Transcript of ENGINE OPERATION - Synthetic Warehouse Tech...revolution of crankshaft • Multi-pass lubrication...
ENGINE OPERATION
Presented by: Len Groom & Shane Hickey
Presenter
Presentation Notes
Shane: Thank you, a part of what Len and I do at AMSOIL is launch products and provide the support for these products. We start with an idea, driven from our research, recent trends, new technology and feedback and suggestions from our you..our dealers (yes, we do actually listen to you) From there we work with a larger team to come up with the formulation where we’ll test and validate that oil through field testing and through third party testing. Our team will position and market each product leading up to the launch and continue to support each product while it’s in the field with proof of performance. And that’s just a part of what we do, but today, we’ll be talking about engine operation and what actually happens once oil is poured into the engine.
AGENDA/OUTLINE Engine Components Common Engine Block Designs Four Functions of Combustion 4-Stroke & 2-Stroke Engine Lubrication Systems Cooling Systems Intake Systems Carburetion Electronic Fuel Injection Ignition Systems Exhaust Systems Fuel Types Emissions
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• Air-fuel mixture is burned under pressure in the cylinder • Burning fuel is transferred into movement
ENGINE TRANSFORMS FUEL INTO ENERGY
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ENGINE COMPONENTS
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• Comprise strong housing that holds the crankshaft • Built to withstand the constant turning of the crankshaft
CYLINDER BLOCK, HEAD & CRANKCASE
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Propelled by the movement of the pistons and transforms the reciprocating action of the connecting rods into rotary action for the transmission (and eventually wheels).
CRANKSHAFT
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Crankshaft connects to Pistons through Connecting Rods
CONNECTING RODS
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Wrist Pins
Connecting Rods Crankshaft Connecting
Rods
Wrist Pins
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Presentation Notes
So the crankshaft connects to the piston through the connecting rods you can see here that look like wrenches with an open hole at the end. Together, the crankshaft and piston form a device that converts reciprocating motion (piston moving up and down in the cylinder) into rotating motion (allowing for the connecting rod to be pushed around the crankshaft)
• Provide a seal between the combustion chamber and crankcase
• Prevent blow-by of exhaust gases
PISTON & PISTON RINGS
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Piston crown can be flat, domed or contoured
Presenter
Presentation Notes
And you heard me mention reciprocating motion. The piston moves up and down in the cylinder and that’s what we call the reciprocating motion. That back and forth up and down movement. Pistons rings are crucial because they act as a seal between the combustion chamber and the crankcase. The piston on the right was taken from a 2 stroke weed wacker. Piston’s from 2-stroke engines only have 2 rings.. The piston on the left is from a 4 stroke engine and all four stroke pistons have a third ring which acts as an oil control ring. It controls the amount of oil that lubricates the piston and it’s skirt. That oil control ring is important because it prevents too much oil from entering the combustion chamber where it would be lost.
PISTON ELEMENTS
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Presenter
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And when everything comes together you see we have the piston
• Air and fuel are ignited in the cylinder
• Explosion drives the piston downward
• Connecting rod transfers motion to the crankshaft
INSIDE THE ENGINE CYLINDER
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Cylinder
Connecting Rod
Piston
Presenter
Presentation Notes
Now let’s take a look at all the pieces together inside the cylinder. The air and fuel enter the cylinder and are ignited creating that explosion and delivering the power that drives the piston downward. You can also see the connecting rod that transfers the power and motion (that rotary motion to the crankshaft that will transfer power to the transmission and other engine parts….so we can see all the pieces of the puzzle starting to come together.
