The diesel engine (also known as a compression-ignition or CI engine),
named after Rudolf Diesel, is an internal combustion engine in which
ignition of the fuel which is injected into the combustion chamber is
caused by the elevated temperature of the air in the cylinder due to
mechanical compression (adiabatic compression). Diesel engines work by
compressing only the air. This increases the air temperature inside
the cylinder to such a high degree that atomised diesel fuel that is
injected into the combustion chamber ignites spontaneously. This
contrasts with spark-ignition engines such as a petrol engine
(gasoline engine) or gas engine (using a gaseous fuel as opposed to
petrol), which use a spark plug to ignite an air-fuel mixture. In
diesel engines, glow plugs (combustion chamber pre-warmers) may be
used to aid starting in cold weather, or when the engine uses a lower
compression-ratio, or both. The original diesel engine operates on the
"constant pressure" cycle of gradual combustion and produces no
A diesel engine built by MAN AG in 1906
Detroit Diesel timing
Fairbanks Morse model 32
The diesel engine has the highest thermal efficiency (engine
efficiency) of any practical internal or external combustion engine
due to its very high expansion ratio and inherent lean burn which
enables heat dissipation by the excess air. A small efficiency loss is
also avoided compared to two-stroke non-direct-injection gasoline
engines since unburned fuel is not present at valve overlap and
therefore no fuel goes directly from the intake/injection to the
exhaust. Low-speed diesel engines (as used in ships and other
applications where overall engine weight is relatively unimportant)
can have a thermal efficiency that exceeds 50%.
Diesel engines may be designed as either two-stroke or four-stroke
cycles. They were originally used as a more efficient replacement for
stationary steam engines. Since the 1910s they have been used in
submarines and ships. Use in locomotives, trucks, heavy equipment and
electricity generation plants followed later. In the 1930s, they
slowly began to be used in a few automobiles. Since the 1970s, the use
of diesel engines in larger on-road and off-road vehicles in the US
increased. According to the British Society of Motor Manufacturing and
Traders, the EU average for diesel cars accounts for 50% of the total
sold, including 70% in France and 38% in the UK.
The world's largest diesel engine put in service in 2006 is currently
Common Rail marine diesel, which produces
a peak power output of 84.42 MW (113,210 hp) at
2 Operating principle
2.1 Major advantages
2.2 Early fuel injection systems
2.3 Fuel delivery
2.4 Mechanical and electronic injection
2.5 Indirect injection
2.6 Direct injection
2.7 Unit direct injection
Common rail direct injection
2.9 Cold weather problems
2.10 Supercharging and turbocharging
3.1 Size groups
3.2 Basic types
3.3 Early engines
3.4 Modern high and medium-speed engines
3.5 Gas generator
4 Advantages and disadvantages versus spark-ignition engines
4.1 Fuel economy
4.7 Cylinder cavitation and erosion damage
4.8 Quality and variety of fuels
5 Fuel and fluid characteristics
6.1 Fuel flammability
6.2 Maintenance hazards
7.1 Passenger cars
7.2 Railroad rolling stock
7.3 Other transport uses
7.4 Non-road diesel engines
7.5 Military fuel standardisation
7.6 Non-transport uses
8 Engine speeds
8.1 High-speed engines
8.2 Medium-speed engines
8.3 Low-speed engines
9 Current and future developments
9.1 Low heat rejection engines
10 See also
12 External links
Diesel's prototype engine
Diesel's first experimental engine 1893
Hot bulb engine
The definition of a "Diesel" engine to many has become an engine that
uses compression ignition. To some it may be an engine that uses heavy
fuel oil. To others an engine that does not use spark ignition.
However the original cycle proposed by
Rudolf Diesel in 1892 was a
constant temperature cycle (a cycle based on the Carnot theory) that
would require much higher compression than what is needed for
compression ignition. Diesel's idea was to compress the air so tightly
that the temperature of the air would exceed that of combustion. In
his 1892 US patent (granted in 1895) #542846 Diesel describes the
compression required for his cycle:
"pure atmospheric air is compressed, according to curve 1 2, to such a
degree that, before ignition or combustion takes place, the highest
pressure of the diagram and the highest temperature are obtained-that
is to say, the temperature at which the subsequent combustion has to
take place, not the burning or igniting point. To make this more
clear, let it be assumed that the subsequent combustion shall take
place at a temperature of 700°. Then in that case the initial
pressure must be sixty-four atmospheres, or for 800° centigrade the
pressure must be ninety atmospheres, and so on. Into the air thus
compressed is then gradually introduced from the exterior finely
divided fuel, which ignites on introduction, since the air is at a
temperature far above the igniting-point of the fuel. The
characteristic features of the cycle according to my present invention
are therefore, increase of pressure and temperature up to the maximum,
not by combustion, but prior to combustion by mechanical compression
of air, and there upon the subsequent performance of work without
increase of pressure and temperature by gradual combustion during a
prescribed part of the stroke determined by the cut-oil".
In later years Diesel realized his original cycle would not work and
he adopted the constant pressure cycle. Diesel describes the cycle in
his 1895 patent application. Notice that there is no longer a mention
of compression temperatures exceeding the temperature of combustion.
Now all that is mentioned is the compression must be high enough for
"1. In an internal-combustion engine, the combination of a cylinder
and piston constructed and arranged to compress air to a degree
producing a temperature above the igniting-point of the fuel, a supply
for compressed air or gas; a fuel-supply; a distributing-valve for
fuel, a passage from the air supply to the cylinder in communication
with the fuel-distributing valve, an inlet to the cylinder in
communication with the air-supply and with the fuel-valve, and a
cut-oil, substantially as described." See US patent # 608845 filed
1895 / granted 1898
History shows that the invention of the
Diesel engine was not based
solely on one man's idea, but was the culmination of many different
ideas that were developed over time.
In 1806, Claude and
Nicéphore Niépce (brothers) developed the first
known internal combustion engine and the first fuel injection system.
Pyréolophore fuel system used a blast of air provided by a
bellows to atomize Lycopodium (a highly combustible fuel made from
broad moss). Later coal dust mixed with resin became the fuel. Finally
in 1816 they experimented with alcohol and white oil of petroleum (a
fuel similar to kerosene). They discovered that the kerosene type fuel
could be finely vaporized by passing it through a reed type device,
this made the fuel highly combustible.
George Brayton developed and patented a 2 stroke, oil fueled
constant pressure engine "The Ready Motor". This engine used a metered
pump to supply fuel to an injection device in which the oil was
vaporized by air and burned as it entered the cylinder. These were
some of the first practical internal combustion engines to supply
motive power. Brayton's engines were installed in several boats, a
rail car, 2 submarines and a bus. Early Diesel engines use a
Throughout the 1880s, Brayton continued trying to improve his engines.
In 1887 Brayton developed and patented a 4 stroke direct injection oil
engine (US patent #432,114 of 1890, application filed in 1887) The
fuel system used a variable quantity pump and liquid fuel high
pressure spray type injection. The liquid was forced through a spring
loaded relief type valve (injector) which caused the fuel to become
divided into small droplets (vaporized). Injection was timed to occur
at or near the peak of the compression stroke. A platinum igniter or
ignitor provided the source of ignition. Brayton describes the
invention as follows: "I have discovered that heavy oils can be
mechanically converted into a finely-divided condition within a firing
portion of the cylinder, or in a communicating firing chamber."
Another part reads "I have for the first time, so far as my knowledge
extends, regulated speed by variably controlling the direct discharge
of liquid fuel into the combustion chamber or cylinder into a
finely-divided condition highly favorable to immediate combustion".
This was likely the first engine to use a lean burn system to regulate
engine speed / output. In this manner the engine fired on every power
stroke and speed / output was controlled solely by the quantity of
In 1890, Brayton developed and patented a 4 stroke air blast oil
engine (US patent #432,260) The fuel system delivered a variable
quantity of vaporized fuel to the center of the cylinder under
pressure at or near the peak of the compression stroke. The ignition
source was an igniter made from platinum wire. A variable quantity
injection pump provided the fuel to an injector where it was mixed
with air as it entered the cylinder. A small crank driven compressor
provided the source for air. This engine also used the lean burn
Brayton died in 1893, but would be credited with the invention of the
constant pressure Brayton cycle.
In 1885, the English inventor
Herbert Akroyd Stuart
Herbert Akroyd Stuart began
investigating the possibility of using paraffin oil (very similar to
modern-day diesel) for an engine, which unlike petrol would be
difficult to vaporise in a carburettor as its volatility is not
sufficient to allow this.
The hot bulb engines, first prototyped in 1886 and built from 1891 by
Richard Hornsby and Sons, used low pressure fuel injection system.
Hornsby-Akroyd oil engine
Hornsby-Akroyd oil engine used a comparatively low compression
ratio, so that the temperature of the air compressed in the combustion
chamber at the end of the compression stroke was not high enough to
Combustion instead took place in a separated
combustion chamber, the "vaporizer" or "hot bulb" mounted on the
cylinder head, into which fuel was sprayed. Self-ignition occurred
from contact between the fuel-air mixture and the hot walls of the
vaporizer. As the engine's load increased, so did the temperature
of the bulb, causing the ignition period to advance; to counteract
pre-ignition, water was dripped into the air intake.
In 1892, Akroyd Stuart patented a water-jacketed vaporizer to allow
compression ratios to be increased but primarily to reduce
auto-ignition problems at higher loads and compression ratios. In the
same year, Thomas Henry Barton at Hornsbys built a working
high-compression version for experimental purposes, whereby the
vaporizer was replaced with a cylinder head, therefore not relying on
air being preheated, but by combustion through higher compression
ratios. It ran for six hours—the first time automatic ignition was
produced by compression alone, however such a claim is not
substantiated by any source and since until 1907 hotbulb engines were
supposed to be charged with fuel at the intake stroke, although
separately from air, such an engine would have been prone to failure,
poor performance or extreme malfunctioning due to
pre-ignition. 
Herbert Akroyd Stuart
Herbert Akroyd Stuart was a pioneer in developing compression ignition
aided by retained heat of combustion in the bulb, Rudolf Diesel
however, was subsequently credited with the true compression ignition
engine relying solely on heat of compression and not any other form of
retained heat. Higher compression and thermal efficiency along with
injection timing of fuel and vaporization of fuel through injection
system and not by heated surface is what distinguishes Diesel's patent
of 3,500 kilopascals (508 psi).
In 1892, Diesel received patents in Germany, Switzerland, the United
Kingdom and the United States for "Method of and Apparatus for
Converting Heat into Work". In 1893, he described a
"slow-combustion engine" that first compressed air thereby raising its
temperature above the igniting-point of the fuel, then gradually
introducing fuel while letting the mixture expand "against resistance
sufficiently to prevent an essential increase of temperature and
pressure", then cutting off fuel and "expanding without transfer of
heat". In 1894 and 1895, he filed patents and addenda
in various countries for his Diesel engine; the first patents were
issued in Spain (No. 16,654), France (No. 243,531) and
Belgium (No. 113,139) in December 1894, and in Germany
(No. 86,633) in 1895 and the United States (No. 608,845) in
1898. He operated his first successful engine in 1897.
On February 17, 1894, the redesigned engine ran for 88 revolutions -
one minute; with this news, Maschinefabrik Augsburg's stock rose by
30%, indicative of the tremendous anticipated demands for a more
efficient engine. In 1896, Diesel rushed to have a prototype running,
in order to maintain the patent. The first engine ready for testing
was built on December 31, 1896; a much different engine than the one
they had started with. In 1897, between deal signing, and
brainstorming episodes they succeed, the engine runs; 16.93 kW
with an efficiency of 16.6%, he is granted the patent. By 1898, Diesel
had become a millionaire. His engines were used to power pipelines,
electric and water plants, automobiles and trucks, and marine craft.
They were soon to be used in mines, oil fields, factories, and
Pyréolophore uses the first fuel injection system and is
used for powering a boat. In 1807 is granted a patent.
1874 George Brayton's constant pressure "Ready Motor" uses a metered
fuel pump and burns oil fuel inside the cylinder.
Herbert Akroyd Stuart
Herbert Akroyd Stuart builds a prototype hot bulb engine.
George Brayton builds an engine that uses a spring loaded
injector and solid metered injection system (lean burn
George Brayton builds an "Air Blast" injection engine with a lean
Herbert Akroyd Stuart
Herbert Akroyd Stuart patents an internal combustion engine that
uses a "hot bulb" and pressurized fuel injection.
1892: Akroyd Stuart builds his first working Diesel engine.
1893: Rudolf Diesel's essay titled Theory and Construction of a
Rational Motor appeared.
1893: February 23,
Rudolf Diesel obtained a patent (RP 67207) titled
"Arbeitsverfahren und Ausführungsart für Verbrennungsmaschinen"
(Working Methods and Techniques for Internal
1893: August 10, Diesel built his first prototype in Augsburg, This
engine never ran under its own power.
