A valve train or valvetrain is a mechanical system that controls operation of the valves in an internal combustion engine, in which a sequence of components transmits motion throughout the assembly. A traditional reciprocating internal combustion engine uses valves to control air and fuel flow into and out of the cylinders, the valve train consists of valves, rocker arms, pushrods and camshaft. Valve train opening/closing and duration, as well as the geometry of the train, controls the amount of air. Timing for open/close/duration is controlled by the camshaft that is synchronized to the crankshaft by a chain, camless This layout uses no camshafts at all. Technologies such as solenoids are used to actuate the valves. The valve train is the system responsible for operation of the valves. Valves are usually of the type, although many others have been developed such as sleeve, slide. Poppet valves typically require small coil springs, appropriately named valve springs and they are attached to the valve stem ends, seating within spring retainers.
Depending on the used, the valves are actuated directly by a rocker arm, finger. Overhead camshaft engines use fingers or bucket tappets, upon which the cam lobes contact, rocker arms are actuated by a pushrod, and pivot on a shaft or individual ball studs in order to actuate the valves. Pushrods are long, slender metal rods seated within the engine block, at the bottom ends the pushrods are fitted with lifters, either solid or hydraulic, upon which the camshaft, located within the cylinder block, makes contact. The camshaft pushes on the lifter, which pushes on the pushrod, which pushes on the rocker arm, camshafts must actuate the valves at the appropriate time in the combustion cycle. In order to accomplish this the camshaft is linked to and kept in synchronisation with the crankshaft through the use of a chain, rubber belt. Because these mechanisms are essential to the timing of valve actuation they are named timing chains, timing belts. Typical normal-service engine valve-train components may be too lightweight for operating at high revolutions per minute, valve float will damage the valvetrain over time, and could cause the valve to be damaged as it is still partially open while the piston comes to the top of its stroke.
Upgrading to high pressure valve springs could allow higher valvetrain speeds, high-output and engines used in competition feature camshafts and valvetrain components that are designed to withstand higher RPM ranges. These changes include additional modifications such as larger-sized valves combined with freer breathing intake, automakers offer factory-approved performance parts to increase engine output, and numerous aftermarket parts vendors specialize in valvetrain modifications for various engine applications
Weber is an Italian company which produced carburetors, it is owned by Magneti Marelli Powertrain S. p. A. which is in turn part of the Fiat Group. Carburetor production in Italy ended in 1992, although Weber carburetor production was shifted to Madrid, edoardo Weber began his automotive career working for Fiat, first at their Turin plant and at a dealership in Bologna. After the war, with prices high, he reached a certain success in selling conversion kits for running trucks on kerosene instead. The company was established as Fabbrica Italiana Carburatori Weber in 1923 when Weber produced carburetors as part of a kit for Fiats. Weber pioneered the use of two-stage twin barrel carburetors, with two venturis of different sizes, the one for low speed running and the larger one optimised for high speed use. In the 1930s Weber began producing twin-barrel carburetors for motor racing where two barrels of the size were used. These were arranged so that each cylinder of the engine has its own carburetor barrel and these carburetors found use in Maserati and Alfa Romeo racing cars.
Twin updraught Webers fed superchargers on the 1938 Alfa Romeo 8C competition vehicles, after Webers death in 1945, Fiat finally assumed control of the company in 1952. In 1986, Fiat took control of Webers competitor Solex and this was reorganized as Magneti Marelli Powertrain S. p. A. in 2001. Genuine Weber carburetors were produced in Bologna, Italy up until 1992, when production was transferred to Madrid, Weber Carburetors are sold for both street and off-road use, with the twin choke sidedraught DCOE being the most common one. They are sold in what is referred to as a Weber Conversion kit, in modern times, fuel injection has replaced carburetors in both production cars and most modern motor racing, although Weber carburetors are still used extensively in classic and historic racing. They are supplied as high quality replacements for problematic OEM carburetors, Weber fuel system components are distributed by Magneti Marelli, Webcon UK Ltd. and, in North America, by several organizations, including Worldpac, marketing under the Redline name.
