Volkswagen 1-litre car

Concept

The objective was to develop a vehicle with a fuel consumption of no more than one litre per 100 kilometres, using all technical possibilities available. The principal point was to show how state-of-the-art technology can be used to reduce fuel consumption and still come up with a safe, usable and roadworthy vehicle.

Volkswagen's Research and Development division enthusiastically took up the challenge to design the world's most economical car, and created a ready-to-drive car in just three years. Volkswagen's study is registered for use on public highways, and the journey from Wolfsburg to Hamburg demonstrates that the 1-litre car is technically feasible and offers driving pleasure of a very special kind. Project manager Dr. Thomas Gänsicke: "It really is a fascinating experience to drive through the night at 100 km/h with the fuel consumption indicator showing just 1.0 ltr./100 km, and nothing but the stars above your head."

The key objectives in the development were to minimise all driving resistances through lightweight construction and outstanding aerodynamics, and to develop new tyres and running gear components, taking ergonomics, current safety standards and familiar control functions into account.

However, the target, a fuel consumption level of one litre per 100 kilometres, meant abandoning conventional vehicle concepts. With a width of just 1.25 metres, the 1-litre car is extraordinarily narrow, the driver and passenger sit in tandem, the transversely installed engine is centrally located in front of the rear axle, the plastic bodywork has the highly aerodynamic shape of a teardrop.





In close cooperation with numerous suppliers, existing components were examined, assessed and modified, and brand new concepts were advanced. This was the case in particular for the wheels/tyres, the starter-alternator, the bodywork and the lighting.

The sports-car-like 1-litre car will thus be the technological forerunner of future vehicle generations.

Engine

Even in the initial concept phase of the 1-litre car, different drive concept simulations showed that diesel was the only real option for the drive system, as only this combustion principle meets the maximum requirements for optimum energy exploitation. Here, the experience of the technical development team that created the three-litre Lupo was of great benefit. However, a 3-cylinder engine was out of the question for a fuel consumption level of just one litre per 100 kilometres. A 2-cylinder engine was also quickly dismissed. The final solution was a one-cylinder naturally-aspirated diesel engine with a displacement of just 0.3 litres. The direct injection diesel engine makes use of the most efficient injection system available today: a unit injection element with 6-hole jet and pre-injection. It provides a high working pressure of 2,000 bar.

The one-cylinder SDI engine in the 1-litre car is not a mere derivative of the familiar engines, but is rather a completely new, technically highly sophisticated development. Two overhead camshafts actuate roller rocker fingers which in turn actuate three valves, two inlet valves and one exhaust outlet valve. These are then fed from the engine through a titanium exhaust system with reduced backpressure.

The two overhead camshafts are driven by a strengthened toothed belt. The engine is an aluminium monobloc construction. That means that the cylinder head and crankcase of the compression-ignition engine are cast as a single piece. But that is not the end of the lightweight construction, for also here, all technically feasible stops have been pulled. The fuel pump housing is made of magnesium. The trapezoidal connecting rod is made of particle-reinforced titanium. The success of these measures becomes evident on the scales: dry (i.e. without operating fluids like oil and water), the engine weighs in at an unbelievably light 26 kilograms. Ready for operation, including the starter-alternator, it is just 12 kilograms more.




Besides the reduction in weight, various measures were taken inside the engine to optimise fuel consumption. To minimise frictional resistance, the running area of the cylinder has been laser alloyed, roller rocker fingers reduce friction in the valve drive, even the tension of the piston rings has been reduced.

The centrally mounted one-cylinder SDI diesel engine is transversely installed in front of the rear axle, has a displacement of 299 cc and generates its maximum output (6.3 kW / 8.5 bhp) at 4,000 rpm. The maximum torque of 18.4 Newton metres is delivered at 2,000 rpm.

Even with this apparently low output and power development, the extremely light vehicle weight (which is comparable to that of an average touring motorcycle) and the excellent aerodynamics (with a drag coefficient of 0.159 — much better that a motorcycle and far better any series production vehicle) provide for a lively performance. For example, the 1-litre car reaches a top speed of 120 km/h.

Moreover, Volkswagen's economical wunderkind is suitable for everyday use despite the extremes of its design. And that includes its range. It is not difficult to calculate the range available with the 6.5 litre tank: the two-seater can travel up to 650 kilometres on a single filling.

Gearbox

Volkswagen 1-litre car — Newly conceived automated direct shift gearbox

Starter-alternator, start-stop system and freewheel function help save fuel

Six-speed gearbox selects gears sequentially and automatically

Due to the small installation space available for the engine-gearbox unit, new approaches were also required in the power transmission system. Here, a compact automated sequential 6-speed gearbox with a specially tuned shift program is used. This optimises power transmission, reducing fuel consumption.

It was not possible to simply take a gearbox off the shelf, for once again, the motto was: save weight. And so the gearbox housing is made of magnesium, all gears and shafts are hollow, and bolts are made of titanium. In addition, a special high-lubricity oil ensures the 6-speed gearbox, which weighs a mere 23 kilograms, always runs smoothly.

The gearshift mechanism is electro-hydraulically actuated via finely-tuned sensors, eliminating the need for a clutch pedal. There is also no need for a gear lever, for upshifts and downshift are made fully automatically. Here, the best possible engine and gearbox shift points are selected for optimum fuel economy. Gear selection — forwards, reverse or neutral — is made using a turn switch on the right-hand side of the cockpit.

The automated gearbox is coupled to a start-stop system, which includes a freewheel function. In overrun mode, the vehicle switches the engine off. The vehicle then rolls without the engine running. Development engineers call this gliding — alluding to the silent flight of a glider. The engine starts up again immediately when the magnesium accelerator pedal is depressed. A specially developed starter-alternator makes sure the engine is immediately restarted. Positioned between the engine and gearbox and using a dual clutch system, this works as both current generator and flywheel. In gliding mode, both clutches are open. When the driver presses the accelerator pedal again, the clutch between the engine and the starter-alternator is closed, causing the still turning flywheel to restart the engine without consuming any electrical current. Apart from this, the crankshaft starter-alternator, which eliminates the need for a conventional alternator and starter motor, has a so-called boost function which is able to supply additional power to supplement the power of the engine. But that is not all the starter-alternator does. While braking, the negative acceleration energy is fed into the alternator and recovered (recuperation).

Bodywork

Both the silhouette of the 1-litre car and its front view are more reminiscent of a narrow sports car than of a typical research vehicle. The reason: In order to achieve a consumption of one litre, the engineers not only had to do wonders with the drive unit — they also had to exploit the aerodynamic possibilities to the utmost (cd = 0.159). Since the 1-litre car was to be a two-seater, but the frontal area had to be kept as small as possible, the only option was to arrange the two seats in line ahead, as in a racing bobsleigh or a glider. Entry is effected via a 1.5-metre-long gullwing door, which is drawn down on the left side to make the process more convenient.

The wheels have also been sheathed. The rear wheels disappear entirely behind their trim, and the front wheels are equipped with all-over wheel caps in carbon fibre. Even the side cooling air inlets only open when the engine needs cooling, and otherwise stay shut. Viewed from above, the teardrop shape of the body and the steep cut-off at the rear are clearly visible. The necessary downthrust on the rear axle is provided by an aerodynamically optimised underbody trim and a diffuser on the rear end.

In order to achieve the lowest possible cd figure, there was never any question of exterior mirrors. However, the 1-litre car's rear visibility is ensured via cameras in the side turn signals. These show the road behind on two small LCD monitors located left and right of the circular central instrument. For parking, the picture is taken from the centrally-mounted rear-view camera in the third brake light, which shows the area directly behind the vehicle.

For the bodywork and the frame, a lightweight solution was used which also takes optimum account of the bearing structure: A combination of a magnesium spaceframe and an outer skin of carbon fibre composite material. With a weight of altogether some 74 kilograms (163 lb), this version is 13 kilograms (28.6 lb.) lighter than a combination of aluminium spaceframe with carbon fibre outer skin.