1894 Diesel's second prototype runs for the first time.
1895 Diesel applies for a second patent US Patent # 608845
1896 Blackstone & Co, a Stamford farm implement they built lamp
start oil engines.
Adolphus Busch licenses rights to the Diesel Engine for the US
1897: After 4 years Diesel's prototype engine is running and finally
ready for efficiency testing and production.
1898: Diesel licensed his engine to Branobel, a Russian oil company
interested in an engine that could consume non-distilled oil.
Branobel's engineers spent four years designing a ship-mounted engine.
1899: Diesel licensed his engine to builders
Krupp and Sulzer, who
quickly became major manufacturers.
1902: Until 1910, MAN produced 82 copies of the stationary diesel
1903: Two first diesel-powered ships were launched, both for river and
canal operations: La Petite-Pierre in France, powered by
Dyckhoff-built diesels, and Vandal tanker in Russia, powered by
Swedish-built diesels with an electrical transmission.
1904: The French built the first diesel submarine, the Z.
1905: Four diesel engine turbochargers and intercoolers were
manufactured by Büchl (CH), as well as a scroll-type supercharger
from Creux (F) company.
Prosper L'Orange and Deutz developed a precisely controlled
injection pump with a needle injection nozzle.
1909: The prechamber with a hemispherical combustion chamber was
Prosper L'Orange with Benz.
1910: The Norwegian sailing research ship
Fram was fitted with an
auxiliary diesel engine, and was thus the first ocean-going ship with
a diesel engine. The Dutch tanker Vulcanus became the first
ocean-going ship exclusively powered by a diesel engine.
1912: The Danish built MS Selandia, the most advanced ocean-going
diesel motor ship in her time. The first locomotive with a diesel
engine also appeared.
1913: US Navy submarines used NELSECO units.
Rudolf Diesel died
mysteriously when he crossed the
English Channel on the
1914: German U-boats were powered by MAN diesels.
Prosper L'Orange obtained a patent on a prechamber insert and
made a needle injection nozzle. First diesel engine from Cummins.
One of the eight-cylinder 3200 I.H.P. Harland and Wolff—Burmeister
& Wain Diesel engines installed in the motorship Glenapp. This was
the highest powered
Diesel engine yet (1920) installed in a ship. Note
man standing lower right for size comparison.
Prosper L'Orange built a continuous variable output injection
1922: The first vehicle with a (pre-chamber) diesel engine was
Tractor Type 6 of the Benz Söhne agricultural tractor OE
1923: The first truck with pre-chamber diesel engine made by MAN and
Daimler-Motoren-Gesellschaft testing the first air-injection
1924: The introduction on the truck market of the diesel engine by
commercial truck manufacturers in the IAA.
building diesel engines.
1924-1925 Fairbanks Morse introduced the 2 stroke Y-VA and Model 32.
It was the first cold start diesel manufactured by Fairbanks and would
become an icon of American industrial power.
1927: First truck injection pump and injection nozzles of Bosch. First
passenger car prototype of Stoewer.
1930s: Caterpillar started building diesels for their tractors.
1930: First US diesel-power passenger car (
Cummins powered Packard)
built in Columbus, Indiana (US).
Beardmore Tornado diesel engines power the British airship R101.
1932: Introduction of the strongest diesel truck in the world by MAN
with 160 hp (120 kW).
1933: First European passenger cars with diesel engines (Citroën
Citroën used an engine of the English diesel pioneer Sir
Harry Ricardo. The car did not go into production due to legal
restrictions on the use of diesel engines.
Yanmar is the first Japanese company to introduce the "HB"
series for commercial use.
General Motors uses its new roots-blown, unit-injected
two-stroke Winton 201A
Diesel engine to power its automotive assembly
exhibit at the Chicago World's Fair (A Century of Progress). The
engine represented a major improvement in power-to-weight ratio and
output flexibility over previous generation Diesels, drawing the
interest of railroad executive
Ralph Budd as a prime mover for
Budd Company builds the first streamlined, stainless steel
passenger train in the US, the Pioneer Zephyr, using a Winton engine.
1934: First turbo diesel engine for a railway train by Maybach. First
streamlined, stainless steel passenger train in the US, the Pioneer
Zephyr, using a Winton engine.
1934: First tank equipped with diesel engine, the Polish 7TP.
1934–35: Junkers Motorenwerke in Germany started production of the
Jumo aviation diesel engine family, the most famous of these being the
Jumo 205, of which over 900 examples were produced by the outbreak of
World War II.
Rudolf Diesel's 1893 patent on his engine design
Mercedes-Benz built the 260D diesel car. AT&SF
inaugurated the diesel train Super Chief. The airship Hindenburg was
powered by diesel engines. First series of passenger cars manufactured
with diesel engine (
Mercedes-Benz 260 D,
Hanomag and Saurer). Daimler
Benz airship diesel engine 602LOF6 for the LZ129 Hindenburg airship.
Soviet Union developed the
Kharkiv model V-2
Kharkiv model V-2 diesel engine,
later used in the
T-34 tanks, widely regarded as the best tank chassis
of World War II.
BMW 114 experimental airplane diesel engine development.
General Motors forms the GM Diesel Division, later to become
Detroit Diesel, and introduces the
Series 71 inline high-speed
medium-horsepower two stroke engine, suitable for road vehicles and
1938: GM introduces the 567 two stroke medium-speed high-horsepower
engine for locomotive, ship and stationary applications; These engines
utilize GM's patented Unit injector. The 567 established the
reliability of Diesel power in rail service, lending impetus to the
dieselization of American railroads.
1938: First turbo diesel engine of Saurer.
Fairbanks-Morse opposed piston diesel engines on the WWII submarine
USS Pampanito (SS-383) (on display in San Francisco)
1942: Tatra started production of
Tatra 111 with air-cooled V12 diesel
1943–46: The common-rail (CRD) system was invented (and patented by)
1944: Development of air cooling for diesel engines by Klöckner
Deutz AG (KHD) for the production stage, and later also for
1953: Turbo-diesel truck for Mercedes in small series.
1954: Turbo-diesel truck in mass production by Volvo. First diesel
engine with an overhead cam shaft of Daimler Benz.
1958 EMD introduces turbocharging for its 567 series of medium speed,
high horsepower locomotive, stationary and marine engines. Every
subsequent engine (645 and 710) would incorporate this turbocharger.
1960: The diesel drive displaced steam turbines and coal fired steam
1962–65: A diesel compression braking system, eventually to be
manufactured by Jacobs (of drill chuck fame) and nicknamed the "Jake
Brake", was invented and patented by Clessie Cummins.
Peugeot introduced the first 204 small cars with a transversally
mounted diesel engine and front-wheel drive.
1973: DAF produced an air-cooled diesel engine.
1976 February: Tested a diesel engine for the
passenger car. The
Common Rail injection system was further
developed by the ETH Zurich from 1976 to 1992.
Mercedes-Benz produced the first passenger car with a
turbo-diesel engine (
Mercedes-Benz 300 SD). Oldsmobile introduced
the first passenger car diesel engine produced by an American car
Peugeot 604, the first turbo-diesel car to be sold in
Intercooler diesel engine from DAF. European
Rail system with the IFA truck type W50 introduced.
BMW 524td, the world's first passenger car equipped with an
electronically controlled injection pump (developed by Bosch). The
same year, the
Fiat Croma was the first passenger car in the world to
have a direct injection (turbocharged) diesel engine.
1987: Most powerful production truck with a 460 hp (340 kW)
MAN diesel engine.
1989: Audi 100, the first passenger car in the world with a
turbocharged direct injection and electronic control diesel
1991: European emission standards
Euro 1 met with the truck diesel
engine of Scania.
Pump nozzle injection introduced in
Volvo truck engines.
Unit injector system by Bosch for diesel engines. Mercedes-Benz
unveils the first automotive diesel engine with four valves per
cylinder. Medium speed high horsepower locomotive, ship and
stationary diesel engines have utilized four valves per cylinder since
at least 1938.
1995: First successful use of common rail in a production vehicle, by
Denso in Japan, Hino "Rising Ranger" truck.
1996: First diesel engine with direct injection and four valves per
cylinder, used in the Opel Vectra.
1997: First common rail diesel engine in a passenger car, the Alfa
BMW made history by winning the 24 Hour
Nürburgring race with
the 320d, powered by a two-litre, four-cylinder diesel engine. The
combination of high-performance with better fuel efficiency allowed
the team to make fewer pit stops during the long endurance race.
Volkswagen introduces three and four-cylinder turbodiesel engines,
with Bosch-developed electronically controlled unit injectors.
Smart presented the first common rail three-cylinder diesel engine
used in a passenger car (the Smart City Coupé).
Euro 3 of Scania and the first common rail truck diesel engine
2002: A street-driven Dodge Dakota pickup with a 735 horsepower
(548 kW) diesel engine built at
Gale banks engineering hauls its
own service trailer to the
Bonneville Salt Flats
Bonneville Salt Flats and set an FIA land
speed record as the world's fastest pickup truck with a one-way run of
222 mph (357 km/h) and a two-way average of 217 mph
Piezoelectric injector technology by Bosch, Siemens and
2004: In Western Europe, the proportion of passenger cars with diesel
engine exceeded 50%. Selective catalytic reduction (SCR) system in
Mercedes, Euro 4 with EGR system and particle filters of MAN. Audi A8
3.0 TDI is the first production vehicle in the world with common rail
injection and piezoelectric injectors.
Audi R10 TDI
Audi R10 TDI won the
12 Hours of Sebring
12 Hours of Sebring and defeated all other
engine concepts. The same car won the 2006 24 Hours of Le Mans. Euro 5
JCB Dieselmax broke the FIA diesel land speed
record from 1973, eventually setting the new record at over
350 mph (563 km/h).
Lombardini develops a new 440 cc twin-cyinder common rail
diesel engine, which two years later sees application in
automotive use, in the
Ligier microcars. At the time, this engine
was considered to be the smallest twin-cyinder engine with a common
Subaru introduced the first horizontally opposed diesel engine
to be fitted to a passenger car. This is a
Euro 5 compliant engine
with an EGR system.
SEAT wins the drivers' title and the
manufacturers' title in the
FIA World Touring Car Championship
FIA World Touring Car Championship with
SEAT León TDI. The achievements are repeated in the following
Volkswagen won the 2009 Dakar Rally held in Argentina and Chile.
The first diesel to do so. Race Touareg 2 models finished first and
second. The same year,
Volvo is claimed the world's strongest truck
with their FH16 700. An inline 6-cylinder, 16 L
(976 cu in) 700 hp (522 kW) diesel engine
producing 3150 Nm (2323.32 lb•ft) of torque and fully complying
Euro 5 emission standards.
2010: Mitsubishi developed and started mass production of its 4N13
1.8 L DOHC I4, the world's first passenger car diesel engine that
features a variable valve timing system. Scania AB's V8 had
the highest torque and power ratings of any truck engine, 730 hp
(544 kW) and 3,500 N⋅m (2,581 ft⋅lb).
Piaggio launches a twin-cyinder turbodiesel engine, with common
rail injection, on its new range of microvans.
Common rail systems working with pressures of 2,500 bar
2015: In the
Volkswagen emissions scandal, the US EPA issued a notice
of violation of the Clean Air Act to
Volkswagen Group after it was
Volkswagen had intentionally programmed turbocharged direct
injection (TDI) diesel engines to activate certain emissions controls
only during laboratory emissions testing.
Electro-Motive Diesel introduces locomotives powered by its new
Diesel engine to comply with USEPA Tier 4 emissions
requirements. Over 80 years of emphasis on two-stroke Diesel power by
EMD and its ancestral companies comes to an end.
p-V Diagram for the Ideal Diesel cycle. The cycle follows the numbers
1–4 in clockwise direction. The horizontal axis is Volume of the
cylinder. In the diesel cycle the combustion occurs at almost constant
pressure. On this diagram the work that is generated for each cycle
corresponds to the area within the loop.
Diesel engine model, left side
Diesel engine model, right side
Diesel cycle and Reciprocating internal combustion engine
The diesel internal combustion engine differs from the gasoline
Otto cycle by using highly compressed hot air to ignite the
fuel rather than using a spark plug (compression ignition rather than
In the true diesel engine, only air is initially introduced into the
combustion chamber. The air is then compressed with a compression
ratio typically between 15:1 and 23:1. This high compression causes
the temperature of the air to rise. At about the top of the
compression stroke, fuel is injected directly into the compressed air
in the combustion chamber. This may be into a (typically toroidal)
void in the top of the piston or a pre-chamber depending upon the
design of the engine. The fuel injector ensures that the fuel is
broken down into small droplets, and that the fuel is distributed
evenly. The heat of the compressed air vaporizes fuel from the surface
of the droplets. The vapour is then ignited by the heat from the
compressed air in the combustion chamber, the droplets continue to
vaporise from their surfaces and burn, getting smaller, until all the
fuel in the droplets has been burnt.
