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Latest Latest Developments In Developments In

IC EnginesIC Engines

Prepared by, Prepared by,

ROHIT.KROHIT.K

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IntroductionIntroduction

IC Engines are one among the most IC Engines are one among the most widely used Prime movers, its widely used Prime movers, its applications are far spread to various applications are far spread to various fields helpful for mankind.fields helpful for mankind.

I’m here to discuss about the recent I’m here to discuss about the recent developments in IC engines which has developments in IC engines which has made it more efficient and nature made it more efficient and nature friendly.friendly.

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Topics of DiscussionTopics of Discussion

IC EnginesIC EnginesLatest Developments in IC Latest Developments in IC

EnginesEngines Variable Valve Timing & LiftVariable Valve Timing & Lift Electronic Fuel InjectionElectronic Fuel Injection Cylinder DeactivationCylinder Deactivation TurbochargersTurbochargers

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Internal Combustion Internal Combustion EnginesEngines

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HistoryHistory• IC engines were commercially manufactured IC engines were commercially manufactured

and sold from mid 19and sold from mid 19thth century century• Those engines had huge differences when Those engines had huge differences when

compared with the modern IC enginescompared with the modern IC engines• The reason for these differences are various The reason for these differences are various

Engineering developments which aims at Engineering developments which aims at higher efficiency, lower cost, simplicity, higher efficiency, lower cost, simplicity, safety etc.safety etc.

• The process of development still continues to The process of development still continues to yield more & more technologies in this yield more & more technologies in this field….field….

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ApplicationsApplications

• AutomobilesAutomobiles• Gas compressionGas compression• PumpingPumping• Power generationPower generation• IrrigationIrrigation

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Major ProblemsMajor Problems

• Low Thermodynamic EfficiencyLow Thermodynamic Efficiency• Incomplete utilization of fuelIncomplete utilization of fuel• Harmful emissionsHarmful emissions• Low fuel efficiencyLow fuel efficiency

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Cylinder Deactivation

Turbochargers

EFI

VVT & Lift

DevelopmentsIn IC Engines

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Variable Valve Timing & Lift

Conventional engines

no relation between valve timing and engine speed

problems creep in at high rpm’s

if valve is set for high rpm problems occur at low rpm’s

VVT engines

They can vary:

Lift of valve Timing of valve

Phase shift of valve timing Valve overlap

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Need for VVT

at high speeds more air for more power and

combustion

at low speeds prevention of leakage of charge and

fuel efficiency

get good mileage

clean emission

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Development of VVT

HONDA - debut in 1991 with Honda NSX

TOYOTA – Corolla

Nissan, Porsche, BMW, Ferrari followed

but not all were same but each having their own

improvisations

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HONDA VTEC

1.Cams

2.Camshaft

3. Rockers

4. Valves

5.Cylinder

6.Intake exhaust

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3 cam lobes for 2 intake or exhaust valves

one high rpm cam - high profile

two low rpm cams – low profile

correspondingly three rocker arms

center one is free to move

at high rpm’s sensors send signals to ECU

ECU opens oil control valve

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oil pressure couples all three rocker arms together

valves move according to third cam profile

timing is increased

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this was DOHC (double overhead camshaft) VTEC

Honda later developed SOHC VTEC• only intake valves had VTEC

then i-VTEC • this system induced swirl

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BMW’s solenoid valve

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Benefits of VVT

smooth idle• valve overlap retarded to zero• pure mixture thus stable combustion• low fuel consumption • torque improvement• exhaust sucks charge and due to early closing charge does not escape• quicker response to sudden power requirements

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EGR effect

• EGR valve used in conventional engine not required here• exhaust mixes with charge and dilutes it • so low combustion temp. and low NOx production• also unburnt gases in exhaust will get completely burnt

better fuel economy

• approx. 20% increase

Improved emission control• very low Nox production due to EGR effect• due to low fuel consumption low CO2 emission

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Electronic Fuel InjectionElectronic Fuel Injection

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THE FUEL DELIVERY SYSTEMTHE FUEL DELIVERY SYSTEM The fuel delivery system consists of the fuel tank, The fuel delivery system consists of the fuel tank,

fuel pump, fuel filter, fuel delivery pipe (fuel rail), fuel pump, fuel filter, fuel delivery pipe (fuel rail), fuel injector, fuel pressure regulator, and fuel fuel injector, fuel pressure regulator, and fuel

return pipe.return pipe.

