Everything you need to know about a diesel engine. What make a diesel engine different than a gasoline engine?

1. Diesel Parts 101
Diesel Part Basics
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2. How Does a Diesel Engine Work? Pt 1
• In theory, diesel engines and gasoline engines are quite similar.
They are both internal combustion engines designed to convert the
chemical energy available in fuel into mechanical energy. This
mechanical energy moves pistons up and down inside the cylinders.
The pistons are connected to a crankshaft, and the up-and-down
motion of the pistons, known as linear motion, creates the rotary
motion needed to turn the wheels of a car forward.
• Both diesel engines and gasoline engines convert fuel into energy
through a series of small explosions or combustions. The major
difference between diesel and gasoline is the way these explosions
happen. In a gasoline engine, fuel is mixed with air, compressed by
pistons and ignited by sparks from spark plugs, In a diesel engine,
however, the air is compressed first and then the fuel is injected.
Because air heats up when it’s compressed, the fuel ignites.
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3. How Does a Diesel Engine Work? Pt 2
• The diesel engine uses a four-stroke combustion cycle just like a gasoline.
The four strokes are:
• Intake stroke – The intake valve opens up, letting air and moving the
piston down.
• Compression stroke – The piston moves back up and compressed the air.
• Combustion stroke – As the piston reaches the top, fuel is injected at just
the right moment and ignited, forcing the piston back down.
• Exhaust stroke – The piston moves back to the top, pushing out the
exhaust created from the combustion out of the exhaust valve.
• Remember that the diesel engine has no spark plug, that it intakes air and
compresses it, and that it then injects the fuel directly into the
combustion chamber (direct injection). It is the heat of the compressed air
that lights the fuel in a diesel engine.
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4. Diesel
Engines
vs
Gasoline
Engines
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http://www.buyautoparts.com/ho
wto/how-do-diesel-engines-
work.htm

5. What is a Diesel Turbocharger?
• The diesel motor in many ways is just like a gasoline motor in form and
function the main difference is the way it causes combustion. A diesel uses
the compression of the cylinder to create the heat needed for the correct
reaction in the cylinders. The correct amount of diesel fuel and air is very
important to the proper operation of the diesel motor. The turbocharger
used in diesel vehicles is there to create the higher amounts of air that the
motor will need to create proper combustion. The turbo uses exhaust
gasses to push the turbine and spin the shaft which in turn spins the
impeller blade which will suck in more air and push it into the engine, thus
creating boost. The boost in the engine is then released after combustion
and in turn spins the turbine faster which spins the shaft faster. This
creates higher and higher levels of boost. Turbos can range in size,
efficiency, type and are usually referred to as power adders due to the fact
that they push the engines horse power higher than it would be at the
naturally aspirated level.
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6. Diesel
Turbocharger
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7. What is a Diesel Injection Pump?
• The diesel motor in many ways is just like a
gasoline motor. The diesel injection pump is a
device that flows fuel into the cylinders of the
engine. This unit is used due to the extreme
pressures that are used in diesel motors as
opposed to gasoline motors. The diesel
injector pump is drive by the timing belt or
timing chain of the engine. The unit uses a
rotor that changes position to allow the fuel to
flow to each of the desired injectors.
source: http://www.buyautoparts.com/howto/what-is-a-diesel-injection-pump.htm

8. Diesel
Injection
Pump
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9. What is a Glow Plug?
• Why Do Diesel Engines Need Glow Plugs?
– Unlike gasoline engines in which spark plugs ignite a premixed
air-fuel mixture in the combustion chamber, diesel engines work
according to the so-called self-ignition process. With this
process, intake air is compressed and close to top dead center
diesel fuel is injected into the combustion chamber. The injected
fuel mixes with the compressed air, evaporates, and ignites
almost simultaneously because the intake air heats up during
compression and diesel fuel has a relatively low ignition
temperature. No external ignition device like a spark plug is
needed. However, with a cold diesel engine, the compression
temperature might not be high enough to ensure proper
ignition of the injected diesel fuel, causing inconvenience to the
driver and increased exhaust emissions. The glow plug- an
electrical heating device – helps solve this problem.
source: http://www.buyautoparts.com/howto/what-is-a-glow-plug.htm

10. How Does A Glow Plug Work?
• A glow plug typically comprises a heating coil in a metal
tube closed at one end and filled with electrically insulating
ceramic powder. The closed end of the metal tube with the
heating coil protrudes through a hole in the cylinder head
into the combustion chamber. When the glow plug is
electrically energized, its heated portion reaches a surface
temperature of more than 1000 degree Celsius within a few
seconds. The air-fuel spray generated by the injection
ignites close to the glow plug and initiates combustion.
• Advanced glow control modules like BERU’s Instant Start
System (ISS) can be integrated into the engine management
system to provide gasoline-like turn-key starting
performance and additional glow functions for highly
sophisticated emission reduction strategies.
source: http://www.buyautoparts.com/howto/what-is-a-glow-plug.htm

11. The Latest Innovations In Glow Plugs
• Driven by ever stricter emission standards, it
will become essential to obtain a better
understanding of combustion processes inside
the cylinder. Glow plugs offer mechanical
access to the combustion chamber.
Engineering efforts have been expended to
utilize the glow plug for advanced sensor
functions.
source: http://www.buyautoparts.com/howto/what-is-a-glow-plug.htm

12. Diesel Parts 101
The End
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