Thursday, December 30, 2010

Extending Turbo Charger life

Tips


Turbo lag
The time required to bring the turbo up to a speed where it can function effectively is called turbo lag




EXTENDING TURBOCHARGER LIFE
The major causes of turbocharger failures are attributed to:
  • Lack of lube oil (quick starts and hot shutdowns)
  • Oil contamination
  • Ingestion of foreign objects
  • Restricted oil drainage
  • Abnormally high exhaust temperatures
1) Lack of Lube oil
Oil not only lubricates the turbocharger's spinning shaft and bearings, it also carries away heat. When oil folw stops or is reduced, heat is immediately transferred from the hot turbine wheel to the bearings, which are also heating up because of the increased friction due to the lack of oil. This combination causes the turbocharger shaft temperature to increase rapidly.
if oil flow down not increase and the process continues, bearings will fail. Once the bearings fail (which can happen in just seconds) seals, shft, turbine and compressore sheels can also be damaged.
The principle causes of turbocharger bearing lubrication problems are low oil pressure , a bent, plugged or undersized oil lube supply line, plugged or restricted oil galleries in the turbocharger, or improper machine start-up and shutdown procedure.
Oil lelvels and pressure should always be closedly monitored and all worn hoses and lines should be replaced. The turbocharger oil supply line should be checked frequently to make sure it is not kinked or bent and it should always be replaced with a line of equal size, length and strength.
The easiest way to damage a turbocharger is through improper start-up and shutdown procedures. Always idle the engine for at least 30 seconds (no load) after start-up and before shutdown. Warming the engine up before applying a load allows oil pressure to build up and lines to fill with oil.
Idling the engine before shutdown allows the engine and turbocharger to cool. "Hot" shutdowns can cause the turbocharger to fail because after high-speed operation the turbocharger will continue to rotate lone after the engine has been shut off and oil pressure has dropped to zero. This will cause heat to build up and possible hearing damage. It can also cause carbon and varnish deposits to form.



2) Oil Contamination
A second cause of turbocharger failures is contaminated oil. it can be caused by a worn or damaged oil filter or not changing the lube oil at recommended intervals. Expecting the oil filter to remove dirt, sand, metal chips, etc. from the oil before they reach the engine or turbocharger can be a costly mistake because contaninated oil may completely bypass the engine oil filter if the oil filter or oil cooler is clogged, if the filter element is improperly installed, or if the oil is thick during cold weather.
  • Four good ways of avoiding oil contamination are:
  • Always inspect the engine thoroughly during major overhaul. Look especially for any sludge or debris left in lube oil galleries.
  • Change lube oil at recommended intervals. Analysis of oil samples at filter chane periods can help identify potentially harmful contaminants in the oil.
  • Clean the area around the oil fill cap before adding oil.

3)  Ingetion of Foreign Objects
The third cause of turbocharger damage is the ingestion of foreign objects. Foreign objects or particaes can be ingested and cause damage to the turbocharger on both compressor and turbine sides. This easy to avoid.
On the compressore side, foreign objects usually take the form of dust, sand, or shreds of air cleaner element that enter through improperly installed air cleaner elements. Leak air inlet piping (loose clamps or torn rubber joints) or torn pleats in dry-type air cleaner elements also create problems.
The result is erosion of compressor blades that can cause the delicately balance wheel to wobble.


4) Restriced oil Drainage
A fourth cause of turbocharger damage is restricted lube oil drainage. Thelubricating oil carries away heat generated by friction fo the bearings and from the hot exhaust gases. If drainage back to the sump is impeded, the bearings will overheat with damage that will ultimately lead to failure.
There ar two primary reasons for restricted drainage. A blocked drain tube, due to either damage or a buildup of sludged oil or high crankcase pressure which can be due to restriced crankcase breather or excessive engine blowby.
Periodically check both the turbocharger oil drain tube and engine breather tube for damge or restriction. Correction of these conditions leads to longer turbocharger life.


5) Abnormally High Exhaust Temperatures
A fifth cause of turbocharger damge is abnormally high exhaust temperatures. Elevated exhaust temperatures cause coking of oil which can lead to bearing failure. Extreme over-temperature operation can case wheel burst.
There are two basic cause of over-temperature. The first is restricted air flow and the second is overpowering the engine. In either case the einge has more fuel than available air for proper combustion, this overfueled condition leads to elevated exhaust temperatures.
Causes of restricted air flow can include damaged inlet piping, clogged air filters, excessive exhaust restriction, or operation at extreme altitudes. Overpowering generally is due to improper fuel delivery or injection timing. If overtemperature operation has been identified, an instpection of the air inlet and exhaust systems should be perfomed. Also, check the fuel delivery and timing.

