Front-engine, rear-wheel-drive layout
In automotive design, an FR, or front-engine, rear-wheel-drive layout is one where the engine is located at the front of the vehicle and driven wheels are located at the rear. This was the traditional automobile layout for most of the 20th century. Modern designs use the front-engine, front-wheel-drive layout. In automotive design, a front mid-engine, rear-wheel-drive layout is one that places the engine in the front, with the rear wheels of vehicle being driven. In contrast to the front-engine, rear-wheel-drive layout, the engine is pushed back far enough that its center of mass is to the rear of the front axle; this aids in weight distribution and reduces the moment of inertia, improving the vehicle's handling. The mechanical layout of an FMR is the same as an FR car; some models of the same vehicle can be classified as either FR or FMR depending on the length of the installed engine and its centre of mass in relation to the front axle. FMR cars are characterized by a long hood and front wheels that are pushed forward to the corners of the vehicle, close to the front bumper.
Grand tourers have FMR layouts, as a rear engine would not leave much space for the rear seats. FMR should not be confused with a "front midships" location of the engine, referring to the engine being located behind the front axle centerline, in which case a car meeting the above FMR center of mass definition could be classified as a FR layout instead; the v35 Nissan Skyline / Infiniti G35 / Nissan 350Z are FM cars. FMR layout came standard in most pre–World War II, front-engine / rear-wheel-drive cars
1949 24 Hours of Le Mans
The 1949 24 Hours of Le Mans was the 17th Grand Prix of Endurance, took place on 25 and 26 June 1949. Luigi Chinetti won the race for a third time in the first Ferrari barchetta by driving 22.5 hours. This race saw the death of British driver Pierre Maréchal when his Aston Martin DB2 was involved in an accident between Arnage and Maison Blanche around 1:00 a.m. Marechal had attempted to pass another car there and he hit an embankment and the hapless Briton was crushed by the overturning car; this was the first race held at the circuit following the end of World War II. Though the war had ended four years prior, major infrastructure reconstruction throughout France meant that the return of the race was of secondary concern, thus was not run until after France had established itself again. Following the end of the war the circuit needed extensive repairs. During the war the RAF the Luftwaffe, had used the airfield by the pits, as well as the 5 km Hunaudières straight as a temporary airstrip. So it was four years before the Automobile Club de l'Ouest was in a position to revive the great race.
Assisted with money from the government, the pits and grandstand had been rebuilt, a new 1000-seat restaurant and administration centre built and the whole track was resurfaced. However one section of the hinterland was still off-limits as it had not yet been cleared of landmines. In that time the car manufacturers had been rebuilding, but still, most of the entry list for this year's race was from cars built before the war. The ACO put preference to those entered in the 1939, race for the Biennial Cup. So there were twelve cars from that race back for the Cup. Otherwise, there were fourteen entries from manufacturers - although "works" entries many were one-car small companies; the regulations used by the ACO were based on those of the new FIA, created in 1946. There were ten classes, based on engine size, at least ten cars had to have been produced before the entry was submitted. Supercharged engines’ equivalence was calculated at 2:1 for engine capacity. However, for this new start, sportscar prototypes were now given admission for the first time, "as an exceptional measure to contribute towards a faster revival of automobile manufacture" by the French Service des Mines, or its foreign equivalent That was, in a sense, just formalising an unofficial practice started in the 1930s, when race-specific cars were entered at Le Mans and other races for the win with no intentions of going into full production.