Combustion occurs at a
substantially constant pressure during the initial part of the power
stroke. The start of vaporisation causes a delay before ignition and
the characteristic diesel knocking sound as the vapour reaches
ignition temperature and causes an abrupt increase in pressure above
the piston (not shown on the P-V indicator diagram). When combustion
is complete the combustion gases expand as the piston descends
further; the high pressure in the cylinder drives the piston downward,
supplying power to the crankshaft.
As well as the high level of compression allowing combustion to take
place without a separate ignition system, a high compression ratio
greatly increases the engine's efficiency. Increasing the compression
ratio in a spark-ignition engine where fuel and air are mixed before
entry to the cylinder is limited by the need to prevent damaging
pre-ignition. Since only air is compressed in a diesel engine, and
fuel is not introduced into the cylinder until shortly before top dead
centre (TDC), premature detonation is not a problem and compression
ratios are much higher.
The p–V diagram is a simplified and idealised representation of the
events involved in a
Diesel engine cycle, arranged to illustrate the
similarity with a Carnot cycle. Starting at 1, the piston is at bottom
dead centre and both valves are closed at the start of the compression
stroke; the cylinder contains air at atmospheric pressure. Between 1
and 2 the air is compressed adiabatically—that is without heat
transfer to or from the environment—by the rising piston. (This is
only approximately true since there will be some heat exchange with
the cylinder walls.) During this compression, the volume is reduced,
the pressure and temperature both rise. At or slightly before 2 (TDC)
fuel is injected and burns in the compressed hot air. Chemical energy
is released and this constitutes an injection of thermal energy (heat)
into the compressed gas.
Combustion and heating occur between 2 and 3.
In this interval the pressure remains constant since the piston
descends, and the volume increases; the temperature rises as a
consequence of the energy of combustion. At 3 fuel injection and
combustion are complete, and the cylinder contains gas at a higher
temperature than at 2. Between 3 and 4 this hot gas expands, again
approximately adiabatically. Work is done on the system to which the
engine is connected. During this expansion phase the volume of the gas
rises, and its temperature and pressure both fall. At 4 the exhaust
valve opens, and the pressure falls abruptly to atmospheric
(approximately). This is unresisted expansion and no useful work is
done by it. Ideally the adiabatic expansion should continue, extending
the line 3–4 to the right until the pressure falls to that of the
surrounding air, but the loss of efficiency caused by this unresisted
expansion is justified by the practical difficulties involved in
recovering it (the engine would have to be much larger). After the
opening of the exhaust valve, the exhaust stroke follows, but this
(and the following induction stroke) are not shown on the diagram. If
shown, they would be represented by a low-pressure loop at the bottom
of the diagram. At 1 it is assumed that the exhaust and induction
strokes have been completed, and the cylinder is again filled with
air. The piston-cylinder system absorbs energy between 1 and 2—this
is the work needed to compress the air in the cylinder, and is
provided by mechanical kinetic energy stored in the flywheel of the
engine. Work output is done by the piston-cylinder combination between
2 and 4. The difference between these two increments of work is the
indicated work output per cycle, and is represented by the area
enclosed by the p–V loop. The adiabatic expansion is in a higher
pressure range than that of the compression because the gas in the
cylinder is hotter during expansion than during compression. It is for
this reason that the loop has a finite area, and the net output of
work during a cycle is positive.
Diesel engines have several advantages over other internal combustion
Diesel fuel has higher energy density and a smaller volume of fuel is
required to perform a specific amount of work.
Diesel engines inject the fuel directly into the combustion chamber,
have no intake air restrictions apart from air filters and intake
plumbing and have no intake manifold vacuum to add parasitic load and
pumping losses resulting from the pistons being pulled downward
against intake system vacuum. Cylinder filling with atmospheric air is
aided and volumetric efficiency is increased for the same reason.
Heavier fuels like diesel fuel have higher cetane ratings and lower
octane ratings, resulting in increased tendency to ignite
spontaneously and burn completely in the cylinders when injected.
Increased compression ratios create higher combustion chamber
temperatures to ignite the injected fuel. Higher compression ratios
increase pumping losses as more work is required to compress intake
air to a smaller volume, but pumping loss increases are offset by
increased power and efficiency. Increasing compression ratios in
spark-ignition engines requires higher octane fuels that are harder to
ignite and burn completely and/or advanced spark timing to avoid
pre-ignition, knocking and resulting performance losses and engine
damage. Power gains from increased compression ratios are reduced in
spark-ignition engines while the pumping losses remain comparable to
similar compression ratio increases in diesel engines.
Because of the above differences in diesel fuels vs. gasoline and
other spark-ignition fuels, diesel engines have higher thermodynamic
efficiency, with heat efficiency of 45% being possible compared to
approximately 30% for spark-ignition engines.
Gasoline engines are
typically 30% efficient while diesel engines can convert over 45% of
the fuel energy into mechanical energy (see
Carnot cycle for further
They have no high voltage electrical ignition system, resulting in
high reliability and easy adaptation to damp environments. The absence
of coils, spark plug wires, etc., also eliminates a source of radio
frequency emissions which can interfere with navigation and
communication equipment, which is especially important in marine and
aircraft applications, and for preventing interference with radio
telescopes. (For this reason, only diesel-powered vehicles are allowed
in parts of the American National Radio Quiet Zone.)
The lack of an electrical ignition system also reduces the parasitic
load on the engine, as the engine does not have to produce the
necessary electricity to ignite the fuel. A significant amount of
electricity is required by a spark ignition system, and as engine
speeds and loads increase, the ignition system consumes
proportionately more electricity, while simultaneously becoming less
efficient. Higher cylinder pressure require a "hotter" spark with more
current present to overcome the pressure and jump the gap from
electrode to electrode in the spark plug. Increased engine speeds and
loads also require the spark to occur more rapidly, resulting in
additional electrical system loads and demands and more engine power
required to meet them. As diesel engine speeds and loads increase, the
higher cylinder temperatures after compression of the intake charge
result in increased injection and ignition efficiency due to increased
fuel atomization. Regardless of fuel system design, a mechanical
diesel fuel injection system and rapid rise of fuel pressure and flow
will result in injection nozzle opening pressure being reached more
rapidly and also earlier in the 4-stroke cycle with more precise fuel
delivery, more precise injection timing and built-in timing advance.
Additional power is required to operate the injection system as engine
speeds and loads increase, but the increase is more offset than in
spark-ignition engines. Modern diesel engines with electronic
injection systems use a large amount of electricity for injection, but
the ability to precisely time injection and even perform multiple
injection events per cycle result in generally increased fuel
efficiency compared to mechanically-injected diesel engines of similar
size and power.
The longevity of a diesel engine is generally about twice that of a
petrol engine due to the increased strength of parts used.
Diesel fuel has better lubrication properties than petrol as well.
Indeed, in unit injectors, the fuel is employed for three distinct
purposes: injector lubrication, injector cooling and injection for
combustion. Although spark-ignition engines and their fuel systems do
not require as much lubricity, the higher lubricity of diesel fuel
aids in providing lubrication to the top of the cylinders and piston
rings where it is most needed to resist the high heat, loads and
friction resulting from compression and combustion. Because diesel
fuels are actually very light oils, excess fuel in the cylinders and
contaminating the crankcase oil is more easily tolerated by diesel
Bus powered by biodiesel
Diesel fuel is distilled directly from petroleum. Distillation yields
some gasoline, but the yield would be inadequate without catalytic
reforming, which is a more costly process.
Although diesel fuel will burn in open air using a wick, it does not
release a large amount of flammable vapor which could lead to an
explosion. The low vapor pressure of diesel is especially advantageous
in marine applications, where the accumulation of explosive fuel-air
mixtures is a particular hazard. For the same reason, diesel engines
are immune to vapor lock.
For any given partial load the fuel efficiency (mass burned per energy
produced) of a diesel engine remains nearly constant, as opposed to
petrol and turbine engines which use proportionally more fuel with
partial power outputs.
They generate less waste heat in cooling and exhaust.
Diesel engines can accept super- or turbo-charging pressure without
any natural limit, constrained only by the design and operating limits
of engine components, such as pressure, speed and load. This is unlike
petrol engines, which inevitably suffer detonation at higher pressure
if engine tuning and/or fuel octane adjustments are not made to
compensate. Diesel engines also require additional fuel and increased
injection timing advance as cylinder pressures and temperatures
increase, otherwise excessive heat and available oxygen will cause a
"lean" condition that will result in combustible materials in the
engine cylinders, such as the aluminum pistons, being burned as the
engine starves for fuel. This is identical to what occurs in
spark-ignition engines when a similar lean condition occurs.
The carbon monoxide content of the exhaust is minimal.
Biodiesel is an easily synthesized, non-petroleum-based fuel (through
transesterification) which can run directly in many diesel engines,
while gasoline engines either need adaptation to run synthetic fuels
or else use them as an additive to gasoline (e.g., ethanol added to
Early fuel injection systems
Diesel's original engine injected fuel with the assistance of
compressed air, which atomized the fuel and forced it into the engine
through a nozzle (a similar principle to an aerosol spray). The nozzle
opening was closed by a pin valve lifted by the camshaft to initiate
the fuel injection before top dead centre (TDC). This is called an
air-blast injection. Driving the compressor used some power but the
efficiency and net power output was more than any other combustion
engine at that time.
Diesel engines in service today raise the fuel to extreme pressures by
mechanical pumps and deliver it to the combustion chamber by
pressure-activated injectors without compressed air. With direct
injected diesels, injectors spray fuel through 4 to 12 small orifices
in its nozzle. The early air injection diesels always had a superior
combustion without the sharp increase in pressure during combustion.
Research is now being performed and patents are being taken out to
again use some form of air injection to reduce the nitrogen oxides and
pollution, reverting to Diesel's original implementation with its
superior combustion and possibly quieter operation. In all major
aspects, the modern diesel engine holds true to Rudolf Diesel's
original design, that of igniting fuel by compression at an extremely
high pressure within the cylinder. With much higher pressures and high
technology injectors, present-day diesel engines use the so-called
solid injection system applied by
George Brayton for his 1887 Brayton
direct injection engine. The indirect injection engine could be
considered the latest development of hot bulb ignition engines.
Over the years many different injection methods have been used. These
can be described as the following.
Air blast, where the fuel is blown into the cylinder by a blast of
Solid fuel / hydraulic injection, where the fuel is pushed through a
spring loaded valve / injector to produce a combustable mist.
Mechanical unit injector, where the injector is directly operated by a
cam and fuel quantity is controlled by a rack or lever.
Mechanical electronic unit injector, where the injector is operated by
a cam and fuel quantity is controlled electronically.
Common rail mechanical injection, where fuel is at high pressure in a
common rail and controlled by mechanical means.
Common rail electronic injection, where fuel is at high pressure in a
common rail and controlled electronically.
Diesel engines are also produced with two significantly different
injection locations: "direct" and "indirect." Indirect injection
engines place the injector in a pre-combustion chamber in the head,
which, due to thermal losses, generally require a "glow plug" to start
and a very high compression ratio, usually between 21:1 and 23:1.
Direct injection engines use a generally donut-shaped combustion
chamber void on the top of the piston.
Thermal efficiency losses are
significantly lower in DI engines which facilitates a much lower
compression ratio, generally between 14:1 and 20:1 but most DI engines
are closer to 17:1. The direct injection (DI) process is significantly
more internally violent and thus requires careful design and more
robust construction. The lower compression ratio also creates
challenges for emissions due to partial burn.
particularly suited to DI engines since the low compression ratio
facilitates meaningful forced induction. The increase in airflow
allows capturing additional fuel efficiency, not only from more
complete combustion, but also from lowering parasitic efficiency
losses when properly operated, by widening both power and efficiency
curves. The violent combustion process of direct injection also
creates more noise, but modern designs using "split shot" injectors or
similar multishot processes have dramatically ameliorated this issue
by firing a small charge of fuel before the main delivery, which
pre-charges the combustion chamber for a less abrupt, and in most
cases slightly cleaner, burn. citation needed
A vital component of all diesel engines is a mechanical or electronic
governor which regulates the idling speed and maximum speed of the
engine by controlling the rate of fuel delivery. Unlike Otto-cycle
engines, incoming air is not throttled and a diesel engine without a
governor cannot have a stable idling speed and can easily overspeed,
resulting in its destruction. Mechanically governed fuel injection
systems are driven by the engine's gear train. These systems
use a combination of springs and weights to control fuel delivery
relative to both load and speed. Modern electronically controlled
diesel engines control fuel delivery by use of an electronic control
module (ECM) or electronic control unit (ECU). The ECM/ECU receives an
engine speed signal, as well as other operating parameters such as
intake manifold pressure and fuel temperature, from a sensor and
controls the amount of fuel and start of injection timing through
actuators to maximise power and efficiency and minimise emissions.