Wednesday, December 29, 2010

Tyre Pressure

Tyre Pressure

Correct tyre pressure can help to extend the life of your tyre, improve vehicle safety and maintain fuel efficiency. Pressure is measured by calculating the amount of air that has been pumped into the inner lining of your tyre in pounds force(PSI) or BAR pressure.




Maintaining correct Tyre Pressures

There are three main reasons why maintaining the right tyre pressure is important. The first is safety. Tyres that are under inflated can overheat; and over inflated tyres can lead to poor vehicle handling on the road.
The second reason is economy. Over or under inflated tyres suffer more damage than those with the correct pressure and need to be replaced more regularly. Vehicles with under-inflated tyres have increased rolling resistance that require more fuel to maintain the same speed.
The third reason for maintaining the correct tyre pressure is the environment. Correct tyre pressures help to maintain optimum fuel efficiency. This can equate to lower Co2 emissions coming from your vehicle than those with incorrect tyre pressures and that has to be good for the environment.
Remember that tyre failure can occur due to under inflation and overloading!
One of the most dangerous conditions that can exist is the slow leak. Sometimes a small nail, screw or other object will puncture a tyre and then act as an inefficient plug. Air pressure drops slowly over a matter of hours or days, undetected by the driver. Your best defense in this circumstance is to be alert to the symptoms of this condition. Be aware of any pulling or vibration that seems unnatural. And listen for any tick-ticking sound—especially audible at slow, parking lot speeds. If you detect this, get off the road and inspect the tyres on the side of the pull, vibration or sound. A bulging sidewall and/or excessively hot tyre indicates a slow leak. Put on your spare tyre and have your Tyrepower Pro repair the punctured unit. Ask the repair technician if any sidewall damage has occurred (a powdery residue inside the tyre indicates this condition). If so, have the tyre replaced.

How To Check Air Pressure
Properly checking tyre pressure requires an accurate air gauge. Many people believe that they can check air pressure just by looking at the tyre and judging the sidewall appearance. Also, many people use the air guages at service stations, which can be grossly inaccurate due to exposure or abuse. Invest in a quality air gauge.

When checking your vehicle's tyre pressure, make sure the tyres are "cold". Cold air pressure means that the vehicle has not yet been driven one kilometer (remember that driving on a tyre as well as being in direct sunlight increases its temperature and air pressure). If you must drive more than one kilometer for air, check and record the air pressure in all your tyres before you leave. Once at the tyre dealer, measure each tyre's inflation again and then note the difference. Inflate the tyres with low pressure to a level that is equal to the recommended cold pressure plus the difference at the higher temperature.
Finally, after completing the pressure check, make sure the valves and extensions are equipped with valve caps to keep out dirt and moisture. Remember to replace the valve assembly when you replace the tyre; it's your best assurance against a sudden or consistent loss of air pressure.



Environmental Impact
How can routine air pressure maintenance impact our environment? Consider that fewer tyres per year would end up in the landfills and scrap heaps that trouble our ecology. How many tyres are we talking about? We estimate that most drivers lose from 10% to as much as 50% of tyre tread life due to underinflation. That's a significant statistic. Now consider the extra fuel we burn to push cars along on soft, underinflated tyres. Tyres do require extra energy to roll if they are under inflated. While the statistics vary widely and inconclusively, the implications are staggering. So maintaining tyre pressure is a small line item in our busy daily routines, but it adds up to big environmental consequences. We must all care and take action to do the right thing.

Other Factors Change Air Pressure
Besides the routine air check, other circumstances necessitate a visit to the air pump. Seasonal changes or altitude changes create a rise or drop in air pressure (for every 10 degrees change in temperature, tyre air pressure changes approximately 7 kpa). But perhaps the most overlooked factor is vehicle loading for trucks and 4WDs. Since these vehicles can be configured and loaded in many ways, the proper inflation pressure should be determined by actual tyre loads. This is best determined by weighing the vehicle; vehicle loading can change from trip to trip



The Benefits of Correct Air Pressure
Keeping the correct air pressure in your tyres is as important as giving your engine a tune up. The economic benefits are perhaps even greater! With the right amount of air pressure, your tyres wear longer, save fuel, enhance handling and prevent accidents. The effects of not maintaining correct air pressure are poor petrol mileage, loss of tyre life, bad handling (perhaps even loss of control), and potential vehicle overloading.



Wednesday, December 8, 2010

Steering system

Introduction

The steering system must provide control over the direction of travel of the vehicle; good maneuverability for parking the vehicle; smooth recovery from turns, as the driver releases the steering wheel; and minimum transmission of road shocks from the road surface.
The effort by the driver is transferred from the steering wheel, down the steering column, to a steering box.
The steering box converts the rotary motion of the steering wheel, to the linear motion needed to steer the vehicle.
It also gives the driver a mechanical advantage.
The linear motion from the steering box is then transferred by tie-rods, to the steering arms at the front wheels. The tie rods have ball joints that allow steering movement, and movement of the suspension.
The steering-arm ball-joints are arranged so that movement in the suspension does not affect steering operation.