Even details such as door locks have been dispensed with, their place being taken by the most up-to-date electronic locking technology. The system automatically unlocks the entry hood when the driver approaches with the sensor. As in a top-range sports car, the engine is brought to life with a starter button.




The passive safety level corresponds to that of a GT sports car registered for racing. With the aid of computer simulations (CAE = Computer Aided Engineering), all kinds of crash types were investigated and the vehicle designed accordingly. So-called crash tubes, with integrated pressure sensors for airbag control in the front end of the car, absorb the entire deformation energy, leaving the footwell unaffected. The aluminium fuel tank — with a filler opening designed for automated robotised filling — is located in the collision-protected area behind the passenger.

Furthermore, active safety is provided by the latest-generation four-channel ABS and the electronic stability program ESP.

Running gear

The shape of the tandem two-seater itself hints at a sports car, and the running gear, the seating position and the mid-engine are further clues that a different concept has been consciously pursued here than that of a traditional passenger car. The low sitting positions of the driver and passenger furthermore favour agile handling and a low centre of gravity, the sporty matching of the running gear ensures a low level of lateral inclination, and in extreme cases the ESP cuts in to lend a hand.

The front axle of the 1-litre car is a work of art in itself. The noblest materials, worked in fine detail, make this type of suspension almost a kind of precision engineering. In design terms it is a double-wishbone axle, with the upper wishbone in magnesium and the lower one and the pivot bearings in aluminium. The wheel hubs are made of titanium, and the balls in the lightweight-construction wheel bearings are ceramic. The knock-out here is the weight: the entire front axle construction including spring-damper unit weighs just eight (!) kilograms (17.6 lb.).

The driven rear axle has an entirely different construction, being designed on the De-Dion principle. The driven suspension has numerous elements of lightweight construction: the leaf springs are made of glass fibre, the transverse tube and the wheel mountings of aluminium, and the wheel hubs of titanium. The drive shafts and the wheel bearings are integrated in the axle.

The direct mechanical steering with its flat-top steering-wheel (whose magnesium skeleton gives it a weight of only 540 grams) is also a minor miracle of lightweight construction. The steering box is made of magnesium, the fabricated hollow rack of aluminium and titanium. Titanium pinions and aluminium track-rods with titanium pivot pins further contribute to the total weight of the steering gear being only 1870 grams.

Safe braking is assured by four alloy disc brakes and alloy brake calipers, combined with the latest-generation anti-lock brake system. An electronic parking brake on the rear axle ensures safe parking of the vehicle. The entire brake system adds only 7.8 kilograms (17.2 lb.) to the lightweight construction total.

Volkswagen has also gone new and extreme ways in minimising the rolling resistance. In close cooperation with a tyre manufacturer, a wheel-and-tyre combination has been developed which puts the least possible mass in the way of propulsion. Like the body, the wheel is made of carbon fibre composite, and at 1.8 kilograms (3.9 lb.) is more than 50 per cent lighter than a traditional wheel. The special tyre mixture and the tread have been designed in such a way that the driving resistance is reduced by 30 per cent in comparison with a standard tyre of the same size. In addition, the wheel bearings (made of titanium) have been specifically designed to be yet lower-friction for this car




Electrics

A further element in fuel saving is the optimisation of the electrical consumers in the vehicle. The aim was to omit none of the important functions, but always to develop the technologically most sophisticated and naturally the lightest solution.

Thus the 1-litre car has Bi-Xenon headlights whose dipped beam is only 32-Watt — but which have a light output of a traditional 60-Watt headlight, and have the advantage that, on account of this low output, no headlight washer system is necessary. The entire headlight element is made of polycarbonate, and weighs only 1,500 grams complete. The daylight beam, all turn signals and the rear light clusters are in LED technology.

The interior is illuminated by LED-fed prismatic rods located at the sides, the opened hood is well-lit in the dark by an electroluminescent foil.

Further technical highlights are the camera system with its displays integrated in the cockpit, the automatic access recognition for unlocking the gullwing door and the push-button starting (Kessy = Keyless Entry, Start and Exit System).

A starter-alternator is used to generate energy, and it incorporates a special function: When the driver depresses the magnesium brake pedal, the braking energy is fed into the alternator and thus recovered (recuperation). Energy storage is via a nickel-metal hydride battery. The on-board network is designed in CAN-Bus technology.

Interior

The interior with its uncluttered, sporty design has plenty of room for two people who, once the turret-like glass roof (made of polycarbonate with integrated sun protection) has been raised, can enter conveniently. The seats too are examples of extremely lightweight construction. Their frames are in magnesium, and instead of classic upholstery the seats have firm yet comfortable fabric covers (M-flex).

The passenger can place his feet comfortably on footrests located left and right of the driver's seat. The driver meanwhile looks through the flat-top steering-wheel with airbag at the cockpit in the style of a modern jet. Left and right of the centrally-placed circular instrument are the monitors relaying the pictures from the two rear-view cameras. In front of these, on the right side the turn switch for gear selection and electric parking brake, and the starter button, are located; on the left the regulator for heating and ventilation, and the light switch.

On account of the optimum energy efficiency, only a small amount of superfluous heat is generated with which to heat the passenger compartment. Heating is therefore provided by an electric four-stage PTC element which is available immediately after starting, such as is used in the Phaeton, together with a four-stage fan.

http://youtu.be/TxutPWP59_U

Piston Failue

　

