suspension (with height adjustment by lengthening/shortening of tie rods) high ground clearance, and for oversized loads a car-wide canvas sunroof, which (until 1955) also covered the boot.

During a production run of 42 years between 1948 and 1990, 3,872,583 2CVs were produced, plus 1,246,306 Fourgonnettes (small 2CV delivery vans), as well as spawning mechanically identical vehicles including the Ami: 1,840,396; the Dyane: 1,444,583; the Acadiane: 253,393; and the Mehari: 144,953, a grand total of 8,756,688, of which there are still 3,382 on the road in the UK as of January 2013.

From 1988 onwards, production took place in Portugal (Mangualde) rather than in France. This arrangement lasted for two years until 2CV production halted. Portuguese built cars, especially those from when production was winding down, have a reputation in the UK for being much less well made and more prone to corrosion than those made in France. Paradoxically the Portuguese plant was more up-to-date than the one in Levallois near Paris, and Portuguese 2CV manufacturing was to higher quality standards.

The 2CV belongs to a short list of vehicles introduced in the middle of the 20th century that remained relevant and competitive for many decades, such as the Jeep, Land Rover Series, Fiat 500, Mini and Volkswagen Beetle.

In 1934 family-owned Michelin, as the largest creditor, took over the bankrupt Citroën company. As far back as 1922, when they first conducted market research, they had been interested in expanding the market for economy cars (and tyres) in France, in the same way that the Ford Model T had done in the US. The new president of Citroën, Pierre Michelin, had even gone as far as to build a scale model of what he had in mind at Michelin before the takeover of Citroën.Citroën had stopped producing the economy cars that established the company after the First World War by the mid-1920s, when they moved to using Budd-type pressed steel bodies. Michelin believed that decision was a contributor to the later bankruptcy. The new management ordered a fresh and detailed market research survey that was conducted by Jacques Duclos. At that time, France had a very large rural population which could not yet afford automobiles. The results of the survey were used by Citroën to prepare a design brief for a low-priced, rugged "umbrella on four wheels" that would enable four small farmers / peasants to drive 50 kg (110 lb) of farm goods to market at 50 km/h (31 mph), in clogs and across muddy unpaved roads if necessary. The car would use no more than 3 L of gasoline to travel 100 km (78 mpg). Most famous, was the design brief requirement be able to drive across a ploughed field while carrying eggs, that the envisaged smallholder customer would be taking to market, without breaking them.

In 1936, Pierre-Jules Boulanger, the vice-president of Citroën and chief of the Engineering and Design department, set the brief to his design team at the Bureau d'études. The TPV (Toute Petite Voiture—"Very Small Car") was to be developed at Michelin facilities at Clermont-Ferrand and at Citroën in Paris in strict secrecy, by the design team who had created the Traction Avant. Boulanger hand picked engineers added to the team, and preferred engineers who had qualified through night school courses, over university trained ones.He believed they were better engineers because of greater practical experience. Boulanger was closely involved with all decisions relating to the TPV, he was obsessed with reducing the weight of the TPV to targets that his engineers thought were impossible. He set up a department that had the job of weighing every component and then redesigning it, to lighten it while still doing its job. He later had the roof raised to allow him to drive while wearing a hat.

Boulanger placed engineer André Lefèbvre in charge of the TPV project. Lefèbvre had designed and raced Grand Prix cars, his own speciality was chassis design and he was particularly interested in maintaining contact between tyres and the road surface. In an era of poor damping, beam axles and leaf springs this gave his cars vastly superior grip and handling to most other cars.

The very first prototypes were bare chassis, with rudimentary controls, seating and roof, that required test drivers to wear the leather flying suits that were used in contemporary open biplanes.By the end of 1937 20 TPV experimental prototypes had been built and tested.

At the end of 1937 Pierre Michelin was killed in a car crash. Boulanger became president of Citroën and Lefèbvre, responsible for engineering and design, though he wasn't head of the department, he was more like a minister without portfolio; he didn't have an official title.