Summary
The steering system provides control over direction of travel, good manoeuvrability, smooth recovery from turns, and minimum transmission of road shocks.



           Diagram of steering system

Monday, December 6, 2010

synchromesh gear system

How synchromesh gear works?

 If the dog teeth, make contact with the gear, but the two parts are spinning at different speeds, the teeth will fail to engage and a loud grinding sound will be heard as they clatter together. For this reason, a modern dog clutch in an automobile has a synchronizer mechanism or synchromesh, which consists of a cone clutch and blocking ring. Before the teeth can engage, the cone clutch engages first which brings the selector and gear to the same speed using friction. Moreover, until synchronization occurs, the teeth are prevented from making contact, because further motion of the selector is prevented by a blocker (or baulk) ring. When synchronization occurs, friction on the blocker ring is relieved and it twists slightly, bringing into alignment certain grooves and notches that allow further passage of the selector which brings the teeth together. Of course, the exact design of the synchronizer varies from manufacturer to manufacturer.

Diagram of synchromesh & syncromesh ring


Sunday, December 5, 2010

water cooling system

Working of water cooling system


Automobile Cooling System
Figure illustrated above describes the functioning of cooling system of an automobile. The key components used in a cooling system are pressure cap, heater hoses, thermostat, heater core, reserve tank, lower hose, transmission cooler, water pump, fan, radiator and upper house. The cooling system of a vehicle operates or functions by directing liquid coolant via passages in the engine block and heads. After that the liquid coolant which flows through passages absorb the heat from an engine. Then this fluid passes through a rubber hose to reach to the radiator. At this stage the hot liquid is cooled by air stream entering the engine compartment via grills. Once it gets cooled, then it goes back to engine and same process repeats again.

Automotives clutch

Operation: The transmission of power happens when one driving shaft (which is one contact with the crankshaft/flywheel) is brought into contact with another shaft which is being driven (The propeller shaft). This is made possible through the clutch and its supporting mechanism. The contact between the two shafts is brought about by applying strong spring loaded pressure through suitable linkage by a pedal operated by the driver.



The clutch basically consists of a clutch plate (or a series of them in larger vehicles) and a clutch assembly which is spring loaded in such a way that when the pedal is pressed, the release levels (as shown in the picture below) are pressed inward, which push against a set of springs that clamp this clutch plate to the flywheel of the engine, thereby releasing the clutch plate. This causes the engine flywheel to rotate freely (the clutch is not in contact anymore) and the gears can be shifted now or the engine can be started (if you are about to start the engine). This clutch plate is always in contact with the engine’s flywheel, by default. It is disengaged only when necessary by the action of the driver on the pedal.

4 stroke engine principle

4 stroke engine principle






1. INTAKE stroke: On the intake or induction stroke of the piston , the piston descends from the top of the cylinder to the bottom of the cylinder, reducing the pressure inside the cylinder. A mixture of fuel and air is forced by atmospheric (or greater) pressure into the cylinder through the intake port. The intake valve(s) then close.
2. COMPRESSION stroke: With both intake and exhaust valves closed, the piston returns to the top of the cylinder compressing the fuel-air mixture. This is known as the compression stroke.
3. POWER stroke.: While the piston is close to Top Dead Center, the compressed air–fuel mixture is ignited, usually by a spark plug (for a gasoline or Otto cycle engine) or by the heat and pressure of compression (for a diesel cycle or CI ). The resulting massive pressure from the combustion of the compressed fuel-air mixture drives the piston back down toward bottom dead center with tremendous force. This is known as the powerstroke, which is the main source of the engine's torque and power.
4. EXHAUST stroke.: During the exhaust stroke, the piston once again returns to top dead center while the exhaust valve is open. This action evacuates the products of combustion from the cylinder by pushing the spent fuel-air mixture through the exhaust valve(s).

2 stroke engine


Mode of operation of the two-stroke engine

1st stroke: The piston is at the bottom of the cylinder. A pipe at the left side is opened and lets the fuel mixture, which is already compressed a bit, flow from the lower to the upper part of the cylinder. The fresh gases expulse now the exhaust through an ejection pipe, which is not closed by the piston at this moment.

2nd stroke: After being hurried upward, the piston now covers the pipe on the left side and the ejection pipe. Because there is no way out any more, the upper, fresh gas mixture gets compressed now. At the same time in the part below fresh gas is taken in by the piston driving upward through the open suction pipe. At the upper dead-center, the compressed fuel mixture is ignited by the sparking plug, the piston is pressed downward while he compresses at the same time the fresh gas below. The process begins again as soon as the piston arrives at its lowest point.






