INTRODUCTION
The automobile industry, including the manufacture of components, is estimated to provide employment
directly to some 550,000 people and indirectly to around 12 mn people. The investment in the industry is
estimated at over Rs 230 bn in the vehicles segment and another about Rs 130 bn in the auto components
segment. The overall production of the industry is placed at over Rs 1000 bn with some Rs 70 bn worth of
output being exported. There are over 17 mn 4- and 6-wheelers and over 15 mn 2- and 3-wheelers plying
on the Indian roads.
Following the liberalisation of the Indian economy in early 1990s and particularly after the opening up
of the auto sector to the global players, the end of the decade presented a vastly transformed scenario for
the industry.
The passenger car segment has been inundated with global giants having set up their own facilities in
India. From 3 main players until the 1980s, the segment has today 13 players, including the multinationals
like General Motors, Ford, Daimler Chrysler, Honda, Hyundai, Fiat, Toyota, Skoda, BMW, Audi and
Volkswagen. Nissan of Japan has also planned an assembly line in India. Its X-Trail SUV was the first
offering. Several others, besides the leader, Maruti Udyog (now Maruti Suzuki) have made the whole industry
a much contested and vibrant sector. Indias own Tata Motors has emerged as an established player in
passenger cars with Indica and Indigo brands, besides being a leader in commercial vehicles segment.
With the launch of Nano, it has ushered in a new chapter in the history of the Indian automobile industry.
In fact, it has trigerred a new interest in mini passenger cars over the entire global automobile industry.
At the start of the new millennium (2000-01), there were a total of 38 active producers of vehicles, with
some operating in more than one segment of the automobile industry. With the exit of several 2-wheeler
manufacturers and others like Daewoo, the total number dropped down to around 30. The liberalisation
process acted as a catalyst and several collaborations were forged.
The Society of Indian Automobile Manufacturers (SIAM), as part of its ‘Vision Statement, had made
projections on the automobile industry. According to these projections, the Indian passenger car industry
is expected to grow to 2.4 mn by the year 2010, against 416,000 in 1997-98. This represents a compounded
annual growth rate (CAGR) of 16% and an increase in its share of the total industry output to 37% from
the current 30%. In the process, the size of the market was expected to touch Rs 680 bn by 2010, compared
to Rs 125 bn in 1997-98. The penetration of passenger cars was expected to increase to 20 per thousand
from 4 per thousand presently.
To achieve global competitiveness in the automobiles industry and also to double its contribution to
the economy by 2010, the Government of India had announced its vision statement in 2002 in the form of
a new auto policy. It aimed at promoting an integrated, phased, enduring and self-sustained growth in the
Indian automotive industry. The broad features of the policy are:
PASSENGER CAR INDUSTRY IN INDIA
From a very modest beginning, the Indian passenger car industry has come a long way. The industry
has the presence of global players like General Motors, Ford, Suzuki, Toyota, Mitsubishi, Honda, Fiat,
Hyundai, Daimler Chrysler, Skoda, Nissan, BMW and Renault. MNCs are widening their product portfolio,
which will further intensify competition. This also marks the next phase of the Indian auto industry after the
sector was opened up.
Looking back, the passenger car industry in India has marked five phases:
Phase I (upto 1984) Regulated and restrained market
Phase II (1985 to 1992) Exploring new technology
Phase III (1995 to 2000) Hurried entry of world players
Phase IV (2001-04) Market maturing with intense competition
Phase V (2005 and after) Globalisation
With about 13 existing players in the passenger car segment, the total installed capacity is of the order
of over a million and a half vehicles. The capacity utilization was as high as over 85% in 2006-07. Total
investment by the car companies is estimated at around Rs 175 bn with related component makers chipping
in another Rs 50 to 60 bn.
The scale of operations of Indian car plants is now beginning to match with the world standards. The
average capacity of a typical Indian car producer exceeds 100,000 units a year. It is 250,000 in Japan and
the US; 125,000 in Brazil and 175,000 in South Korea. Volumes of 100,000 to 150,000 are considered
viable.
In 2006 Maruti Udyog was considered the most trusted company by the Indian customers, according
to a survey on the Corporate Social Responsibility (CSR) conducted by TNS Automotive Global, world’s
largest automotive rating agency. In 2006, Maruti introduced its hatchback ‘SWIFT’ and soon earned title
of the best car of the year. In the following year, that honour was claimed by Honda’s ‘CIVIC’.
The later players, such as Skoda and Toyota lined up the market with Octavia (from Skoda) and Corolla
(from Toyota). Honda and Hyundai have come a long way through City, Accord, Sonata and so on, as their
prized offerings. BMW is setting up an assembly plant in Andhra Pradesh.
Except for Maruti Udyog JV till recently with Suzuki of Japan and Hindustan Motors tie-up with Mitsubishi
also from Japan, and now with that of Mahindra and Mahindra with Renault from France, all the global
players like GM, Ford, Hyundai, DaimlerChrysler, Skoda have their wholly owned subsidiaries in India.
Besides there are other operational alliances, such as between DCM group and Honda in Honda Siel Motors
and Toyota Kirloskar outfit.
There was a noticeable slow down in demand towards the end of 1990s. The beginnings of the new
century witnessed a revival in demand. The quinquennium 2002-2007, infact witnessed on an average a
CAGR of 17.8%, much above the Indian industry. Total market of passenger cars was estimated at Rs
476 bn in 2007-08 which means an increase of 12% over that of the preceding year.