By 1939 the TPV was deemed ready, after 47 technically different and progressively improved experimental prototypes had been built and rigorously tested. Those prototypes made use of aluminium and magnesium parts and had water-cooled flat twin engines with front-wheel drive. The seats were hammocks hung from the roof by wires. The suspension system used front leading arms and rear trailing arms, connected to eight torsion bars mounted beneath the rear seat: a bar for the front axle, one for the rear axle, an intermediate bar for each side, and an overload bar for each side. The front axle was connected to its torsion bars by cable. The overload bar only came into play when the car had three people on board, two in the front and one in the rear, to take account of the extra load of the fourth passenger and fifty kilograms of luggage. It was designed by Alphonse Forceau. This suspension system did not make it into the delayed and redesigned production car.

During the summer of 1939 a pilot run of 250 cars was produced and on 28 August 1939 the car finally received French market homologation. Brochures were printed and preparations were made to present the car, now branded as the Citroën 2CV rather than as the Citroën TPV, at the forthcoming Paris Motor Show in October 1939. However, in September 1939 the government declared war on Germany, following that country's invasion of Poland. It would be another eight months before the Germans invaded France, but an atmosphere of impending disaster appeared much sooner and with less than a month's notice the 1939 motor show was cancelled, and the launch of the 2CV was abandoned.

During the German occupation of France in World War II Boulanger refused to collaborate personally with German authorities and organized and encouraged sabotage against production for the German war effort, to the point where the Gestapo listed him as an important "enemy of the Reich". Boulanger was under constant threat of arrest and deportation to Germany. Michelin, which was Citroën's main shareholder, and Citroën managers decided to hide the TPV project from the Nazis, fearing some military application. Several TPVs were buried at secret locations; one was disguised as a pickup, the others were destroyed, and Boulanger had the next six years to think about further improvements. Until 1994, when three TPVs were discovered in a barn, it was believed that only two prototypes had survived. As of 2003, five TPVs are known. For a long time, it was believed that the project was so well hidden that all the prototypes had been lost at the end of the war. It seems that none of the hidden TPVs were lost after the war, but in the 1950s an internal memo ordered them to be scrapped. The surviving TPVs were, in fact, hidden from the top management by some workers who were sensitive to their historical value.

By 1941, after an increase in aluminium prices of forty percent, an internal report at Citroën showed that producing the TPV post-war would not be economically viable, given the projected further increasing cost of aluminium Boulanger decided to redesign the car to use mostly steel with flat panels, instead of aluminium. The French motor industry before the war believed that aluminium would become cheaper, and become the standard material for car manufacture.The Nazis had attempted to loot Citroën's press tools; this was frustrated, after Boulanger got the French Resistance to re-label the rail cars containing them in the Paris marshalling yard. They ended up all over Europe, and Citroën was by no means sure they would all be returned after the war. After the liberation, Citroën, along with all the other major French car makers, evaluated and were offered the rights to the air-cooled AFG (Aluminium Français Grégoire) prototype, by Jean-Albert Grégoire, who was unaware of the secret TPV project. It emerged in 1946 as the aluminium Panhard Dyna X. In the Spring of 1944 Boulanger made the decision to abandon the water-cooled two-cylinder engine that had been developed for the car and installed in the 1939 versions. Walter Becchia was now briefed to design an air-cooled unit, still of two cylinders, and still of 375cc. Walter Becchia was also supposed to design a three-speed gearbox, but managed to design a four-speed for the same space at little extra cost. At this time French small cars like the Renault Juvaquatre and Peugeot 202 almost invariably featured three-speed transmissions. Even Citroën's own mid-size Traction Avant only had a three-speed gearbox. But the 1936 Italian Fiat 500 "Topolino" 'peoples car' did have a four speed gearbox. Boulanger was displeased when he found out that his instructions had not been followed. Becchia persuaded him that the 4th gear was actually an overdrive, this is why on the early cars the gear change was marked "S" for "surmultiplié" The increased number of gear ratios also helped with the performance penalty caused by the extra weight of switching from light alloys to steel for the body and chassis. Other changes included seats with tubular steel frames with rubber band springing,and a restyling of the body by the Italian Flaminio Bertoni. Also, in 1944 the first studies of the Citroën hydro-pneumatic suspension were conducted using the TPV/2CV.