Other suppliers include Overseas Distributing and Pierce Manifolds, Weber carburetors are marked with a model code on the mounting flange, the body, or on the cover of the float-chamber. This begins with a number which originally indicated the diameter of the throttle bore, after the letters there will be a further number, which may be followed by a letter, e. g. 4B, 13A, these indicate the series. The full designation might be 40 DCOE29,45 DCOE9, etc
Maserati 4CL and 4CLT
The Maserati 4CL and its derived sister model the Maserati 4CLT are single-seat racing cars that were designed and built by Maserati. The 4CL was introduced at the beginning of the 1939 season, as a rival to the Alfa Romeo 158, although racing ceased during World War II, the 4CL was one of the front running models at the resumption of racing in the late 1940s. Experiments with two-stage supercharging and tubular chassis construction eventually led to the introduction of the revised 4CLT model in 1948. The 4CLT was steadily upgraded and updated over the two years, resulting in the ultimate 4CLT/50 model, introduced for the inaugural year of the Formula One World Championship in 1950. Following customary Maserati practice, the engine was mounted into a design almost identical to that of the 4CLs predecessor. Although near-identical in its wheelbase, the 4CLs track was a full 5 cm wider than the 6CM, enveloping this rather conservative chassis was a low, curvaceous alloy-panel body, built in-house by Maserati.
Maserati built a version of the 4CL from the outset. Continued engine development, in response to Alfa Romeos post-war introduction of two-stage supercharging, in an attempt to improve torsional rigidity Maserati began to experiment with tubular section chassis members. These experimental models ran alongside conventional 4CLs throughout the 1947 season, in the hands of Luigi Villoresi the streamliner took pole position on the 4CLs race debut at the 1939 Tripoli Grand Prix, ahead of Mercedes brand new W165s. However, both it and two of the three conventional 4CLs entered retired early in the race with engine troubles, leaving the Silver Arrows to take the victory. Embarrassingly for the team, following this disappointing debut the 4CLs first taste of victory came in the hands of privateer Johnnie Wakefield at the Naples Grand Prix. Through the remainder of 1939 voiturette races Wakefield took two victories, and the works 4CLs picked up another two, before the outbreak of war curtailed international competition.
Villoresi took the 4CL to victory in the 1940 Targa Florio, but with entry restricted to Axis countries, and only Maserati fielding a factory team, on the resumption of competition in 1946 the Maserati 4CL proved the class of the field. Luigi Villoresi immediately returned to winning ways, taking victory in the first race following the cessation of hostilities, tazio Nuvolari and Giorgio Pelassa both took wins in 4CLs, but it was Raymond Sommer and his 4CL who dominated the season. 1947 would prove to be the 4CLs most successful season and, despite Alfa Romeo fielding the revamped 158 and new 308, after the replacement of the factory teams 4CLs by the new 4CLT, many examples of the older cars found their way into privateer hands. It was owing to the 4CLs popularity with privateer entrants that many were still being run in competition at the outset of the Formula One World Championship in 1950. Chassis and engine made to the experimental 4CLs eventually coalesced into the 4CLT. Power was up to approximately 260 bhp, from the 4CLs 220, other changes included the use of roller bearings for the crankshaft, forged rear suspension components, and the chassis was designed to run with hydraulic dampers from the outset
Robert Bosch GmbH
Robert Bosch GmbH, or Bosch, is a German multinational engineering and electronics company headquartered in Gerlingen, near Stuttgart, Germany. It is the worlds largest supplier of automotive components measured by 2011 revenues, the company was founded by Robert Bosch in Stuttgart in 1886. Bosch is 92% owned by Robert Bosch Stiftung, Boschs core products are automotive components, industrial products and building products. The history of the started in a backyard in Stuttgart-West as the Werkstätte für Feinmechanik und Elektrotechnik on November 15,1886. One year later, Bosch presented the first low voltage magneto for gas engines, twenty years later, the first magneto for automobiles followed. The first factory was opened by Bosch in Stuttgart in 1901, in 1906, the company produced its 100, 000-th magneto. In the same year, Bosch introduced the 8-hours day for workers, in 1910, the Feuerbach plant was founded and built close to Stuttgart. In this factory, Bosch started to produce headlights in 1913, in 1917, Bosch was transformed into a corporation.