The car sales in 2007-08 including exports was 1.5 mn vehicles, about 18% increase on the preceding
year’s car sales of some 1.25 mn units.
A new trend in the passenger car market is the exchange schemes launched by car makers. Besides
there is the emergence of pre-owned cars market. In 2006-07, an estimated 12.5% of all car sales was
achieved through exchange of old models on the back of brand loyalty. Maruti has been a major beneficiary
selling reportedly 76,500 cars under the scheme. Others benefiting include Hyundai (16%), GM (8 to 10%)
and Honda (6%).
The sale of pre-owned (or second hand) cars has caught on. Not only Maruti which sold 84,500 cars
through its ‘True Value’ chain of marketing outlets, even global majors like Porsche (40 cars) and Bentley
have also joined the bandwagon. Nearly 20% of the pre-owned market is organized. Some 60% are sold
by individuals through word of mouth, while 20% of the market is controlled by brokers.
Honda Motor Company (HMC) was planning to launch a small car through its subsidiary Honda Seil
Cars India (HSCI), by 2010. The car is expected to take on Maruti Swift, Hyundai Getz, Fiat Palio, General
Motors UV-A and when launched, Volkswagen Polo. Honda is planning to launch new version of premium
sedan Accord following a planned facelift in 2007. The company has plans to increase the production
capacity to 100,000 units by the end 2007, from the existing 60,000 at its Greater Noida facility. The plant
produces City, Civic and Accord brands of cars. Rajasthan state is the likely site for its second car-making
facility to take on the production of its proposed range of hatchback models, including the small car offering
Jazz.
Tata Motors and Fiat had agreed on entering into a joint venture to make cars and engines at a proposed
investment of Rs 40 bn. While the annual capacity for cars would exceed 100,000, the plant will also have
a manufacturing capacity for 200,000 engines. The production was slated to start towards the beginning
of 2008. The venture located at the Fiat plant at Rajnangaon in Maharashtra, will also produce Fiat Grande
Punto and the Linea for Indian and overseas markets. As a follow up to the introduction of the entire
Mercedes Benz line to India, DaimlerChrysler is contemplating to bring in its Chrysler range of vehicles as
well.
Since mid-2006, the D segment has been marked by great launches by all those who matter in the
Industry, not only in India but globally. Honda Civic entered into Indian market in July 2006. With its entry,
the highly competitive entry-level D-segment has got revamped. Honda City in premium C-segment and
Honda Accord in Upper D-segment along Civic, present a very impressive range from the car maker. The
launch of a new variant of Corolla in Japan, which would find its way to the Indian market, may improve on
Toyota’s performance in the market in respect of passenger cars, as earlier the sales were 20% down.
Skoda’s Octavia in the segment is going high on its diesel variant.
As indicated, Volkswagen is entering into the premium segment Passat to be assembled at Skoda
Plant slated for mid 2007. A new plant is coming up at Pune which would roll out Polo hatchback and
notchback in 2009. Its plans cover production of mid-sized Jetta in India. It is however, building market on
imported cars like Touareg and Phaeton in India.
GM launched Chevrolet Spark (April 2007) to take on Alto, Zen Estilo, Wagon R and Santro. The car
is based on Daewoo’s Matiz platform adequately modified to give a different look. Earlier, it had launched
Aveo UVA. The company aims to capture 10% market share by 2010. It has set a target for sale of 40,000
small cars in 2007-08. In 2003, following listless performance of its Opal series, it came with Chevrolet
brands (Tavera-SUV, Optra).
AUTO BULBS/LAMPS
INTRODUCTION
As the name implies it is the lamp used in automobiles but the above said words “used in” have a very
wide meanings. Lamps are one of the most important parts of automobiles making then safe for driving’s
on road. The vehicles act puts a compulsion that every vehicle should be provided head lights, may be
one or more according to the design and necessity of vehicles, to enligthen the road in front of driver
increasing his visibility and enabling him capable of night driving. Further the vehicles should have side
lights and indicator lights for indicating size of vehicles and the direction it is going to take turn in respectively.
The tail light & brake lights has been made compulsory to indicate the existence of the vehicle on the road
& that it is going to stop. Dash board light & number plate lights though not necessary for safety reasons
still increases the facilities to drivers & traffic controllers.
The continuously increasing production of automobile vehicles ensure rapid consumption of product.
Except if retail market can be captured the auto garages & accessory dealers may consume big part of
the product also giving a large margin.
Raw materials like glass, metal seats & caps filament wire & sealing wax etc. are available very easily.
If a plastic molding unit (Injection) is installed additionally and a little more of lamps also can be manufactured
in the factory which, of course, is an expansion programme only.
After this expansion, the profit margin will increase multi-fold. But, then, a larger set-up will have to be
managed, which requires some pre-establishments in order to avoid risks of failures at any particular
junctures of the entire activities.
Auto bulbs: Normally used on automobile vehicles (both Heavy, medium & Light commercial vehicles),
car, Motorcycles, scooter, three wheelers, etc. are the special bulbs. These bulbs operate by 12 volts, &
24 volts batteries or generators inside the vehicle while 6V bulbs are generally used in Scooters. These
bulbs in combination with metallic & plastic seats & covers and rubber gaskets fastened at respective places
of the vehicles form the full units of auto lamps. These auto lamps produce light on the roads at night safe
driving, or but other bulbs indicate other vehicles/traffic users about then immediate intentions. This makes
other to give way for its safe turning or brake etc. The arrangements differ from one type of vehicle to
another.