Opens and closes the cylinder valves at the right time • Valves • Valve-spring assembly • Camshaft • Lifters
VALVETRAIN
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• Uses eccentrics (lobes) to control valve timing • Shape of their profile controls valve action
CAMSHAFT
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Ride on the camshaft and transmit eccentric movement to valve
LIFTERS
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Presenter
Presentation Notes
So you just heard about the camshaft, which also uses rotary motion going around and around. The valves are opening and closing the ports to the cylinder using reciprocating motion. Now you already heard these terms before so you know that something needs to be in the middle of these two motions…. and that’s where the lifters come in. They act as an interceptor that transfers motion and eccentric movement to the valve-train. And there are two types of lifters……
FLAT-TAPPET & ROLLER LIFTERS
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Presenter
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The first one is flat tappet, and you hear this commonly associated with older cars and Hot Rods. And they have a flat bottom which you can see here. Now because they have a flat bottom ..they need an oil that’s high in zinc and phosphorus…..and that’s what we commonly refer as Z-D-D-P. This oil is very important because of that metal to metal contact that’s happening on the camshaft. The oil will act as the barrier between the two contact points. roller lifters are very popular in modern passenger cars, roller lifters have a wheel that acts as the barrier between the camshaft and the valve-train. These lifters produces a lot less friction than the flat tappet because of this wheel. These are also very popular in Harley Davidson and Indian motorcycles.
Allow another element to rotate or slide within it
BEARINGS
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Contain moving elements
ROLLER BEARINGS
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Fixed, non-moving components that require pressurized lubrication to create a fluid barrier that eliminates contact and reduces friction
PLAIN BEARINGS
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COMMON ENGINE BLOCK DESIGNS Inline, V-Style, Opposed, Rotary
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Presenter
Presentation Notes
Now we’ve already discussed all the components of the engine with all it’s parts and pieces. Now we’ll get into the different types and arrangements of engine blocks.
• Cylinders in a single row • Common layout used in many applications (motorcycles, jet
skis, snowmobiles) • Provides good torque
INLINE
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Presenter
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In an inline engine… the cylinders are lined up in a single row. Usually the cylinders are vertica..l but some manufactures will lean them to one side.. Where they are actually called slant engines. Inline engines are found in your toyota’s..your honda’s as well as some power sports applications. A downside to an inline engine.. is once you increase the numbers of cylinders,…it increases the amount of space on the block which takes up more space on the crankshaft..
• Requires less space than inline engine • Two rows of offset cylinders form a “V” shape • Common in large-bore motorcycles
V-STYLE
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The v-style engine doesn’t have this problem… because it requires less space than an inline engine. The V-style engine has two rows of offset cylinders that form the V shape that you see. 4-6 and 8 cylinder engines are very common and you probably drove in one to get here today. Also these V-style engines can pack as many as twelve cylinders with examples such as Ferrari and Lamborghini with their v-Twelve cylinder engines.
• Cylinders lie flat and are arranged perpendicular to either side of crankshaft
• Common to Subaru and Porsche engines
OPPOSED (BOXER)
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• Employs a triangular rotor instead of pistons to produce power • Mainly used in automobile applications (Mazda RX7 & RX8)
ROTARY (WANKEL)
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ENGINE BLOCK DESIGNS IN ACTION
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Presenter
Presentation Notes
http://www.youtube.com/watch?v=ptlJwVWvryY
FOUR FUNCTIONS OF COMBUSTION
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Air and fuel are drawn into the cylinder
#1: INTAKE
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Air and fuel mixture is compressed
#2: COMPRESSION
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Mixture is ignited. Force of combustion is transferred to mechanical motion.
#3: POWER
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Gases from combustion are released from the cylinder to make room for a fresh charge of air and fuel
#4: EXHAUST
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4-STROKE ENGINES Gasoline Diesel
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Presenter
Presentation Notes
So you’ve just learned about the 4 – functions of combustion and while it’s fresh in your mind we are going to find out how they specifically relate to 4-stroke gasoline and diesel engines. Sooo….
