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Diesel Engines
Diesel Engine Fuel Additives Affect Diesel Engine Fuel Economy And Performance. Used Diesel Engines Are Occassionally Thought To Be Rebuilt With New Fuel Injectors. Rebuilt Diesel Generators And Marine Diesel Engines May Need Specialized Tools To Repair Parts. Whether It Be Rebuilt Industrial Diesel Engines.
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 Power and fuel economy of Diesel Engines
Diesel engines are more efficient than gasoline
(petrol) engines of the same power, resulting in lower
fuel consumption. A common margin is 40% more miles per gallon for an efficient
turbodiesel. For example, the current model Škoda Octavia, using Volkswagen
Group engines, has a combined Euro rating of 38 miles per US gallon (6.2 L/100
km) for the 102 bhp (76 kW) petrol engine and 54 mpg (4.4 L/100 km) for the
105 bhp (75 kilowatts) diesel engine.
However, such a comparison doesn't take
into account that diesel fuel is denser and contains about 15% more energy.
Adjusting the numbers for the Octavia, one finds the overall energy efficiency
is still about 20% greater for the diesel version, despite the weight penalty
of the diesel engine. When comparing engines of relatively low power for the
vehicle's weight (such as the 75 hp engines for the VW Golf), the diesel's
overall energy efficiency advantage is reduced further but still between 10
and 15 percent.
While higher compression ratio is helpful
in raising efficiency, diesel engines are much more economical than gasoline
(petrol) engines when at low power and at engine idle. Unlike the petrol engine,
diesels lack a butterfly valve (choke) in the inlet system, which closes at
idle. This creates parasitic drag on the incoming air, reducing the efficiency
of petrol/gasoline engines at idle.
Due to their lower heat losses,
diesel engines have a lower risk of gradually overheating if left idling for
a long periods of time. For example, in many applications, such as marine,
agriculture and railways, diesels are left idling unattended for many hours
or sometimes days. These advantages are especially attractive in locomotives
(see dieselization for more information).
Naturally aspirated diesel engines are heavier
than gasoline engines of the same power for two reasons. The first is that
it takes a larger displacement diesel engine to produce the same power as
a gasoline engine. This is essentially because the diesel must operate at
lower engine speeds. Diesel fuel is injected just before ignition, leaving
the fuel little time to find all the oxygen in the cylinder.
In the gasoline
engine, air and fuel are mixed for the entire compression stroke, ensuring
complete mixing even at higher engine speeds. The second reason
for the greater weight of a diesel engine is it must be stronger to withstand
the higher combustion pressures needed for ignition, and the shock loading
from the detonation of the ignition mixture.
NOTE: DIESEL ENGINE FUEL
ADDITIVES AFFECT DIESEL ENGINE FUEL ECONOMY AND PERFORMANCE.
USED DIESEL ENGINES ARE OCCASSIONALLY THOUGHT TO BE REBUILT
WITH NEW FUEL INJECTORS. REBUILT DIESEL GENERATORS AND MARINE
DIESEL ENGINES MAY NEED SPECIALIZED TOOLS TO REPAIR PARTS.
WHETHER IT BE REBUILT INDUSTRIAL DIESEL ENGINES , CUMMINS
DIESEL ENGINES, DETROIT DIESEL ENGINES, MERCEDES DIESEL ENGINES,
OR PERKINS DIESEL ENGINES, THE OIL PUMPS MAY REQUIRE NEW FILTERS,
WHICH ALSO AFFECT DIESEL FUEL ECONOMY. THE CURRENTLY POPULAR
ISSUE, THOUGH, IS DIESEL FUEL ECONOMY AND DIESEL FUEL ADDITIVES,
DUE TO RECENTLY ESCALATED DIESEL FUEL PRICES. TO COMPENSATE
FOR PRICES MANY ARE BUYING USED DIESEL ENGINES. USED DIESEL
ENGINES STILL PROVIDE ACCEPTABLE DIESEL FUEL ECONOMY, WITH
OR WITHOUT DIESEL FUEL ADDITIVES. CAN BE SENT AT DISCOUNT
PRICES. YOU CAN BUY NOW OR RENT. EQUIPMENT IS ON SALE WITH
A PRICE COST OF LOW DOLLARS AND CENTS. REFUND IS OFTEN IN
CASH IF NOT SATISFIED. IF YOU DECIDE TO BUILD YOUR OWN (DIY)
YOU CAN OFTEN UTILIZE LEFTOVERS FROM FACTORY SECONDS, SURPLUS
, DISCONTINUED MERCHANDISE, GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT,
RETAIL CLOSEOUTS, ITEMS FROM FACTORY REJECTS, OUT OF BUSINESS
SALES & FACTORY CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS!