It took three years from 1945 for Citroën to rework the TPV into what was its third incarnation, resulting in the car being nicknamed the "Toujours Pas Vue" (Still Not Seen) by the press. The development and production, of what was to become the 2CV was also delayed by the incoming 1944 Socialist French government, after the liberation by the Allies from the Germans. The five-year 'Plan Pons' to rationalise car production and husband scarce resources, named after socialist economist Paul-Marie Pons, only allowed Citroën the middle range of the car market, with the Traction Avant. The French government allocated the economy car market, US Marshall Plan aid, US production equipment and supplies of steel, to newly nationalised Renault to produce their Renault 4CV. The 'Plan Pons' came to an end in 1949. Postwar French roads were very different from pre-war ones. Horse-drawn vehicles had re-appeared in large numbers. The few internal combustion engined vehicles present, often ran on town gas stored in gasbags on roofs or wood/charcoal gas from gasifiers on trailers. Only one hundred thousand of the two million pre-war cars were still on the road. These were known as 'Les années grises' or 'the grey years' in France.

Production

Citroën finally unveiled the car at the Paris Salon on October 7, 1948. The car on display was nearly identical to the 2CV type A that would be sold the next year, but it lacked an electric starter, the addition of which was decided the day before the opening of the Salon, after female company secretaries had trouble using the pull cord starter. Walter Becchia had designed in a space for a starter motor to be mounted, even though Boulanger had forbidden them from fitting an electric starter. In keeping with the ultra-utilitarian (and rural) design brief, the canvas roof could be rolled completely open. The Type A had one stop light, and like the black Ford Model T was available only in one colour, grey. The fuel level was checked with a dip stick/measuring rod. The car was heavily criticised by the motoring press and became the butt of French comedians for a short while.One American motoring journalist quipped, "Does it come with a can opener?" The British Autocar correspondent wrote that the 2CV "is the work of a designer who has kissed the lash of austerity with almost masochistic fervour". Nevertheless, Citroën was flooded with orders at the show, and the car had a great impact on the lives of the low-income segment of the population in France.

The 2CV was a great commercial success: within months of it going on sale, there was a three-year waiting list, which soon increased to five years. At that time a second-hand 2CV was more expensive than a new one because the buyer did not have to wait. Production was increased from 876 units in 1949 to 6,196 units in 1950. Grudging respect began to emanate from the international press: towards the end of 1951

In 1951 production reached over 100 cars a week.By the end of 1951 production totalled 16,288. Citroën introduced the 2CV Fourgonnette van. It pioneered the use of a large box rear section, as later used by the Morris Minor, Renault 4, Citroën Acadiane and Citroën C15 vans and copied in the 1990s by Vauxhall/Opel and Ford. The "Weekend" version of the van had collapsible, removable rear seating and rear side windows, enabling a tradesman to use it as a family vehicle at the weekend as well as for business in the week. This was the fore-runner of the Citroën Berlingo and Renault Kangoo people carriers introduced in the 1990s. A pick-up truck version was used by the British Royal Navy for pioneering Royal Marine helicopter carrier amphibious operations aboard HMS Bulwark and Albion in the late 1950s and early 1960s.

A special version of the 2CV was the Sahara, for difficult off-road driving. Built from December 1960 to 1971, The Sahara had an extra engine mounted in the rear compartment and both front and rear-wheel drive. Only 694 Saharas were built. The target markets for these cars were French oil companies, the military, and the police.

From the mid-1950s economy car competition had increased—internationally in the form of the 1957 Fiat 500 and 1955 Fiat 600, and 1959 Austin Mini. On the French home market there was a new small Simca 1000 using licensed Fiat technology, and the new front wheel drive and suspiciously Citroënesque Renault 4, that appeared to have been designed to a very similar, but more modern brief as the 2CV. It marked the beginning of Renault 1960s switch to front engine front wheel drive FF layout, from the rear engine rear wheel drive RR layout. It was the biggest threat to the 2CV, eventually outselling it.