FILAMENT
Auto bulb filaments are made from tungsten wire. Its physical properties depend on method of Mfg.
dimensions & chemical purity. Melting point of this material is 6120°F=3382°C. The Tungsten wire has
lone vapor pressure, high tensile strength with highest modulus of rigidity. The tungsten wires for
manufacturing filaments vary in size according to wattage ratings of bulbs for which being used. Standard
sizes of diameters of tungsten wires available in the market are generally 36,38,40 & 42 Swq.
The tungsten wire manufactures specify the current carrying capacity, of a particular wire, for producing
white hight, and resistance/cm length.
Metal Cap Making & Fixing
Generally CRCA Steel or Aluminium alloy sheets are used to make bulb caps, which ultimately make
contacts with holder conductor carrying current from the energy source.
Purchased sheets are sheared to strips of calculated widths on a shearing machine. These sheets are
then blanked on the power presses under punch & die satin action. Finally, the circular blank of sheets are
drawn/deep drawn in either a mechanical or hydraulic press. If required, final trimming can also be done
on a press in order to make the cap edges clean & free from burs.
So prepared cap goes to assembly with the auto bulb. With this, the assembly and manufacturing parts
are over for a bulb unit, only to followed by testings like resis tence, heat generation and shock withstanding
tests. All tested bulbs are then packed for sales if not intended for its assembly with frame/Cover/Gasket/
holder etc to form a complete unit of auto lamps.
AUTOMOBILE WORK SHOP
INTRODUCTION
A limited nos. of manufacturers of various types of automobile vehicles in India had their limited
capacities of production e.g. Ashok Leyland, Hindustan Motors. Models designs were changed rarely. Hence
these vehicles either could does not attract or could not reach the aspiring purchasers. A revolution has
come in the automobile industry with the introduction of light vehicles manufactured by Maruti Udyog Ltd.,
DCM Toyota Ltd.,
More & More enterprises are coming up with something designs, research and development
consequently more no. of vehicles are produced. Above inspection/ survey indicates, that future of service
stations/workshop centre for automobile have a tremendous scope. It is observed that department however
central or state Govt. consumers thousand of vehicles for their purposes.
Behind any product on the market today stands a vast accumulation of the results of scientific research
in engineering, metallurgy and design. The modern automobile is typical of this advance oil mechanisms
have been improved. In some cases, they have been replaced with newer mechanisms employing a different
principle we are inclined to think that the Zenith has been reached as each new model is introduced. But
doubtless research will continue and new models with new features will continue to come off the lines.
Each new model automobile becomes another example of the powers of science and of the scientific
method. Development of the new model involved all five steps used in the scientific method. It is evidenced by the tremendous.
Putting the new model into production and the actual production itself provide further evidence of
scientific method through production scheduler & control, acquisition of raw materials plant and machinery
layout, supply of parts, synchronization and operation of assembly lines.
In the field of automobile servicing this “Scientific method” can and should be used by the mechanic
whenever possible in arriving at correct solutions to automotive trouble shooting problems. Many motor
vehicles troubles involve trouble shooting or diagostic procedure. This must not be a hit and miss or trial
Properties
Modern automobile workshop/Service Centre involves primarily the construction operation and
maintenance of automobile w.r.t. each of its states and in all of its properties. Each part of an automobile
is made of a material that has properties, which enable it to carry out its functions. The fuel that powers
that machine to produce motion and the lubricating oils that reduce friction represent matter the is essential
to operation through not an integral part of automobile itself. The tools, the equipment and the atmosphere
of the shop itself are each examples of matter. Hydraulic jacks and air compressor employ matter in the
form of liquids and gases respectively.
The average automobile has approximately 15,000 parts. There are more than 32000 fastness, including
nuts, both, screws and rivets. Heavy automobile weight approximately more than two tons and in about
71% steel body.
Modern automobile research is investigation and testing the possibilities of such solids as fiber glass
and other plastics for use in car bodies. The use of such solids would mean less weight, and properties of
these plastics have been developed to compare favorably with many metals. Limited uses of plastics include
the simulation of wood panels in station wagon bodies and accessories.
The heavy vehicles body made by mainly M.S. plate and few parts of the body made by plastic and
few parts may be made by wooden. Heavy automobile engines imported or may be indigenous
The personnels and technicians heading their respective departments, must be hard working, apt in
decision making, swift if delivering their duties in a commercial spirit, and dedicated to give the best of
their capabilities. Along with many marketing strategies that a factory can adopt to attract customers, a
high level of work satisfaction to the dealt customers is very much significant. In truck bodies, wood works
and steel structures are in abundance while in bus bodies sheet metal work, piping work, and many other
Speciality works find a proportionate place along with wood and steel structural works.
Painting is necessary for both trucks and buses, but the method of painting, pre and post treatments,
etc. different enormously. In a truck most of the painting is done on wooden surfaces, mainly for decorative
purpose while in bus bodies, the painted surfaces are usually metallic and paint/primers are applied in
coats mainly for protective purpose and also for decorative purposes. Instructions, markings and warnings
on suitable places are done by painted displays. The main fabrication activities in practice are: - (i) oxyacetylene
gas flame cutting and welding, (ii) Electric Arc welding and cutting.