WHEN BUYING ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN
EXPRESS, AND VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST
AND SECOND QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR
AT CLOSEOUT AND DISTRESSED SALES. WE DO NOT BROKER OR BUY
THESE ITEMS FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL
FOR USED EQUIPMENT, REPOSSESSIONS, JUNK, INSURANCE SALVAGE
OR FREIGHT SALVAGE. DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE
OF GENERAL SUPPLY FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN,
BUY NOW, BUY NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER.
SAVE $ $ $ $ $ $ $ $ $ $.
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As a result, the reciprocating mass (the
piston and connecting rod), and the resultant forces to accelerate and to
decelerate these masses, are substantially higher the heavier, the bigger
and the stronger the part, and the laws of diminishing returns of component
strength, mass of component and inertia - all come into play to create a balance
of offsets, of optimal mean power output, weight and durability.
Yet it is this same build
quality that has allowed some enthusiasts to acquire significant power increases
with turbocharged engines through fairly simple and inexpensive modifications.
A gasoline engine of similar size cannot put out a comparable power increase
without extensive alterations because the stock components would not be able
to withstand the higher stresses placed upon them.
Since a diesel engine is already built to
withstand higher levels of stress, it makes an ideal candidate for performance
tuning with little expense. However it should be said that any modification
that raises the amount of fuel and air put through a diesel engine will increase
its operating temperature which will reduce its life and increase its service
interval requirements. These are issues with newer, lighter, high performance
diesel engines which aren't "overbuilt" to the degree of older engines
and are being pushed to provide greater power in smaller engines.
The addition of a turbocharger or supercharger
to the engine greatly assists in increasing fuel economy and power output, mitigating the fuel-air intake speed limit mentioned
above for a given engine displacement. Boost pressures can be higher on diesels
than gasoline engines, and the higher compression ratio allows a diesel engine
to be more efficient than a comparable spark ignition engine.
Although the calorific value of the fuel
is slightly lower at 45.3 MJ/kg (megajoules per kilogram) to gasoline at 45.8
MJ/kg, diesel fuel is much denser and fuel is sold by volume, so diesel contains
more energy per litre or gallon. The increased fuel economy of the diesel
over the gasoline engine means that the diesel produces less carbon dioxide
(CO2) per unit distance.
Recently, advances in production and changes
in the political climate have increased the availability and awareness of
biodiesel, an alternative to petroleum-derived diesel fuel with a much lower
net-sum emission of CO2, due to the absorption of CO2 by plants used to produce
the fuel.
The two main factors that held diesel engine
back in private vehicles until quite recently were their low power outputs
and high noise levels (characterised by knock or clatter, especially at low
speeds and when cold). This noise was caused by the sudden ignition of the
diesel fuel when injected into the combustion chamber.
This noise
was a product of the sudden temperature change, hence it was more
pronounced at low engine temperatures. A combination of improved mechanical
technology (such as two-stage injectors which fire a short 'pilot charge'
of fuel into the cylinder to warm the combustion chamber before delivering
the main fuel charge) and electronic control (which can adjust the timing
and length of the injection process to optimise it for all speeds and temperatures)
have almost totally solved these problems in the latest generation of common-rail
designs.
Poor power and narrow torque bands have
been solved by the use of turbochargers and intercoolers. How diesel engines really work
Compressing the gas raises its temperature,
the method by which fuel is ignited in diesel engines. Air is drawn into the
cylinders and is compressed by pistons at compression ratios as high as 25:1,
higher than used for a spark-ignition engines.
At the end of the compression stroke, at
the start of the power stroke, diesel fuel is injected continuously into the
combustion chamber through an atomizer, igniting from contact the compressed
air whose temperature is initially about 700–900 °C (1300–1650 °F). Combustion
further heats the air in the chamber, increasing its pressure to move the
piston downward.
