Engineer World

  Contents of Exhaust gas: The largest part of most combustion gas is Nitrogen (N2 ),  Water vapor (H2O) and  Carbon-dioxide (CO2 ) these are not toxic A relatively small part of combustion gas is toxic substances , such as  Carbon Monoxide (CO) from incomplete combustion,  Hydrocarbon (HC) from un-burnt fuel,  Nitrogen Oxide (NOx ) from excessive combustion temperatures  Particulate matter (PM).  Treatment of Exhaust gas: The Exhaust gas has more pollutant so that it should be reduced to prevent the pollution form the exhaust gas There are some treatment carried out for Exhaust gases are below      Exhaust Gas Recirculation(EGR) Selective Catalytic Reduction(SCR) Exhaust gas Recirculation(EGR) :  The diesel engines to run more efficiently cause them to run at higher temperature this leads to the creation of Nitrogen Oxides (NOx). The Combination of Nitrogen and Oxygen in the air to form Nitrogen Oxide . In order to reduce NOx an engine should run at a lower temperat

 The commonly occurring troubles in the lubricating system are unduly low or excessively high oil pressures. Low oil pressure Low oil level, which may be checked by the dipstick. Fill till the correct level or to Crankcase. The oil may have been diluted with constant use, which has to be changed. High oil pressure The oil used may be of too high a viscosity, which may be drained out and the oil with correct viscosity filled in. The oil lines, galleries may be clogged, which may be cleaned. Oil pressure gauge may be defective which may be inspected and repaired. Grades of Engine oil: The Society of Automotive Engineers (SAE) developed a scale for both engine (motor oil grades) and transmission oils. Viscosity is notated using the common classification “XW-XX”. The number preceding the “W” (winter) rates the oil’s flow (viscosity) at zero degrees Fahrenheit (-17.8 degrees Celsius). The lower the number, the less the oil thickens in cold weather.  The numbers “XX” indica

The moving parts of an I.C engine are likely to wear off due to continuous rubbing action of one part with another. In order to avoid an early wearing of the engine parts, a proper lubrication arrangement is provided in I.C. engines. Lubrication is an art of admitting a lubricant (oil, grease, etc.) between two surfaces that are in contact and in relative motion The main parts of an automotive engine require lubrication are: Main crankshaft bearings Big end bearings Gudgeon pin bearings  Piston rings and cylinder walls Camshaft and camshaft bearings Timing Gears Valve mechanism  Purpose of Lubrication: It reduces wear and tear of the moving parts. It damps down the vibrations of the engine. It dissipates the heat generated from the moving parts due to friction. It cleans the moving parts. It makes the piston gas-tight. Properties of Lubricant: Suitable viscosity Should not react with lubricating surfaces No tendency to form deposits by reacting with air, water, fuel or the

 Reasons to provide cooling system in engine: The even expansion of piston in the cylinder may result in seizure of the piston. High temperatures reduce strength of piston and cylinder liner. Overheated cylinder may lead to pre-ignition of charge, in case of SI engine. Physical and chemical changes may occur in lubricating oil which may case sticking of piston rings and excessive wear of cylinder. If the cylinder head temperature is high the volumetric efficiency and power output of engine reduces. Over cooling : Starting of engine becomes difficult. Engine life is reduced due to corrosion. Some of the heat which could be used to expand the gases will be lost. The fuel will not vaporize properly and some of the gases produced by combustion will condense on the cylinder walls. Inadequate lubrication of the engine, due to oil not being warm enough to flow freely.  Methods of Cooling: There are mainly following two methods/System of Cooling  Air Cooling Water/Liquid Cooling

Check the coolant level in your vehicle if it is overheating . If there is insufficient coolant in the vehicle, overheating will occur while driving. Add the appropriate amount of coolant to the coolant reservoir. Inspect your vehicle's thermostat to determine if it is stuck. If your thermostat is stuck, your vehicle will overheat almost immediately after driving a short distance. Another way to check the thermostat is to start the car, open the hood and feel the radiator hose. If the lower part of the radiator hose is hot and the upper part is cool, the thermostat is stuck.  Look at your fan belt to determine if it is broken or loose . Tighten the connections for the fan belt or replace it if necessary. Determine if the cooling system is clogged. Drain and flush the coolant from the cooling system to unclog it. Check the water pump to see if it is faulty and replace it if necessary *******Thanks*******