Different members of body structures and sub-structures are fastened together by either welding or
bolt/screw, or riveting or male-female joint fixing, or bracket mounting, or adhesive pasting/pressing methods,
depending on deceivability of a technique in terms of mechanical properties and environmental friendliness.
Buses and trucks are subjected to several types of jerks and impacts arising from road conditions,
influences of vehicle speed on structures used, wind speeds and directions environments and many more
factors.
AUTOMOBILE GASKETS
INTRODUCTION
Most of the methods of effecting a leak tight joint between two relatively static surfaces full into one of
the following two categories :
1. The use of gasket material, which requires an externally applied compression force to maintain
sealing contact, and
2. The use of automatic seals such as 0-rings and V-rings which rely on the system pressure in addition
to a small amount of pre load during assembly to maintain sealing contact.
The gasket is a layer of packing material firmly held between contact surfaces on two pieces whose
joint is to be sealed with the gasket. Gaskets are made in many different shapes to suit the shapes of
various mating pieces. The simplest type of gasket is that used to seal the joint between two circular flanges,
as might be used in making a joint in piping. The gasket is made of a thin sheet of material, satisfactory
for the service, having through it a hole corresponding to the internal diameter of the pipe. After being
inserted between the flanges, flange bolts draw the latter tightly together, compressing the gasket material
until it tightly seals the joint. Some gaskets are steroidal in shape, but most are flat. The services they
perform range from that of sealing against leakage of the liquids in water lines to render gas tight high
temperatures joints as those in engine exhaust manifolds. To prevent gaskets from blowing out, male or
female or tongue and groove facing may be required so that hard gaskets can be seated adequately.
Compressed asbestos sheet gaskets are usually used for service up to 300 pounds pressure and 400*C.
For higher pressure and higher temperature services (up to 590*C), metal asbestos spiral wound type
gaskets are often used. Such gaskets also find wide applications for high pressure steam service, but they
are usually used with a smooth flange finish. When used with raised facing, a solid metallic ring on the
outside (to limit gasket compression) is supplied with spiral wound types.
USES & APPLICATIONS
Gaskets in general have provided the best means of positively sealing hydraulic or pnelematic
equipment. Gaskets are used wherever two stationary pieces of metal are brought together in equipment
handling liquids or gasses. That why Gaskets are also termed static seals. The specific uses of these gaskets
are:
1. Auto Engines (Petrol & Diesel)
2. Tractor Engines.
3. Stationary Diesel Engines of all made & sizes.
4. Generators & Heavy Pump.
5. Compressors of all make & types. for further detail, please contact....
METAL GASKETS
Solid metal gaskets are designed for use in applications involving high temperatures or where nonmetallic
gaskets are unsuitable because of corrosiveness of medium. A wide range of materials &
configuration are available. Their degree of chemical & heat resistance depends on selected metal. The
principal limitations of metal gasket materials are their poor compressibility. Improved compression sealing
characteristics are achieved by combining metals with softer materials is, asbestos, TFE or rubber. Among
the most popular in this group is the spiral wound gasket, which is constructed from a spiral-wound, specially
formed metal strip & an alternating nonmetallic strip. The metals used for the gaskets are copper, Brass,
Aluminum, Tin sheets. They are most suitable for gasket. The spring action of the formed metal reacts to
compression, internal
Pressure changes, and temperature, variations, & non-metallic filter easily compress under bolt load
& improves sealability.
CORK
Because of its low cost and excellent compressibility, cork is a widely used gasket material. Gasket
density is maintained easily, usually at 224-481 kg/3 (14-30 1b/ft3), depending upon the cork particle size.
The cushioning effect of cork also is very valuable in sealing fragile surfaces, eg. Glass or ceramics. Resin
bonded cork gaskets are mixed with natural or phenol resins and then are formed and cured at moderate
temperatures. Cork-rubber composition provide a transition between Compressible cork and no
compressible rubber gaskets. The degree of their compressibility is controlled by varying the cork-rubber
ratio. The presence or rubber gives these gaskets better conformability and fatigue resistance.
Apparent Viscosity
Although consistency/penetration is used to assess the ease of flow of grease to application point, it
gives little indication of the force required to pump the grease through a long pipeline, nor does it give any
indication of the frictional resistance offered by the grease in a bearing. Such service characteristics depend
on the viscosity of the grease.
Grease is a non-Newtonian material, which does not begin to flow until a shear stress exceeding its
yield point is applied. After this, if the shear stress is increased further, the flow rate increases little more
proportionally and viscosity decreases. For grease, this observed viscosity is called “Apparent Viscosity”
which is measured by the ratio of shear stress to shear rate. The apparent viscosity varies with temperature
and shear rate both, and so it is normally reported at specific temperature and flow rate.
The apparent viscosity may again by defined as the shearing stress in dyne/cm2 required to move
either of the two parallel plates 1 cm apart, relative to each other at a velocity of 1 cm/sec, the space
between the plates filled with the fluid. This is expressed in poise.
The apparent viscosity helps in predicting the handling and dispensing properties, and leakage tendency
of grease, etc. ASTM-D. 1092 gives the method of determining such viscosity.
Drop Point
Drop point of a grease is the temperature at which the first drop of grease falls out from the orifice of
test cup under prescribed test conditions. The methods commonly used are ASTM-D 566 and ASTM-D-
2265. Conventional soap thickened greases do not have a true melting point, but have a melting range
during which they become progressively softer. Some other type of grease may separate oil without any
apparent change in state.