A connecting rod transmits this motion to
a crankshaft to convert linear to rotary motion and delivers power to an output
shaft. Scavenging (pushing products of combustion from the cylinder and drawing
in a fresh air) the engine is done either by ports or valves. To increase
power, a diesel engine may by mechanical supercharger or by an exhaust turbine,
have a turbocharger to to increase intake air volume. Use of an aftercooler/intercooler
to cool intake air after compression by a supercharger improves efficiency.
In cold weather,
diesel engines can be difficult to start because the cold
metal of the cylinder block and head draw out the heat created in the cylinder
during the compression stroke, thus preventing ignition. Most Diesel engines
use small electric heaters called glow plugs inside the cylinder help ignite
fuel when starting.
Some even use resistive grid
heaters in the intake manifold to warm the inlet air until the engine reaches
operating temperature. Engine block heaters (electric resistive heaters in
the engine block) connected to the utility grid are often used when an engine
is turned off for extended periods (more than an hour) in cold weather to
reduce startup time and engine wear. Diesel fuel is also prone to 'waxing'
in cold weather, a term for the solidification of diesel oil into a crystalline
state.
The crystals build up in the fuel (especially
in fuel filters), eventually starving the engine of fuel. Low-output electric
heaters in fuel tanks and around fuel lines are used to solve this problem.
Also, most engines have a 'spill return' system, by which any excess fuel
from the injector pump and injectors is returned to the fuel tank.
Once the engine has warmed, returning warm
fuel prevents waxing in the tank. Fuel technology has improved recently so
that with special additives waxing no longer occurs in all but the coldest
climates.
A vital component
of older diesel engine systems is the governor, which limits the
speed of the engine by controlling the rate of fuel delivery. Unlike in petrol
(gasoline) engines, incoming air is not throttled and an engine without a
governor can overspeed. Older injection systems were driven by a gear system
from the engine and thus supplied fuel in proportion with engine speed.
Modern, electronically controlled
engines apply controls similar to those of petrol engines and limit the maximum
RPM through
an electronic control module (ECM) or electronic control unit (ECU)—the engine-mounted
computer. The ECM/ECU receives an engine speed signal from a sensor and controls
the amount of fuel and (start of injection) timing through electric or hydraulic
actuators.
Controlling
the timing of the start of injection of fuel into the cylinder is a key to
minimizing emissions, and maximizing fuel economy (efficiency),
of the engine. The timing is usually measured in units of crank angle of the
piston before Top Dead Center (TDC). For example, if the ECM/ECU initiates
fuel injection when the piston is 10 degrees before TDC, the start of injection,
or timing, is said to be 10 deg BTDC. Optimal timing will depend on the engine
design as well as its speed and load.
Advancing the start of injection (injecting
before the piston reaches TDC) results in higher in-cylinder pressure and
temperature, and higher efficiency, but also results in higher emissions of
oxides of nitrogen (NOx) through higher temperatures. At the other extreme,
delayed start of injection causes incomplete combustion and emits visible
smoke made of particulate matter (PM) and unburned hydrocarbon (HC).
Fuel injection in diesel engines
Early fuel injection systems
The modern diesel engine is a combination
of two inventors' creations. In all major aspects, it holds true to Diesel's
original design, that of the fuel being ignited by compression at an extremely
high pressure within the cylinder. However, nearly all present-day diesel
engines use the so-called solid injection system invented by Herbert Akroyd
Stuart, for his hot bulb engine (a compression-ignition engine that precedes
the diesel engine and operates slightly differently).
Solid injection is where the
fuel is raised to extreme pressures by mechanical pumps and delivered to the
combustion chamber by pressure-activated injectors in an almost solid-state
jet. Diesel's original engine injected fuel with the assistance of compressed
air, which atomised the fuel and forced it into the engine through a nozzle.
This is called an air-blast injection.
The size of the compressor needed to power
such a system made early diesel engines very heavy and large for their power
outputs, and the need to drive a compressor lowered power output even more.
Early marine diesels often had smaller auxiliary engines whose sole purpose
was to drive the compressors to supply air to the main engine's injector system.
Such a system was too bulky and inefficient to be used for road-going automotive
vehicles.
Solid injection systems are
lighter, simpler, and allow for much higher RPMs, and so are universally used
for automotive diesel engines. Air-blast systems provide very efficient combustion
under low-speed, high-load conditions, especially when running on poor-quality
fuels, so some large cathedral marine engines use this injection method. Air-blast
injection also raises the fuel temperature during the injection process, so
is sometimes known as hot-fuel injection. In contrast, solid injection is
sometimes called cold-fuel injection.