The ACO reserved the right to disqualify a car not entered'in the spirit of the regulations'. In days of petrol rationing, there was considerable interest in the Index of Performance - the measure of cars making an improvement on its nominal assigned distance, based on engine size. Entrants had to choose to run on either diesel or `' ternary" fuel. All fuel was supplied by the ACO. Fuel and water could only be topped up after 25 laps had been run, ACO inspectors sealed the radiator and oil-caps after each refill. A spare wheel, fire extinguisher and toolkit had to be carried in the car and on-circuit repairs could only be done by the driver, with the onboard tools. Night-time was defined as being between 4.30 am. There was the Hors Course rule, whereby after 12 hours, any car that had not completed 80% of its corresponding Performance Index distance was disqualified; the car had to be running to take the chequered flag with a final lap taking no longer than 30 minutes. Prizemoney still overwhelmingly favoured the Index of Performance, awarding FF1,000,000 to that competition's winner, whereas only 10% of that - FF100,000 was awarded to the winners on overall distance and of the Biennial Cup.
FF10,000 was awarded to the leader at the end of each hour, increasing to FF25,000 at the 6-hour mark, FF50,000 at 12-hours, FF100,000 at 18-hours and FF200,000 at the 24th hour. So a car leading start-to-finish would still only reap FF675,000 compared to the Index of Performance. There was a FF50,000 prize with the Coupe des Dames for the top female driver. From a staggering initial list of over a hundred prospective entries, the ACO trimmed the field down to 49 starters. There were 18 cars in the S3000 and S5000 categories - 3 British cars; these included 3 Talbots, 7 Delahayes, 4 Delages and a Delettrez, driven by its constructor brothers – the first diesel-engined car to compete at Le Mans, using an engine from an American Army GMC truck. The Talbot-Lagos included the two biggest cars in the field: a new SS saloon for André Chambas’ Ecurie Verte team, a 2-seater sportscar modified from the current T26 grand-prix car for Paul Vallée's works-supported Ecurie France team. Both used the new 4.5 L straight-6 engine.
The third Talbot was a modified pre-war T150C raced by the capable father-and-son Rosier team. Most French hopes rested on the Delahayes: there were two new 4.5L 175 S raced by Parisian car-dealer Charles Pozzi, as well as five entered pre-war type 135 CS, running the smaller 3.6-litre 160 bhp engine. Delage was represented by four D6S cars, all entered. Built just after war's end in the Delahaye factory, but based on a pre-war chassis and the old 3.0-litre, 145 bhp engine The three British cars were a 2.4L Healey Elliott saloon driven to and from the race from England, a unique 1938 Bentley sedan designed for the Greek tycoon Nico Embiricos, a brand-new Asto
In both road and rail vehicles, the wheelbase is the distance between the centers of the front and rear wheels. For road vehicles with more than two axles, the wheelbase is the distance between the steering axle and the centerpoint of the driving axle group. In the case of a tri-axle truck, the wheelbase would be the distance between the steering axle and a point midway between the two rear axles; the wheelbase of a vehicle equals the distance between its rear wheels. At equilibrium, the total torque of the forces acting on a vehicle is zero. Therefore, the wheelbase is related to the force on each pair of tires by the following formula: F f = d r L m g F r = d f L m g where F f is the force on the front tires, F r is the force on the rear tires, L is the wheelbase, d r is the distance from the center of mass to the rear wheels, d f is the distance from the center of gravity to the front wheels, m is the mass of the vehicle, g is the gravity constant. So, for example, when a truck is loaded, its center of gravity shifts rearward and the force on the rear tires increases.
The vehicle will ride lower. The amount the vehicle sinks will depend on counter acting forces, like the size of the tires, tire pressure, the spring rate of the suspension. If the vehicle is accelerating or decelerating, extra torque is placed on the rear or front tire respectively; the equation relating the wheelbase, height above the ground of the CM, the force on each pair of tires becomes: F f = d r L m g − h c m L m a F r = d f L m g + h c m L m a where F f is the force on the front tires, F r is the force on the rear tires, d r is the distance from the CM to the rear wheels, d f is the distance from the CM to the front wheels, L is the wheelbase, m is the mass of the vehicle, g is the acceleration of gravity, h c m is the height of the CM above the ground, a is the acceleration. So, as is common experience, when the vehicle accelerates, the rear sinks and the front rises depending on the suspension; when braking the front noses down and the rear rises.:Because of the effect the wheelbase has on the weight distribution of the vehicle, wheelbase dimensions are crucial to the balance and steering.