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• THE AIR INDUCTION SYSTEM THE AIR INDUCTION SYSTEM • The air induction system consists of the air cleaner, air flow The air induction system consists of the air cleaner, air flow

meter, throttle valve, air intake chamber, intake manifold meter, throttle valve, air intake chamber, intake manifold runner, and intake valve.runner, and intake valve.

• When the throttle valve is opened, air flows through the air When the throttle valve is opened, air flows through the air cleaner, through the air flow past the throttle valve, and cleaner, through the air flow past the throttle valve, and through a well tuned intake manifold runner to the intake through a well tuned intake manifold runner to the intake valve. valve.

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ELECTRONIC CONTROL SYSTEMELECTRONIC CONTROL SYSTEM • The electronic control system consists of various engine The electronic control system consists of various engine

sensors, Electronic Control Unit (ECU), fuel injector sensors, Electronic Control Unit (ECU), fuel injector assemblies, and related wiring. assemblies, and related wiring.

• The ECU determines precisely how much fuel needs to be The ECU determines precisely how much fuel needs to be delivered by the injector by monitoring the engine sensors. delivered by the injector by monitoring the engine sensors.

• The ECU turns the injectors on for a precise amount of time, The ECU turns the injectors on for a precise amount of time, referred to as injection pulse width or injection duration, to referred to as injection pulse width or injection duration, to deliver the proper air/fuel ratio to the engine. deliver the proper air/fuel ratio to the engine.

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Examples of EFIExamples of EFI

• Multi Point Fuel Injection ( MPFI )Multi Point Fuel Injection ( MPFI )• Direct Injection ( DI )Direct Injection ( DI )

* * Common Rail Direct Injection Common Rail Direct Injection ( CRDi )( CRDi )

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MPFIMPFI• In this system each cylinder has number In this system each cylinder has number

of injectors to supply/spray fuel in the of injectors to supply/spray fuel in the cylinders as compared to one injector cylinders as compared to one injector located centrally to supply/spray fuel in located centrally to supply/spray fuel in case of single point injection system.case of single point injection system.

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Direct injectionDirect injection

Direct injection means injecting the fuel Direct injection means injecting the fuel directly into the cylinder instead of directly into the cylinder instead of premixing it with air in separate intake premixing it with air in separate intake ports. That allows for controlling ports. That allows for controlling combustion and emissions more combustion and emissions more precisely precisely

Partial load High loadPartial load High load

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Common Rail Direct Injection (CRDi)Common Rail Direct Injection (CRDi)

The fuel is supplied directly to a common rail from The fuel is supplied directly to a common rail from

where it is injected directly onto the pistons which where it is injected directly onto the pistons which ensures the onset of the combustion in the whole fuel ensures the onset of the combustion in the whole fuel mixture at the same time.mixture at the same time.

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ADVANTAGES OF EFIADVANTAGES OF EFI

• Uniform Air/Fuel Mixture Distribution Uniform Air/Fuel Mixture Distribution

• Excellent Fuel Economy With Improved Excellent Fuel Economy With Improved Emissions ControlEmissions Control

• Highly Accurate Air/Fuel Ratio Control Highly Accurate Air/Fuel Ratio Control throughout All Engine Operating throughout All Engine Operating Conditions Conditions

• Improved Cold Engine Startability and Improved Cold Engine Startability and Operation Operation

• Superior Throttle Response and PowerSuperior Throttle Response and Power• Simpler Mechanics, Reduced Adjustment Simpler Mechanics, Reduced Adjustment

SensitivitySensitivity

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Cylinder DeactivationCylinder DeactivationCylinder Deactivation is the method of deactivating Cylinder Deactivation is the method of deactivating Cylinders as per the Power requirement of the Engine in Cylinders as per the Power requirement of the Engine in order to achieve better Fuel efficiency as well as Emission order to achieve better Fuel efficiency as well as Emission Control. Control.

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How it worksHow it works

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• In conventional engines, valve lifters are operated by the engine’s In conventional engines, valve lifters are operated by the engine’s camshaft, and lift a pushrod that operates the valves in the cylinder camshaft, and lift a pushrod that operates the valves in the cylinder head. In the DOD V8 engines, the special de-ac lifters are installed in head. In the DOD V8 engines, the special de-ac lifters are installed in cylinders 1, 4, 6 and 7, while the remaining cylinders use conventional cylinders 1, 4, 6 and 7, while the remaining cylinders use conventional lifters.lifters.