Heavy Duty Technology: Piston Failure Analysis
By Dennis Nail
While there are many "cut and dried" reasons for aluminum piston failures, the majority can be attributed to a combination of various conditions. The air/fuel, coolant and oil systems and relationships between various engine operations and the cylinder liner temperatures are critical to maintaining proper operation of all cylinder components.
A variety of conditions can cause excessive piston growth or melting, and each will cause varying results – including catastrophic engine failure.
The correct air/fuel ratio balance of an engine is most critical for piston longevity, durability and proper engine operation. The combination of too much fuel or too little air will have the same result – thermal growth or piston crown erosion. This can be attributed to clogged air intakes, restricted exhaust, malfunctioning turbo, incorrect fuel pump calibration, injector contamination, and of course, injection or engine timing.
Heavy-duty diesel pistons are designed to give long service life with the proper air/fuel ratio balance. Any of these attributes will shorten piston life or cause catastrophic engine failure.
Coolant temperatures are another major area of concern. However, this is not always a blatant case of running out of engine coolant. Low coolant levels, old coolant, lack of maintenance such as plugged radiators, air in the system and restricted air flow, or a combination of the above factors can cause excessive piston growth resulting in ring scuffing, skirt or crown scuffing and ultimately piston seizure.
The piston cooling jets help to control piston crown temperatures. The most common conditions of inoperative piston cooling spray jets are misalignment and restricted oil passages. It is very important to remove the piston spray jets prior to cylinder component removal and installation. Metal jets are easily misaligned or fractured from contact by the cylinder component assembly, while plastic jets can be cracked or broken.
Once the cylinder components are installed, the piston spray jets can be checked for proper alignment and operation. Failure to follow this procedure will result in higher piston crown temperatures, which will migrate down to the piston skirt area. The increase in piston skirt temperature will expand the diameter above the allowable tolerance and eliminate the piston-to-liner clearances, resulting in piston seizure.
Engine operation
Severe lugging or lower engine revolutions cause a decrease in fresh air volume, resulting in piston crown overheating. Excessively high engine revolutions, described as "over-speeding" can stretch the component tolerance "stack-up," causing the pistons to contact the valves, which can cause piston or valve damage. Material displaces from the piston crown due to the valve impact, and wedges in between the piston skirt and liner wall. This creates an adhesion condition, which leads to piston seizure.
Piston Failure Analysis Identification
Piston Crown Scuffing
Probable Causes
Piston Crown Burning
Probable Causes
Quarter Point Skirt Scuffing
Probable Causes
Center Point Skirt Scuffing
Probable Cause
Piston Ring Scuffing
Probable Causes
Piston Crown Cooling
Severe Piston Crown Temps
Probable Causes
Assembly Errors
Probable Causes
When piston failure has occurred, it is extremely important to thoroughly inspect all of the engine components during the disassembly procedure. This thorough inspection will lead you to the possible cause or causes of the piston failure and will ensure that the same piston failure doesn’t occur once the engine is repaired and placed back into service by your customer.
Shehjad Ali is technical support managerPiston ring end gap misalignment
Expander end gap is same as oil ring end gap.Assembly errors can and will contribute to high base pressure and can cause oil to bypass the rings. This can create a build-up of abrasive carbon, which can lead to ring scuffing, a loss of ring control, and possible piston seizure.Over-fueling
Fresh air intake restriction
Exhaust restrictionThe burnt oil shown in the example on page 63 clearly indicates that the piston crown was overheating. The burnt oil creates a thermal barrier, and does not allow the fresh-cooled oil to pull any heat from the piston crown, compounding an already existing condition.These indications determine if the piston cooling was a contributor or the possible cause of a piston failure. The two pictures at the right show this. On the top is an example of insufficient crown cooling. The example on the bottom shows proper crown cooling. Fuel wash-down
Debris ingestion
Severe overloadingRing scuffing leads to ring face wear, which results in ring face damage and a loss of ring control. This causes high base pressure, oil consumption and possible piston scoring, due to the abrasive materials created by the ring scuffing condition. This can cause piston seizure if not addressed.Cold engine start at high loads or rpm.Piston skirts are not round, but elliptical, until the engine reaches operating temperature. When a cold engine is started and is operated at high loads or rpm, center point skirt scuffing may occur.Overheating of coolant system
Lack of heat transfer in cylinder
Lack of piston crown coolingThe piston skirt is the gauged bearing clearance area, and it is important to maintain minimum piston skirt temperatures. If excessive heat is allowed to migrate down to the skirt area, thermal expansion will eliminate the piston-to-liner clearance, and will cause skirt scuffing.Improper injection timing
Injector contamination
Nozzle failure
Lack of fresh air supply
Exhaust restriction
Excessive use of etherPiston crown erosion is commonly known as "Piston Burning" and is normally a result of an improper air/fuel ratio balance.Over-fueling of specific cylinder
Lack of fresh air to that cylinder
Exhaust restriction
Engine or injection timing
Lack of piston crown coolingCrown scuffing occurs when the piston rapidly exceeds normal operating temperatures. Typically, this is caused by an over-fueling condition, a result of either too much fuel or too little air. In some applications, a lack of oil cooling the crown can also cause rapid piston crown growth, resulting in a loss of crown-to-cylinder liner clearance, creating crown scuffing and possible seizure. at excessive loads, described as "severe lugging" or running the engine above the rated speed recommended by the manufacturer’s specifications, can also lead to cylinder component damage. Greater loads equate to higher engine component temperatures.

Hybrid Technolgy

The Beijing Olympics saw a total of 80 hybrid and alternative fuel vehicles on public demonstration as ordinary taxis and transport for Olympic officials last year. After the Games the cars were quickly whisked back to their respective manufacturers and stripped down for evaluation. The Olympic hybrid car program had been the first stage in a far-reaching plan to gradually introduce China’s people to the concept of energy-saving and more environmentally friendly vehicles. The vehicles taking part had performed their onerous ferrying duties without fault, enabling the manufacturers to go on to the next stage in the process. Late in 2008, one of China’s newest car manufacturers, BYD of Shenzhen, announced the world’s first production plug-in hybrid car. A series of announcements by China’s other domestic car manufacturers surrounded this astonishing news. Brilliance announced its medium-powered hybrid at the Guangzhou fair in November and Chery put two models – one a hybrid and the other a fully electric car – onto the market early in the new year. The local press was full of environmental claims, but some of the prices were almost double those of conventional models. February 2009 saw the annual Chinese People’s Political Consultative Conference in Beijing, at which the Ministry of Finance publicly announced the provision of 10 billion yuan (around U.S. $1.4 billion) of extremely generous subsidies for purchasers of hybrid and alternative energy ("new energy" as they are known in China) vehicles. China’s new large-scale public demonstration and trial funded by the Ministry of Finance will take place in 13 large urban areas, including Beijing and Shanghai. Each local area is to purchase new hybrid and alternative energy vehicles, comprising government transport, public service (postal service and sanitation, for example) and public transport vehicles. The vast majority will be passenger cars and light commercial vehicles, and they will include mild, medium, and full hybrids, range extender hybrids, alternative fuel, and fully electric. Enormous subsidies are also on hand to support the purchase of heavy duty fuel cell buses. "We are investing a lot of money to ensure that each urbanized area takes at least 1000 vehicles, and if the program succeeds, it will help to raise private buyers’ awareness and acceptance of these new technologies and expand their coverage," a Ministry of Finance official who was unwilling to be named told AEI. The program will run for three years and the funds will come from various sources, including the state, local government, and local public transport authorities. The official said the funds will not be available up front for purchase of these vehicles. Instead, the money "will be refunded for each purchase upon production of the relevant vehicle purchase documents." Details of the subsidies: Trial regionsBeijing, Changchun, Changsha, Chongqing, Dalian, Hangzhou, Hefei, Jinan, Kunming, Nanchang, Shanghai, Shenzhen, and Wuhan Vehicle typeChinese yuanU.S.$Note Passenger car and light commercial vehicle subsidies HybridUp to 50,000$7315divided into five levels, depending on economy Pure electric60,000$8780 Fuel cell250,000$36,580 Hybrid fuel economymin. 5% improvement for light commercial vehicles, min. 10% improvement for passenger cars Subsidies for buses over 30 ft (9.1 m) long Hybrid80,000 - 420,000$11,700 - $61,450depends on battery chemistry (lead-acid, NiMH, or lithium) Pure electric500,000$73,150 Fuel cell600,000$87,790 The new subsidies will provide a healthy stimulus to ensure that high technology R&D on hybrid and new energy vehicle continues around the country – by universities, suppliers, and manufacturers themselves. One form of motive power that was conspicuous by its absence was the diesel engine. China faces a relative shortage of this fuel as a result of its relatively high production cost and competition for diesel and other heavy fuel oil by other industries in China. AEI Details of current hybrid and alternative energy vehicles in China: BrillianceThe BS6　"Zunchi" medium hybrid sedan uses a locally developed turbocharged 1.8-L gasoline engine. The electric traction motor is rated at 10 kW and uses an NiMH battery pack, which, along with the vehicle controller, is produced in the Shanghai region. The powertrain performs start-stop, regenerative braking, and boost functions, with a claimed improvement in economy of up to 35% against similar-sized sedans. Brilliance, which assembles BMW 3- and 5-Series sedans in partnership in Shenyang, has equipped the car with a manual gearbox. Negotiations to supply a limited number of vehicles to urban areas are ongoing. The company also has plans to introduce a mild hybrid vehicle in the near future, possibly based on its new FRV hatchback model. BYDShenzhen-based BYD’s F3 DM plug-in hybrid is a "range extender."It uses an electric motor for traction, with battery charging and occasional peak power demand assistance being provided by a 1.0-L gasoline engine. Although the company has actively promoted the U.S. $22,000 sales price of this model, it is, as with all of China’s other hybrid and alternative energy vehicles, primarily intended for purchase by government departments. The company has achieved a handful of sales to private buyers, however. The BYD-patented battery uses a proprietary iron chemistry that is said to be much more cost-effective, enabling it to provide an affordable challenge to lithium batteries. BYD had already shown a plug-in hybrid version of its midsize sedan, the F6 DM, at various motor shows and is planning to introduce this model in the next few months. The all-wheel-drive pure electric e6 lifestyle monobox concept vehicle, however, contrary to earlier production announcements, is now not expected to go into production within the next two or three years. CheryChery announced the 1.6-L A5 BSG (belt starter generator) last January and is working on a similarly equipped A3 sedan and hatchback for launch around the middle of the year. The A5 BSG’s purchase price makes it the only start-stop hybrid on the market available for under 80,000 yuan (U.S. $11,700). The company is also readying an ISG (integrated starter generator) mild hybrid version of the A5 sedan,　which it had already demonstrated during the Olympics. It links a 1.3-L engine to a 12 kW electric motor running on 151 V. Chery sent more than 100 production managers to work with Ricardo in the U.K.　to develop its BSG and ISG models. The　collaboration resulted in the design of not only the vehicles themselves but also included the vehicle controller, battery, and traction motor elements. Chery announced production of its S18 electric five-door　hatchback city car in February. It uses the same platform as the seven-model Faira city car range that will soon enter series production. A 40 Ah lithium iron phosphate battery provides　336 V current to power the 40 kW electric motor. Maximum speed is a claimed 120 km/h (75 mph) and range is 120-150 km (75-93 mi). A full charge takes 4-6 hours. FAWChina’s first domestic vehicle manufacturer is working on a full hybrid capable of running long distances under electric power. The B70HEV, also known as the Besturn, uses a bespoke AMT (automated manual transmission) and is expected to supply up to 20 units to Tianjin and Chengdu by the end of 2010. The ramp up to series production is expected in 2012. FAW also plans to produce 100 hybrid buses for Dalian and Changchun. GeelyGeely’s rounded little Panda city hatchback is currently being readied for the market in pure plug-in electric form, but the production date has not yet been fixed. Domestic manufacturers of pure electric and plug-in hybrids face the challenge of how to charge the battery: the vast majority of Chinese households do not have garages and do not have readily available power sources with which to charge their vehicles. This should not affect the electric Panda’s sales performance with regards to the current large-scale encouragement program. The Geely spokesman said, "Government departments generally have garage parking facilities where the vehicle can be recharged. The problem of where to charge the vehicle for the general public is still a challenge that needs to be solved, but we are working on it." Geely has also developed CNG and ethanol-powered versions of a number of its existing vehicles and already produces these in limited numbers. A new methanol-powered drivetrain is also being developed but as yet is unable to go to market because "the government has not yet established any rules for this power source." The challenge aheadThe Ministry of Finance’s launch of this massive hybrid and alternative energy program is obviously a source of great encouragement to the car manufacturers. But the issue of high cost remains, at least for the initial limited production runs. The OEMs obviously have their work cut out as they strive to bring costs down to acceptable levels, notwithstanding the generous subsidies that have been offered to ease the process. In addition to this factor, the automakers also have to ensure that their models are able to provide robust – three years or 150,000 km (90,000 mi) – fault-free performance, along with all the necessary servicing, spare parts, and maintenance network. With their low emissions and modern engine designs capable of meeting Euro 4 and 5 regulations, however, the makers of gasoline-engined cars appear　best placed to take early advantage of worldwide export opportunities for energy-saving vehicles in coming years. spoke to a number of domestic car manufacturers to see how the program was progressing. At present there is a high level of activity as manufacturers demonstrate vehicles and negotiate purchase contracts with various government bodies. Initial contracts are for small numbers of vehicles, but most manufacturers speak of a shift to series production within the next two years as volume increases and the costs begin to come down. China Brilliance, for instance, speaks of a gradual ramp up to volume production some time during the course of 2010-2011.