For example, a car with a much greater weight load on the rear tends to understeer due to the lack of the load on the front tires and therefore the grip from them. This is why it is crucial, when towing a single-axle caravan, to distribute the caravan's weight so that down-thrust on the tow-hook is about 100 pounds force. A car may oversteer or "spin out" if there is too much force on the front tires and not enough on the rear tires; when turning there is lateral torque placed upon the tires which imparts a turning force that depends upon the length of the tire distances from the CM. Thus, in a car with a short wheelbase, the short lever arm from the CM to the rear wheel will result in a greater lateral force on the rear tire which means greater acceleration and less time for the driver to adjust and prevent a spin out or worse. Wheelbases provide the basis for one of the most common vehicle size class systems; some luxury vehicles are offered with long-wheelbase variants to increase the spaciousness and therefore the luxury of the vehicle.
This practice can be found on full-size cars like the Mercedes-Benz S-Class, but ultra-luxury vehicles such as the Rolls-Royce Phantom and large family cars like the Rover 75 came with'limousine' versions. Prime Minister of the United Kingdom Tony Blair was given a long-wheelbase version of the Rover 75 for official use, and some SUVs like the VW Tiguan and Jeep Wrangler come in LWB models In contrast, coupé varieties of some vehicles such as the Honda Accord are built on shorter wheelbases than the sedans they are derived from. The wheelbase on many commercially available bicycles and motorcycles is so short, relative to the height of their centers of mass, that they are able to perform stoppies and wheelies. In skateboarding the word'wheelbase' is used for the distance between the two inner pairs of mounting holes on the deck; this is different from the distance between the rotational centers
Aston Martin 2-Litre Sports
The Aston Martin 2-Litre Sports was a sports car sold by Aston Martin from 1948 to 1950. It was the first product of the company under new owner, David Brown, is retrospectively known as the DB1; the car was based on the Aston Martin Atom prototype. Just 15 were sold; the Atom was an Aston Martin project developed during World War II. Its tube-frame chassis and 2.0 L four-cylinder engine were developed by Claude Hill. Shortly after David Brown purchased Aston Martin, construction began on an updated version; this prototype was entered at the 24 Hours race at Spa in 1948 as a way of testing its durability, the car won the race outright with drivers St. John Horsfall and Leslie Johnson; the Spa car was rebuilt and shown at the London Motor Show as an example of a new "Spa Replica" series for public sale, but there were no takers. The single Spa car has been until kept in the Dutch Motor Museum. In 2006 it returned to the UK and has been restored. Along with the cycle-wing Spa car, Brown directed Aston to build a 2-seat roadster with a more conventional body for the London show.
This 2-Litre Sports, as the name suggested, used the 2.0 L Claude Hill engine. This 90 hp unit could propel the light vehicle to 93 mph. 13 of the cars wore an open roadster body, as shown in London, complete with a 3-part grille suggesting the Aston Martin design. One unusual feature of these cars was the compartment in one front wing for the spare wheel. One more 2-Litre car was shipped as a chassis for custom coachwork. After the 1950 introduction of the replacement DB2, with the W. O. Bentley designed Lagonda straight-6 engine, the 2-Litre Sports became known as the DB1. At this point only 12 had been produced, however since the DB2 was a hardtop and a customer wanted a softtop, chassis numbers 13,14 and 15 were produced to special order. "Aston Martin Two Litre Sports". AstonMartins.com. Retrieved 23 June 2005
Overhead valve engine
An overhead valve engine, or "pushrod engine", is a reciprocating piston engine whose poppet valves are sited in the cylinder head. An OHV engine's valvetrain operates its valves via a camshaft within the cylinder block, cam followers and rocker arms; the OHV engine was an advance over the older flathead engine, whose valves were sited within the cylinder block. Some early "OHV" engines known as "F-heads" used both side-valves and overhead valves. A variation over the OHV design is the overhead camshaft, or "OHC", whose camshaft lies in the cylinder head itself, above the valves. To avoid confusion, OHC engines are not referred to as OHV despite having their valves in the head. In early 1894, Rudolf Diesel's second Diesel engine prototype was built with a cylinder head featuring push rods, rocker arms, poppet valves. Diesel had published this design in 1893. In 1896, U. S. patent 563,140, awarded to William F. Davis, illustrated a gasoline engine with the same head configuration, patenting his solution to the problem of how to cool the head, which problem had made the overhead valve engine difficult before then.