The drop point of grease gives no indication of the maximum service condition that the grease will
withstand, as many other factors come into play at high temperature lubrication. It only gives an indication
that grease is approaching the operating limits of satisfactory performance. Normally no grease remains
serviceable at temperature approaching it’s drop point and maximum permissible service temperature can
be found only through experience.
LUBE OIL
INTRODUCTION
Lube oil is a substance (often a liquid) introduced between two moving surfaces to reduce
the friction between them, improving efficiency and reducing wear. They may also have the function of
dissolving or transporting foreign particles and of distributing heat.
One of the single largest applications for lubricants, in the form of motor oil, is to protect the internal
combustion engines in motor vehicles and powered equipment. Practically lube oil contain 90% base oil
(most often petroleum fractions, called mineral oils) and less than 10% additives. Vegetable oils or synthetic
liquids such as hydrogenated polyolefins, esters, silicones, fluorocarbons and many others are sometimes
used as base oils. Additives deliver reduced friction and wear, increased viscosity, improved viscosity index,
resistance to corrosion and oxidation, aging or contamination, etc.
The basic functions of a lubricant are friction and wear reduction, heat removal and contaminant
suspension. Apart from important application in internal combustion engines, vehicles and industrial gear
boxes, compressors, turbines or hydraulic systems, there are vast numbers of other applications, which
mostly require specifically tailored lubricants. Designing a lubricant to perform above stated functions in
different systems is a complex task, involving a careful balance of properties both in the lube base stocks
and the performance enhancing additives. Between 5000 and 10000 different lubricant formulations are
necessary to satisfy more than 90% of all lubricant applications.
Lubricants today are classified into two major groups: Automotive lubricants and Industrial lubricants.
Automotive lubricants have to perform in different types of vehicles both petrol and diesel under a variety
of operating conditions. Modern vehicles are fuel efficient and comfortable with high levels of performance.
They are required to meet stringent emission norms. Quality requirement of such lubricants are established
by the Society of Automotive Engineers (SAE) and are specified in its classification system. Industrial
lubricants can be subdivided into industrial oils and industrial specialties. Specialties in this case are
principally greases, metal working lubricants and solid lubricant films. Quality requirements for these types
of lubricants are defined by Original Equipment Manufacturers (OEM) and end users of the products. On
the global lubricants market, automotive lubricants account for more than 60% of volumes sold.
Keep Moving Parts Apart
Lube oil are typically used to separate moving parts in a system. This has the benefit of reducing friction
and surface fatigue together with reduced heat generation, operating noise and vibrations. Lubricants achieve
this by several ways. The most common is by forming a physical barrier i.e. a thin layer of lubricant separates
the moving parts. This is termed hydrodynamic lubrication. In cases of high surface pressures or
temperatures the fluid film is much thinner and some of the forces are transmitted between the surfaces
through the lubricant. This is termed elasto-hydrodynamic lubrication.
Reduce Friction
Typically the lubricant-to-surface friction is much less than surface-to-surface friction in a system without
any lubrication. Thus use of a lubricant reduces the overall system friction. Reduced friction has the benefit
of reducing heat generation and reduced formation of wear particles as well as improved efficiency.
Lubricants may contain additives known as friction modifiers that chemically bind to metal surfaces to reduce
surface friction even when there is insufficient bulk lube oil present for hydrodynamic lubrication, e.g.
protecting the valve train in a car engine at startup.
Transfer Heat
Lube oil can transfer heat. Lube oil much more effective on account of their high specific heat capacity.
Typically the liquid lubricant is constantly circulated to and from a cooler part of the system, although
lubricants may be used to warm as well as to cool when a regulated temperature is required. This circulating
flow also determines the amount of heat that is carried away in any given unit of time. High flow systems
can carry away a lot of heat and have the additional benefit of reducing the thermal stress on the lubricant.
Thus lower cost liquid lubricants may be used. The primary drawback is that high flows typically require
larger sumps and bigger cooling units. A secondary drawback is that a high flow system that relies on the
flow rate to protect the lubricant from thermal stress is susceptible to catastrophic failure during sudden
system shut downs. An automotive oil-cooled turbocharger is a typical example. Turbochargers get red
hot during operation and the oil that is cooling them only survives as its residence time in the system is
very short i.e. high flow rate. If the system is shut down suddenly (pulling into a service area after a high
speed drive and stopping the engine) the oil that is in the turbo charger immediately oxidizes and will clog
the oil ways with deposits. Over time these deposits can completely block the oil ways, reducing the cooling
with the result that the turbo charger experiences total failure typically with seized bearings.
API GL-4 AND GL-5 GEAR OILS
Multipurpose Gear Oils are used for the lubrication of gears operated under severe conditions, including
automotive applications. High quality HVI base stocks blended with a sulfur-phosphorous extreme pressure
additive package provide superior performance including anti-weld, anti-scuff, and anti-wear properties.
Multipurpose Gear Oils are not appropriate for systems requiring limited-slip properties.
Multipurpose Gear Oils are available in API GL-4 and GL-5 performance levels. The GL-4 level is
designed for spiral-bevel and hypoid gears under moderate speeds and loads. This level is recommended
for some manual transmissions and transaxles and to meet the obsolete MIL-L- 2105 specification.