The Beijing Olympics saw a total of 80 hybrid and alternative fuel vehicles on public demonstration as ordinary taxis and transport for Olympic officials last year. After the Games the cars were quickly whisked back to their respective manufacturers and stripped down for evaluation. The Olympic hybrid car program had been the first stage in a far-reaching plan to gradually introduce China’s people to the concept of energy-saving and more environmentally friendly vehicles. The vehicles taking part had performed their onerous ferrying duties without fault, enabling the manufacturers to go on to the next stage in the process. Late in 2008, one of China’s newest car manufacturers, BYD of Shenzhen, announced the world’s first production plug-in hybrid car. A series of announcements by China’s other domestic car manufacturers surrounded this astonishing news. Brilliance announced its medium-powered hybrid at the Guangzhou fair in November and Chery put two models – one a hybrid and the other a fully electric car – onto the market early in the new year. The local press was full of environmental claims, but some of the prices were almost double those of conventional models. February 2009 saw the annual Chinese People’s Political Consultative Conference in Beijing, at which the Ministry of Finance publicly announced the provision of 10 billion yuan (around U.S. $1.4 billion) of extremely generous subsidies for purchasers of hybrid and alternative energy ("new energy" as they are known in China) vehicles. China’s new large-scale public demonstration and trial funded by the Ministry of Finance will take place in 13 large urban areas, including Beijing and Shanghai. Each local area is to purchase new hybrid and alternative energy vehicles, comprising government transport, public service (postal service and sanitation, for example) and public transport vehicles. The vast majority will be passenger cars and light commercial vehicles, and they will include mild, medium, and full hybrids, range extender hybrids, alternative fuel, and fully electric. Enormous subsidies are also on hand to support the purchase of heavy duty fuel cell buses. "We are investing a lot of money to ensure that each urbanized area takes at least 1000 vehicles, and if the program succeeds, it will help to raise private buyers’ awareness and acceptance of these new technologies and expand their coverage," a Ministry of Finance official who was unwilling to be named told AEI. The program will run for three years and the funds will come from various sources, including the state, local government, and local public transport authorities. The official said the funds will not be available up front for purchase of these vehicles. Instead, the money "will be refunded for each purchase upon production of the relevant vehicle purchase documents." Details of the subsidies: Trial regionsBeijing, Changchun, Changsha, Chongqing, Dalian, Hangzhou, Hefei, Jinan, Kunming, Nanchang, Shanghai, Shenzhen, and Wuhan Vehicle typeChinese yuanU.S.$Note Passenger car and light commercial vehicle subsidies HybridUp to 50,000$7315divided into five levels, depending on economy Pure electric60,000$8780 Fuel cell250,000$36,580 Hybrid fuel economymin. 5% improvement for light commercial vehicles, min. 10% improvement for passenger cars Subsidies for buses over 30 ft (9.1 m) long Hybrid80,000 - 420,000$11,700 - $61,450depends on battery chemistry (lead-acid, NiMH, or lithium) Pure electric500,000$73,150 Fuel cell600,000$87,790 The new subsidies will provide a healthy stimulus to ensure that high technology R&D on hybrid and new energy vehicle continues around the country – by universities, suppliers, and manufacturers themselves. One form of motive power that was conspicuous by its absence was the diesel engine. China faces a relative shortage of this fuel as a result of its relatively high production cost and competition for diesel and other heavy fuel oil by other industries in China.AEI spoke to a number of domestic car manufacturers to see how the program was progressing. At present there is a high level of activity as manufacturers demonstrate vehicles and negotiate purchase contracts with various government bodies. Initial contracts are for small numbers of vehicles, but most manufacturers speak of a shift to series production within the next two years as volume increases and the costs begin to come down. China Brilliance, for instance, speaks of a gradual ramp up to volume production some time during the course of 2010-2011.Details of current hybrid and alternative energy vehicles in China: Brilliance The BS6　"Zunchi" medium hybrid sedan uses a locally developed turbocharged 1.8-L gasoline engine. The electric traction motor is rated at 10 kW and uses an NiMH battery pack, which, along with the vehicle controller, is produced in the Shanghai region. The powertrain performs start-stop, regenerative braking, and boost functions, with a claimed improvement in economy of up to 35% against similar-sized sedans. Brilliance, which assembles BMW 3- and 5-Series sedans in partnership in Shenyang, has equipped the car with a manual gearbox. Negotiations to supply a limited number of vehicles to urban areas are ongoing. The company also has plans to introduce a mild hybrid vehicle in the near future, possibly based on its new FRV hatchback model. BYD Shenzhen-based BYD’s F3 DM plug-in hybrid is a "range extender."It uses an electric motor for traction, with battery charging and occasional peak power demand assistance being provided by a 1.0-L gasoline engine. Although the company has actively promoted the U.S. $22,000 sales price of this model, it is, as with all of China’s other hybrid and alternative energy vehicles, primarily intended for purchase by government departments. The company has achieved a handful of sales to private buyers, however. The BYD-patented battery uses a proprietary iron chemistry that is said to be much more cost-effective, enabling it to provide an affordable challenge to lithium batteries. BYD had already shown a plug-in hybrid version of its midsize sedan, the F6 DM, at various motor shows and is planning to introduce this model in the next few months. The all-wheel-drive pure electric e6 lifestyle monobox concept vehicle, however, contrary to earlier production announcements, is now not expected to go into production within the next two or three years. Chery Chery announced the 1.6-L A5 BSG (belt starter generator) last January and is working on a similarly equipped A3 sedan and hatchback for launch around the middle of the year. The A5 BSG’s purchase price makes it the only start-stop hybrid on the market available for under 80,000 yuan (U.S. $11,700). The company is also readying an ISG (integrated starter generator) mild hybrid version of the A5 sedan,　which it had already demonstrated during the Olympics. It links a 1.3-L engine to a 12 kW electric motor running on 151 V. Chery sent more than 100 production managers to work with Ricardo in the U.K.　to develop its BSG and ISG models. The　collaboration resulted in the design of not only the vehicles themselves but also included the vehicle controller, battery, and traction motor elements. Chery announced production of its S18 electric five-door　hatchback city car in February. It uses the same platform as the seven-model Faira city car range that will soon enter series production. A 40 Ah lithium iron phosphate battery provides　336 V current to power the 40 kW electric motor. Maximum speed is a claimed 120 km/h (75 mph) and range is 120-150 km (75-93 mi). A full charge takes 4-6 hours. FAW China’s first domestic vehicle manufacturer is working on a full hybrid capable of running long distances under electric power. The B70HEV, also known as the Besturn, uses a bespoke AMT (automated manual transmission) and is expected to supply up to 20 units to Tianjin and Chengdu by the end of 2010. The ramp up to series production is expected in 2012. FAW also plans to produce 100 hybrid buses for Dalian and Changchun. Geely Geely’s rounded little Panda city hatchback is currently being readied for the market in pure plug-in electric form, but the production date has not yet been fixed. Domestic manufacturers of pure electric and plug-in hybrids face the challenge of how to charge the battery: the vast majority of Chinese households do not have garages and do not have readily available power sources with which to charge their vehicles. This should not affect the electric Panda’s sales performance with regards to the current large-scale encouragement program. The Geely spokesman said, "Government departments generally have garage parking facilities where the vehicle can be recharged. The problem of where to charge the vehicle for the general public is still a challenge that needs to be solved, but we are working on it." Geely has also developed CNG and ethanol-powered versions of a number of its existing vehicles and already produces these in limited numbers. A new methanol-powered drivetrain is also being developed but as yet is unable to go to market because "the government has not yet established any rules for this power source." The challenge ahead The Ministry of Finance’s launch of this massive hybrid and alternative energy program is obviously a source of great encouragement to the car manufacturers. But the issue of high cost remains, at least for the initial limited production runs. The OEMs obviously have their work cut out as they strive to bring costs down to acceptable levels, notwithstanding the generous subsidies that have been offered to ease the process. In addition to this factor, the automakers also have to ensure that their models are able to provide robust – three years or 150,000 km (90,000 mi) – fault-free performance, along with all the necessary servicing, spare parts, and maintenance network. With their low emissions and modern engine designs capable of meeting Euro 4 and 5 regulations, however, the makers of gasoline-engined cars appear　best placed to take early advantage of worldwide export opportunities for energy-saving vehicles in coming years.