Henry Ford's Quadricycle of 1896 had valves in the head, with push rods for exhaust valves only, the intake using suction valves. In 1898, Detroit bicycle manufacturer Walter Lorenzo Marr built a motor-trike with a one-cylinder OHV engine with push rods for both exhaust and intake. In 1900, David Buick hired Marr as chief engineer at the Buick Auto-Vim and Power Company in Detroit, where he worked until 1902. Marr's engine employed pushrod-actuated rocker arms, which in turn pushed valves parallel to the pistons. Marr left Buick to start his own automobile company in 1902, the Marr Auto-Car, made a handful of cars with overhead valve engines, before coming back to Buick in 1904; the OHV engine was patented in 1902 by Buick's second chief engineer Eugene Richard, at the Buick Manufacturing Company, precursor to the Buick Motor Company. The world's first production overhead valve internal combustion engine was put into the first production Buick automobile, the 1904 Model B, which used a 2-cylinder Flat twin engine, with 2 valves in each head.
The engine was designed by David Buick. Eugene Richard of the Buick Manufacturing Company was awarded US Patent #771,095 in 1904 for the valve in head engine, it included rocker arms and push rods, a water jacket for the head which communicated with the one in the cylinder block, lifters pushed by a camshaft with a 2-to-1 gearing ratio to the crankshaft. Arthur Chevrolet was awarded US Patent #1,744,526 for an adapter that could be applied to an existing engine, thus transforming it into an Overhead Valve Engine; the Wright Brothers built their own airplane engines, starting in 1906, they used overhead valves for both exhaust and intake, with push rods and rocker arms for the exhaust valves only, the intake valves being "automatic suction" valves. They built a V-8 engine with this valve configuration in 1910. In 1949, Oldsmobile introduced the Rocket V8, the first V-8 engine with OHV's to be produced on a wide scale. General Motors is the world's largest pushrod engine producer, producing I4, V6 and V8 pushrod engines.
Most other companies use overhead cams. Nowadays, automotive use of side-valves has disappeared, valves are all "overhead". However, most are now driven more directly by the overhead camshaft system. Few pushrod-type engines remain in production outside of the United States market; this is in part a result of some countries passing laws to tax engines based on displacement, because displacement is somewhat related to the emissions and fuel efficiency of an automobile. This has given OHC engines a regulatory advantage in those countries, which resulted in few manufacturers wanting to design both OHV and OHC engines. However, in 2002, Chrysler introduced a new pushrod engine: a 5.7-litre Hemi engine. The new Chrysler Hemi engine presents advanced features such as variable displacement technology and has been a popular option with buyers; the Hemi was on the Ward's 10 Best Engines list for 2003 through 2007. Chrysler produced the world's first production variable-valve OHV engine with independent intake and exhaust phasing.