• Efficient • Powerful • Quiet • Power stroke every other
revolution of crankshaft • Multi-pass lubrication
4-STROKE ENGINE CHARACTERISTICS
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Presenter
Presentation Notes
4-Stroke engines are very efficient and powerful. They are most times quieter than their 2 stroke counterpart. A very important thing to remember about 4-strokes….is there is a power stroke EVERY OTHER revolution of the crankshaft. So that means that for every 2 revolutions of the crankshaft there is one power stroke. Also, 4-stroke engines use multi-pass lubrication. This means basically that you need to change your oil in a 4-stroke engine. It is re-used in the oil sump and re-circulates throughout the engine.
Valve used for air intake and exhaust combustion events (4-stroke engines) Intake valve delivers the fuel-air mixture to the cylinder Exhaust valve releases burned gases out of the cylinder
4-STROKE ENGINE DESIGN
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4-stroke gasoline cylinder
Presenter
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So inside the valve train of a 4 stroke engine. The valves are used for air intake and for the release of the exhaust. So the air/fuel enters in through the intake valve,…it’s compressed…burnt…and then the exhaust valve opens for the release of the burnt up gases out of the cylinder. Now this is a simple illustration here but most modern cars use 4 valves…2 intake,.,.and 2 exhaust….
Consists of intake, compression, power, and exhaust events that occur in four separate strokes.
GASOLINE/DIESEL ENGINE 4-STROKE CYCLE
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Presenter
Presentation Notes
So Len already touched on the four functions of combustion and in both gasoline and diesel engines there are four separate strokes of the piston. The intake, compression, power and exhaust. If you come away with anything from this presentation it would be to remember these four strokes of the piston…and looking at an actual real time example…….
GASOLINE 4-STROKE CYCLE DEMONSTRATION
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Presenter
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You can see the intake, compression, power and exhaust…intake, compression, power and exhuast……the power stroke is occuring when the cylinder turns yellow. Also it’s tough to see but you can see that the power stroke explodes during every other revolution of the crankcase….
2-STROKE ENGINES Gasoline
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• Lightweight • High power • Power stroke every revolution • Single-pass/total-loss
lubrication • Exhaust power valves
2-STROKE ENGINE CHARACTERISTICS
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Cylinder ports used for air intake and exhaust combustion events (2-stroke engines) Intake port delivers the fuel-oil mixture to the cylinder through the transfer port Exhaust port releases burned gases out of the cylinder
CONVENTIONAL 2-STROKE ENGINE DESIGN
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2-stroke gasoline cylinder (scavenging design)
1. Intake and compression occur in one stroke 2. Power and exhaust occur in the second stroke
GASOLINE 2-STROKE CYCLE
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1 2
GASOLINE 2-CYCLE DEMONSTRATION
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ENGINE LUBRICATION SYSTEMS 4-Stroke Wet-Sump Dry-Sump 2-Stroke
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Presenter
Presentation Notes
We’ve learned about engine components, engine blocks, 4 strokes and 2 strokes…now we’ll be looking at how oil actually lubricates in different engine systems.
• Oil is held in a dedicated oil sump • Oil is not burned as part of the combustion cycle
4-STROKE LUBRICATION
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Presenter
Presentation Notes
In 4-stroke engines, you heard me talk about multi-pass lubrication…which we all know now means that oil is held in a dedicated oil sump and is re-used. That’s why we need to change our oil in our cars. The goal of this simple picture here is to show you the path that the oil takes through the a 4-cycle engine. Through the connecting rods…. around the crankshaft….. up over the cam bearings and recycled over again back to the crankshaft….
Oil is held in a pan beneath the engine
WET-SUMP SYSTEM
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Presenter
Presentation Notes
http://www.youtube.com/watch?v=24AbjTx5x7E
Oil pump is located in a remote location to provide pressurized oil to the engine when the wet-sump system cannot provide adequate lubrication
DRY-SUMP SYSTEM
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Presenter
Presentation Notes
http://www.youtube.com/watch?v=5wqo5RkMrU0
Oil is burned with the fuel during combustion cycle. It must lubricate the engine before it is consumed • Wet case – fuel enters
crankcase and mixes with oil • Dry case – oil only in
crankcase
2-STROKE LUBRICATION
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COOLING SYSTEMS Air Liquid
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Presenter
Presentation Notes
The goal of cooling systems are to transfer the heat that is produced from the power stroke of the engine to the external atmosphere. At the exact moment of combustion, temperatures in the cylinder can exceed 4,000 degrees. So it’s extremely hot and if that heat isn’t handled properly it’s going to cause a lot of damage. So the two types of cooling systems are air and liquid.