The GL-5 Multipurpose Gear Oils have multi-grade characteristics and are recommended for hypoid
gears in moderate and severe service, including shock-loading, and some manual transmissions. GL-5
Gear Oils meet MIL-L-2105D, Mack GO-J, Rockwell 0-76-D (80W-90) and 0-76-D (85W-140) specifications.
GL-5 Multipurpose Gear Oils also meet API category MT-1 (PG-1) for truck manual transmissions and
proposed category PG-2 for high-speed final drives in trucks, buses and other heavy duty equipment.
Two/Three Wheel Lubricants
Lubrication of a two-stroke petrol engine is quite different from that of a four-stroke engine, as it is not
possible to have separate lubricating oil sump. Hence a two-stroke petrol engine is always lubricated by a
petroil mixture. The lubricating oil is mixed with petrol in suitable proportion as per the manufacturer’s
recommendation. In the latest generation Two-stroke engines, the lubricating oil is directly injected by an
accurate metering device from a separate tank into the petrol in quantities dependent on the speed and
load of the engine.
When the petrol mixture enters the crankcase, because of the high temperatures prevailing, the petrol
fraction vaporizes leaving a thin oil film of lubricant on the crankcase, cylinder walls, crankshaft and bearings.
The primary requirement of two-stroke engine oil is its ability to readily mix with petrol and burn without
leaving too much ash. The oil should reduce engine wear, spark plug fouling, combustion chamber deposits,
piston ring sticking, exhaust port blocking and silencer deposits. In addition the oil should have the ability
to keep the engine clean at high engine operating temperatures and prevent bearing corrosion at lean oilfuel
ratios.
4 Stroke Engine Oil
Four stroke two wheelers have a different lubrication requirement than a two stroke two wheelers since
it does not use the Petrol mixed with oil. These engines are like the four stroke engines used in Cars. A
separate Oil sump in the engine lubricates the various moving parts in the engine.
The main differences between the four strokes Engine in a Two Wheeler and in a Car are:
• Two wheeler Engines are Single Cylinder Engines where as Car engines are multi cylinder (3 or 4
or 6 cylinder engines).
• The Engines in two wheelers are air-cooled engines where as Car engines are Water / Coolant
cooled Engines. The air drag across the engines as the vehicle moves cools the engines in two
wheelers.
• In two wheelers the Engine, the clutch and the Gear trains are housed in a single unit and lubricated
by the same oil where as in a car, Engine, Clutch and gearboxes are separate unit and lubricated
by separate oils.
These differences in Engine configuration demands a separate quality of Oil for use in four stroke
Engines in two wheeler. The air cooled Engines suffers the most in terms cooling efficiency wherein the
vehicles running at slow speed, such as city driving condition, leading to higher Engine operating temperature
compared to a car Engines where the Engine is cooled by the coolant leading to more or less constant
operating Temperature irrespective of the Speed of the Vehicle. This higher operating temperature
encountered demands oils with very high thermal and Oxidation stability and also higher viscosity grades.
AUTOMOBILE PISTON RINGS
INTRODUCTION
The piston is a cylindrical part that reciprocates in an engine cylinder. Piston rings provide a seal between
the cylinder wall and piston. A good seal is essential between the piston and cylinder-bore wall to prevent
blow-by, i.e., the escape of burnt fuel gases from the combustion chamber, past the piston, which ultimately
reaches the crankcase. It is not practical to fit the piston with the entire cylinder bore in contact, in the
manner to create a perfect seal, to prevent the blow-by, because in that condition, the piston cannot move
forward and backward without tremendous frictional heat that might damage most of the engine parts.
Thus, piston rings are used to provide the necessary seal. The rings are installed in grooves made in the
piston at designed spacing. The piston-rings with relatively much smaller surface area in contact with cylinder
wall, cause less frictional heat and yet ensure full prevention of blow - by problem by providing reasonably
required seal.
Piston rings are basically of two types:
1. Compression - rings and
2. Oil control rings.
The compression rings seal in the air - fuel mixtures as it is compressed and provide compression
pressure till the mixture burns.
The oil control rings scrape off excessive oil from the cylinder wall and then they return it to the oil
pan.
A piston can be installed with two or more numbers of compression and oil control rings. The rings are
split at a point, so that they can expand and slip over the piston - head while remaining into their respective
groove cut over the piston surface. Rings for automotive engines have usually butt joints, but in heavyduty
engines, the joints may be angled, lapped or of the sealed type. Rings are marginally larger, when set
in piston-grooves, than the piston diameter, to which they are attached. When they are installed, they are
compressed from all sides of the cylinder-bore, and thus, the open ends are nearly closed in the pistoncylinder
assembly. This compression of rings puts them in initial tension and they press tightly against cylinder
wall.
Uses & Applications
Piston is a solid or hollow disc like plunger fitting closely in a bore of a cylinder into which it reciprocates
from Top Dead Centre (TDC) to Bottom Dead Centre (BDC) and in the process imparts motion to the vehicle.
Piston ring is a metallic ring of C.I., wrought iron, steel or gunmetal etc. Cast iron piston rings are preferred
for IC engines. Piston rings are used as the peripheral part of the piston. Rings offer a steam-tight or gastight
joint between cylinder wall and piston. This arrangement saves leakage of burnt/half burnt fuel mixture
and increases piston’s efficiency to impart motion. Depending on piston size, engine capacity etc., the size
of piston rings use in automobile engines is wide and varied. Every auto-engine uses these rings essentially
in varying numbers and as compression ring, oil-control ring or spare ring. The use of piston rings reduces
the piston weight, improves engine performance, restricts road-pollution and saves the other parts of the
engine from damaging.