In 1926, Bosch started to produce windscreen wipers, and in 1927, Bosch bought the gas appliances production from Junkers & Co. in 1932. In the same year, the company developed its first power drill, in 1937, Bosch was transformed into a limited liability company. Boschs subsidiary, Dreilinden Maschinenbau GmbH was a manufacturer in Kleinmachnow. This subsidiary employed forced laborers, prisoners of war and concentration camp detainees, there are two books published by Angela Martin and Hanna Sjöberg that report about Boschs use of slave labor. Since 2006, there is a commemoration in the forced labor camp. On March 12,1942, the founder, Robert Bosch. After the second war, Bosch established a partnership with the Japanese company Denso. In 1964, the Robert Bosch Stiftung was founded, Bosch founded a new development center in Schwieberdingen in 1968, and headquarters moved to Gerlingen in 1970. In 1981, the company participated on an equity basis in the Telefonbau & Normalzeit GmbH that was renamed Telenorma in 1985, in 1994, this part of the company was renamed as Bosch Telecom GmbH.
In 2000, Bosch sold the Private Networks area, in 2001, Bosch acquired the Mannesmann Rexroth AG which was renamed to Bosch Rexroth AG
Ferrari 365 GT4 2+2, 400 and 412
The Ferrari 365 GT4 2+2, Ferrari 400 and Ferrari 412 are front-engined V12 2+2 grand tourers made by Italian manufacturer Ferrari between 1972 and 1989. The three cars are related, using the same body and engine evolved over time. Following Ferrari practice, their numeric designations refer to their engines single-cylinder displacement expressed in cubic centimetres, the 365 GT4 2+2 was introduced in 1972 to replace the 365 GTC/4. It evolved into the 400, the first Ferrari available with an automatic transmission, in 1979 the 400 was replaced by the fuel injected 400 i. The improved 412 ran from 1985 to 1989, bringing to an end Ferraris longest-ever production series, however, entered as grey imports. Ferrari turned to frequent styling partner Leonardo Fioravanti at Pininfarina, whose design for the 365 GT4 2+2 was a clear departure from its fastback predecessor. It followed Fioravantis Ferrari 365 GTB/4 Daytona as the second Ferrari to feature the characteristic swage line dividing the body into upper and lower halves, various coachbuilders, such as Carrozzeria Pavesi and Straman, offered convertible conversions of the 400 series.
Switzerlands Felber showed a shooting brake version on 400 GT basis called the Felber Croisette at the 1981 Geneva Salon de lAuto, the tubular steel chassis was based on that of the GTC/4, but the wheelbase was lengthened 200 mm to 2,700 mm. The bodies were steel, with a floor, they were manufactured by Pininfarina at its Turin plant. Suspension consisted of double wishbones, coil springs coaxial with the shock absorbers, and anti-roll bars all around, under the bonnet there was a Tipo F101 Colombo V12 that underwent many changes through the years. It was a head and block, four overhead cams. The transmission was conventionally coupled directly to the engine, as on the GTC/4, brakes were discs on all four wheels. In 1972, just a year after the launch of the GTC/4, a new 2+2 debuted at the Paris Motor Show, the name refers to the single cylinder displacement, four overhead camshafts and seat configuration. Most of the mechanicals, including the 4,390.35 cc engine, were carried over from its predecessor, the V12 used six side-draft Weber 38 DCOE 59/60 carburetors and produced 340 PS at 6200 rpm.