• Cooling fins along cylinder walls increase surface area to conduct away heat
• Typically operate at higher temperatures than liquid-cooled engines
AIR-COOLED ENGINES
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Presenter
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And in an air cooled engine, the heat produced from the power stroke is transferred to the atmosphere through the cooling fins. Cooling fins conduct heat away from the cylinder wall by increasing the surface area of the engine. So image you are boiling a pot of water: if you take that pot off the stove and stick your hand in it, your hand’s going to burn. Now imagine if you take that same pot off the heat and pour it on the floor..then stick your hand in the water, what’s going to happen? It’s probably not going to burn you..will it? That’s because your increasing the surface area of the water. And that’s exactly what the cooling fins are doing. They increase the surface area of the cylinder. Air cooled engines are also more sensitive to environmental conditions. They operate at different temperatures according to it’s external environment. So if you’re riding your motorcycle in one of these 35 degree summer days in Minnesota the engine will be a lot cooler than if you’re stuck in dry intense 100 degree weather at Sturgis.
• Coolant passages/water jackets surround cylinder to carry heat away from the engine
LIQUID-COOLED ENGINES
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Presenter
Presentation Notes
http://www.youtube.com/watch?v=mA9FemBpphw Now liquid cooled engines on the other hand aren’t as sensitive to environmental conditions. They use the water/coolant mixture to act as a medium to carry out the heat produced by the power stroke. It travels out to the radiator where it’s transferred into the atmosphere and the water/coolant recirculates and does the job over and over again. So the important things to remember…Air cooled engines are sensitive to environment conditions whereas liquid cooled engines are not.
INTAKE SYSTEMS Gasoline Diesel
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Gasoline Intake System All of the components that blend and deliver the fuel-air mixture to the cylinder
Diesel Intake System All of the components that deliver air to the cylinder
GASOLINE & DIESEL INTAKES
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Normally-aspirated System Uses the vacuum created by the piston’s downward movement to draw air into the system. Forced Induction System compresses the air entering the cylinder to maximize power.
• Turbocharger • Supercharger
INTAKE SYSTEMS COMPARED
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Presenter
Presentation Notes
Talk about….
CARBURETION Carburetor System Carburetor Examples
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• Blends correct amount of fuel-air mixture for combustion
• Most modern vehicles use a fuel-injection system; however, some small engines still use a carbureted system
CARBURETOR SYSTEM
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CARBURETORS
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Carburetor
Intake Manifold
Air Box
ELECTRONIC FUEL INJECTION Throttle Body Multi-port Direct 2-Stroke Semi-Direct 2-Stroke Direct
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Fuel-air intake is electronically controlled More efficient than a carburetor but has limitations
ELECTRONIC FUEL INJECTION
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Pros • Greater power density • Lower oil consumption • Lower smoke & emissions
Injects fuel through the throttle body assembly on top of the engine; injectors at the top of the manifold are shared between all cylinders. Used in many passenger car/truck applications and early 2-stroke applications.
THROTTLE BODY INJECTION
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• Has fuel injectors placed in the intake ports • Provides precise fuel delivery and fuel economy
MULTIPORT INJECTION SYSTEM
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Fuel is directly injected into the combustion chamber
DIRECT INJECTION
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Injects fuel into the airstream of the rear transfer port • Improves emissions • Improves fuel economy • Delivers fuel to transfer port
2-STROKE SEMI-DIRECT INJECTION
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• Next-generation DI technology
2-STROKE DIRECT INJECTION
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IGNITION SYSTEMS Gasoline Engines Diesel Engines
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Presenter
Presentation Notes
Looking back at the four functions of combustion we have intake, compression, power and exhaust. Now at the top of the compression stroke and before the power stroke something needs to happen. Something that will cause the explosion of power. That’s where ignition systems come into play.