Because the vast majority of diesel engines
in service today use solid injection, the information below relates to that
system.
Mechanical and electronic injection of Diesel Engines
Older engines make use of a mechanical fuel
pump and valve assembly which is driven by the engine crankshaft, usually
from the timing belt or chain. These engines use simple injectors which are
basically very precise spring-loaded valves which will open and close at a
specific fuel pressure. The pump assembly consists of a pump which pressurizes
the fuel and a disc-shaped valve which rotates at half crankshaft speed.
The valve has a single aperture to the pressurized
fuel on one side, and one aperture for each injector on the other. As the
engine turns, the valve discs will line up and deliver a burst of pressurized
fuel to the injector at the cylinder about to enter its power stroke. The
injector valve is forced open by the fuel pressure, and the diesel is injected
until the valve rotates out of alignment and the fuel pressure to that injector
is cut off.
Engine speed is controlled
by a third disc, which rotates only a few degrees and is controlled by the
throttle lever. This disc alters the width of the aperture through which the
fuel passes, and therefore how long the injectors are held open before the
fuel supply is cut, which controls the amount of fuel injected.
Older diesel
engines with mechanical injection pumps could be inadvertently run in reverse, albeit very inefficiently as witnessed by massive
amounts of soot being ejected from the air intake. This was often a consequence
of bump starting a vehicle using the wrong gear.
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There
are 10,282 words on this page.
Find this page
fast. Type 33leseid
in a searchbox . (that's diesel33 spelled backwards)
NOTE: DIESEL ENGINE FUEL
ADDITIVES AFFECT DIESEL ENGINE FUEL ECONOMY AND PERFORMANCE.
USED DIESEL ENGINES ARE OCCASSIONALLY THOUGHT TO BE REBUILT
WITH NEW FUEL INJECTORS. REBUILT DIESEL GENERATORS AND MARINE
DIESEL ENGINES MAY NEED SPECIALIZED TOOLS TO REPAIR PARTS.
WHETHER IT BE REBUILT INDUSTRIAL DIESEL ENGINES , CUMMINS
DIESEL ENGINES, DETROIT DIESEL ENGINES, MERCEDES DIESEL ENGINES,
OR PERKINS DIESEL ENGINES, THE OIL PUMPS MAY REQUIRE NEW FILTERS,
WHICH ALSO AFFECT DIESEL FUEL ECONOMY. THE CURRENTLY POPULAR
ISSUE, THOUGH, IS DIESEL FUEL ECONOMY AND DIESEL FUEL ADDITIVES,
DUE TO RECENTLY ESCALATED DIESEL FUEL PRICES. TO COMPENSATE
FOR PRICES MANY ARE BUYING USED DIESEL ENGINES. USED DIESEL
ENGINES STILL PROVIDE ACCEPTABLE DIESEL FUEL ECONOMY, WITH
OR WITHOUT DIESEL FUEL ADDITIVES. CAN BE SENT AT DISCOUNT
PRICES. YOU CAN BUY NOW OR RENT. EQUIPMENT IS ON SALE WITH
A PRICE COST OF LOW DOLLARS AND CENTS. REFUND IS OFTEN IN
CASH IF NOT SATISFIED. IF YOU DECIDE TO BUILD YOUR OWN (DIY)
YOU CAN OFTEN UTILIZE LEFTOVERS FROM FACTORY SECONDS, SURPLUS
, DISCONTINUED MERCHANDISE, GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT,
RETAIL CLOSEOUTS, ITEMS FROM FACTORY REJECTS, OUT OF BUSINESS
SALES & FACTORY CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS!
WHEN BUYING ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN
EXPRESS, AND VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST
AND SECOND QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR
AT CLOSEOUT AND DISTRESSED SALES. WE DO NOT BROKER OR BUY
THESE ITEMS FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL
FOR USED EQUIPMENT, REPOSSESSIONS, JUNK, INSURANCE SALVAGE
OR FREIGHT SALVAGE. DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE
OF GENERAL SUPPLY FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN,
BUY NOW, BUY NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER.
SAVE $ $ $ $ $ $ $ $ $ $.
|
This contrasts with the more modern method
of having a separate fuel pump (or set of pumps) which supplies fuel constantly
at high pressure to each injector. Each injector then has a solenoid which
is operated by an electronic control unit, which enables more accurate control
of injector opening times that depend on other control conditions, such as
engine speed and loading, resulting in better engine performance and fuel
economy.