In 1960 the 2CV was updated. In particular the corrugated Citroën H Van style "ripple bonnet" of convex swages was replaced (except for the Sahara), with one using six larger concave swages and looked similar until the end of production. Prior to this demand so outstripped supply that Citroën did not need to spend money on marketing, apart from a few dealer leaflets, at all. A new marketing effort was set up to seriously market the 2CV.The 1960s were the heyday of the 2CV, when production finally caught up with demand. In 1964 the fuel original dip stick/measuring rod, was replaced with a fuel gauge.

In 1967 Citroën launched a new model based on the 2CV chassis, with an updated but still utilitarian body, with a hatchback (a hatchback kit was available from citroen for the 2cv, and aftermarket kits are available) that boosted practicality: the Citroën Dyane. This was in response to the direct competition by the Renault 4, that had used so many stolen design ideas from the 2CV and Traction Avant that Citroën contemplated legal action at the time of its launch. (Similarly, Volkswagen had had to pay legal damages over the Beetle in the 1960s.) At the same time, Citroën developed the Méhari off-roader.

The purchase price of the 2CV was always very low. In Germany in the 1960s, for example, it cost about half as much as a Volkswagen Beetle.

From 1961, the car was offered, at extra cost, with the flat-2 engine size increased to 602 cc (36.7 cu in), although for many years the smaller 425 cc (25.9 cu in) engine  continued to be available in France and certain export markets where engine size was critical in determining car tax levels. In 1970 the car gained rear light units from the Citroën Ami 6, and also standardised a third side window in the rear pillar on 2CV6 (602 cc) models. All 2CVs from this date can run on unleaded fuel. 1970s cars featured rectangular headlights.

The highest annual production was in 1974. Sales of the 2CV were reinvigorated by the 1974 oil crisis. The 2CV after this time became as much a youth lifestyle statement as a basic functional form of transport. This renewed popularity was encouraged by the Citroën "Raid" intercontinental endurance rallies of the 1970s where customers could participate by buying a new 2CV, fitted with a ruggedising 'P.O.' kit (which stands for Pays d'Outre-mer - overseas countries),to cope with thousands of miles of very poor or off-road routes.

In September 1975, a base model called the 2CV Spécial was introduced. In order to keep the price as low as possible, Citroën removed the third side window, the ashtray, and virtually all trim from the car. For the first few years of production, the Spécial was only available in yellow.

Service INSTRUCTIONS:

• fuel: petrol, 80-85 Oct
• engine sump oil: 1.76 imp 2.1 US qt. 2 1, SAE 20 (winter) 30 (summer), change every 3100 miles, 5000 km,
• gearbox and final drive oil: 0.88 imp qt, 1.06 US qt, 1 1, SAE 80, change every 11200 miles, 18000 km
• greasing: every 900 miles, 1500 km, 4 points; tappet
• clearances: inlet 0.008 in, 0.20 mm, exhaust 0.008 in, 0.20 mm; valve timing (inlet) opens 30 before tdc and closes 450 after bdc, (exhaust) opens 450 before bdc and closes 110 after tdc; wre pressure (medium load): front 18 psi,

The 1981 James Bond movie For Your Eyes Only Citroën 2CV

In 1981 a bright yellow 2CV was driven by James Bond in the film For Your Eyes Only, including an elaborate set piece car chase through a Spanish olive farm, in which Bond uses the unique abilities of the modestly powered 2CV to escape his pursuers in Peugeot 504 sedans. The car in the film was fitted with the flat-4 engine from a Citroën GS for slightly more power.Citroën launched a special edition 2CV "007" to coincide with the 2CV product placement in the film, it was fitted with the standard flat-2 engine, painted in yellow with "007" on the front doors and fake bullet hole stickers. This car was also popular in miniature, from Corgi Toys.