The gearbox was a five-speed, all-synchromesh manual with a single-plate clutch, five-spoke alloy wheels were mounted on Rudge knock-off hubs, Borrani wire wheels were still offered at extra cost. Fittingly for a grand tourer, standard equipment included leather upholstery, electric windows. The GT4 was replaced in 1976 by the identical looking Ferrari 400. At the 1976 Paris Motor Show Ferrari unveiled the replacement for the 365 GT4 2+2, the new 400 was offered in two models,400 Automatic, using a GM THM400 3-speed automatic transmission, and 400 GT, using a five-speed transmission
In an internal combustion engine, the cylinder head sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber and this joint is sealed by a head gasket. In most engines, the head provides space for the passages that feed air and fuel to the cylinder, the head can be a place to mount the valves, spark plugs, and fuel injectors. With a chain drive to a camshaft, the extra length of chain needed for an overhead cam design could give trouble from wear. Early sidevalve engines were in use at a time of simple fuel chemistry, low octane ratings and this made their combustion chamber design less critical and there was less need to design their ports and airflow carefully. One difficulty experienced at this time was that the low compression ratio implied a low expansion ratio during the power stroke, exhaust gases were thus still hot, hotter than a contemporary engine, and this led to frequent trouble with burnt exhaust valves. A major improvement to the engine was the advent of Ricardos turbulent head design.
This reduced the space within the chamber and the ports. Most importantly, it used turbulence within the chamber to thoroughly mix the fuel and this, of itself, allowed the use of higher compression ratios and more efficient engine operation. Despite common knowledge, the limit on performance is not the gas flow through the valves. With high speed engines and high compression, the limiting difficulty becomes that of achieving complete and efficient combustion, efficient engines thus tend towards the pent roof or hemi designs, where the valves are brought close in to the centre of the space. Where fuel quality is low and octane rating is poor, compression ratios will be restricted, in these cases, the sidevalve engine still has much to offer. Such engines remained in production into the 1990s, only being replaced when the fuels available in the field became more likely to be diesel than petrol. In the overhead valve design, the head contains the poppet valves. In the overhead camshaft design, the head contains the valves, spark plugs and inlet/exhaust tracts just like the OHV engine.
The number of heads in an engine is a function of the engine configuration. Almost all inline engines today use a cylinder head that serves all the cylinders. A V engine has two heads, one for each cylinder bank of the V
Formula One is the highest class of single-seat auto racing that is sanctioned by the Fédération Internationale de lAutomobile. The FIA Formula One World Championship has been the form of racing since the inaugural season in 1950. The formula, designated in the name, refers to a set of rules, the F1 season consists of a series of races, known as Grands Prix, held worldwide on purpose-built F1 circuits and public roads. The results of each race are evaluated using a system to determine two annual World Championships, one for drivers, one for constructors. The racing drivers are required to be holders of valid Super Licences, the races are required to be held on tracks graded 1, the highest grade a track can receive by the FIA. Most events are held in locations on purpose-built tracks, but there are several events in city centres throughout the world. Formula One cars are the fastest road racing cars in the world. Formula One cars race at speeds of up to approximately 375 km/h with engines currently limited in performance to a maximum of 15,000 RPM, the cars are capable of lateral acceleration in excess of five g in corners.
The performance of the cars is very dependent on electronics – although traction control and other driving aids have been banned since 2008 – and on aerodynamics, the formula has radically evolved and changed through the history of the sport. F1 had a global television audience of 425 million people during the course of the 2014 season. Grand Prix racing began in 1906 and became the most popular internationally in the second half of the twentieth century. The Formula One Group is the holder of the commercial rights. Its high profile and popularity have created a major merchandising environment, since 2000 the sports spiraling expenditures and the distribution of prize money favoring established top teams have forced complaints from smaller teams and led several teams to bankruptcy. On 23 January 2017 it was confirmed that Liberty Media had completed its $8 billion acquisition of Delta Topco, the Formula One series originated with the European Grand Prix Motor Racing of the 1920s and 1930s.