This design is also mechanically
simpler than the combined pump and valve design, making it generally more
reliable, and less noisy, than its mechanical counterpart.
Both mechanical and electronic injection
systems can be used in either direct or indirect injection configurations.
Indirect injection of Diesel Engines
An indirect injection diesel
engine delivers fuel into a chamber off the combustion chamber, called a prechamber,
where combustion begins and then spreads into the main combustion chamber,
assisted by turbulence created in the chamber. This system allows smoother,
quieter running, and because combustion is assisted by turbulence, injector
pressures can be lower, which in the days of mechanical injection systems
allowed high-speed running suitable for road vehicles (typically up to speed
of around 4,000 rpm).
The prechamber had the disadvantage of increasing
heat loss to the engine's cooling system and restricting the combustion burn,
which reduced the efficiency by between 5-10% in comparison to a direct injection
engine, and nearly all require some form of cold-start device such as glow
plugs. Indirect injection engines were used widely in small-capacity high-speed
diesel engines in automotive, marine and construction uses from the 1950s,
until direct-injection technology advanced in the 1980s.
Indirect
injection engines are cheaper to build and it is easier to produce smooth,
quiet running vehicles with a simple mechanical system, so such engines
are still often used in applications which carry less stringent emissions
controls than road-going vehicles, such as small marine engines, generators,
tractors, and pumps. With electronic injection systems, indirect injection
engines are still used in some road-going vehicles, but most prefer the greater
efficiency of direct injection.
During the development of the high-speed
diesel engine in the 1930s, various engine manufacturers developed their own
type of pre-combustion chamber. Some, such as Mercedes, had complex internal
designs. Others, such as the Lanova pre-combustion chamber, used a mechanical
system to adjust the shape of the chamber for starting and running conditions.
However, the most commonly-used design turned
out to be the 'Comet' series of swirl chambers developed by Harry Ricardo,
using a two-piece spherical chamber with a narrow 'throat' to induce turbulence.
Most European manufacturers of high-speed diesel engines used Comet-type chambers
or developed their own versions (Mercedes stayed with their own design for
many years), and this trend continues with current indirect-injection engines.
Direct injection of Diesel Engines
Modern diesel engines make use of one of
the following direct injection methods:
Distributor pump direct injection of Diesel Engines
The first incarnations of direct injection diesels
used a rotary pump much like indirect injection diesels; however the injectors were mounted in the top of the combustion chamber
rather than in a separate pre-combustion chamber. Examples are vehicles such
as the Ford Transit and the Austin Rover Maestro and Montego with their Perkins
Prima engine.
The problem with these vehicles
was the harsh noise that they made and particulate (smoke) emissions. This
is the reason that in the main this type of engine was limited to commercial
vehicles— the notable exceptions being the Maestro, Montego and Fiat Croma
passenger cars. Fuel consumption was about fifteen to twenty percent lower
than indirect injection diesels, which for some buyers was enough to compensate
for the extra noise.
One of the
first small-capacity, mass-produced direct-injection engines that could be
called refined was developed by the Rover Group.[citation needed]
The '200Tdi' 111 hp] 2.5-litre four-cylinder turbodiesel was used by Land
Rover in their vehicles from 1989, and the engine used an aluminum cylinder
head, Bosch two-stage injection and multi-phase glow plugs to produce a smooth-running
and economical engine while still using mechanical fuel injection.
This type of engine was transformed by electronic
control of the injection pump, pioneered by Volkswagen Audi group with the
Audi 100 TDI introduced in 1989. The injection pressure was still only around
300 bar, but the injection timing, fuel quantity, exhaust gas recirculation
and turbo boost were all electronically controlled.
This gave much more precise control of these
parameters which made refinement much more acceptable and emissions acceptably
low. Fairly quickly the technology trickled down to more mass market vehicles
such as the Mark 3 Golf TDI where it proved
to be very popular. These cars were both more economical and more powerful
than indirect injection competitors of their day.
NOTE: DIESEL ENGINE FUEL
ADDITIVES AFFECT DIESEL ENGINE FUEL ECONOMY AND PERFORMANCE.