Wear of Piston-Rings
Cool operating temperature creates some abnormal and harmful by-products from the air-fuel mixture
combustion. For example, the heavier portions of gasoline do not vaporise and remain as un burnt fuel or
hydrocarbons. Moreover, engine surface that remain relatively cool tend to quench part of the burning airfuel
mixture and leave some partially burned fuel as soot.
The problem is multiplied as the temperature of by-products fuels drops and moisture content condenses
during combustion. Thus, the un burnt fuel, soot and moisture squeeze past the piston rings as blow-by
gases, washing the oil off the cylinder walls and diluting the lubricating oil contained in the pan. This type
of contamination exposes piston-rings and cylinder walls to excessive wear and scuffing when coolant
temperature falls below 150°F or 65.6°C. The condensed moisture also combines with unburnt hydrocarbons
and other additives to form carbonic acid, sulphuric acid, hydro-bromic acid, nitric acid and hydrochloric
acid. These acids cause engine wear by corrosion and rust. Rusting accelerates when coolant temperature
is below 130°F or 43.3°C. The engine, that operates too cool, produces excessive hydrocarbon emissions,
as part of the gasoline does not vaporise and remains hydrocarbons. While part of these hydrocarbon
mixes with moisture and passes into the oil pan via blow-by gases, the remaining hydrocarbons pass from
exhaust pipe with spent gases. Clearly, then, for proper engine performance ie., reduced wear and reduced
hydrocarbons in emissions, an engine must warm-up as quickly as possible and maintain a given
temperature.
AUTOMOBILE RADIATORS
INTRODUCTION
The pioneers of the internal combustion engine men such as Renoir. Otto, and Benz, could never have
dreamed of the fantastic revolution that the automobile was to bring about in twentieth century life but it
was the genious and perseverance of these men and others like them which, by sending the first motor
driven vehicles on the road, quickened the pace of industrial and social progress throughout the modern
world. It is on record that first motor car appeared on the streets of India in the year 1898. It is also on
record that the car is made of more than 5,000 components. By the turn of the century, Mumbai had its
first taxi car, and in 1903 an American Company began to operate a public taxi service with a fleet of 50
cars. The automobile has helped man to break through the barriers of distance. The far off places of
yesterday are the next door neighbour hoods of todays. Mobility by road has brought about the interlinking
of communities which once lived in isolation. Thus integrating into common as what were once vastly
separate regions of the country. The rural farmers are now able to send their agricultural produce especially
vegetables, fruits, and other perishable commodities to urban places and to obtain in return their needs of
finished goods, such as cloth, leather goods etc. An automobile has more than 5,000 components, and is
one of the most complicated finished products turned out in large quantities. The structure of the industry
is, therefore, some intricate. A finished automobile is the result of contribution from three distinct sources,
the main automobile manufacturers whose products are used not only for automobiles but for other purposes
as well, 25-35 percent. It is clear from the figures that automobile industry is one of the ancillaries.
NEED OF RADIATORS IN AUTOMOBILE
The reciprocating piston engine, which provides the motive powder for majority of vehicles, makes
use of only a proportion of the total energy contained in the fuel it consumes. The actual quantity of this
energy converted to useful work in the combustion chamber is critically influenced by the physical
characteristics of the piston or engine. It has been shown that about one quarter of the heat of combustion
of the passes through the cylinder walls in an ordinary engine. This quantity of heat is considerable and if
the cylinder were a plain met barrel, it would very soon become red hot, and the engine would cease to
operate since incoming charge would ignite whilst the inlet valve was open, moreover, as burnt away, the
piston would certainly rise up. As the temperature of the burning gases is about 1500*C and that of the
exhaust gases from 600*C To 800*C, it will be evident that the average temperature in the provide some
means for keeping the temperature of cylinder down to reasonable limits. In order to ensure that the cylinder
temperature is not excessive, the heat conducted through its walls must be dissipated in either of the
following ways.
1. By providing cooling or radiating fine of sufficient area, and arranging for an air current to blow
past these fins, in order to carry off the surplus heat.
2. By providing a water jacket around the hotter parts of the cylinder barrel and the combustion head,
and circulating water around the same.
3. By the arranging for the oil supplied for lubrication purposes to cool the cylinder barrels.
4. By injecting a water spray into the cylinder.
The most effective and cheapest method is the water cooling. For cooling, the hot water coming out
after taking the excessive heat from the cylinder, radiators is used. The heat conducted by water is dissipated
into atmosphere by using air blow through the finned surface area.
MECHANISM OF ENGINE COOLING BY RADIATOR
In the case of water-cooled engines, it is necessary to dissipate the heat conducted through the cylinder
walls by circulating water through a cooling device known as radiator the principle of a typical car engine
water cooling system. The water is made to circulate through a large number of very small section tubes
in the radiator having large cooling surfaces. Air is forced past the outer surfaces of these tubes and carries
off the surplus heat. This system is therefore an air-cooling process with the intermediary of water to carry
the cylinder heat to the cooling device, or radiator. The amount of heat that can be dissipated or got rid of
by a radiator depends upon a number of factors of which the principle ones are as follows:-
1. The relative wind velocity.
2. The cooling surface.
3. The ratio of tube depth to diameter.
4. The air density.
5. The water and air temperatures.
6. Design of radiator.
7. Conductivity of metals used.
As previously stated, the purpose of the radiator is to dissipate or to remove heat of the cooling water
as rapidly as possible, and with the lightest and least bulky form of construction. Modern radiators are now
very efficient and light, yet they will stand up to their work for long periods. The principle of must radiators
design lies in the provision of a large number of small sectioned water spaces extending from top to bottom,
and a maximum external cooling surface area exposed to the cooling air. There is a water reservoir at
both top and bottom of the radiator, into which the outlet pipe to the cylinder jacket are led respectively.