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 measured in degrees of
crank angle of the piston before top dead centre. For example, if the
ECM/ECU initiates fuel injection when the piston is 10° before TDC,
the start of injection, or timing, is said to be 10° BTDC. Optimal
timing will depend on the engine design as well as its speed and load,
and is usually 4°
BTDC in 1,350–6,000 HP, net, "medium speed"
locomotive, marine and stationary diesel engines.
Advancing the start of injection (injecting before the piston reaches
to its SOI-TDC) results in higher in-cylinder pressure and
temperature, and higher efficiency, but also results in increased
engine noise due to faster cylinder pressure rise and increased oxides
of nitrogen (NOx) formation due to higher combustion temperatures.
Delaying start of injection causes incomplete combustion, reduced fuel
efficiency and an increase in exhaust smoke, containing a considerable
amount of particulate matter and unburned hydrocarbons. citation
Mechanical and electronic injection
Many configurations of fuel injection have been used over the course
of the 20th century.
Most present-day diesel engines use a mechanical single plunger
high-pressure fuel pump driven by the engine crankshaft. For each
engine cylinder, the corresponding plunger in the fuel pump measures
out the correct amount of fuel and determines the timing of each
injection. These engines use injectors that are very precise
spring-loaded valves that open and close at a specific fuel pressure.
Separate high-pressure fuel lines connect the fuel pump with each
cylinder. Fuel volume for each single combustion is controlled by a
slanted groove in the plunger which rotates only a few degrees
releasing the pressure and is controlled by a mechanical governor,
consisting of weights rotating at engine speed constrained by springs
and a lever. The injectors are held open by the fuel pressure. On
high-speed engines the plunger pumps are together in one unit. The
length of fuel lines from the pump to each injector is normally the
same for each cylinder in order to obtain the same pressure delay.
A cheaper configuration on high-speed engines with fewer than six
cylinders is to use an axial-piston distributor pump, consisting of
one rotating pump plunger delivering fuel to a valve and line for each
cylinder (functionally analogous to points and distributor cap on an
Many modern systems have a single fuel pump which supplies fuel
constantly at high pressure with a common rail (single fuel line
common) to each injector. Each injector has a solenoid operated by an
electronic control unit, resulting in more accurate control of
injector opening times that depend on other control conditions, such
as engine speed and loading, and providing better engine performance
and fuel economy.
Both mechanical and electronic injection systems can be used in either
direct or indirect injection configurations.
Two-stroke diesel engines with mechanical injection pumps can be
inadvertently run in reverse, albeit in a very inefficient manner,
possibly damaging the engine. Large ship two-stroke
diesels are designed to run in either direction, obviating the need
for a gearbox.
Ricardo Comet indirect injection chamber
Main article: Indirect injection
An indirect diesel injection system (IDI) engine delivers fuel into a
small chamber called a swirl chamber, pre combustion chamber, pre
chamber or ante-chamber, which is connected to the cylinder by a
narrow air passage. Generally the goal of the pre chamber is to create
increased turbulence for better air / fuel mixing. This system also
allows for a smoother, quieter running engine, and because fuel mixing
is assisted by turbulence, injector pressures can be lower. Most IDI
systems use a single orifice injector. The pre-chamber has the
disadvantage of lowering efficiency due to increased heat loss to the
engine's cooling system, restricting the combustion burn, thus
reducing the efficiency by 5–10%.. IDI engines are also more
difficult to start and usually require the use of glow plugs. IDI
engines may be cheaper to build but generally require a higher
compression ratio than the DI counterpart. IDI also makes it easier to
produce smooth, quieter running engines with a simple mechanical
injection system since exact injection timing is not as critical. Most
modern automotive engines are DI which have the benefits of greater
efficiency and easier starting; however, IDI engines can still be
found in the many ATV and small diesel applications.
Different types of piston bowls
Direct injection diesel engines inject fuel directly into the
cylinder. Usually there is a combustion cup in the top of the piston
where the fuel is sprayed. Many different methods of injection can be
Electronic control of the fuel injection transformed the direct
injection engine by allowing much greater control over the
Unit direct injection
Main article: Unit Injector
Unit direct injection also injects fuel directly into the cylinder of
the engine. In this system the injector and the pump are combined into
one unit positioned over each cylinder controlled by the camshaft.
Each cylinder has its own unit eliminating the high-pressure fuel
lines, achieving a more consistent injection. 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 (MAN SE, CAT, Cummins,
Detroit Diesel, Electro-Motive Diesel, Volvo). With recent
advancements, the pump pressure has been raised to 2,400 bars
(240 MPa; 35,000 psi), allowing injection parameters
similar to common rail systems.
Common rail direct injection
Main article: Common rail
"Common Rail" injection was first used in production by Atlas Imperial
Diesel in the 1920s. The rail pressure was kept at a steady 2,000 -
4,000 psi. In the injectors a needle was mechanically lifted off of
the seat to create the injection event. Modern common rail systems
use very high-pressures. In these systems an engine driven pump
pressurizes fuel at up to 2,500 bar (250 MPa;
36,000 psi),[not in citation given] in a "common rail". The
common rail is a tube that supplies each computer-controlled injector
containing a precision-machined nozzle and a plunger driven by a
solenoid or piezoelectric actuator.
Cold weather problems
In cold weather, high speed diesel engines can be difficult to start
because the mass of the cylinder block and cylinder head absorb the
heat of compression, preventing ignition due to the higher
surface-to-volume ratio. Pre-chambered engines make use of small
electric heaters inside the pre-chambers called glowplugs, while
direct-injected engines have these glowplugs in the combustion
Many engines use resistive heaters in the intake manifold to warm the
inlet air for starting, or until the engine reaches operating
temperature. Engine block heaters (electric resistive heaters in the
engine block) connected to the utility grid are used in cold climates
when an engine is turned off for extended periods (more than an hour),
to reduce startup time and engine wear. Block heaters are also used
for emergency power standby Diesel-powered generators which must
rapidly pick up load on a power failure. In the past, a wider variety
of cold-start methods were used. Some engines, such as Detroit
Diesel engines used[when?] a system to introduce small amounts of
ether into the inlet manifold to start combustion. Others used a mixed
system, with a resistive heater burning methanol. An impromptu method,
particularly on out-of-tune engines, is to manually spray an aerosol
can of ether-based engine starter fluid into the intake air stream
(usually through the intake air filter assembly).
Diesel fuel is also prone to waxing or gelling in cold weather; both
are terms for the solidification of diesel oil into a partially
crystalline state. The crystals build up in the fuel system
(especially in fuel filters), eventually starving the engine of fuel
and causing it to stop running. 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.
Due to improvements in fuel technology with additives, waxing rarely
occurs in all but the coldest weather when a mix of diesel and
kerosene may be used to run a vehicle. Gas stations in regions with a
cold climate are required to offer winterized diesel in the cold
seasons that allow operation below a specific Cold Filter Plugging
Point. In Europe these diesel characteristics are described in the EN
Supercharging and turbocharging
Many diesels are now turbocharged and some are both turbo charged and
supercharged. A turbocharged engine can produce more power than a
naturally aspirated engine of the same configuration. A supercharger
is powered mechanically by the engine's crankshaft, while a
turbocharger is powered by the engine exhaust.
improve the fuel economy of diesel engines by recovering waste
heat from the exhaust, increasing the excess air factor, and
increasing the ratio of engine output to friction losses.
A two-stroke engine does not have a discrete exhaust and intake stroke
and thus is incapable of self-aspiration. Therefore, all two-stroke
engines must be fitted with a blower or some form of compressor to
charge the cylinders with air and assist in dispersing exhaust gases,
a process referred to as scavenging. In some cases, the engine may
also be fitted with a turbocharger, whose output is directed into the
A few designs employ a hybrid blower / turbocharger (a
turbo-compressor system) for scavenging and charging the cylinders,
which device is mechanically driven at cranking and low speeds to act
as a blower, but which acts as a true turbocharger at higher speeds
and loads. A hybrid turbocharger can revert to compressor mode during
commands for large increases in engine output power.
As turbocharged or supercharged engines produce more power for a given
engine size as compared to naturally aspirated engines, attention must
be paid to the mechanical design of components, lubrication, and
cooling to handle the power. Pistons are usually cooled with
lubrication oil sprayed on the bottom of the piston. Large "Low speed"
engines may use water, sea water, or oil supplied through telescoping
pipes attached to the crosshead to cool the pistons.
Diesel engine with Roots blower, typical of Detroit Diesel
Electro-Motive Diesel Engines
There are three size groups of Diesel engines
Small—under 188 kW (252 hp) output
There are two basic types of Diesel Engines
Four stroke cycle
Two stroke cycle
In 1897, when the first
Diesel engine was completed, Adolphus Busch
traveled to Cologne and negotiated exclusive right to produce the
Diesel engine in the US and Canada. In his examination of the engine,
it was noted that the Diesel at that time operated at thermodynamic
efficiencies of 27%, while a typical expansion steam engine would
operate at about 7-10%.
In the early decades of the 20th century, when large diesel engines
were first being used, the engines took a form similar to the compound
steam engines common at the time, with the piston being connected to
the connecting rod by a crosshead bearing. Following steam engine
practice some manufacturers made double-acting two-stroke and
four-stroke diesel engines to increase power output, with combustion
taking place on both sides of the piston, with two sets of valve gear
and fuel injection. While it produced large amounts of power, the
double-acting diesel engine's main problem was producing a good seal
where the piston rod passed through the bottom of the lower combustion
chamber to the crosshead bearing, and no more were built. By the 1930s
turbochargers were fitted to some engines. Crosshead bearings are
still used to reduce the wear on the cylinders in large long-stroke
main marine engines.
Modern high and medium-speed engines
Yanmar 2GM20 marine diesel engine, installed in a sailboat
As with petrol engines, there are two classes of diesel engines in
current use: two-stroke and four-stroke. The four-stroke type is the
"classic" version, tracing its lineage back to Rudolf Diesel's
prototype. It is also the more commonly used form, being the preferred
power source for many motor vehicles, especially buses and trucks.
Much larger engines, such as used for railroad locomotion and marine
propulsion, are often two-stroke units, offering a more favourable
power-to-weight ratio, as well as better fuel economy. The most
powerful engines in the world are two-stroke diesels of mammoth
Two-stroke diesel engine operation is similar to that of petrol
counterparts, except that fuel is not mixed with air before induction,
and the crankcase does not take an active role in the cycle. The
traditional two-stroke design relies upon a mechanically driven
positive displacement blower to charge the cylinders with air before
compression and ignition. The charging process also assists in
expelling (scavenging) combustion gases remaining from the previous
The modern form of the two-stroke diesel is based on the efforts of
Charles F. "Boss" Kettering and his colleagues at General Motors
Corporation, who designed an aspirating system in which a blower
pressurizes a chamber in the engine block that is often referred to as
the "air box," and exhaust gases are scavenged under pressure from the
air intake (uniflow scavenging). The concept was introduced with the
Winton 201A engine in 1933, which was used in locomotive manufacture
from 1934 to 1938 and in submarines. Experience with the Winton 201A
was used in development of GM's 567 locomotive engine introduced in
1938, which launched dieselization of American railroads and from
which the later 645 and 710 engines were derived. However, a
significant improvement built into most later EMD engines is the
mechanically assisted turbo-compressor, which provides charge air
using mechanical assistance during starting (thereby obviating the
necessity for Roots-blown scavenging), and provides charge air using
an exhaust gas-driven turbine during normal operations—thereby
providing true turbocharging and additionally increasing the engine's
power output by at least fifty percent.[a] Also in 1938 GM
miniaturized two-stroke Diesel power with the (high-speed) Detroit
Series 71 engine, bringing Diesel power to a form suitable for
trucks, buses, and smaller boats. In 2015, Electro-Motive Diesel
shifted their emphasis to four-stroke locomotive power in the interest
of complying with USEPA Tier 4 emissions requirements, introducing the
Three English Electric 7SRL diesel-alternator sets being installed at
the Saateni Power Station,
In a two-stroke diesel engine, as the cylinder's piston approaches the
bottom dead centre exhaust ports or valves are opened relieving most
of the excess pressure after which a passage between the air box and
the cylinder is opened, permitting air flow into the cylinder. The
air flow blows the remaining combustion gases from the cylinder—this
is the scavenging process. As the piston passes through bottom centre
and starts upward, the passage is closed and compression
commences, culminating in fuel injection and ignition. Refer
to two-stroke diesel engines for more detailed coverage of aspiration
types and supercharging of two-stroke diesel engines.
Normally, the number of cylinders are used in multiples of two,
although any number of cylinders can be used as long as the load on
the crankshaft is counterbalanced to prevent excessive vibration. The
inline-six-cylinder design is the most prolific in light- to
medium-duty engines, though small V8 and larger inline-four
displacement engines are also common. Small-capacity engines
(generally considered to be those below five litres in capacity) are
generally four- or six-cylinder types, with the four-cylinder being
the most common type found in automotive uses. Five-cylinder diesel
engines have also been produced, being a compromise between the smooth
running of the six-cylinder and the space-efficient dimensions of the
four-cylinder. Diesel engines for smaller plant machinery, boats,
tractors, generators and pumps may be four, three or two-cylinder
types, with the single-cylinder diesel engine remaining for light
stationary work. Direct reversible two-stroke marine diesels need at
least three cylinders for reliable restarting forwards and reverse,
while four-stroke diesels need at least six cylinders.