USED DIESEL ENGINES ARE OCCASSIONALLY THOUGHT TO BE REBUILT
WITH NEW FUEL INJECTORS. REBUILT DIESEL GENERATORS AND MARINE
DIESEL ENGINES MAY NEED SPECIALIZED TOOLS TO REPAIR PARTS.
WHETHER IT BE REBUILT INDUSTRIAL DIESEL ENGINES , CUMMINS
DIESEL ENGINES, DETROIT DIESEL ENGINES, MERCEDES DIESEL ENGINES,
OR PERKINS DIESEL ENGINES, THE OIL PUMPS MAY REQUIRE NEW FILTERS,
WHICH ALSO AFFECT DIESEL FUEL ECONOMY. THE CURRENTLY POPULAR
ISSUE, THOUGH, IS DIESEL FUEL ECONOMY AND DIESEL FUEL ADDITIVES,
DUE TO RECENTLY ESCALATED DIESEL FUEL PRICES. TO COMPENSATE
FOR PRICES MANY ARE BUYING USED DIESEL ENGINES. USED DIESEL
ENGINES STILL PROVIDE ACCEPTABLE DIESEL FUEL ECONOMY, WITH
OR WITHOUT DIESEL FUEL ADDITIVES. CAN BE SENT AT DISCOUNT
PRICES. YOU CAN BUY NOW OR RENT. EQUIPMENT IS ON SALE WITH
A PRICE COST OF LOW DOLLARS AND CENTS. REFUND IS OFTEN IN
CASH IF NOT SATISFIED. IF YOU DECIDE TO BUILD YOUR OWN (DIY)
YOU CAN OFTEN UTILIZE LEFTOVERS FROM FACTORY SECONDS, SURPLUS
, DISCONTINUED MERCHANDISE, GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT,
RETAIL CLOSEOUTS, ITEMS FROM FACTORY REJECTS, OUT OF BUSINESS
SALES & FACTORY CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS!
WHEN BUYING ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN
EXPRESS, AND VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST
AND SECOND QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR
AT CLOSEOUT AND DISTRESSED SALES. WE DO NOT BROKER OR BUY
THESE ITEMS FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL
FOR USED EQUIPMENT, REPOSSESSIONS, JUNK, INSURANCE SALVAGE
OR FREIGHT SALVAGE. DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE
OF GENERAL SUPPLY FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN,
BUY NOW, BUY NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER.
SAVE $ $ $ $ $ $ $ $ $ $.
|
Common rail direct injection of Diesel Engines
In older diesel engines, a distributor-type
injection pump, regulated by the engine, supplies bursts of fuel to injectors
which are simply nozzles through which the diesel is sprayed into the engine's
combustion chamber.
In common rail systems, the distributor
injection pump is eliminated. Instead an extremely high pressure pump stores
a reservoir of fuel at high pressure - up to 1,800 bar (180 MPa, 26,000 psi)
- in a "common rail", basically a tube which in turn branches off
to computer-controlled injector valves, each of which contains a precision-machined
nozzle and a plunger driven by a solenoid, or even by piezo-electric actuators
(now employed by Mercedes for example, in their high power output 3.0L V6
common rail diesel).
Most European automakers have
common rail diesels in their model lineups, even for commercial vehicles.
Some Japanese manufacturers, such as Toyota,
Nissan and recently Honda, have also developed common rail diesel engines.
Different car makers refer to their common
rail engines by different names, e.g. DaimlerChrysler's CDI, Ford Motor Company's
TDCi (most of these engines are manufactured by PSA), Fiat Group's (Fiat,
Alfa Romeo and Lancia) JTD, Renault's dCi, GM/Opel's CDTi (most of these engines
are manufactured by Fiat, other by Isuzu), Hyundai's CRDi, Mitsubishi's DI-D,
PSA Peugeot Citroën's HDi (Engines for commercial diesel vehicles are made
by Ford Motor Company), Toyota's D-4D, and so on.
Unit direct injection of Diesel Engines
Unit direct
injection also injects fuel directly into the cylinder of the engine. However, in this system the injector and the pump are combined into
one unit positioned over each cylinder. Each cylinder thus has its own pump,
feeding its own injector, which prevents pressure fluctuations and allows
more consistent injection to be achieved.