　

In-vehicle Networking

In-vehicle Networking:
As we all know that in the vehicle all electrical and electronics parts and components were connected through wiring harness to transmit signal / information from one point to another point. In conventional wiring harness system dedicated wires required for each and every signal. For few featured vehicle this system is good and cost effective but when we talk about a vehicle with luxury features, this system become more complex and costly. To avoid that complexity In-Vehicle networking comes in picture which is also known as multiplex wiring.
In-vehicle Networking
 –Connect the vehicle's electronic equipments.
 –Facilitate the sharing of information and resources among the distributed applications.
 –Change the point-to-point wiring of centralized ECUs to the in-vehicle networking of distributed ECUs.
Aims of In-vehicle Networking:
 –Open Standard
 –Ease to Use
 –Cost Reduction
 –Improved Quality
Benefits of In-vehicle Networking:
 –More reliable vehicle
 –More functionality at lower price
 –Standardization of interfaces and components
 –Faster introduction of new technologies
 –Functional Extendibility
 –Decreasing wiring harness weight and complexity
 –Electronic Control Units are shrinking and are directly applied to actuators and sensors

In-vehicle Networking or multiplexing is based on serial protocols. Modern automobile’s protocols are listed below

S.N Protocol Name Speed Use Origin
1 D2B 5Mbit/s High Speed electrical or optical mainly for digital audio Auto
2 MOST 22.5Mbit/s High Speed (audio, video, control) Auto
3 FlexRay 10Mbit/s High Speed x-by-wire, safety-critical control) Auto
4 Byteflight 10Mbit/s High Speed constant latencies, airbag, sear-belt Auto
5 TTP 5~25Mbit/s High Speed real-time distributed/fault-tolerant apps Auto
6 Bluetooth 10Mbits/s High Speed wireless for infotainment equipments Consumer
7 CAN 50-1000kbit/s Low Speed Controls Auto
8 J1850 10.4kbit/s and 41.6kbit/s Low Speed Controls Auto
9 LIN 20kbps Low Speed Controls Auto

 

Protocol Comparison:

 • Class A (<20 kbit/s) : LIN, CAN
 • Class B (50-500 kbit/s) : CAN, J1850
 • MMedia (> 20 Mbit/s) : MOST, Firewire
 • Wireless : GSM, Bluetooth
 • Safety : Byteflight, TTP/C, Flexray

1. D2B (Domestic Data Bus)
–Matsushita and Philips jointly developed
–Has promoted since 1992
–D2B was designed for audio-video communications, computer peripherals, and automotive media applications
 –The Mercedes-Benz S-class vehicle uses the D2B optical bus to network the car radio, autopilot and CD systems
 –The Tele-Aid connection, cellular phone, and Linguatronic voice-recognition application

2. Media-Oriented Systems Transport (MOST)
 –It was initiated in 1997
 –Supports both time-triggered and event-triggered traffic with predictable frame transmission at speeds of 25Mbps
 –Using plastic optic fiber as communication medium
 –The interconnection of telematics and infotainment such as video displays, GPS navigation systems, active speaker and digital radio
 –More than 50 firms—including Audi, BMW, Daimler-Chrysler, Becker Automotive, and Oasis Silicon Systems—developed the protocol under the MOST Cooperative

3. FlexRay
 –FlexRay is a fault-tolerant protocol designed for high-data-rate, advanced-control applications, such as X-by-wire systems (high-speed safety-critical automotive systems)
 –Provides both time-triggered and event-triggered message transmission
 –Messages are sent at 10Mbps
 –Both electrical and optical solutions are adopted for the physical layer
 –The ECUs are interconnected using either a passive bus topology or an active star topology
 –FlexRay complements CAN and LIN being suitable for both powertrain systems and XBW systems

4. Byteflight
 –Developed from 1996 by BMW
 –A flexible time-division multiple access (TDMA) protocol using a star topology for safety-related applications
 –Messages are sent in frames at 10Mbps support for event-triggered message transmission
 –Guarantees deterministic (constant) latencies for a bounded number of high priority real-time message
 –The physical medium used is plastic optical fiber
 –Byteflight is a very high performance network with many of the features necessary for X-by-wire

5. Time-triggered protocol (TTP)
 –It was released in 1998
 –It is a pure time-triggered TDMA protocol
 –Frames are sent at speeds of 5-25Mbps depending on the physical medium
 –Designed for real-time distributed systems that are hard and fault tolerant
 –It is going on to reach speeds of 1Gbps using an Ethernet based star architecture

6. Bluetooth
 –An open specification for an inexpensive, short-range (10-100 meters), low power, miniature radio network.
 –Easy and instantaneous connections between Bluetooth-enabled devices without the need for cables
 –Vehicular uses for Bluetooth include hands-free phone sets; portable DVD, CD, and MP3 drives; diagnostic equipment; and handheld computers.

