Louis-Rene Panhard and Emile Levassor
Louis-Rene Panhard was born in Paris in 1841, and qualified there as an engineer. He then joined the Perin firm which specialised in making wood-working machinery, and after a while he encouraged them to diversify into metal working as well. In 1872, he was joined there by his friend and former fellow student Emile Levassor, three years his junior, when he acquired an interest in the firm which became Perin Panhard & Cie.
In 1886, Perin died, and the proprietorship passed into the hands of Panhard and Levassor. In that same year, a friend of the latter, Edouard Sarazin, acquired the Daimler patent rights for France - but the following year he died, and his widow later married Levassor.
The stage was now set for the two friends to enter the motorcar industry. They began by making a car with a V-twin Daimler engine carried amidships. It ran successfully in 1891, but the partners were not themselves convinced, and after trying rear-engined layouts they finally settled on one that was to become classical: they put the engine at the front with its crankshaft aligned longitudinally with the chassis, the gearbox in line behind it, and thence transmitted the drive to the rear wheels.
C'est Brutal, Mais ea Marche
Originally, the final drive was by a central chain, and the gearbox was not quite what we understand by the term because the gear wheels were actually exposed, not encased. Nevertheless, it was an archetypal gearbox as it had four forward speeds and a reverse, with an arrangement of main-shaft, lay-shaft and sliding gears. It was not so easily managed: the gear change lever worked through a quadrant, making it impossible to pass from one speed to any but the adjacent ratios, with an unpredictable neutral lurking somewhere between. It was a device of which Panhard himself said, 'C'est brutal, mais ea marche'.
In fact, the whole car was incredibly crude: the chassis frame was made of wood, armoured here and there with flitch plates, the tyres were solid, the 'radiator' or heat exchanger for the engine coolant was behind the engine itself, steering was by tiller, and engine ignition by hot-tube - although this last complaint should be levelled against Daimler, whose engines were employed under licence. By 1895, the Panhard had at least acquired a float-feed carburetor of Maybach type, in place of the earlier surface carburetor, but the car was still difficult to control.
With solid tyres doing nothing to mollify the ride, the springs had to be very flexible, explaining the choice of the full-elliptic variety; and in the absence of dampers they allowed the car to shake like a jelly, because of the vibrations coming from the unbalanced engine. Even the controls available to the driver were difficult and confusing: there were no fewer than three brakes, in addition to the sprag by which the car might be checked against running backwards downhill. First there was a footbrake working on the transmission, then a handbrake lever which, when pushed, tightened brake bands on the rear hubs and simultaneously disengaged the clutch; and finally a crank handle with a screw jack to force spoon brakes against the rear tyres.
The 1894 Paris to Rouen Trial
To make things even more difficult for the driver, the car was directionally unstable, the steering having no castor action nor any other kind of self-centring effect. Despite its utalitarian nature, a Panhard was awarded joint first place in the 1894 Paris to Rouen trial, tying with a Peugeot. In the following year the first 'real' motor race was held, over 732 miles from Paris to Bordeaux and back, and this was won by Levassor himself who drove his Panhard for 48 hours, 48 minutes to average 15 mph
It was not quite a standard production car: this was the year when enclosed gearboxes first appeared, and Levassor doubtless also made good use of the overrider which freed the engine from the restraints of the governor - a system of levers between the camshaft and the valve stem which gave an interrupter effect that normally limited the engine to 750 rpm, at which it delivered somewhat less than four horsepower. This interrupter gear could be adjusted, to alter the maximum engine speed, or entirely inhibited, in which case the crankshaft could spin up to its giddy maximum of 1250 rpm.
That year, 1895, also saw the first appearance of wheel steering as an alternative to the tiller, and of the 2.4-liter Daimler Phonix engine that was a twin-cylinder version of the original. The following year came a four-cylinder engine for the racers, to be made available in 1898 to the public - but by then Levassor was dead, as the result of an accident during the race from Paris to Marseille and back.
Still the improvements came: aluminum gearbox casings in 1897, pneumatic tyres in 1898, tubular radiators ahead of the engine in 1899 and, by 1900, the classic Panhard format was complete, with final drive by side chains, piano-type pedals and single-quadrant gear change in place of the double quadrant that had added to the complexities of the original cars.
Panhard's Racing Success in Decline
It was evidence of the improvement that was enforced and accelerated by participation in racing, for in the late 1890s the competition scene had been virtually stolen by Panhard. From 1895 to 1900 inclusive, the cars won 15 out of 22 races, the most successful rival being
Mors with a score of three.
However, when the 20th century began in 1901, the Panhard had passed its prime, and its subsequent decline was due to the firm's apparent inability to keep up with technical progress elsewhere. The 1901 Mercedes designed by Maybach for Daimler-Benz represented an enormous advance in broad concept and detail execution, and it was the cars built in its image - Fiat and Richard Brasier - which were in the ascendant in racing.