• The special hydraulically-activated de-ac lifters that enable Displacement The special hydraulically-activated de-ac lifters that enable Displacement on Demand. on Demand.

• The hydraulically operated de-ac lifters have a spring-loaded locking pin The hydraulically operated de-ac lifters have a spring-loaded locking pin actuated by oil pressure.actuated by oil pressure.

• For deactivation, hydraulic pressure dislodges the locking pin, collapsing For deactivation, hydraulic pressure dislodges the locking pin, collapsing the top portion of the lifter into the bottom and removing contact with the top portion of the lifter into the bottom and removing contact with the pushrod. The result is that the bottom of each de-ac lifter rides up the pushrod. The result is that the bottom of each de-ac lifter rides up and down on the cam lobe but the top does not move the push rod.and down on the cam lobe but the top does not move the push rod.

• Without the lifting, the valves do not operate and combustion in that Without the lifting, the valves do not operate and combustion in that cylinder stops. During reactivation, the oil pressure is removed, and the cylinder stops. During reactivation, the oil pressure is removed, and the lifter locks at full length. The pushrods, and therefore the valves, operate lifter locks at full length. The pushrods, and therefore the valves, operate normally. normally.

• The final Displacement on Demand component is the LOMA. This The final Displacement on Demand component is the LOMA. This assembly is a cast aluminum plate, installed in place of a conventional assembly is a cast aluminum plate, installed in place of a conventional engine block cover. The LOMA holds four solenoids, control wiring and engine block cover. The LOMA holds four solenoids, control wiring and cast-in oil passages. The solenoids are managed by the ECM, and each cast-in oil passages. The solenoids are managed by the ECM, and each one controls oil flow to a de-ac lifter, activating and de-activating the one controls oil flow to a de-ac lifter, activating and de-activating the valves at one cylinder as required for Displacement on Demand.valves at one cylinder as required for Displacement on Demand.

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• ADVANTAGES OF CYLINDER ADVANTAGES OF CYLINDER DEACTIVATED ENGINES DEACTIVATED ENGINES

• Increased fuel efficiency (10-20%)Increased fuel efficiency (10-20%)• Decreased emissions from deactivated Decreased emissions from deactivated

cylinderscylinders• Better breathing capability of the Better breathing capability of the

engine, thereby reducing power engine, thereby reducing power consumed in suction stroke.consumed in suction stroke.

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• DISADVANTAGES OF CYLINDER DISADVANTAGES OF CYLINDER DEACTIVATIONDEACTIVATION

• Engine balancing-Engine balancing- Deactivating Deactivating cylinders can cause change in engine cylinders can cause change in engine balancing which can lead to very violent balancing which can lead to very violent vibration and increased noise levels. vibration and increased noise levels.

• Increased cost of manufacturingIncreased cost of manufacturing• Overall increase in weight-Overall increase in weight- Due to Due to

the presence of additional components the presence of additional components like hydraulic lines used in hydraulic like hydraulic lines used in hydraulic sub system, lifter locking mechanism, sub system, lifter locking mechanism, and solenoid valves etc. and solenoid valves etc.

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TURBOCHARGERSTURBOCHARGERS• Turbochargers allow an Turbochargers allow an

engine to burn more fuel engine to burn more fuel and air by packing more and air by packing more into the existing cylinders. into the existing cylinders.

• The typical boost provided The typical boost provided by a turbocharger is 6 to by a turbocharger is 6 to 8 pounds per square inch 8 pounds per square inch (psi). (psi).

• You would expect to get You would expect to get 50 percent more power. 50 percent more power. It's not perfectly efficient, It's not perfectly efficient, so you might get a 30- to so you might get a 30- to 40-percent improvement 40-percent improvement instead. instead.

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• The turbocharger is bolted to The turbocharger is bolted to the the exhaust manifoldexhaust manifold of the of the engine. The exhaust from the engine. The exhaust from the cylinders spins the cylinders spins the turbineturbine, , which works like a gas turbine which works like a gas turbine engine. engine.

• The turbine is connected by a The turbine is connected by a shaft to the shaft to the compressorcompressor, which , which is located between the air filter is located between the air filter and the intake manifold. The and the intake manifold. The compressor pressurizes the air compressor pressurizes the air going into the pistons. going into the pistons.

• The exhaust from the cylinders The exhaust from the cylinders passes through the passes through the turbine turbine bladesblades, causing the turbine to , causing the turbine to spin. The more exhaust that spin. The more exhaust that goes through the blades, the goes through the blades, the faster they spin. faster they spin.