7. Controller area network (CAN)
 –Was initiated in 1981 and developed by Bosch developed the controller
 –Message frames are transmitted in an event-triggered fashion
 –Up to 1Mbps transmission speed
 –It is a robust, cost-effective general control network, but certain niche applications demand more specialized control networks.

8. The SAE J1850 Standard
 –supports two main alternatives, a 41.6 kbps PWM approach (dual wires), and a 10.4kbps VPW (single wire) approach.

9. Local interconnect network (LIN)
 –A master-slave, time-triggered protocol
 –As a low-speed (20kbps), single-wire
 –LIN is meant to link to relatively higher-speed networks like CAN
 –LIN reveals the security of serial networks in cars
 –network is used in on-off devices such as car seats, door locks, sunroofs, rain sensors, and door mirrors

Exhaust Energy recovery

Even the most efficient IC engine of today can at the most squeeze out 25% of the fuel's energy and convert it into useful mechanical energy. The rest is wasted has exhaust heat, coolant heat, noise and friction(see image). Of this, significant amount is wasted as exhaust heat. It will be great break-through if this energy is tapped and converted into useful work. Three possible ways of tapping this energy
1) Petlier modules: Uses differential heat of exhaust and ambient temperature to produce electricity
2) Water tube boiler & turbine system: A miniature water tube boiler which uses exhaust heat to produce steam which can drive a generator attached to a turbine
3) Vapour absorption airconditioning: Use exhaust heat to cool the cabin by using vapour absorption refrigeration cycle.

The technologies mentioned in point 1 & 2 can replace the conventional alternator, reducing about 2kW load from the IC engine.

The technology mentioned in the mentioned in point 3 can replace the AC compressor, reducing about 3kW load from the engine.

Suming up we can recover atleast 5kW of useful energy from the exhaust, thereby giving 5kW additional power for traction from the same engine. Effectively the engine can be downsized, giving better fuel economy. If the concept proves successful and economical this could be big releif for customers at this time of rising fuel prices

Gear Box

GM's New Fuel-Cell Car

Energy

GM's New Fuel-Cell Car

The flexible electric car platform is innovative, but the fuel-cell version is freighted with hydrogen's flaws.

• Monday, April 23, 2007
• By Kevin Bullis

Last week General Motors (GM) unveiled a hydrogen-fuel-cell-powered version of its Chevrolet Volt concept, a family of electric cars that get a portion of their energy from being plugged into the electrical grid. The first version, announced in January, married plug-in electric drive to a gasoline or ethanol generator that can recharge the battery.
But swapping out the generator for a fuel cell may be a step backward. That is in part because producing the hydrogen needed to power the fuel-cell version could increase rather than decrease energy demand, and it may not make sense economically.
"The possibility that this vehicle would be built successfully as a commercial vehicle seems to me rather unlikely," says Joseph Romm, who managed energy-efficiency programs at the Department of Energy during the Clinton administration. "If you're going to the trouble of building a plug-in and therefore have an electric drive train and a battery capable of storing a charge, then you could have a cheap gasoline engine along with you, or an expensive fuel cell." Consumers will likely opt for the cheaper version, Romm notes.
Still, the Volt is part of a promising trend toward automotive electrification--which could decrease petroleum use and reduce carbon emissions. It is part of GM's response to an anticipated future in which both petroleum and carbon-dioxide emissions will carry a heavy price, driving consumers to buy vehicles that run on alternative, low-carbon power sources.
The new Volt, announced in Shanghai, replaces the generator with a fuel cell and cuts the battery pack in half, in part to make room for storing hydrogen. The lithium-ion battery pack can be recharged by plugging it in. The fuel cell kicks in immediately when the car is started and provides power at a constant rate at which it is most efficient. If more power is needed, such as for acceleration or high speeds, the battery provides a boost of power, much like what happens in today's gas-electric hybrid vehicles. When less power is needed, such as when the vehicle is stopped or at low speeds, the battery stores energy to be used later.
By allowing the fuel cell to run at a constant rate, the batteries improve efficiency, cutting down on hydrogen consumption. The battery further improves efficiency by storing energy generated during braking. Compared with earlier prototypes, the new concept also uses a more advanced fuel-cell design (thinner stainless-steel parts were substituted for thick composite parts) and the vehicle is lighter, making it possible to have a 300-mile range using half the hydrogen.
The car emits no harmful emissions from the tailpipe. But because hydrogen fuel today is primarily made from fossil fuels this means the carbon-dioxide emissions are simply happening someplace else, Romm notes. He says that using renewable energy to charge up the battery in the gas-generator version of the Volt makes more sense than using it to make hydrogen. That's because it's more efficient to charge a battery than to make hydrogen, compress it, and then convert it back into electricity using a fuel cell.

 

Nick Zielinski, the chief engineer at GM responsible for advanced vehicle concepts, says that GM released the fuel-cell version in China because hydrogen has a better chance of taking hold there. In China, energy infrastructure is still being developed, and gasoline and electricity may not be available everywhere. "They could develop a hydrogen infrastructure much sooner than we do here. And a fuel-cell vehicle may make more sense than a plug-in-to-grid option because hydrogen may be much more accessible," Zielinski says. He adds that "hydrogen, when it's generated in a renewable way, produces no emissions. And that's where I think we'd like to get to."
With the Volt, the power source can vary according to the proposed market. In the original version revealed in January, likely to attract customers in the United States, the first 40 miles of driving are powered by energy stored in a battery pack that can be recharged by plugging it in. (See "GM's New Electric Vehicle.") That's enough range for a typical daily commute. For longer trips, a gas- or ethanol-powered generator recharges the battery, allowing for an additional 600 miles of range. In Europe, diesel generators can be used, rather than gasoline generators or fuel cells.
Other major automakers are also developing plug-in fuel-cell and battery-powered vehicles. In January, Ford unveiled a vehicle that runs off stored power in the battery for the first 25 miles before a fuel cell starts recharging the battery, which can add an additional 200 miles of range. As with GM's Volt, the fuel cell could be replaced by a gas or diesel generator.
Both the fuel-cell and generator versions of the Volt will face challenges, but it's likely that the fossil-fuel versions will reduce carbon-dioxide emissions more than the fuel-cell versions. The Volt equipped with a gas-powered generator has a large battery pack that will allow most drivers to skip the gas station altogether for daily commuting. And because the generator is very efficient, even for trips longer than 40 miles it may use less gas than ordinary cars. Of course, total carbon emissions will depend on the source of the electricity for charging the battery, but the relatively high efficiency of power plants compared with conventional vehicles will likely lead to lower carbon-dioxide emissions overall.
The main challenge with this vehicle is that a big enough lithium-ion battery pack, made to withstand the abuse of automotive applications, hasn't yet been created. Zelinski says that no more major breakthroughs in battery-cell technology are needed. All that's left is to integrate hundreds of these cells to make a big battery pack. That's going to be challenging, but, he says, "it's something that can be handled in a straightforward, solid-engineering way."

Tata Indica eV2 launched at a starting price of Rs 2.95 lakh

Tata Motors on Thursday said it has launched new diesel and petrol variants of its hatchback Indica, priced between Rs 2.95 lakh and Rs 3.95 lakh (ex-showroom, Delhi). 

The company claimed that the diesel vehicle gives a mileage of 25 km per litre as per Automotive Research Association of India (ARAI) and is the most fuel efficient car in India. 