The desire to improve the diesel engine's power-to-weight ratio
produced several novel cylinder arrangements to extract more power
from a given capacity. The uniflow opposed-piston engine uses two
pistons in one cylinder with the combustion cavity in the middle and
gas in- and outlets at the ends. This makes a comparatively light,
powerful, swiftly running and economic engine suitable for use in
aviation. An example is the Junkers Jumo 204/205. The Napier Deltic
engine, with three cylinders arranged in a triangular formation, each
containing two opposed pistons, the whole engine having three
crankshafts, is one of the better known.
Main article: Free-piston engine
Before 1950, Sulzer started experimenting with two-stroke engines with
boost pressures as high as 6 atmospheres, in which all the output
power was taken from an exhaust gas turbine. The two-stroke pistons
directly drove air compressor pistons to make a positive displacement
gas generator. Opposed pistons were connected by linkages instead of
crankshafts. Several of these units could be connected to provide
power gas to one large output turbine. The overall thermal efficiency
was roughly twice that of a simple gas turbine. This system was
derived from Raúl Pateras Pescara's work on free-piston engines in
Advantages and disadvantages versus spark-ignition engines
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The MAN S80ME-C7 low speed diesel engines use 155 grams (5.5 oz)
of fuel per kWh for an overall energy conversion efficiency of 54.4%,
which is the highest conversion of fuel into power by any single-cycle
internal or external combustion engine (The efficiency of a
combined cycle gas turbine system can exceed 60%.) Diesel engines
are more efficient than gasoline (petrol) engines of the same power
rating, 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 6.2 L/100 km (46 mpg‑imp;
38 mpg‑US) for the 102 bhp (76 kW) petrol engine and
4.4 L/100 km (64 mpg‑imp; 53 mpg‑US) for the
105 bhp (78 kW) diesel engine.
However, such a comparison does not take into account that diesel fuel
is denser and contains about 15% more energy by volume. Although the
calorific value of the fuel is slightly lower at 45.3 MJ/kg
(megajoules per kilogram) than petrol at 45.8 MJ/kg, liquid diesel
fuel is significantly denser than liquid petrol. This is significant
because volume of fuel, in addition to mass, is an important
consideration in mobile applications.
Adjusting the numbers to account for the energy density of diesel
fuel, the overall energy efficiency is still about 20% greater for the
While a higher compression ratio is helpful in raising efficiency,
diesel engines are much more efficient than gasoline (petrol) engines
when at low power and at engine idle. Unlike the petrol engine,
diesels lack a butterfly valve (throttle) in the inlet system, which
closes at idle. This creates parasitic loss and destruction of
availability of the incoming air, reducing the efficiency of petrol
engines at idle. In many applications, such as marine, agriculture,
and railways, diesels are left idling and unattended for many hours,
sometimes even days. These advantages are especially attractive in
locomotives (see dieselisation).
Even though diesel engines have a theoretical fuel efficiency of
75%, in practice it is lower. Engines in large diesel
trucks, buses, and newer diesel cars can achieve peak efficiencies
around 45%, and could reach 55% efficiency in the near future.
However, average efficiency over a driving cycle is lower than peak
efficiency. For example, it might be 37% for an engine with a peak
efficiency of 44%.
Diesel engines produce more torque than petrol engines for a given
displacement due to their higher compression ratio. Higher pressure in
the cylinder and higher forces on the connecting rods and crankshaft
require stronger, heavier components. Heavier rotating components
prevent diesel engines from revving as high as petrol engines for a
given displacement. Diesel engines generally have similar power and
inferior power to weight ratios as compared to petrol engines. Petrol
engines must be geared lower to get the same torque as a comparable
diesel but since petrol engines rev higher both will have similar
acceleration. An arbitrary amount of torque at the wheels can be
gained by gearing any power source down sufficiently (including a hand
crank). For example, a theoretical engine with a constant
200 ft.lbs of torque and a 3000 rpm rev limit has just as much
power (a little over 114 hp) as another theoretical engine with a
constant maximum 100 ft.lbs of torque and a 6000 rpm rev limit. A
(lossless) 2 to 1 reduction gear on the second engine will output a
constant maximum 200 ft.lbs of torque at a maximum of 3000 rpm,
with no change in power. Comparing engines based on (maximum) torque
is just as useful as comparing them based on (maximum) rpm.
Conditions in the diesel engine differ from the spark-ignition engine
due to the different thermodynamic cycle. In addition the power and
engine speed are directly controlled by the fuel supply, rather than
by controlling the air supply as in an otto cycle engine.
The average diesel engine has a poorer power-to-weight ratio than the
petrol engine. This is because the diesel must operate at lower engine
speeds due to the need for heavier, stronger parts to resist the
operating pressure caused by the high compression ratio of the engine,
which increases the forces on the parts due to inertial forces.
Some diesel engines are designed for commercial use.
Diesel engines usually have longer stroke lengths chiefly to
facilitate achieving the necessary compression ratios. As a result,
piston and connecting rods are heavier and more force must be
transmitted through the connecting rods and crankshaft to change the
momentum of the piston. This is another reason that a diesel engine
must be stronger for the same power output as a petrol engine.
Yet it is this characteristic that has allowed some enthusiasts to
acquire significant power increases with turbocharged engines by
making fairly simple and inexpensive modifications. A petrol engine of
similar size cannot put out a comparable power increase without
extensive alterations because the stock components cannot 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 at 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 service requirements.
Main article: Diesel exhaust
Since the diesel engine uses less fuel than the petrol engine per unit
distance, the diesel produces less carbon dioxide (CO2) per unit
distance. Recent 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. However, the use of waste vegetable oil, sawmill
waste from managed forests in Finland, and advances in the production
of vegetable oil from algae demonstrate great promise in providing
feed stocks for sustainable biodiesel that are not in competition with
When a diesel engine runs at low power, there is enough oxygen present
to burn the fuel—diesel engines only make significant amounts of
carbon monoxide when running under a load.
Diesel fuel is injected just before the power stroke. As a result, the
fuel cannot burn completely unless it has a sufficient amount of
oxygen. This can result in incomplete combustion and black smoke in
the exhaust if more fuel is injected than there is air available for
the combustion process. Modern engines with electronic fuel delivery
can adjust the timing and amount of fuel delivered, and so operate
with less waste of fuel. In a mechanical system fuel timing system,
the injection and duration must be set to be efficient at the
anticipated operating rpm and load, and so the settings are less than
ideal when the engine is running at any other RPM. The electronic
injection can "sense" engine revs, load, even boost and temperature,
and continuously alter the timing to match the given situation. In the
petrol engine, air and fuel are mixed for the entire compression
stroke, ensuring complete mixing even at higher engine speeds.
Diesel exhaust is well known for its characteristic smell, but this
smell in recent years has become much less due to use of low sulfur
Diesel exhaust has been found to contain a long list of toxic air
contaminants. Among these pollutants, fine particle pollution is an
important cause of diesel's harmful health effects. However, when
diesel engines burn their fuel with high oxygen levels, this results
in high combustion temperatures and higher efficiency, and these
particles tend to burn, but the amount of NOx pollution tends to
NOx pollution can be reduced with diesel exhaust fluid, which is
injected into the exhaust stream, and catalytically destroys the NOx
Exhaust gas recirculation
Exhaust gas recirculation which works by
recirculating a portion of an engine's exhaust gas back to the engine
cylinders also has very positive effects on NOx emissions, because the
lower proportion of available oxygen lowers the maximum temperature of
The distinctive noise of a diesel engine is variably called diesel
clatter, diesel nailing, or diesel knock. Diesel clatter is
caused largely by the diesel combustion process; the sudden ignition
of the diesel fuel when injected into the combustion chamber causes a
pressure wave. Engine designers can reduce diesel clatter through:
indirect injection; pilot or pre-injection; injection timing;
injection rate; compression ratio; turbo boost; and exhaust gas
Common rail diesel injection systems permit
multiple injection events as an aid to noise reduction. Diesel fuels
with a higher cetane rating modify the combustion process and reduce
diesel clatter. CN (Cetane number) can be raised by distilling
higher quality crude oil, by catalyzing a higher quality product or by
using a cetane improving additive.
A combination of improved mechanical technology such as multi-stage
injectors which fire a short "pilot charge" of fuel into the cylinder
to initiate combustion before delivering the main fuel charge, higher
injection pressures that have improved the atomisation of fuel into
smaller droplets, and electronic control (which can adjust the timing
and length of the injection process to optimise it for all speeds and
temperatures), have partially mitigated these problems in the latest
generation of common-rail designs, while improving engine
For most industrial or nautical applications, reliability is
considered more important than light weight and high power.
The lack of an electrical ignition system greatly improves the
reliability. The high durability of a diesel engine is also due to its
overbuilt nature (see above).
Diesel fuel is a better lubricant than
petrol and thus, it is less harmful to the oil film on piston rings
and cylinder bores as occurs in petrol powered engines; it is routine
for diesel engines to cover 400,000 km (250,000 mi) or more
without a rebuild.
Due to the greater compression ratio and the increased weight of the
stronger components, starting a diesel engine is harder than starting
a gasoline engine of similar design and displacement. More torque from
the starter motor is required to push the engine through the
compression cycle when starting compared to a petrol engine. This can
cause difficulty when starting in winter time if using conventional
automotive batteries because of the lower current available.
Either an electrical starter or an air-start system is used to start
the engine turning. On large engines, pre-lubrication and slow turning
of an engine, as well as heating, are required to minimise the amount
of engine damage during initial start-up and running. Some smaller
military diesels can be started with an explosive cartridge, called a
Coffman starter, which provides the extra power required to get the
machine turning. In the past, Caterpillar and John Deere used a small
petrol pony engine in their tractors to start the primary diesel
engine. The pony engine heated the diesel to aid in ignition and used
a small clutch and transmission to spin up the diesel engine. Even
more unusual was an
International Harvester design in which the diesel
engine had its own carburetor and ignition system, and started on
petrol. Once warmed, the operator moved two levers to switch the
engine to diesel operation, and work could begin. These engines had
very complex cylinder heads, with their own petrol combustion
chambers, and were vulnerable to expensive damage if special care was
not taken (especially in letting the engine cool before turning it
Cylinder cavitation and erosion damage
Diesel engine problems
Quality and variety of fuels
Petrol/gasoline engines are limited in the variety and quality of the
fuels they can burn. Older petrol engines fitted with a carburetor
required a volatile fuel that would vaporise easily to create the
necessary air-fuel ratio for combustion. Because both air and fuel are
admitted to the cylinder, if the compression ratio of the engine is
too high or the fuel too volatile (with too low an octane rating), the
fuel will ignite under compression, as in a diesel engine, before the
piston reaches the top of its stroke. This pre-ignition causes a power
loss and over time major damage to the piston and cylinder. The need
for a fuel that is volatile enough to vaporise but not too volatile
(to avoid pre-ignition) means that petrol engines will only run on a
narrow range of fuels. There has been some success at dual-fuel
engines that use petrol and ethanol, petrol and propane, and petrol
In diesel engines, a mechanical injector system vaporizes the fuel
directly into the combustion chamber or a pre-combustion chamber (as
opposed to a Venturi jet in a carburetor, or a fuel injector in a fuel
injection system vaporising fuel into the intake manifold or intake
runners as in a petrol engine). This forced vaporisation means that
less-volatile fuels can be used. More crucially, because only air is
inducted into the cylinder in a diesel engine, the compression ratio
can be much higher as there is no risk of pre-ignition provided the
injection process is accurately timed. This means that cylinder
temperatures are much higher in a diesel engine than a petrol engine,
allowing less volatile fuels to be used.
Diesel fuel is a form of light fuel oil, very similar to kerosene
(paraffin), but diesel engines, especially older or simple designs
that lack precision electronic injection systems, can run on a wide
variety of other fuels. Some of the most common alternatives are Jet
A-1 type jet fuel or vegetable oil from a very wide variety of plants.
Some engines can be run on vegetable oil without modification, and
most others require fairly basic alterations.
Biodiesel is a pure
diesel-like fuel refined from vegetable oil and can be used in nearly
all diesel engines. Requirements for fuels to be used in diesel
engines are the ability of the fuel to flow along the fuel lines, the
ability of the fuel to lubricate the injector pump and injectors
adequately, and its ignition qualities (ignition delay, cetane
number). Inline mechanical injector pumps generally tolerate
poor-quality or bio-fuels better than distributor-type pumps. Also,
indirect injection engines generally run more satisfactorily on
bio-fuels than direct injection engines. This is partly because an
indirect injection engine has a much greater 'swirl' effect, improving
vaporisation and combustion of fuel, and because (in the case of
vegetable oil-type fuels) lipid depositions can condense on the
cylinder walls of a direct-injection engine if combustion temperatures
are too low (such as starting the engine from cold).