The formula is a set of rules that all cars must meet. Formula One was a new formula agreed upon after World War II during 1946, the first world championship race was held at Silverstone, United Kingdom in 1950. A championship for constructors followed in 1958, national championships existed in South Africa and the UK in the 1960s and 1970s. Non-championship Formula One events were held for years, but due to the increasing cost of competition
Compared to OHV pushrod systems with the same number of valves, the reciprocating components of the OHC system are fewer and have a lower overall mass. Though the system drives the camshafts may be more complex, most engine manufacturers accept that added complexity as a trade-off for better engine performance. The fundamental reason for the OHC valvetrain is that it offers an increase in the ability to exchange induction. Another performance advantage is gained as a result of the better optimised port configurations made possible with overhead camshaft designs, with no intrusive pushrods, the overhead camshaft cylinder head design can use straighter ports of more advantageous cross-section and length. The OHC design allows for higher speeds than comparable cam-in-block designs. The higher engine speeds thus allowed increases power output for a given torque output, in earlier OHC systems, including inter-war Morrises and Wolseleys, oil leaks in the lubrication systems were an issue. Single overhead camshaft is a design in which one camshaft is placed within the cylinder head, in the SOHC design, the camshaft operates the valves directly, traditionally via a bucket tappet, or via an intermediary rocker arm. SOHC cylinder heads are less expensive to manufacture than double overhead camshaft cylinder heads.
Timing belt replacement can be easier since there are fewer camshaft drive sprockets that need to be aligned during the replacement procedure, SOHC designs offer reduced complexity compared to overhead valve designs — when used for multivalve cylinder heads, in which each cylinder has more than two valves. Exhaust and inlet manifolds were both on the side of the engine block. This did, offer excellent access to the spark plugs, in the early 1980s, Toyota and Volkswagen Group used a directly actuated, SOHC parallel valve configuration with two valves for each cylinder. The Toyota system used hydraulic tappets, the Volkswagen system used bucket tappets with shims for valve clearance adjustment. Honda used a similar system in their motorcycles, using the term Unicam for the concept. This system uses one camshaft for each bank of cylinder heads, with the cams operating directly onto the valve and indirectly, through a short rocker arm. This allows a compact, light valvetrain to operate valves in a combustion chamber.
The Unicam valve train was first used in single cylinder dirt bikes, a dual overhead camshaft valvetrain layout is characterised by two camshafts located within the cylinder head, one operating the intake valves and the other one operating the exhaust valves. This design reduces valvetrain inertia more than is the case with a SOHC engine, a DOHC design permits a wider angle between intake and exhaust valves than do SOHC engines. This can allow for a less restricted airflow at higher engine speeds, DOHC with a multivalve design allows for the optimum placement of the spark plug which, in turn, improves combustion efficiency
Alfa Romeo 158/159 Alfetta
The Alfa Romeo 158/159, known as the Alfetta, is one of the most successful racing cars ever produced. The 158 and its derivative, the 159, took 47 wins from 54 Grands Prix entered and it was originally developed for the pre-World War II voiturette formula and has a 1. 5-litre straight-8 supercharged engine. Following World War II, the car was eligible for the new Formula One introduced in 1947, in the hands of drivers such as Nino Farina, Juan-Manuel Fangio and Luigi Fagioli, it dominated the first two seasons of the World Championship of Drivers. The first version of this successful racing car, the 158, was made during 1937/1938, the main responsibility for engineering was given to Gioacchino Colombo. The cars name refers to its 1. 5-litre engine and eight cylinders, the voiturette class was for racing cars with 1. 5-litre engines, standing in the same relation to the top Grand Prix formula as the GP2 series does to Formula One today. Alfas 3-litre racing cars in 1938 and 1939 were the Tipo 308,312 and 316, the 158 debuted with the works Alfa Corse team at the Coppa Ciano Junior in August 1938 at Livorno, where Emilio Villoresi took the cars first victory.
At that time the 1479.56 cc engine produced around 200 bhp at 7000 rpm. with the help of a single-stage Roots blower, more success came at the Coppa Acerbo, Coppa Ciano and Tripoli Grand Prix in May 1940. Soon World War II stopped development of the car for six years, after the war the engine was developed further to push out 254 bhp in 1946. In 1947, the Alfetta was put back into service, the new rules allowed 1500 cc supercharged and 4500 cc naturally aspirated engines. The 158 was modified again, this time to produce over 300 bhp and was denoted as Tipo 158/47, the car made a tragic debut in the 1948 Swiss Grand Prix where Achille Varzi lost control of his car and was killed. Another loss for the team came in practice for the 1949 Buenos Aires Grand Prix, in 1950, the 158 was eligible for the new World Championship of Drivers. The Alfa Romeo team included talented drivers such as Giuseppe Farina and Juan Manuel Fangio, at the end of the 1950 season, a further updated version known as the 159 was produced, which was used for the 1951 season.