The new car -- eV2 -- comes with a CR4 common rail diesel engine. It has a displacement of 1396 cc delivering 70 PS @ 4000 RPM. It has a torque of 140 NM at a lower 1800-3000 RPM. The company claims that the new CR4 engine has resulted in 32% increase in power, 65% increase in torque as well as a 46% improvement on fuel efficiency. The petrol option will run on a multi-point fuel injection engine. Both these engines are compliant with BS4 emission norms. 

The new Indica ev2 comes with features like Auto-Drive Assist, which ensures that while climbing a gradient the engine will not stall even if the foot is completely taken off the clutch, thus enabling the driver to easily shift his foot to the accelerator. Clutch-To-Start feature that will ensure that one cannot crank the engine unless the clutch is fully engaged, hence there is no risk of re-crank if engine is on. 

"The Tata Indica eV2 is in the range of Rs 3.95 lakh and Rs 4.77 lakh (ex-showroom, Delhi) for the CR4 diesel engine and in the range of Rs 2.95 lakh and Rs 3.58 lakh (ex-showroom Delhi) for the MPFI petrol," Tata Motors statement said. 

Indica eV2 range is available in four colours- Apple Green, Neo Orange, Arctic Silver and Mint White. The car comes with a warranty of 24 months or 75000 km whichever is earlier.

Basics of Internal Combustion Engines

The ­principle behind any reciprocating internal combustion engine: If you put a tiny amount of high-energy fuel (like gasoline) in a small, enclosed space and ignite it, an incredible amount of energy is released in the form of expanding gas. You can use that energy to propel a potato 500 feet. In this case, the energy is translated into potato motion. You can also use it for more interesting purposes. For example, if you can create a cycle that allows you to set off explosions like this hundreds of times per minute, and if you can harness that energy in a useful way, what you have is the core of a car engine!

Figure 1

Almost all cars currently use what is called a four-stroke combustion cycle to convert gasoline into motion. The four-stroke approach is also known as the Otto cycle, in honor of Nikolaus Otto, who invented it in 1867. The four strokes are illustrated in Figure 1. They are:

• Intake stroke
• Compression stroke
• Combustion stroke
• Exhaust stroke

You can see in the figure that a device called a piston replaces the potato in the potato cannon. The piston is connected to the crankshaft by a connecting rod. As the crankshaft revolves, it has the effect of "resetting the cannon." Here's what happens as the engine goes through its cycle:

1. The piston starts at the top, the intake valve opens, and the piston moves down to let the engine take in a cylinder-full of air and gasoline. This is the intake stroke. Only the tiniest drop of gasoline needs to be mixed into the air for this to work. (Part 1 of the figure)
2. Then the piston moves back up to compress this fuel/air mixture. Compression makes the explosion more powerful. (Part 2 of the figure)
3. When the piston reaches the top of its stroke, the spark plug emits a spark to ignite the gasoline. The gasoline charge in the cylinder explodes, driving the piston down. (Part 3 of the figure)
4. Once the piston hits the bottom of its stroke, the exhaust valve opens and the exhaust leaves the cylinder to go out the tailpipe. (Part 4 of the figure)

Now the engine is ready for the next cycle, so it intakes another charge of air and gas.

Notice that the motion that comes out of an internal combustion engine is rotational, while the motion produced by a potato cannon is linear (straight line). In an engine the linear motion of the pistons is converted into rotational motion by the crankshaft. The rotational motion is nice because we plan to turn (rotate) the car's wheels with it anyway.

Basic Engine Parts

The core of the engine is the cylinder, with the piston moving up and down inside the cylinder. The engine described above has one cylinder. That is typical of most lawn mowers, but most cars have more than one cylinder (four, six and eight cylinders are common). In a multi-cylinder engine, the cylinders usually are arranged in one of three ways: inline, V or flat (also known as horizontally opposed or boxer), as shown in the following figures.

Figure 2. Inline - The cylinders are arranged in a line in a single bank.

Figure 3. V - The cylinders are arranged in two banks set at an angle to one another.

Figure 4. Flat - The cylinders are arranged in two banks on opposite sides of the engine.

Different configurations have different advantages and disadvantages in terms of smoothness, manufacturing cost and shape characteristics. These advantages and disadvantages make them more suitable for certain vehicles.

Let's look at some key engine parts in more detail.

Spark plug

The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur. The spark must happen at just the right moment for things to work properly.

Valves

The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust. Note that both valves are closed during compression and combustion so that the combustion chamber is sealed.

Piston

A piston is a cylindrical piece of metal that moves up and down inside the cylinder.

Piston rings

Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the cylinder. The rings serve two purposes:

• They prevent the fuel/air mixture and exhaust in the combustion chamber from leaking into the sump during compression and combustion.
• They keep oil in the sump from leaking into the combustion area, where it would be burned and lost.

Most cars that "burn oil" and have to have a quart added every 1,000 miles are burning it because the engine is old and the rings no longer seal things properly.

Connecting rod

The connecting rod connects the piston to the crankshaft. It can rotate at both ends so that its angle can change as the piston moves and the crankshaft rotates.

Crankshaft

The crankshaft turns the piston's up and down motion into circular motion just like a crank on a jack-in-the-box does.

Sump

The sump surrounds the crankshaft. It contains some amount of oil, which collects in the bottom of the sump (the oil pan).

Engine Problems

So you go out one morning and your engine will turn over but it won't start... What could be wrong? Now that you know how an engine works, you can understand the basic things that can keep an engine from running. Three fundamental things can happen: a bad fuel mix, lack of compression or lack of spark. Beyond that, thousands of minor things can create problems, but these are the "big three." Based on the simple engine we have been discussing, here is a quick rundown on how these problems affect your engine:

Bad fuel mix - A bad fuel mix can occur in several ways:

• You are out of gas, so the engine is getting air but no fuel.
• The air intake might be clogged, so there is fuel but not enough air.
• The fuel system might be supplying too much or too little fuel to the mix, meaning that combustion does not occur properly.
• There might be an impurity in the fuel (like water in your gas tank) that makes the fuel not burn.

Lack of compression - If the charge of air and fuel cannot be compressed properly, the combustion process will not work like it should. Lack of compression might occur for these reasons:

• Your piston rings are worn (allowing air/fuel to leak past the piston during compression).
• The intake or exhaust valves are not sealing properly, again allowing a leak during compression.
• There is a hole in the cylinder.

The most common "hole" in a cylinder occurs where the top of the cylinder (holding the valves and spark plug and also known as the cylinder head) attaches to the cylinder itself. Generally, the cylinder and the cylinder head bolt together with a thin gasket pressed between them to ensure a good seal. If the gasket breaks down, small holes develop between the cylinder and the cylinder head, and these holes cause leaks.

Doing regular engine maintenance can help you avoid future repairs.

Lack of spark - The spark might be nonexistent or weak for a number of reasons:

• If your spark plug or the wire leading to it is worn out, the spark will be weak.
• If the wire is cut or missing, or if the system that sends a spark down the wire is not working properly, there will be no spark.
• If the spark occurs either too early or too late in the cycle (i.e. if the ignition timing is off), the fuel will not ignite at the right time, and this can cause all sorts of problems.

Many other things can go wrong. For example:

• If the battery is dead, you cannot turn over the engine to start it.
• If the bearings that allow the crankshaft to turn freely are worn out, the crankshaft cannot turn so the engine cannot run.
• If the valves do not open and close at the right time or at all, air cannot get in and exhaust cannot get out, so the engine cannot run.
• If someone sticks a potato up your tailpipe, exhaust cannot exit the cylinder so the engine will not run.
• If you run out of oil, the piston cannot move up and down freely in the cylinder, and the engine will seize.

In a properly running engine, all of these factors are within tolerance.

As you can see, an engine has a number of systems that help it do its job of converting fuel into motion. We'll look at the different subsystems used in engines in the next few sections.