It is often reported that Diesel designed his engine to run on peanut
oil, but this is false. Patent number 608845 describes his engine as
being designed to run on pulverulent solid fuel (coal dust). Diesel
stated in his published papers, "at the Paris Exhibition in 1900
(Exposition Universelle) there was shown by the Otto Company a small
diesel engine, which, at the request of the French Government ran on
Arachide (earth-nut or peanut) oil (see biodiesel), and worked so
smoothly that only a few people were aware of it. The engine was
constructed for using mineral oil, and was then worked on vegetable
oil without any alterations being made. The French Government at the
time thought of testing the applicability to power production of the
Arachide, or earth-nut, which grows in considerable quantities in
their African colonies, and can easily be cultivated there." Diesel
himself later conducted related tests and appeared supportive of the
Most large marine diesels run on heavy fuel oil (sometimes called
"bunker oil"), which is a thick, viscous and almost flameproof fuel
which is very safe to store and cheap to buy in bulk as it is a waste
product from the petroleum refining industry. The fuel must not only
be pre-heated, but must be kept heated during handling and storage in
order to maintain its pumpability. This is usually accomplished by
steam tracing on fuel lines and steam coils in fuel oil tanks. The
fuel is then preheated to over 100C before entering the engine in
order to attain the proper viscosity for atomisation.
Fuel and fluid characteristics
Main article: Diesel fuel
Diesel engines can operate on a variety of different fuels, depending
on configuration, though the eponymous diesel fuel derived from crude
oil is most common. The engines can work with the full spectrum of
crude oil distillates, from natural gas, alcohols, petrol, wood gas to
the fuel oils from diesel oil to residual fuels. Many automotive
diesel engines would run on 100% biodiesel without any modifications.
The type of fuel used is selected to meet a combination of service
requirements, and fuel costs. Good-quality diesel fuel can be
synthesised from vegetable oil and alcohol.
Diesel fuel can be made
from coal or other carbon base using the Fischer–Tropsch process.
Biodiesel is growing in popularity since it can frequently be used in
unmodified engines, though production remains limited. Recently,
biodiesel from coconut, which can produce a very promising coco methyl
ester (CME), has characteristics which enhance lubricity and
combustion giving a regular diesel engine without any modification
more power, less particulate matter or black smoke, and smoother
engine performance. The Philippines pioneers in the research on
Coconut based CME with the help of German and American scientists.
Petroleum-derived diesel is often called petrodiesel if there is need
to distinguish the source of the fuel.
Pure plant oils are increasingly being used as a fuel for cars, trucks
and remote combined heat and power generation especially in Germany
where hundreds of decentralised small- and medium-sized oil presses
cold press oilseed, mainly rapeseed, for fuel. There is a Deutsches
Institut für Normung fuel standard for rapeseed oil fuel.
Residual fuels are the "dregs" of the distillation process and are a
thicker, heavier oil, or oil with higher viscosity, which are so thick
that they are not readily pumpable unless heated. Residual fuel oils
are cheaper than clean, refined diesel oil, although they are dirtier.
Their main considerations are for use in ships and very large
generation sets, due to the cost of the large volume of fuel consumed,
frequently amounting to many tonnes per hour. The poorly refined
biofuels straight vegetable oil (SVO) and waste vegetable oil (WVO)
can fall into this category, but can be viable fuels on non-common
rail or TDI PD diesels with the simple conversion of fuel heating to
80 to 100 degrees Celsius to reduce viscosity, and adequate filtration
to OEM standards. Engines using these heavy oils have to start and
shut down on standard diesel fuel, as these fuels will not flow
through fuel lines at low temperatures. Moving beyond that, use of
low-grade fuels can lead to serious maintenance problems because of
their high sulphur and lower lubrication properties. Most diesel
engines that power ships like supertankers are built so that the
engine can safely use low-grade fuels due to their separate cylinder
and crankcase lubrication.
Normal diesel fuel is more difficult to ignite and slower in
developing fire than petrol because of its higher flash point, but
once burning, a diesel fire can be fierce.
Fuel contaminants such as dirt and water are often more problematic in
diesel engines than in petrol engines. Water can cause serious damage,
due to corrosion, to the injection pump and injectors; and dirt, even
very fine particulate matter, can damage the injection pumps due to
the close tolerances that the pumps are machined to. All diesel
engines will have a fuel filter (usually much finer than a filter on a
petrol engine), and a water trap. The water trap (which is sometimes
part of the fuel filter) often has a float connected to a warning
light, which warns when there is too much water in the trap, and must
be drained before damage to the engine can result. The fuel filter
must be replaced much more often on a diesel engine than on a petrol
engine, changing the fuel filter every 2–4 oil changes is not
uncommon for some vehicles.
Diesel fuel is less flammable than petrol, leading to a lower risk of
fire caused by fuel in a vehicle equipped with a diesel engine.
In yachts, diesel engines are often used because the petrol (gasoline)
that fuels spark-ignition engines releases combustible vapors which
can lead to an explosion if it accumulates in a confined space such as
the bottom of a vessel. Ventilation systems are mandatory on
United States Army
United States Army and
NATO use only diesel engines and turbines
because of fire hazard. Although neither gasoline nor diesel is
explosive in liquid form, both can create an explosive air/vapor mix
under the right conditions. However, diesel fuel is less prone due to
its lower vapor pressure, which is an indication of evaporation rate.
The Material Safety Data Sheet for ultra-low sulfur diesel fuel
indicates a vapor explosion hazard for diesel indoors, outdoors, or in
Gasoline fuel was a problem for the US Army Sherman tanks during World
War II since a direct hit would often ignite them. Crews nicknamed
them "Ronsons" after the lighter which advertised "lights up first
every time". Their advantage was the simplicity of producing these
tanks, allowing the allies to have a numerical advantage from 14 to 1
to 50 to 1 over German tanks.
Fuel injection introduces potential hazards in engine maintenance due
to the high fuel pressures used. Residual pressure can remain in the
fuel lines long after an injection-equipped engine has been shut down.
This residual pressure must be relieved, and if it is done so by
external bleed-off, the fuel must be safely contained. If a
high-pressure diesel fuel injector is removed from its seat and
operated in open air, there is a risk to the operator of injury by
hypodermic jet-injection, even with only 100 pounds per square inch
(690 kPa) pressure. The first known such injury occurred in
1937 during a diesel engine maintenance operation.
Diesel exhaust has been classified as an IARC Group 1 carcinogen. It
causes lung cancer and is associated with an increased risk for
The characteristics of diesel have different advantages for different
Diesel engines have long been popular in bigger cars and have been
used in smaller cars such as superminis in Europe since the 1980s.
They were popular in larger cars earlier, as the weight and cost
penalties were less noticeable. Diesel engines tend to be more
economical at regular driving speeds and are much better at city
speeds. Their reliability and life-span tend to be better (as
detailed). Some 40 percent or more of all cars sold in Europe are
diesel-powered where they are considered a low CO2 option.
Mercedes-Benz in conjunction with
Robert Bosch GmbH
Robert Bosch GmbH produced
diesel-powered passenger cars starting in 1936 and very large numbers
are used all over the world (often as "Grande Taxis" in the Third
World). Diesel-powered passenger cars are very popular in
since the price of diesel fuel there is lower as compared to petrol.
As a result, predominantly petrol-powered car manufacturers including
the Japanese car manufacturers produce and market diesel-powered cars
in India. Diesel-powered cars also dominate the Indian taxi industry.
Railroad rolling stock
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Diesel engines have eclipsed steam engines as the prime mover on all
non-electrified railroads in the industrialized world. The first
diesel locomotives appeared in the early 20th century, and diesel
multiple units soon after. While electric locomotives have replaced
the diesel locomotive for some passenger traffic in Europe and Asia,
diesel is still today very popular for cargo-hauling freight trains
and on tracks where electrification is not feasible. Most modern
diesel locomotives are actually diesel-electric locomotives: the
diesel engine is used to power an electric generator that in turn
powers electric traction motors with no mechanical connection between
diesel engine and traction. After 2000, environmental requirements has
caused higher development cost for engines, and it has become common
for passenger multiple units to use engines and automatic mechanical
gearboxes made for trucks. Up to four such combinations might be used
to achieve enough power in a train.
Other transport uses
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Larger transport applications (trucks, buses, etc.) also benefit from
the Diesel's reliability and high torque output. Diesel displaced
paraffin (or tractor vaporising oil, TVO) in most parts of the world
by the end of the 1950s with the US following some 20 years later.
In merchant ships and boats, the same advantages apply with the
relative safety of
Diesel fuel an additional benefit. The German
pocket battleships were the largest Diesel warships, but the German
torpedo-boats known as E-boats (Schnellboot) of the Second World War
were also Diesel craft. Conventional submarines have used them since
before World War I, relying on the almost total absence of carbon
monoxide in the exhaust. American
World War II
World War II Diesel-electric
submarines operated on two-stroke cycle, as opposed to the four-stroke
cycle that other navies used.
Non-road diesel engines
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Non-road diesel engines include mobile equipment and vehicles that are
not used on the public roadways such as construction equipment and
Military fuel standardisation
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NATO has a single vehicle fuel policy and has selected diesel for this
purpose. The use of a single fuel simplifies wartime logistics. NATO
and the United States Marine Corps have even been developing a diesel
military motorcycle based on a Kawasaki off-road motorcycle the KLR
650, with a purpose designed naturally aspirated direct injection
Cranfield University in England, to be produced in the US,
because motorcycles were the last remaining gasoline-powered vehicle
in their inventory. Before this, a few civilian motorcycles had been
built using adapted stationary diesel engines, but the weight and cost
disadvantages generally outweighed the efficiency gains.
A 1944 V12 2,300 kW power plant undergoing testing &
Diesel engines are also used to power permanent, portable, and backup
generators, irrigation pumps, corn grinders, and coffee
Within the diesel engine industry, engines are often categorized by
their rotational speeds into three unofficial groups:
High-speed engines (> 1,000 rpm),
Medium-speed engines (300–1,000 rpm), and
Slow-speed engines (< 300 rpm).
High- and medium-speed engines are predominantly four-stroke engines,
except for the
Detroit Diesel two-stroke range. Medium-speed engines
are physically larger than high-speed engines and can burn lower-grade
(slower-burning) fuel than high-speed engines. Slow-speed engines are
predominantly large two-stroke crosshead engines, hence very different
from high- and medium-speed engines. Due to the lower rotational speed
of slow- and medium-speed engines, there is more time for combustion
during the power stroke of the cycle, allowing the use of
slower-burning fuels than high-speed engines.
High-speed (approximately 1,000 rpm and greater) engines are used
to power trucks (lorries), buses, tractors, cars, yachts, compressors,
pumps and small electrical generators. As of 2008, most high-speed
engines have direct injection. Many modern engines, particularly in
on-highway applications, have common rail direct injection, which is
Medium-speed engines are used in large electrical generators, ship
propulsion and mechanical drive applications such as large compressors
or pumps. Medium speed diesel engines operate on either diesel fuel or
heavy fuel oil by direct injection in the same manner as low-speed
Engines used in electrical generators run at approximately 300 to
1000 rpm and are optimized to run at a set synchronous speed
depending on the generation frequency (50 or 60 hertz) and
provide a rapid response to load changes. Typical synchronous speeds
for modern medium-speed engines are 500/514 rpm (50/60 Hz),
600 rpm (both 50 and 60 Hz), 720/750 rpm, and
As of 2009, the largest medium-speed engines in current production
have outputs up to approximately 20 MW (27,000 hp) and are
supplied by companies like MAN B&W, Wärtsilä, and
Rolls-Royce (who acquired Ulstein Bergen Diesel in 1999). Most
medium-speed engines produced are four-stroke machines, however there
are some two-stroke medium-speed engines such as by EMD
(Electro-Motive Diesel), and the Fairbanks Morse OP (Opposed-piston
Typical cylinder bore size for medium-speed engines ranges from
20 cm to 50 cm, and engine configurations typically are
offered ranging from in-line 4-cylinder units to V-configuration
20-cylinder units. Most larger medium-speed engines are started with
compressed air direct on pistons, using an air distributor, as opposed
to a pneumatic starting motor acting on the flywheel, which tends to
be used for smaller engines. There is no definitive engine size
cut-off point for this.
It should also be noted that most major manufacturers of medium-speed
engines make natural gas-fueled versions of their diesel engines,
which in fact operate on the Otto cycle, and require spark ignition,
typically provided with a spark plug. There are also dual
(diesel/natural gas/coal gas) fuel versions of medium and low speed
diesel engines using a lean fuel air mixture and a small injection of
diesel fuel (so-called "pilot fuel") for ignition. In case of a gas
supply failure or maximum power demand these engines will instantly
switch back to full diesel fuel operation.