There were the occasional victories that still fell to Panhard, whose engines grew bigger and bigger in the effort to remain competitive. This led Panhard to just one more noteworthy innovation. The rules for the
Gordon Bennett races (the most important of the early years of the century prior to the inauguration of the Grand Prix in 1906) included a maximum weight prescription of 1000 kilogram’s; and if engines were to be as large as Panhard (and, to be fair, others) were making them, they needed to be built with a mind for weight saving.
It was Panhard who designed engines with forged-steel cylinder barrels and integral heads, each cylinder being bolted separately to the upper deck of the crankcase, with inlet and exhaust ports and sparking-plug bosses welded onto the head of each cylinder and a thin copper water jacket neatly tailored to fit round the cylinder.
Paul and Hippolyte Panhard
It was this constructional principle that was adopted for a number of aero-engines in the ensuing years, and was also taken up by Mercedes for the engines of their racing cars - to such good purpose that Daimler-Benz only abandoned the technique when producing a sports-racing version of their 1955 Grand Prix car. In everything else, Panhard remained doggedly conservative, and the touring cars suffered just as much as the racers.
However, shortly before he died in 1908, Louis-Rene Panhard retired from the business and handed over its control to his sons Paul and Hippolyte; and it is surely significant that within a year the old wooden chassis frame began to be replaced by pressed-steel frames, that a new mono bloc 2.4-liter engine had high-tension magneto ignition, and that by 1910 the quadrant gearchange had been ousted by a gate type such as Mercedes had introduced nine years earlier.
1911 marked an even more significant departure from the firm's previous practice: not only was it the last year in which the two-cylinder engines were made, it was one id which the first production Panhard with a sleeve-valve engine was introduced. The sleeve-valve system chosen was that patented by Knight, and later developed not only by Panhard but also by Daimler,
Minerva,
Willys and others.
Each cylinder carried a detachable head deeply spigoted into the barrel, the spigot having a circumferential clearance into which the top ends of the two concentric valve sleeves could poke when at the tops of their strokes. Each of the sleeves was reciprocated by a small connecting rod from an auxiliary crankshaft rotating at half engine speed, The crank throws were spaced so that the two sleeves were out of phase by 160°, and with the intake port just below the cylinder-head insert on one side of the engine, and the exhaust port almost exactly opposite it, the motions of the sleeves uncovered each port in due turn.
The Knight engine
For relatively large displacement engines run at modest crankshaft rates, this double-sleeve valve gear was very suitable. The performance it yielded was not particularly high, the port sizes being somewhat restricted by the limitations on sleeve movement, but the mechanism was much quieter in operation than poppet valves. Lubrication of the sleeves did present difficulties, which were kept at bay by limiting the engine's operating speeds, but for touring cars of generous engine size such as the range upon which Panhard now embarked, the sleeve-valve engine had a great deal to commend it.
When they resumed normal business in 1919, after the intervention of World War 1, Panhard did make some poppet-valved cars, but it was a brief production, finished in 1922. Their main programme was built around the Knight engine, and by the middle 1920s they had improved its performance considerably by the introduction of light steel sleeves in place of cast iron, enabling a longer sleeve travel to be exploited, the outer sleeve being lined with white bearing metal on its inner surface to minimise frictional losses and the danger of seizure.
Thereafter, the larger versions of the Panhard could be impressively fast, even though they trailed an oppressive cloud of oil smoke in their wake when driven hard. By 1924, when all models had front-wheel brakes, dynamotor starters, and four-speed gearboxes, the 4.8-liter, four-cylinder Panhard needed little modification before taking the world hour record at 115.3 mph in 1925.
Enlarged to 5·3 liters in 1929, the standard car could then exceed 90 mph. A six-cylinder series was begun in 1927, followed shortly by a massive and refined straight-eight, with centralised chassis lubrication, coil ignition and an all-helical constant-mesh gearbox. But not all the cars were big and fast, but they were all smooth and impressive, many of them carrying bodywork of considerable charm and sometimes elegance. The best were very expensive, costing more than the most luxurious Renault of the day, which was no mean car itself in any sense.
The Panhard Dynamic
Modern design features continued to be introduced, but seldom with such startling effect as was achieved in 1937 when a model known as the Dynamic was introduced. As ever, it had a sleeve-valve engine, a six-cylinder affair in sizes ranging from 2.5 to 3.8 liters. However, with its hydraulic brakes, backbone chassis, worm-gear final drive, and all-round independent suspension by torsion bars, it was almost aggressively up to date in its chassis.
As far as the body was concerned, it was more than up to date, it was positively futuristic: the driver sat in the centre, the headlamps were faired in, all four wheels were largely enclosed by deep spats or valances on the mudguards, there were wraparound extensions to the windscreen, triple windscreen wipers, and some extremely bizarre styling. It is possible that the car might eventually have been successful, particularly after its constructors relented and put the driver on the left again in 1939, but war came and such questions had to be left open.
The Post-War Dyna Series
When the war was over, the needs of motorists in general and the French in particular were very different; so were the cars that Panhard set itself to produce in 1945. This marked the beginning of the Dyna series, cars based on a design by the distinguished front-wheel-drive exponent, J. A. Gregoire who had been associated in pre-war days with the Tracta.