  Differential is an integral part of all four wheelers. A differential is used to allow the wheels to spin at different speeds. This is necessary when the vehicle turns.  Parts of Differential: Pinion drive gear: transfer power from the drive shaft to the ring gear. Ring gear: will transfer power to differential case assembly. Rear drive axel: Transfer torque from differential assembly to the drive wheels. Spider gears: The spider gear lies at the heart of the differential and special mention should be made about its rotation. Differential case assembly: Hold the gear and drive the axel. Working of Differential: When turning, the inner and outer wheels have arcs of different turning radii. The inner wheels travel less distance than the outer wheels. From the drive shaft power is transferred to the pinion gear first, since the pinion and ring gear are meshed, power flows to the ring gear. As the spider gear is connected with the ring gear, power flows

Fuel-Injection System is vital to the working and performance of CI engine  This system serves the purpose of initiating and controlling the combustion to meet the demand requirements  Fuel is injected into combustion chamber towards the end of compression.  It is atomized as it enters under high velocity and the droplets get vaporized to form a fuel-air mixture. Functional Requirements of an Injection System:  The following requirements must be met by the Fuel Injection (FI) System:  Accurate metering of fuel injected per cycle to meet changing demand of speed & load. Precise timing of fuel injection in the cycle to ensure performance; power, fuel economy, emissions. Proper control of rate of injection to achieve desired heat release during combustion without knocking.  Proper atomization of fuel into fine droplets  Proper spray pattern to ensure rapid mixing of fuel & air  Uniform distribution of fuel droplets throughout the combustion chamber.  To supply equa

Ignition system is a system in an internal combustion engine that produces the spark to ignite the mixture of fuel and air.  It includes the battery, ignition coil, distributor, spark plugs, and associated switches and wiring.  It is a part of the electrical system which carries the electrical current to a current plug.  It gives the spark to ignite the air-fuel mixture at the correct time Ignition Function:   It produces 30,000 volt spark across spark plug  It Distributes high voltage spark to each spark plug in correct sequence  Time of the spark occurs when piston is near to top dead center  Spark timing varies with load, speed, and other conditions Basic Ignition System: The components in ignition system are as follow:  Battery,  Switch ignition distributor  Ignition coil  Spark plugs and  Necessary wiring Ignition System types: A battery of 12 volts is generally employed. However, a very high voltage surge (of about 25,000 volts in modern engines) is required for ign

       A fuel filter is a filter in the fuel line that screens out dirt and rust particles from the fuel, normally made into cartridges containing a filter paper. Primary Filter : In most designs, the primary filter is located between the fuel tank and the fuel supply pump.  A primary filter contains a coarse filter material that removes the larger foreign matter.  They are metal filters and only allow fine particles to pass through them.  Solid materials larger than 10 to 50 microns remain outside the metal disks, while the larger foreign matter and most of the water settle to the bottom of the bowl. This matter can be removed through a drain plug.  A ball relief valve in the filter cover enables the fuel to bypass the filter element if the disks become clogged.  Most types of heavy equipment have a fuel pressure gauge that indicates when the filters are dirty. Secondary filter : The secondary filter is usually located between the fuel supply pump and the fuel injec

          Clutch is a mechanical device that facilitates transmission of power and motion from one component (the driving member) to another (the driven member) when engaged, with a provision for disengagement whenever required. Function of Clutch: It can be disengaged. This allows engine cranking and permits the engine to run without delivering power to the transmission.  While disengaging, it permits the driver to shift the transmission into various gear according to operating condition.  While engaging, the clutch slips momentarily. this provides smooth engagement and lessens the shock on gears, shaft and other parts of automobile.  While engaging, the clutch transmits the power to the wheel without slipping, in ideal condition. Main Parts of Clutch: These are known as the principle parts of the clutch. • Driving Member  • Driven Member  • Operating Member Driving Member: Driving member has a flywheel which is mounted on the engine crankshaft. A disc is bolted to flywheel w