The MAN B&W 5S50MC 5-cylinder, 2-stroke, low-speed marine diesel
engine. This particular engine is found aboard a 29,000 tonne chemical
Also known as slow-speed, or traditionally oil engines, the largest
diesel engines are primarily used to power ships, although there are a
few land-based power generation units as well. These extremely large
two-stroke engines have power outputs up to approximately 85 MW
(114,000 hp), operate in the range from approximately 60 to
200 rpm and are up to 15 m (50 ft) tall, and can weigh
over 2,000 short tons (1,800 t). They typically use direct
injection running on cheap low-grade heavy fuel, also known as bunker
C fuel, which requires heating in the ship for tanking and before
injection due to the fuel's high viscosity. Often, the waste heat
recovery steam boilers attached to the engine exhaust ducting generate
the heat required for fuel heating. Provided the heavy fuel system is
kept warm and circulating, engines can be started and stopped on heavy
Large and medium marine engines are started with compressed air
directly applied to the pistons. Air is applied to cylinders to start
the engine forwards or backwards because they are normally directly
connected to the propeller without clutch or gearbox, and to provide
reverse propulsion either the engine must be run backwards or the ship
will use an adjustable propeller. At least three cylinders are
required with two-stroke engines and at least six cylinders with
four-stroke engines to provide torque every 120 degrees.
Companies such as MAN B&W Diesel, and
Wärtsilä design such large
low-speed engines. They are unusually narrow and tall due to the
addition of a crosshead bearing. As of 2007, the 14-cylinder
Wärtsilä-Sulzer 14RTFLEX96-C turbocharged two-stroke diesel engine
Wärtsilä licensee Doosan in Korea is the most powerful
diesel engine put into service, with a cylinder bore of 960 mm
(37.8 in) delivering 114,800 hp (85.6 MW). It was put
into service in September 2006, aboard what was then the world's
largest container ship
Emma Maersk which belongs to the A.P.
Moller-Maersk Group. Typical bore size for low-speed engines ranges
from approximately 35 to 98 cm (14 to 39 in). As of 2008,
all produced low-speed engines with crosshead bearings are in-line
configurations; no Vee versions have been produced.
Low-speed diesel engines (as used in ships and other applications
where overall engine weight is relatively unimportant) often have a
thermal efficiency which exceeds 50%.
Current and future developments
See also: Diesel car history
As of 2008, many common rail and unit injection systems already employ
new injectors using stacked piezoelectric wafers in lieu of a
solenoid, giving finer control of the injection event.
Variable geometry turbochargers have flexible vanes, which move and
let more air into the engine depending on load. This technology
increases both performance and fuel economy. Boost lag is reduced as
turbo impeller inertia is compensated for.
Accelerometer pilot control (APC) uses an accelerometer to provide
feedback on the engine's level of noise and vibration and thus
instruct the ECU to inject the minimum amount of fuel that will
produce quiet combustion and still provide the required power
(especially while idling).
The next generation of common rail diesels is expected to use variable
injection geometry, which allows the amount of fuel injected to be
varied over a wider range, and variable valve timing (see Mitsubishi's
4N13 diesel engine) similar to that of petrol engines. Particularly in
the United States, coming tougher emissions regulations present a
considerable challenge to diesel engine manufacturers. Ford's HyTrans
Project has developed a system which starts the ignition in 400 ms,
saving a significant amount of fuel on city routes, and there are
other methods to achieve even more efficient combustion, such as
homogeneous charge compression ignition, being studied.
Japanese and Swedish vehicle manufacturers are also developing diesel
engines that run on dimethyl ether (DME).
Some recent diesel engine models utilize a copper alloy heat exchanger
technology (CuproBraze) to take advantage of benefits in terms of
thermal performance, heat transfer efficiency, strength/durability,
corrosion resistance, and reduced emissions from higher operating
Low heat rejection engines
A special class of prototype internal combustion piston engines has
been developed over several decades with the goal of improving
efficiency by reducing heat loss. These engines are variously
called adiabatic engines; due to better approximation of adiabatic
expansion; low heat rejection engines, or high temperature
engines. They are generally piston engines with combustion
chamber parts lined with ceramic thermal barrier coatings. Some
make use of pistons and other parts made of titanium which has a low
thermal conductivity and density. Some designs are able to
eliminate the use of a cooling system and associated parasitic losses
altogether. Developing lubricants able to withstand the higher
temperatures involved has been a major barrier to
Aircraft diesel engine
Carbureted compression ignition model engine
Diesel automobile racing
Gasoline direct injection
Glow plug (model engine)
Hulsebos-Hesselman axial oil engines
History of the internal combustion engine
Hot bulb engine
Hybrid power source
Junkers Jumo 205—The more successful of the first series of
production diesel aircraft engines.
Napier Deltic—a high-speed, lightweight diesel engine used in fast
naval craft and some diesel locomotives.
Partially premixed combustion
Petrol engine, petrol
Relative cost of electricity generated by different sources
Six-stroke engine—40% improved efficiency over 4-stroke by using
wasted heat to generate steam.
SVO—straight vegetable oil—alternative fuel for diesel engines.
Wärtsilä-Sulzer RTA96-C—world's most powerful, most efficient and
largest Diesel engine.
WVO—waste vegetable oil—filtered, alternative fuel for diesel
^ In the 16-cylinder variant of EMD's 645F series, a Roots-blown
engine could produce a maximum of 2,000 horsepower (1,500 kW). A
turbocharged engine could produce up to 3,500 horsepower
(2,600 kW)—a 75% increase—although the engine was not
particularly reliable at this rating; however a 50% increase to 3,000
horsepower (2,200 kW) proved to be exceptionally reliable and
most such examples are still operating today, some forty years after
these were built.
^ a b c d e Low Speed Engines Tech Paper, MAN Diesel
^ a b "
Mitsubishi Heavy Industries
Mitsubishi Heavy Industries Technical Review Vol.45 No.1
(2008)" (PDF). Archived (PDF) from the original on October 4, 2010.
Retrieved October 3, 2010.
^ "Gazette. five years dizelizatsiyu". Techincom.ru (in Russian).
March 26, 2007. Archived from the original on November 13, 2013.
Retrieved September 27, 2013.
^ Wartsila Sulzer,
Common Rail Diesel RT96C.
^ "Worlds Largest Most Efficient Diesel Engine—Wartsila".
Claverton-Energy.com. June 19, 2009. Archived from the original on
November 18, 2010. Retrieved April 3, 2010.
^ US patent (granted in 1895) #542846 pdfpiw.uspto.gov
^ "Patent Images". Pdfpiw.uspto.gov. Retrieved October 28, 2017.
^ Diesel, Rudolf (October 28, 1897). "Diesel's Rational Heat Motor: A
Lecture". Progressive Age Publishing Company. Retrieved October 28,
2017 – via Google Books.
^ a b c "Archived copy". Archived from the original on July 29, 2017.
Retrieved September 4, 2016.
^ "Patent Images". Pdfpiw.uspto.gov.
^ "Automotive Industries". Chilton Company, Incorporated. August 23,
2017 – via Google Books.
^ "The Michigan Technic". UM Libraries. August 23, 2017 – via Google
^ "Brayton Petroleum Engine Co. - 1893 Article-Brayton Petroleum
Engine Co., Petroleum Engine - VintageMachinery.org".
^ "Engineering". Office for Advertisements and Publication. August 23,
1892 – via Google Books.
^ "The Akroyd Oil Engine". Ray Hooley's—Ruston-Hornsby—Engine
Pages. Archived from the original on May 24, 2011. Retrieved
^ "Diesel has come a long way but still doesn't get the tax breaks it
deserves". The Scotsman, Scotland on Sunday. 2003-01-16. Archived from
the original on 2012-05-25. Retrieved 2007-07-29.
^ Ransome-Wallis, Patrick (2001). Illustrated Encyclopedia of World
Railway Locomotives. Courier Dover Publications. p. 28.
^ McNeil, Ian (1990). An Encyclopaedia of the History of Technology.
Taylor & Francis. pp. 310–311.
^ Wrangham, D.A. (1956). The Theory & Practice of Heat Engines.
Cambridge University Press. p. 664.
^ Icons of Invention: The Makers of the Modern World from Gutenberg to
Gates. ABC-CLIO. ISBN 9780313347436. Retrieved 2013-02-07.
^ METHOD OF AND APPARATUS FOR CONVERTING HEAT INTO WORK, United States
Patent No. 542,846, Filed Aug 26 1892, Issued July 16, 1895, Inventor
Rudolf Diesel of Berlin Germany
Combustion Engine, U. S. Patent number 608845, Filed Jul 15
1895, Issued August 9, 1898, Inventor Rudolf Diesel, Assigned to the
Diesel Motor Company of America (New York)
^ Moon, John F. (1974).
Rudolf Diesel and the Diesel Engine. London:
Priory Press. ISBN 978-0-85078-130-4.
^ a b A brief biography of Rudolph Diesel Authored by Martin Leduc,
1999, Updated 2008, 2013 
^ (M.E.), William Robinson (August 23, 1890). "Gas and Petroleum
Engines: A Practical Treatise on the Internal
Combustion Engine". E.
& F.N. Spon – via Google Books.
^ Gas Engine. Gas Engine Publishing Company. 1915.
^ "Gas and air engine".
^ "akroyd-stuart-or-diesel". Motor Sport Magazine. 2014-07-07.
^ Cameron, Alan; Farndon, Roy (1984). Scenes from Sea and City:
Lloyd's List 1734-1984. Lloyd's List.
^ Diesel, Rudolf (August 23, 1894). "Theory and Construction of a
Rational Heat Motor". E. & F. N. Spon – via Google Books.
^ a b The Diesel engine. Busch–Sulzer Bros.-Diesel Engine Company,
St. Louis Busch. 1913.
^ "Patent Images". Pdfpiw.uspto.gov.
^ a b Pospiech, Peter (December 27, 2012). "Memorable 2012: 100th
Anniversary of MV SELANDIA". Maritime Propulsion. Maritime Activity
Reports, Inc. Retrieved 3 October 2014.
^ Pearce, William (September 1, 2012). "Fairbanks Morse Model 32
^ "The Diesel Odyssey of Clessie Cummins", by Lyle Cummins, 1998,
^ "Sir Harry Ricardo". Oldengine.org. Archived from the original on
November 18, 2010. Retrieved April 3, 2010.
^ a b
Mercedes-Benz Diesel History, The 260D Diesel Car.
^ US Patent #2,408,298, filed April 1943, awarded Sept 24, 1946
^ 1954–1959 W120 (180 D) 180 D OM636 VII
Dieselvariante des 180, ab 1958 Ausstellfenster. Leistung: 43 PS.
^ US Patent #3,220,392, filed June 4, 1962, granted Nov 30, 1965.
^ Autocar, 17 May 1982.
^ "Archived copy". Archived from the original on February 22, 2014.
^ "News and events". fiat.com. Archived from the original on February
6, 2012. Retrieved June 20, 2007.
^ "Archived copy". Archived from the original on February 22, 2014.
Retrieved February 12, 2014.
^ "Atwork Casestudies: Daimler Benz". www.3dsystems.ru.
^ Zhao, Hua (2010). Advanced Direct Injection
Technologies and Development: Diesel Engines. Woodhead Publishing
Limited. p. 8. ISBN 9781845697457.
^ "New Powertrain Technologies Conference". autonews.com. Archived
from the original on September 27, 2011. Retrieved December 11,
^ "VW 3-cylinder diesels" (PDF). Theaa.com. Retrieved 28 October
^  Archived May 23, 2012, at the Wayback Machine.
^ "Bosch's Third-Generation
Common Rail System For Diesel Engines
Reduces Emissions 20 Percent". Robert Bosch LLC. - Media Center. 15
September 2003. Retrieved 4 May 2016.
^ "Perfect piezo". The Engineer. 6 November 2003. Retrieved 4 May
2016. At the recent Frankfurt motor show, Siemens, Bosch and Delphi
all launched piezoelectric fuel injection systems.
^ "The New Audi A8 3.0 TDI quattro with Piezo
Common Rail System".
AudiWorld. 27 February 2004. Retrieved 4 May 2016. The 3.0 TDI is the
first production diesel model in the world to have the pioneering
common rail fuel injection concept with piezo inline injectors. This
permits up to five injection processes per operating stroke and an
injection pressure of 1,600 bar.
^  Archived April 13, 2014, at the Wayback Machine.
^ "Innovativ: Der neue DCI-Motor". November 5, 2009. Archived from the
original on November 5, 2009.
^ "Archived copy". Archived from the original on April 15, 2014.
Retrieved April 12, 2014.
Volvo FH16 700—New
Car and Used
Car Pictures on". Lincah.com.
January 9, 2009. Archived from the original on November 18, 2010.
Retrieved May 11, 2009.