The radiator tube system connects these two water reservoirs or headers, so that when the engine is working
there is a continuous series of water streams flowing from top bottom. In addition, the radiator is provided
with a filling cap at top, an emptying tap at the bottom , and an over flow or steam pipe inside.
U-BOLTS
INTRODUCTION
Screw fasteners are broadly classified as :-
i. Bolts,
ii. Studs,
iii. Cap Screws,
iv. Machine Screws,
v. Set Screws,
vi. Carriage Bolts, and
vii. Wood Screws.
Bolts in various dimensions & head-shapes are available. Bolts, preferably used in through holes with
the help of an appropriate nut, are furnished with square/hexagonal heads. Bolts can be supplied unfinished,
semi-finished & fully finished conditions. Automotive bolts have hexagonal head. These bolts have greater
head depth than regular bolts but have less width across flats. Limits of tolerances are well defined by
international standards over all dimensions. Top of the head is flat & chamfered at /_30o while the bearing
surface is washer-faced. Either coarse or fine threads of class- 2A are used.
Minimum thread length = 2D + 1/4" for bolts upto and including 6" length. Longer bolts are threaded
over a length L = 2D + 1/2". On the other hand, the total length & thread lengths of ‘Stud Bolts’ are generally
determined by the particular service requirement.
PROPERTIES
RAW MATERIALS AND ITS REQUIREMENTS
The only raw material for the production of plain rivets is the steel wire of required, gauge. Steel is
chromium here since the steel rivets are most commonly used in every type of work. The composition of
steel counts much is given the required qualities to the product. To obtain smooth operations the wire rod
should be as clean as possible and free form rust the diameter of the wire should also be as accurate as
possible. Normally, the steels of the following percentage composition are used in the manufacture of high tensile steel rivets.
Centre Bolt Design
Centre bolts hold the spring leaves together where the bolt head serves as a locating dowel during
installation of the spring on the vehicle. For ‘under slung’ springs, the bolt head should be adjacent to the
main leaf (master leaf) while for ‘ever slung’ spring, the bolt head should be adjacent to the shortest leaf.
Centre bolts are often highly stressed in spring handling and in service. Therefore, high mechanical
properties of centre bolts are necessary.
The bolthole diameter in the spring leaves for incorporating the centre bolt, must be atleast equal to
the thickness of the heaviest leaf inorder to permit cold punching. If the bolthole diameter happens to be
less than the thickness of the heaviest leaf, then, the leaf must be heated first, and then, punched to form
the hole.
Leaves thicker than 0.50 inch are not permitted for cold punching. However, the centre bolthole should
not be too large w.r.t. leaf thickness.
Centre bolt shearing can be eliminated in heavy vehicles which occurs due to driving & braking forces,
by providing a cup for nesting into the axle seat around the centre bolt.
Resulphurised steels possess good machinability, but on the other hand, contain inclusions like iron
sulphide which initiates fractures.
Scrapless nuts can be best produced from rimmed resulphurised steels (i.e. AISI-1106, & 1110)
Where hardenability, fatigue strength and machinability properties are important, formability factor is
compromised to some extent. Thus, use of high carbon steels & high alloy steels becomes necessary.
The feed wire surface must be free from defects like seams, blow holes/pits etc. Non-uniform cross-sections
of wire is not allowed in headers or extrudes. Wire diameter is taken of slightly higher size and cold drawn
to exact size prior to cold forging.
The steel wire coils used should have been well tested by the coil supplier. (i) Splitting test & (ii) Rupture
test, apart from surface defects. Defects may lead to premature bolt failures in service. A vacuum degassed
steel is usually found cleaner, and when it is cold rolled into billets & bars, prior to making rods & wire, the
coil can be said to be free from imperfections. It is recommended to select the bolt material judiciously.
Instead of installing separate header, feeder & trimming units, a compact multi-station bolt forming m/c
can be installed. This is highly automatic, gives faster production, reduces material handling & rejections.
But, such a multi-station m/c is bound to be costly.
This is necessary to use right type of lubricants in sufficient quantity at each stage of bolt forming. At
the end of all these forming & trimming operations, the bolts are cleaned by wood dust by tumbling in a
perforated drum carrying wood dust. This removes grease etc., from the surface. Now, washed & dried
bolts are automatically fed between two plates each carrying thread design the surfaces contacting the
bolt shank. The thread depth is attained in more than one passes. Here again, light lubrication will be
required.
Now, bolts are cleaned & dried prior to heat treatment. The hardness is checked by sampling the testpieces.
Further, bolts can be applied surface protective coats by phosphating or zinc plating techniques.
A bolt supplier can supply the bolts without heat treatment or with heat treatment as black bolt. They
can also be required to supply bolts with phosphating and/or with zinc plating. Provisions should be available
for processing bolts & nuts according to requirements of customers.