This version had reworked rear suspension, the old swing axle was replaced with a De-Dion axle, but this amount of power out of a small engine with a big supercharger came at a price – it had horrendous fuel consumption. It did 1 1⁄2 miles to the gallon – compared to the Talbot-Lagos of the time, the reason for this was because the simplistically designed engine had been virtually unmodified, while bigger superchargers had been added over time. Still, the Alfa had the edge on performance and with wins in Switzerland and Spain, for their second-to-last World Championship race, the Italian Grand Prix at Monza, Alfa Romeo introduced a new evolution version known as the 159M, the M standing for Maggiorata. After an unsuccessful bid by Alfa Romeo to obtain government assistance to meet development costs, the cars last Grand Prix win came in 1953 at Merano Grand Prix, Italy. * The Constructors Championship was not awarded until 1958
A petrol engine is an internal combustion engine with spark-ignition, designed to run on petrol and similar volatile fuels. In most petrol engines, the fuel and air are usually pre-mixed before compression, the process differs from a diesel engine in the method of mixing the fuel and air, and in using spark plugs to initiate the combustion process. In a diesel engine, only air is compressed, and the fuel is injected into very hot air at the end of the compression stroke, and self-ignites. The first practical petrol engine was built in 1876 in Germany by Nikolaus August Otto, although there had been attempts by Étienne Lenoir, Siegfried Marcus, Julius Hock. The first petrol engine was prototyped in 1882 in Italy by Enrico Bernardi. British engineer Edward Butler constructed the first petrol combustion engine. Butler invented the spark plug, ignition magneto, coil ignition and spray jet carburetor, with both air and fuel in a closed cylinder, compressing the mixture too much poses the danger of auto-ignition — or behaving like a diesel engine.
Spark plugs are typically set statically or at idle at a minimum of 10 degrees or so of crankshaft rotation before the piston reaches T. D, higher octane petrol burns slower, therefore it has a lower propensity to auto-ignite and its rate of expansion is lower. Thus, engines designed to run high-octane fuel exclusively can achieve higher compression ratios, Petrol engines run at higher rotation speeds than diesels, partially due to their lighter pistons, connecting rods and crankshaft and due to petrol burning more quickly than diesel. However the lower compression ratios of petrol engines give petrol engines lower efficiency than diesel engines, Bedford OB bus Bedford M series lorry GE 57-ton gas-electric boxcab locomotive Petrol engines may run on the four-stroke cycle or the two-stroke cycle. For details of working cycles see, Four-stroke cycle Two-stroke cycle Wankel engine Common cylinder arrangements are from 1 to 6 cylinders in-line or from 2 to 16 cylinders in V-formation. Flat engines – like a V design flattened out – are common in airplanes and motorcycles and were a hallmark of Volkswagen automobiles into the 1990s.
Flat 6s are still used in many modern Porsches, as well as Subarus, less common, but notable in vehicles designed for high speeds is the W formation, similar to having 2 V engines side by side. Alternatives include rotary and radial engines the latter typically have 7 or 9 cylinders in a single ring, Petrol engines may be air-cooled, with fins, or liquid-cooled, by a water jacket and radiator. The coolant was formerly water, but is now usually a mixture of water and either ethylene glycol or propylene glycol, the cooling system is usually slightly pressurized to further raise the boiling point of the coolant. Petrol engines use spark ignition and high current for the spark may be provided by a magneto or an ignition coil. In modern car engines the ignition timing is managed by an electronic Engine Control Unit, the most common way of engine rating is what is known as the brake power, measured at the flywheel, and given in kilowatts or horsepower. This is the mechanical power output of the engine in a usable