This type of injection system, also developed
by Bosch, is used by Volkswagen AG in cars (where it is called a Pumpe-Düse-System
- literally "pump-nozzle system") and by Mercedes Benz (PLD) and most major diesel engine manufacturers
in large commercial engines (CAT, Cummins, Detroit Diesel). With recent advancements, the pump pressure
has been raised to 2,050 bar (205 MPa), allowing injection parameters similar
to common rail systems.
Hypodermic injection
injury hazard of Diesel Engines
Because many diesel engine
fuel injection systems operate at extremely high pressure, there is a risk
of injury by hypodermic injection of fuel, if the fuel injector is removed
from its seat and operated in open air.
Types of diesel engines
Early diesel engines
Rudolph Diesel intended his engine to replace
the steam engine as the primary power source for industry. As such diesel
engines in the late 19th- and early 20th-centuries used the same basic layout
and form as industrial steam engines, with long-bore cylinders, external valve
gear, cross-head bearings and an open crankshaft connected to a large flywheel.
NOTE: DIESEL ENGINE FUEL
ADDITIVES AFFECT DIESEL ENGINE FUEL ECONOMY AND PERFORMANCE.
USED DIESEL ENGINES ARE OCCASSIONALLY THOUGHT TO BE REBUILT
WITH NEW FUEL INJECTORS. REBUILT DIESEL GENERATORS AND MARINE
DIESEL ENGINES MAY NEED SPECIALIZED TOOLS TO REPAIR PARTS.
WHETHER IT BE REBUILT INDUSTRIAL DIESEL ENGINES , CUMMINS
DIESEL ENGINES, DETROIT DIESEL ENGINES, MERCEDES DIESEL ENGINES,
OR PERKINS DIESEL ENGINES, THE OIL PUMPS MAY REQUIRE NEW FILTERS,
WHICH ALSO AFFECT DIESEL FUEL ECONOMY. THE CURRENTLY POPULAR
ISSUE, THOUGH, IS DIESEL FUEL ECONOMY AND DIESEL FUEL ADDITIVES,
DUE TO RECENTLY ESCALATED DIESEL FUEL PRICES. TO COMPENSATE
FOR PRICES MANY ARE BUYING USED DIESEL ENGINES. USED DIESEL
ENGINES STILL PROVIDE ACCEPTABLE DIESEL FUEL ECONOMY, WITH
OR WITHOUT DIESEL FUEL ADDITIVES. CAN BE SENT AT DISCOUNT
PRICES. YOU CAN BUY NOW OR RENT. EQUIPMENT IS ON SALE WITH
A PRICE COST OF LOW DOLLARS AND CENTS. REFUND IS OFTEN IN
CASH IF NOT SATISFIED. IF YOU DECIDE TO BUILD YOUR OWN (DIY)
YOU CAN OFTEN UTILIZE LEFTOVERS FROM FACTORY SECONDS, SURPLUS
, DISCONTINUED MERCHANDISE, GARAGE CLEAN OUTS, WAREHOUSE CLEANOUT,
RETAIL CLOSEOUTS, ITEMS FROM FACTORY REJECTS, OUT OF BUSINESS
SALES & FACTORY CLEAN OUTS. FINALLY, DON'T OVERLOOK CLOSEOUTS!
WHEN BUYING ONLINE, PAYPAL, MASTERCARD, DISCOVER, AMERICAN
EXPRESS, AND VISA ARE ALMOST ALWAYS ACCEPTED. RENTALS OF FIRST
AND SECOND QUALITY ARE POSSIBLE. SPECIAL PRICES ALWAYS APPEAR
AT CLOSEOUT AND DISTRESSED SALES. WE DO NOT BROKER OR BUY
THESE ITEMS FOR RESALE. ORDINARILY, THE SALE PRICE IS FINAL
FOR USED EQUIPMENT, REPOSSESSIONS, JUNK, INSURANCE SALVAGE
OR FREIGHT SALVAGE. DISTRESSED MERCHANDISE CAN BE A GOOD SOURCE
OF GENERAL SUPPLY FOR INDUSTRIAL MATERIALS AND PRODUCTS. AGAIN,
BUY NOW, BUY NOW, BUY NOW. THE SALE PRICE MAY NEVER BE LOWER.
SAVE $ $ $ $ $ $ $ $ $ $.
|
Smaller engine would be built with vertical
cylinders, whilst most medium- and large-sized industrial engines were built
with horizontal cylinders, just as steam engines had been. Engines could be
built with more than one cylinder in both cases. The largest early diesels
resembled the triple-expan | |