The system is called CamInCam, was first used in the 600 horsepower SRT-10 engine for the 2008 Dodge Viper. Early air-cooled ohv BMW boxer motorcycle engines had long pushrods and a single centrally-mounted camshaft; the pushrods were short, allowing higher rpm and more power. For instance, the BMW R1100S could achieve an output of 98 hp at 8,400 rpm, with no risk of valve bounce. Since 2013, BMW flat-twin motorcycle engines have had OHC valve actuation. OHV engines have some advantages over OHC engines: Smaller overall packaging: because of the camshaft's location inside the engine block, OHV engines are more compact than an overhead cam engine of comparable displacement. For example, Ford's 4.6 L OHC modular V8 is larger than the 5.0 L I-head Windsor V8. GM's 4.6 L OHC Northstar V8 is taller and wider than GM's larger displacement 5.7 to 7.0 L I-head LS V8. The Ford Ka uses the Kent Crossflow/Endura-E OHV engine to fit under its low bonnet line; because of the more compact size of an engine of a given displacement, a pushrod engine of given external dimensions can have greater displacement than an OHC engine of the same external size.
As a result, the pushrod engine can sometimes produce just as much power as the OHC engine, but with greater torque (contrary to popular belief, this is due to the greater displacement of
Spa 24 Hours
The Total 24 Hours of Spa is an endurance racing event for cars held annually in Belgium since 1923 at the Circuit de Spa-Francorchamps. It is sponsored by Total S. A.. The Spa 24 Hours was conceived by Jules de Their and Henri Langlois Van Ophem just one year after the inaugural 24 Hours of Le Mans was run, it debuted in 1924 over a 15 kilometres circuit on public roads between the towns of Francorchamps and Stavelot, under the auspices of the Royal Automobile Club Belgium. The present 7.004 kilometres circuit was inaugurated in 1979. The Spa 24 Hours was part of the European Touring Car Championship from 1966 to 1973, again in 1976 and from 1982 to 1988; the event counted towards the World Sportscar Championship in 1953 and the World Endurance Championship in 1981. As on the Nürburgring, both a 24h and a 1000 km race is held at Spa, as the 1000 km Spa for sports car racing were introduced in 1966. Cars entered have spanned from the Russian Moskvitch and models with sub-1 liter engines such as the NSU Prinz TT to the luxurious V8-powered Mercedes-Benz 300 SEL 6.3.
Tuned by Mercedes-AMG, the 6834 cc and 420 hp so-called "Red pig" finished as high as second in 1971. With the participation of Swiss Lilian Bryner on the victorious Ferrari 550 of the BMS Scuderia Italia team, the 2004 race marked the first time in history that a female driver was part of the winning team of a 24-hour endurance race in a Gran Turismo with more than 500 hp; the best manufacturer wins the Coupe du Roi, not the race winners. The cup is won by the manufacturer with the most points, accrued by cars that are made by the same manufacturer. For example, Australian car manufacturer Holden won the Coupe du Roi in 1986 despite their cars finishing the race in 18th, 22nd and 23rd positions outright; the current version of the Spa 24 Hours is an event under the Blancpain Endurance Series calendar, although it was run as part of the FIA GT Championship featuring GT1 and GT2 machinery, by various touring car series. The cars run fall under the FIA GT3 and GT3 Cup classifications. Motorcycle endurance racing series.
Total Spa 24 Hours website: Available in English and Dutch 1971 results 1972 results 1981 results FIA GT Website
W. O. Bentley
Walter Owen Bentley, MBE was an English engineer who designed engines for cars and aircraft, raced cars and motorcycles, founded Bentley Motors Limited in Cricklewood near London. He was known as "W. O." without any need to add the word Bentley. Bentley, born in Hampstead, was the youngest of his Adelaide-born parents’ nine children, his father was retired businessman Alfred Bentley, mother was Emily, née Waterhouse. As the son of a prosperous family he was educated at Clifton College in Bristol from 1902 until 1905, when at the age of 16 he left to start work as an apprentice engineer with the Great Northern Railway at Doncaster in Yorkshire; the premium five-year apprenticeship with Great Northern, which cost his father £75, taught W. O. to design complex railway machinery and gave him practical experience in the technical procedures to cast and build it. He recalled: "The sight of one of Patrick Stirling's eight-foot singles could move me profoundly." While with Great Northern, he came close to realizing his childhood ambition to drive one of their Atlantic express locomotives, when at the end of his apprenticeship he acquired footplate experience as a second fireman on main-line expresses.