^ "Geneva 2010: Mitsubishi ASX (Outlander Sport) Debuts in Geneva",
Mitsubishi Motors UK Geneva motor show 2010 presskit
^ "New Scania V8 truck range". Archived from the original on November
^ "Big Lorry Blog Archives - Truckanddriver.co.uk".
^ "Bosch compact: Pressure in diesel engines". Automotive World. 28
November 2013. Retrieved 4 May 2016.
Denso announces 2500 bar common rail injection system".
^ "'It Was Installed For This Purpose,' VW's U.S. CEO Tells Congress
About Defeat Device". NPR. 8 October 2015. Retrieved 19 October
^ "EPA, California Notify
Volkswagen of Clean Air Act Violations /
Carmaker allegedly used software that circumvents emissions testing
for certain air pollutants". US: EPA. 18 September 2015. Retrieved 1
^ Jordans, Frank (21 September 2015). "EPA: Volkswagon Thwarted
Pollution Regulations For 7 Years". CBS Detroit. Associated Press.
Retrieved 24 September 2015.
^ "Abgasaffäre: VW-Chef Müller spricht von historischer Krise". Der
Spiegel. Reuters. 28 September 2015. Retrieved 28 September
^ Combined gas law
^ "Diesel Engine." Archived November 21, 2010, at the Wayback Machine.
Freedom CAR & Vehicle Technologies Program. US Department of
Energy, Aug. 2003. Web.
^ "When Used under Identical Operating Conditions, a Diesel Engine
Will Likely Produce at Least Twice the Engine Life of a Gas Engine".
TheDieselPage.com. Archived from the original on November 18, 2010.
Retrieved October 3, 2010.
^ Belzowski, Bruce (March 2013). "Total Cost of Ownership: A Gas
Versus Diesel Comparison" (PDF). University of Michigan. Retrieved
April 10, 2016.
^ "Triple-Fuel Honda Powered 12 kW Generator".
CentralMaineDiesel.com. Archived from the original on November 18,
2010. Retrieved May 11, 2009.
^ "Approximate Diesel Generator Fuel Consumption Chart".
DieselServiceAndSupply.com. Archived from the original on November 18,
2010. Retrieved May 11, 2009.
^ Ransome-Wallis, Patrick (2001). Illustrated Encyclopedia of World
Railway Locomotives. Courier Dover Publications. p. 32 fg. 5
^ "Carbon Monoxide Poisoning: Operating Fossil Fuel Engines Inside
Buildings". Abe.IAState.edu. Archived from the original on September
7, 2008. Retrieved October 3, 2010.
^ Needs citation?
^ a b c "Archived copy". Archived from the original on January 23,
2010. Retrieved January 8, 2009.
^ "Archived copy". Archived from the original on January 7, 2009.
Retrieved January 11, 2009.
^ "Diesel injection pumps, Diesel injectors,
Diesel fuel pumps,
turbochargers, Diesel trucks all at First Diesel Injection LTD".
Firstdiesel.com. Archived from the original on November 18, 2010.
Retrieved May 11, 2009.
^ "IDI vs DI" Diesel hub
^ "Diesel Fuel Injection—How-It-Works". Diesel Power. June 2007.
Retrieved November 24, 2012.
^ "Pumpe-Düse-Einspritztechnik". Archived from the original on August
13, 2009. Retrieved May 17, 2009.
^ "Diesel, The efficient pump injector unit". Archived from the
original on March 31, 2009. Retrieved September 30, 2008.
Common Rail Fuel Injection Hannu Jääskeläinen, Magdi K. Khair
^ "Audi Reveals World's Most Powerful Diesal [sic] Passenger Car".
Audi UK. 19 September 2006. Archived from the original on February 10,
2007. Retrieved 4 May 2016.
^ The Free Library  "
Detroit Diesel Introduces DDEC
March 13, 1995, accessed March 14, 2011.
^ Heywood Internal
Combustion Engine Fundamentals Figure 15–40 shows
better, and much bigger, efficiency of turbo engine versus NA version
Piston cooling methods – Advantage and disadvantages of
water cooled and oil cooled pistons". Machinery spaces. Retrieved
November 21, 2012.
^ a b "Two and Four Stroke Diesel Engines". Encyclopædia Britannica
^ Museum, Deutsches. "Deutsches Museum: The First Diesel Engine,
^ "The Largest And Most Powerful Diesel Engine in The World". Amusing
Planet. March 21, 2013. Archived from the original on March 29, 2014.
Retrieved March 29, 2014.
^ "The Most Powerful Diesel Engine in the World". Bath.ac.uk. Archived
from the original on November 18, 2010. Retrieved April 3, 2010.
^ Charge air induction is necessarily symmetrical about bottom dead
center; in the
Electro-Motive Diesel examples, this is 45 degrees
before bottom dead center to 45 degrees after bottom dead center; the
only remaining variables are the timing of the opening and closing of
the four poppet valves in the head, and these are timed to maximize
both scavenging and compression.
^ Electro-Motive Diesel, a medium-speed engine, initiates injection at
4 degrees before top dead center; a high-speed engine may initiate
injection at another point in the cycle.
^ Modern High-Speed Oil Engines, Volume II by C. W. Chapman, published
by The Caxton Publishing Co. Ltd. Reprinted in July 1949
^ "MHI Achieves 1,600°C Turbine Inlet Temperature in Test Operation
of World's Highest Thermal Efficiency "J-Series" Gas Turbine".
Mitsubishi Heavy Industries. May 26, 2011. Archived from the original
on March 18, 2012.
^ "Medium and Heavy Duty Diesel Vehicle Modeling Using a Fuel
Consumption Methodology" (PDF). US EPA. 2004. Retrieved
^ "Motivations for Promoting Clean Diesels" (PDF). US Department of
Energy. 2006. Archived from the original (PDF) on October 7,
^ Michael Soimar (April 2000). "The Challenge Of CVTs In Current
Heavy-Duty Powertrains". Diesel Progress North American Edition.
Archived from the original on December 7, 2008.
^ "Engine Genetics".
Perkins Engines Company Limited. 2006.
^ a b "
Combustion in IC (Internal Combustion) Engines": Slide 37.
Retrieved November 1, 2008.
^ "Engine & fuel engineering—Diesel Noise". Retrieved November
Biodiesel Handbook, Chapter 2—The History of Vegetable Oil
Based Diesel Fuels, by Gerhard Knothe, ISBN 978-1-893997-79-0
Yacht Safety Bureau The
Yacht Safety Bureau, Inc.in the State of New
^ "Microsoft Word—MSDS Low
Sulfur Diesel #2.doc" (PDF). Archived
(PDF) from the original on November 21, 2010. Retrieved December 21,
^ Alan Axelrod; Jack A. Kingston, ed. (2007). "armor, US".
Encyclopedia of World War II. H W Fowler. pp. 89–90.
^ Agha, F.P. (1978). "High-pressure paint gun injuries of hand:
clinical and roentgen aspects". NY State Journal of Medicine. 78:
^ Rees, C.E. (1937). "Penetration of Tissue by Fuel Oil Under High
Pressure from a Diesel Engine". Journal of the American Medical
Association. 109 (11): 866–867.
^ "IARC: Diesel Engine Exhaust Carcinogenic" (PDF). International
Agency for Research on Cancer (IARC). Archived from the original
(Press release) on September 13, 2012. Retrieved June 12, 2012. June
12, 2012 – After a week-long meeting of international experts, the
International Agency for Research on Cancer (IARC), which is part of
the World Health Organization (WHO), today classified diesel engine
exhaust as carcinogenic to humans (Group 1), based on sufficient
evidence that exposure is associated with an increased risk for
^ Pirotte, Marcel (1984-07-05). "Gedetailleerde Test:
TRD" [Detailed Test]. De AutoGids (in Flemish). Brussels, Belgium:
Uitgeverij Auto-Magazine. 5 (125): 6. CS1 maint: Unrecognized
^ "Is your diesel pump costing you money?" (PDF). NSW Department of
Primary Industries. Archived from the original (PDF) on July 20, 2011.
Retrieved July 12, 2011.
^ "All About Tortillas". Phillip Landmeier. 2009. Retrieved November
^ "Small-Scale Coffee Processing" (PDF). Practical Action, The
Schumacher Center for Technology & Development. Retrieved July 12,
Wärtsilä 64 Technology Review". Archived from the original (PDF)
on June 15, 2013. Retrieved October 3, 2010.
^ a b "Dual-fuel-electric LNG carriers" (PDF). Archived from the
original (PDF) on November 18, 2010.
^ Payne, F. William. User's Guide to Natural Gas Technologies.
^ "Man Diesel Se - Press->Press & Trade Press
Releases->Trade Press Releases ->Stationary
Power->Medium-Speed". Manbw.com. November 19, 2008. Archived from
the original on November 18, 2010. Retrieved May 11, 2009.
^ "Diesel Fuel Injection". Archived from the original on September 23,
2008. Retrieved September 30, 2008.
^ "Variable Geometry
Turbocharger (VGT)". Archived from the original
on November 18, 2010.
Accelerometer Design and Applications". Archived from the original
on January 7, 2010.
^ Craig Goodfellow; cited in Neil Beasley (2004). Engineering at the
Cutting Edge (documentary television series). The Discovery
^ "ABG Tech analysis and driving impression: GM's
Archived from the original on November 18, 2010.
Ether (DME) Fueled Crane
Truck Begins World's 1st Public
Road Test". Retrieved August 8, 2012.
^ "DME Vehicle—Demonstration of DeMethyl
Ether Vehicle for
Sustainable Transport". Retrieved August 8, 2012.
^ "Browse Papers on Adiabatic engines : Topic Results - SAE
^ Schwarz, Ernest; Reid, Michael; Bryzik, Walter; Danielson, Eugene
(March 1, 1993). "
Combustion and Performance Characteristics of a Low
Heat Rejection Engine" – via papers.sae.org.
^ Bryzik, Walter; Schwarz, Ernest; Kamo, Roy; Woods, Melvin (March 1,
1993). "Low Heat Rejection From High Output Ceramic Coated Diesel
Engine and Its Impact on Future Design" – via papers.sae.org.
^ Danielson, Eugene; Turner, David; Elwart, Joseph; Bryzik, Walter
(March 1, 1993). "Thermomechanical Stress Analysis of Novel Low Heat
Rejection Cylinder Head Designs" – via papers.sae.org.
^ Nanlin, Zhang; Shengyuan, Zhong; Jingtu, Feng; Jinwen, Cai; Qinan,
Pu; Yuan, Fan (March 1, 1993). "Development of Model 6105 Adiabatic
Engine" – via papers.sae.org.
^ Kamo, Lloyd; Kleyman, Ardy; Bryzik, Walter; Schwarz, Ernest
(February 1, 1995). "Recent Development of Tribological Coatings for
High Temperature Engines" – via papers.sae.org.
Wikimedia Commons has media related to Diesel engines.
Wikimedia Commons has media related to Rudolf Diesel.
Wikisource has the text of the 1921
Collier's Encyclopedia article
The short film The Diesel Story (1952) is available for free download
at the Internet Archive
"Introduction to Two Stroke Marine Diesel Engine" on YouTube
"The Engine That Powers the World" BBC Documentary on YouTube
Gas engine #151468 filed 1874
Direct injection oil engine Sep 15, 1887
US Patent 439702 Petroleum Engine or Motor, filed 1889.
Hydrocarbon Engine #432260 Jan 16 1890
Method of and Apparatus for Converting Heat into Work. # 542846 filed
US Patent 502837 Engine operated by the explosion of mixtures of gas
or hydrocarbon vapor and air, dated August 8, 1893.
Combustion Engine #608845 filed 1895
US Patent 845140
Combustion Engine, dated February 26, 1907
Timeline of heat engine technology
Part of the
Cylinder head (crossflow, reverse-flow)
Starter ring gear
Pneumatic valve springs
Variable valve timing
Cold air intake
Electronic throttle control
Naturally aspirated engine
Short ram air intake
Variable-length intake manifold
Warm air intake
Gasoline direct injection
Stratified charge engine
Turbo fuel stratified injection
High tension leads
Electrics and engine
Air–fuel ratio meter
Automatic Performance Control
Car battery (lead–acid battery)
Crankshaft position sensor
Drive by wire
Electronic control unit
Engine control unit
Engine coolant temperature sensor
Idle air control actuator
Mass flow sensor
Throttle position sensor
Automobile emissions control
Diesel particulate filter
Antifreeze (ethylene glycol)
Viscous fan (fan clutch)
Cylinder head porting
Personal luxury car
Leisure activity vehicle
Cabriolet / Convertible
Coupé de Ville
Drophead coupe (Convertible)
Saloon / Sedan
Sedanca de Ville (
Coupé de Ville)
Spider / Spyder (Roadster)
Town car (
Coupé de Ville)
Gasoline / petrol (direct injection)
Homogeneous charge compression ignition
Layout (engine / drive)
Front / front
Front mid / front
Rear / front
Front / rear
Rear mid / rear
Rear / rear
Front / four-wheel
Mid / four-wheel
Rear / four-wheel