WorkingWorking

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ADVANTAGES:ADVANTAGES:

• More power compared to the same size More power compared to the same size naturally aspirated engine.naturally aspirated engine.

• Better thermal efficiency over naturally Better thermal efficiency over naturally aspirated engine and supercharged aspirated engine and supercharged engine because the engine exhaust is engine because the engine exhaust is being used to do the useful work which being used to do the useful work which otherwise would otherwise would

• have been wasted.have been wasted.• Better Fuel Economy by the way of Better Fuel Economy by the way of

more power and torque from the same more power and torque from the same sized engine.sized engine.

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DISADVANTAGES:DISADVANTAGES:

• Lack of response called the Turbo Lag. If the Lack of response called the Turbo Lag. If the turbo is too big,  the boost will build up slowly turbo is too big,  the boost will build up slowly because more exhaust pressure will be needed because more exhaust pressure will be needed to overcome the rotational inertia on the larger to overcome the rotational inertia on the larger turbine reducing throttle response but more turbine reducing throttle response but more peak power. If the turbo is too small the turbo peak power. If the turbo is too small the turbo lag wont be as big but the peak power would lag wont be as big but the peak power would be lesser. So the turbocharger size is a very be lesser. So the turbocharger size is a very important consideration when deciding on it important consideration when deciding on it for a particular engine.for a particular engine.

• Non liner rise in power and torque.Non liner rise in power and torque.• CostCost• Complexity: Turbocharger spins at very high Complexity: Turbocharger spins at very high

revolutions (1lakh + per minute!!!), hence revolutions (1lakh + per minute!!!), hence proper cooling and lubrication is essential.proper cooling and lubrication is essential.

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ConclusionConclusion

• Though the various technologies discussed above are Though the various technologies discussed above are incorporated in all modern internal combustion engines, incorporated in all modern internal combustion engines, we are still able to achieve only a maximum fuel efficiency we are still able to achieve only a maximum fuel efficiency of about 5 to 10 percent more than the previous versions. of about 5 to 10 percent more than the previous versions. Also 100 percent emission free internal combustion Also 100 percent emission free internal combustion engines have only been a dream to mankind.engines have only been a dream to mankind.

• We are only able to extract a maximum of less than a half We are only able to extract a maximum of less than a half of energy contained in the fuel supplied, even after using of energy contained in the fuel supplied, even after using the latest internal combustion engine which houses most the latest internal combustion engine which houses most of the technologies discussed earlier. There is a wide of the technologies discussed earlier. There is a wide scope of opportunities for new research and development scope of opportunities for new research and development programs in this field.programs in this field.

• The crises like Global Warming & Scarcity of Petroleum The crises like Global Warming & Scarcity of Petroleum fuels have put a strong thrust on every manufacturer of IC fuels have put a strong thrust on every manufacturer of IC engines to build an Efficient and Pollution free engines. engines to build an Efficient and Pollution free engines. We can expect many more technologies in the near future We can expect many more technologies in the near future which would advance the present day IC engine far which would advance the present day IC engine far better. better.

• As the famous quote says “Necessity is the mother of all As the famous quote says “Necessity is the mother of all inventions”, we have felt the necessity and hence hope inventions”, we have felt the necessity and hence hope that healthy inventions would follow. that healthy inventions would follow.

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REFERENCESREFERENCES• ““Design and Development of a Mechanical Design and Development of a Mechanical

Variable Valve Actuation System”, Ronald J. Variable Valve Actuation System”, Ronald J. Pierik & James F. Burkhard, Delphi Automotive Pierik & James F. Burkhard, Delphi Automotive Systems, SAE Technical Paper 2000-01-1221Systems, SAE Technical Paper 2000-01-1221

• www.wabashtech.comwww.wabashtech.com• www.delphi.comwww.delphi.com• www.madsci.orgwww.madsci.org• www.toyotamotors.comwww.toyotamotors.com• Overdrive March 2003Overdrive March 2003• Autocar December 2003Autocar December 2003• Society of Automobile Engineers (SAE) Society of Automobile Engineers (SAE)

Technical papersTechnical papers• Automotive industries LtdAutomotive industries Ltd• DOMKUNDWAR, “A course in IC engines”. DOMKUNDWAR, “A course in IC engines”. • CROUSE/ANGLIN, “Automotive mechanics”.CROUSE/ANGLIN, “Automotive mechanics”.

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Thank youThank you