IGNITION SYSTEMS: GASOLINE
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Presenter
Presentation Notes
So in a gasoline engine the ignition coil generates the spark that is fed to the distributor cap and is sent to whichever piston is at the top of the compression stroke. Now as we all know in our own equipment when something doesn’t start the number one rule is to check for that spark. Because if we don’t have a spark we aren’t going to be getting any power. That spark needs to come before the power.
1. Ignites air-fuel mixture by first compressing air, raising its temperature
2. Injects fuel into the hot air, which ignites
IGNITION SYSTEMS: DIESEL
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Presenter
Presentation Notes
Diesel engines are very different that gasoline engines. You need to understand that whenever air is compressed… it’ll eventually explode. This is true for gasoline and diesel engines. However, the compression is much stronger for diesel engines. And when that air is compressed… it becomes extremely hot. So in a diesel engine when the piston is at the top of the compression stroke… fuel is injected into the cylinder which ignites,.. producing that explosion you hear rattling in the engine. Remember..you don’t have a single spark in a diesel engine… so when fuel is injected into the cylinder.. It’s ignited at different times …and that produces the rattling noise that’s associated with diesel engines.
EXHAUST SYSTEMS Four-Stroke Two-Stroke
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Presenter
Presentation Notes
So the explosion that occurs in these engines need to exit the engine through a designed path and now we’ll talk about how and where the exhaust goes. These systems are extremely different in 4 stroke and 2 stroke engines.
• Separate from the other strokes • Valve is used to open and close port
FOUR-STROKE EXHAUST
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Presenter
Presentation Notes
In a 4-stroke it’s relatively simple to understand. You have the air/fuel exhaust exiting the exhaust valve and through the exhaust manifold… from there it will run through a catalytic converter into the muffler and out into the atmosphere. The exhaust is very hot and it’s specifically routed in a way where it doesn’t come into contact with the important pieces of the engine. In a 2-stroke it’s an entirely different story.
• Relies on sound waves created during the power stroke to hold the air-fuel mixture in the cylinder
• Power valves provide a much larger usable power band • More power, less fuel
TWO-STROKE EXHAUST
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Presenter
Presentation Notes
There is no easy way to describe the exhaust of a 2-stroke because they rely on sound waves that hold the air-fuel in the cylinder. Another difference in 2-strokes are that they have exhaust power valves and they provide the engine with a much larger usable power band. So you get a higher output power at lower rpm’s…This all equates to more power, with less fuel….you here a lot about carbon deposits and low ash formulations from us and our competitors when referencing exhaust power valves. That’s very important because if you get to much depositing on these power valves they’ll stick and cause the engine to seize.
• Reduce pollutants released from engine’s exhaust • Stricter emissions legislation forces OEMs to develop more
efficient ways of curbing pollutants • Some systems have proven to cause problems such as fuel
dilution
EMISSIONS SYSTEMS FUNCTIONS & CHALLENGES
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• Catalytic converter • Chemical reaction — reduces hydrocarbon (HC), carbon monoxide (CO) and oxides of nitrogen (NOX) • Results in Carbon dioxide (CO2) and Water (H20)
• Exhaust gas recirculation (EGR) • Injects exhaust into intake tract • Lowers combustion temperatures
• Diesel Particulate Filter (DPF)
TYPES OF EMISSIONS SYSTEMS
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Refer to your Engine Operation Training Manual for additional information.
ADDITIONAL INFORMATION & REVIEW
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SUMMARY Four Functions of Combustion Major Engine Components & Designs 2- and 4-Stroke Engine Lubrication Fuel Injection Cooling Systems Emissions