One of his last pre-war designs had been for Hotchkiss, a car known as the
Amilcar Compound, with a small four-cylinder engine driving the front wheels, independent suspension all round and a unit construction of body and chassis that was based before integration on a substantial frame and bulkhead structure in aluminum alloy. For his post-war car, Gregoire still concentrated on light weight and independent suspension, still with an aluminum-alloy frame and bulkhead structure, but now with a 600cc horizontally opposed twin-cylinder engine, air cooled and furnished with overhead valves, capable of a modest 15 bhp and enough to give so light a car tolerable performance.
The Kendall and Harknett
Plans had been made to produce the car in England as the Kendall, and here in Australia as the Harknett, but it was Panhard who took it on and developed it. As amended, it had a live rear axle and a four-speed gearbox with an overdrive top, but in general it was entirely in the spirit of the original Gregoire design, with light-alloy bodywork and a commendably high ratio of cabin to overall length.
Many of its detail features were to be emulated by others, an example being the wheels which were little more than light-alloy rims bolted to the brake drums. This original car was soon followed by a 750cc version developing 32 horsepower, and by 1952 there was an 850cc version as well.
Then in 1954 the Dyna became a front-wheel-drive car, with an entirely new body design that many people thought ugly and bulbous but many others recognised as streamlined and capacious and therefore efficient. It was still a light-alloy car in the main, although notable in that no castings were used in the body.
It could carry six people at 80 mph, it could average 40 mpg and it was so effective a car that sales doubled, to reach 30,000 in 1957. One of the least apparent of its features (or perhaps one of the least visible, but evident enough by its noise) was the engine, a beautifully designed flat-twin unusual in almost every detail.
The Unusual but Brilliant Flat Twin Engine
The cylinders were cast integral with their heads in substantial light alloy with shallow fins, cast-iron liners being pressed into the bores to accommodate 85 mm pistons of 75 mm stroke, giving a swept volume of 850cc. The high-domed pistons reciprocated on connecting rods with roller-bearing big ends on a built-up crankshaft, beneath which was a single camshaft communicating with the overhead valves by pushrods and roller-ended tappets.
The valves were inclined in hemispherical cylinder heads, but the rest of the valve gear was most unusual and extremely impressive. Instead of conventional coil springs, there were torsion bars to return the valves to their seats: separate forked rockers engaged under the valve-stem collars, pivoted on roller bearings coaxial with a pair of torsion bars. The valve could thus be shorter by a spring length and correspondingly lighter than in conventional designs.
The pivot for the rocker which pushed it open was interesting, too, being a spherical bearing that could be moved up and down a threaded pillar to adjust the valve clearance. Later versions were even more refined, the bearing being automatically positioned by oil pressure to give all the virtues of hydraulic zero-lash tappets without the surge, lubrication and corrosion problems endemic in them.
It was a powerful engine: in its milder form it gave 50 bhp at 5750 rpm, but for the very smartly bodied Tigre of 1961 it gave 60 bhp, and even more in the 24 CT and CD sports coupes which were introduced in 1964 and could exceed 100 mph.
The Tigre Panhard
The Tigre could do over 90, but the 24 CT was more compact and therefore very much more sporting. It was also not a little intimidating: car reviewers of the time described the gear change as feeling akin to a stick in the mud, and the handling displayed typical front-wheel-drive characteristics magnified almost to the point of absurdity, with very sharp reactions to variations of throttle in mid-corner. Nevertheless, the basic Dyna Panhard had the makings of a thoroughly effective ultra-light sports-racing car, and many were the specialist designs prepared on the basis of Panhard mechanical elements.
Deutsch and Bonnet started as early as 1948, Veritas in 1950, and the very special Monopole Panhard with extravagantly streamlined bodywork won the index of performance at Le Mans three years running, from 1950 onwards. Similar streamliners succeeded there in 1953 and again in 1963 - and in between there were rally successes which included a class win in the 1954 Monte Carlo event and an outright win in 1961.
In that year, the regulations had been modified to give smaller-engined cars a chance and, whether by accident or design, the regulations favored what Panhard had available far more than anything else on the market. The win was therefore dismissed as a matter for controversy, but it cannot be denied that the little Panhard was a very effective car on most kinds of roads, and its outstanding efficiency deserved recognition.
Alas, a new ban on cars of less than 1-Iitre capacity at Le Mans was a bitter blow and, although Deutsch tried to get round this by supercharging the engine (which according to the rules was equivalent to doubling the cylinder displacement) in 1964, the experiment was a failure because the cars retired.
They were interesting development machines, with five-speed gearboxes, Girling disc brakes and 70 bhp at their disposal; but the development programme was doomed not to be pursued. In 1965, the Panhard Company was finally integrated with, or swallowed by,
Citroen which had acquired an interest in Panhard ten years earlier. In 1967, only the coupe versions of the Dyna were made, the 24 CT having disc brakes on all wheels as a memento of that last Le Mans effort, but Citroen needed the factory space, and there were no more.