Petrol engine principle

Diagram of 4-s petrol engine cycle






This cycle have 4 cycle namely they are:


1. INTAKE stroke: On the intake or induction stroke of the piston , the piston descends from the top of the cylinder to the bottom of the cylinder, reducing the pressure inside the cylinder. A mixture of fuel and air is forced by atmospheric (or greater) pressure into the cylinder through the intake port. The intake valve(s) then close.
2. COMPRESSION stroke: With both intake and exhaust valves closed, the piston returns to the top of the cylinder compressing the fuel-air mixture. This is known as the compression stroke.
3. POWER stroke.: While the piston is close to Top Dead Center, the compressed air–fuel mixture is ignited, usually by a spark plug  (for a gasoline or Otto cycle engine) or by the heat and pressure of compression (for a diesel cycle or compression ignition engine). The resulting massive pressure from the combustion of the compressed fuel-air mixture drives the piston back down toward bottom dead center with tremendous force. This is known as the power stroke, which is the main source of the engine's torque and power.
4. EXHAUST stroke.: During the exhaust stroke, the piston once again returns to top dead center while the exhaust valve is open. This action evacuates the products of combustion from the cylinder by pushing the spent fuel-air mixture through the exhaust valve(s).

diesel engine

inventor of diesel engine is Rudolf Diesel I n 1878.


 Fig:  Principle cycle of diesel engine


A diesel engine uses high compression [intake air that is compressed / squished] into a very small space inside each cylinder causing extreme heat! This is called 'Heat Of Compression' which ignites a very fine high pressure mist of diesel fuel that is injected into the cylinder at the exact time.
So you now know that a gasoline engine needs a high energy spark to run while a diesel uses 'Heat Of Compression'


THE FOUR STROKE PRINCIPLE

Every engine today runs on FOUR STROKES or FOUR CYCLES- both these terms mean the same. Here is how the four stroke diesel engine operates.
The four strokes are: INTAKE-COMPRESSION-POWER-EXHAUST. The pistons, valves and injectors work together in each cylinder in a set sequence over and over.

1} INTAKE STROKE:
Intake valves in the cylinder head open allowing pressurized air to enter each cylinder while the piston is travelling downward.{the pressurized air supply is made possible by the TURBOCHARGER which pushes air into the intake system giving the diesel engine a boost of air to keep up with instantaneous injection of fuel}

2} COMPRESSION STROKE:
When the piston starts to make it's way back upward the valves close which traps the intake air in the cylinder which allows compression to take place, the HEAT OF COMPRESSION is reached when the piston reaches the top of the cylinder, the diesel fuel is then injected into the cylinder at the precise time.

3} POWER STROKE:
After injection takes place an explosion occurs in the cylinder because of the combination of heat and atomized diesel fuel. This causes the piston to be forced downward which produces torque and the horsepower required from a typical diesel engine.

4} EXHAUST STROKE:
After the power stroke the piston moves upward once again while the exhaust valves open allowing the previously ignited gases to escape to the atmosphere out the exhaust system.

Automobile manufactures

 Alpha Sports ,Bullet, Chrysler Australia (produced the Valiant), West Coast Motors, Chrysler Canada Ltd., Chalmers Motor Car of Canada, Fisher Motor Company. Ltd., General Motors of Canada Ltd., Renault, First Automotive Works (FAW), Great Wall, Shanghai Automotive, Alpine/Alpine-Renault, Bugatti, Peugeot, Volkswagen, Audi, Skoda , Lamborghini, Bentley, Mercedes-Benz, Chrysler, Jeep, BMW, Rolls-Royce, Audi, Daimler, MAN, Opel, Porsche, Tata Motors, Reva, Premier, Mahindra, Hindustan, HeroHonda, Bajaj Tempo, Ashok Leyland, Alfa Romeo, Abarth, Ferrari, Lamberti, Daihatsu, Honda, Isuzu, Mazda, Mitsubishi, Nissan , Subaru, Subaru, Toyota Motor Corporation, Perodua, Proton, Hyundai, Kia Motors, SsangYong, Alvis Cars, Aston Martin, Aston Martin, Leyland, Jaguar, Mini/MINI, Rover, Hummer, 

Automobile Introduction

An automobilemotor car or car is a wheeled motor vehicles used for transporting passengers, which also carries its own engine or motor. Most definitions of the term specify that automobiles are designed to run primarily on roads, to have seating for one to fifty people ( Excluding driver ), It may have 2 or more wheels. Primarily automobile are 
design to transport passenger & goods.The word automobile comes, via the France 'automobile' from ancient Greek.firstly automobile  fuel is petrol later Diesel,bio diesel,solar,hydrogen,electricity etc ,now a days scientist 
are trying on water too. The only disadvantage of automobile is it cause air pollution ,noise pollution etc.