Engine Valve Train and Ignition Systems

Most engine subsystems can be implemented using different technologies, and better technologies can improve the performance of the engine. Let's look at all of the different subsystems used in modern engines, beginning with the valve train.

The valve train consists of the valves and a mechanism that opens and closes them. The opening and closing system is called a camshaft. The camshaft has lobes on it that move the valves up and down, as shown in Figure 5.

Figure 5. The camshaft

Most modern engines have what are called overhead cams. This means that the camshaft is located above the valves, as you see in Figure 5. The cams on the shaft activate the valves directly or through a very short linkage. Older engines used a camshaft located in the sump near the crankshaft. Rods linked the cam below to valve lifters above the valves. This approach has more moving parts and also causes more lag between the cam's activation of the valve and the valve's subsequent motion. A timing belt or timing chain links the crankshaft to the camshaft so that the valves are in sync with the pistons. The camshaft is geared to turn at one-half the rate of the crankshaft. Many high-performance engines have four valves per cylinder (two for intake, two for exhaust), and this arrangement requires two camshafts per bank of cylinders, hence the phrase "dual overhead cams." 

The ignition system (Figure 6) produces a high-voltage electrical charge and transmits it to the spark plugs via ignition wires. The charge first flows to a distributor, which you can easily find under the hood of most cars. The distributor has one wire going in the center and four, six, or eight wires (depending on the number of cylinders) coming out of it. These ignition wires send the charge to each spark plug. The engine is timed so that only one cylinder receives a spark from the distributor at a time. This approach provides maximum smoothness.

Figure 6. The ignition system Engine Cooling, Air-intake and Starting Systems The cooling system in most cars consists of the radiator and water pump. Water circulates through passages around the cylinders and then travels through the radiator to cool it off. In a few cars (most notably Volkswagen Beetles), as well as most motorcycles and lawn mowers, the engine is air-cooled instead (You can tell an air-cooled engine by the fins adorning the outside of each cylinder to help dissipate heat.). Air-cooling makes the engine lighter but hotter, generally decreasing engine life and overall performance. Diagram of a cooling system showing how all the plumbing is connected So now you know how and why your engine stays cool. But why is air circulation so important? Most cars are normally aspirated, which means that air flows through an air filter and directly into the cylinders. High-performance engines are either turbocharged or supercharged, which means that air coming into the engine is first pressurized (so that more air/fuel mixture can be squeezed into each cylinder) to increase performance. The amount of pressurization is called boost. A turbocharger uses a small turbine attached to the exhaust pipe to spin a compressing turbine in the incoming air stream. A supercharger is attached directly to the engine to spin the compressor. Increasing your engine's performance is great, but what exactly happens when you turn the key to start it? The starting system consists of an electric starter motor and a starter solenoid. When you turn the ignition key, the starter motor spins the engine a few revolutions so that the combustion process can start. It takes a powerful motor to spin a cold engine. The starter motor must overcome: All of the internal friction caused by the piston rings The compression pressure of any cylinder(s) that happens to be in the compression stroke The energy needed to open and close valves with the camshaft All of the "other" things directly attached to the engine, like the water pump, oil pump, alternator, etc. Because so much energy is needed and because a car uses a 12-volt electrical system, hundreds of amps of electricity must flow into the starter motor. The starter solenoid is essentially a large electronic switch that can handle that much current. When you turn the ignition key, it activates the solenoid to power the motor. Engine Lubrication, Fuel, Exhaust and Electrical Systems When it comes to day-to-day car maintenance, your first concern is probably the amount of gas in your car. How does the gas that you put in power the cylinders? The engine's fuel system pumps gas from the gas tank and mixes it with air so that the proper air/fuel mixture can flow into the cylinders. Fuel is delivered in three common ways: carburetion, port fuel injection and direct fuel injection. In carburetion, a device called a carburetor mixes gas into air as the air flows into the engine. In a fuel-injected engine, the right amount of fuel is injected individually into each cylinder either right above the intake valve (port fuel injection) or directly into the cylinder (direct fuel injection). Oil also plays an important part. The lubrication system makes sure that every moving part in the engine gets oil so that it can move easily. The two main parts needing oil are the pistons (so they can slide easily in their cylinders) and any bearings that allow things like the crankshaft and camshafts to rotate freely. In most cars, oil is sucked out of the oil pan by the oil pump, run through the oil filter to remove any grit, and then squirted under high pressure onto bearings and the cylinder walls. The oil then trickles down into the sump, where it is collected again and the cycle repeats. The exhaust system of a Porsche 911. Now that you know about some of the stuff that you put in your car, let's look at some of the stuff that comes out of it. The exhaust system includes the exhaust pipe and the muffler. Without a muffler, what you would hear is the sound of thousands of small explosions coming out your tailpipe. A muffler dampens the sound. The exhaust system also includes a catalytic converter. The emission control system in modern cars consists of a catalytic converter, a collection of sensors and actuators, and a computer to monitor and adjust everything. For example, the catalytic converter uses a catalyst and oxygen to burn off any unused fuel and certain other chemicals in the exhaust. An oxygen sensor in the exhaust stream makes sure there is enough oxygen available for the catalyst to work and adjusts things if necessary. Besides gas, what else powers your car? The electrical system consists of a battery and an alternator. The alternator is connected to the engine by a belt and generates electricity to recharge the battery. The battery makes 12-volt power available to everything in the car needing electricity (the ignition system,radio, headlights, windshield wipers, power windows and seats, computers, etc.) through the vehicle's wiring. Producing More Engine Power Using all of this information, you can begin to see that there are lots of different ways to make an engine perform better. Car manufacturers are constantly playing with all of the following variables to make an engine more powerful and/or more fuel efficient. Increase displacement - More displacement means more power because you can burn more gas during each revolution of the engine. You can increase displacement by making the cylinders bigger or by adding more cylinders. Twelve cylinders seems to be the practical limit. Increase the compression ratio - Higher compression ratios produce more power, up to a point. The more you compress the air/fuel mixture, however, the more likely it is to spontaneously burst into flame (before the spark plug ignites it). Higher-octane gasolines prevent this sort of early combustion. That is why high-performance cars generally need high-octane gasoline -- their engines are using higher compression ratios to get more power. The turbocharger system of the Nissan GT-R. Stuff more into each cylinder - If you can cram more air (and therefore fuel) into a cylinder of a given size, you can get more power from the cylinder (in the same way that you would by increasing the size of the cylinder). Turbochargers and superchargers pressurize the incoming air to effectively cram more air into a cylinder.  Cool the incoming air - Compressing air raises its temperature. However, you would like to have the coolest air possible in the cylinder because the hotter the air is, the less it will expand when combustion takes place. Therefore, many turbocharged and supercharged cars have anintercooler. An intercooler is a special radiator through which the compressed air passes to cool it off before it enters the cylinder. See  Let air come in more easily - As a piston moves down in the intake stroke, air resistance can rob power from the engine. Air resistance can be lessened dramatically by putting two intake valves in each cylinder. Some newer cars are also using polished intake manifolds to eliminate air resistance there. Bigger air filters can also improve air flow. Let exhaust exit more easily - If air resistance makes it hard for exhaust to exit a cylinder, it robs the engine of power. Air resistance can be lessened by adding a second exhaust valve to each cylinder (a car with two intake and two exhaust valves has four valves per cylinder, which improves performance -- when you hear a car ad tell you the car has four cylinders and 16 valves, what the ad is saying is that the engine has four valves per cylinder). If the exhaust pipe is too small or the muffler has a lot of air resistance, this can cause back-pressure, which has the same effect. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system. When you hear that a car has "dual exhaust," the goal is to improve the flow of exhaust by having two exhaust pipes instead of one. Make everything lighter - Lightweight parts help the engine perform better. Each time a piston changes direction, it uses up energy to stop the travel in one direction and start it in another. The lighter the piston, the less energy it takes. Inject the fuel - Fuel injection allows very precise metering of fuel to each cylinder. This improves performance and fuel economy.