"My longest day,” he said, “was London to Leeds and back, on the return journey doing Wakefield to King's Cross non-stop for 175 miles. This was a total day's run of 400 miles, entailing a consumption of about seven tons of coal, every pound of it to be shovelled. Not a bad day's exercise." He completed his apprenticeship in the summer of 1910 but decided that the railways did not offer him enough scope for a satisfying career. In 1909 and 1910 Bentley raced Quadrant and Indian motorcycles, he competed in two Isle of Man Tourist Trophy races, on a Rex in 1909 and as a member of Indian's factory team in 1910. He did not finish in either event, he was fascinated by the cabbies' ingenuity at fiddling the meters. In 1912 he joined his brother, H. M. Bentley, in a company called "Bentley and Bentley" that sold French DFP cars. Dissatisfied with the performance of the DFPs, yet convinced that success in competition was the best marketing for them, W. O. was inspired by a paperweight to have pistons made for the engine in aluminium alloy.
Fitted with the alloy pistons and a modified camshaft, a DFP took several records at Brooklands in 1913 and 1914. At the outbreak of war Bentley knew that using aluminium alloy pistons in military applications would benefit the national interest: they improved power output and ran cooler, allowing higher compression ratios and higher engine speeds; as security considerations prevented his broadcasting the information to engine manufacturers, he contacted the official liaison between the manufacturers and the Navy. That man, Commander Wilfred Briggs, would be his senior officer throughout the war. Commissioned in the Royal Naval Air Service, Bentley was sent to share with the manufacturers the knowledge and experience he had gained from the modifications to the engines of the DFP cars he sold in Britain. Following his first consultation, with the future Lord Hives at Rolls-Royce, the company’s first aero engine, named the Eagle, was designed with pistons of aluminium instead of cast-iron or steel.
Bentley next visited Louis Coatalen at Sunbeam, with the result that the same innovation was used in all their aero engines. Bentley visited Gwynnes, whose Chiswick factory made French Clerget engines under licence, he liaised between the squadrons in France and the Chiswick factory's engineering staff; when the Clerget licensees proved unwilling to implement Bentley’s more important suggestions the Navy gave him a team to design his own aero engine at the Humber factory in Coventry. Designated the BR1, Bentley Rotary 1, the engine was fundamentally different from the Clerget except in the design of the cam mechanism, retained to facilitate production. A prototype was running in the early summer of 1916; the bigger BR2 followed in early 1918. In recognition, Bentley was awarded the MBE. After he was invited In 1920 to make a claim, which the Clerget licensees contested unsuccessfully, the Royal Commission on Awards to Inventors awarded him £8,000. After the war, in early 1919, W. O. and his brother founded Bentley Motors Limited.
They formed a group at small premises in Cricklewood to turn his aero engines business into one of car production. In a group that included Frank Burgess and Harry Varley, they set about designing a high quality sporting tourer for production under the name Bentley Motors. Clive Gallop joined the team as an engine designer to help develop their 3,000 cubic centimetres straight-4 engine; the 3-litre engine ran for the first time in Baker Street, London. A plaque marks the building in what is now Chagford Street NW1. W. O.’s first complete Bentley 3 Litre car began road tests in January 1920 and the first production version, made in Cricklewood, was delivered in September 1921. Its durability earned widespread acclaim. W. O.’s motto was "To build a good car, a fast car, the best in class." His cars raced in hill climbs and at Brooklands, the lone 3 Litre entered by the company in the 1922 Indianapolis 500 mile race and driven by Douglas Hawkes finished thirteenth at an average speed of 74.95 mph. Bentley entered a team of his new 3-litre modified and race-prepared cars in the 1922 Tourist Trophy driving himself in Bentley III.