Automobile Engine:
An internal combustion engine (ICE) is an engine where the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine the expansion of the high-temperature and high-pressure gases produced by combustion apply direct force to some component of the engine. The force is applied typically to pistons, turbine blades, or a nozzle. This force moves the component over a distance, transforming chemical energy into useful mechanical energy. The first commercially successful internal combustion engine was created by Étienne Lenoir around 1859.The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the six-stroke piston engine and the Wankel rotary engine. A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.Firearms are also a form of internal combustion engine.Internal combustion engines are quite different from external combustion engines, such as steam or Stirling engines, in which the energy is delivered to a working fluid not consisting of, mixed with, or contaminated by combustion products. Working fluids can be air, hot water, pressurized water or even liquid sodium, heated in a boiler. ICEs are usually powered by energy-dense fuels such as gasoline or diesel, liquids derived from fossil fuels. While there are many stationary applications, most ICEs are used in mobile applications and are the dominant power supply for cars, aircraft, and boats.Typically an ICE is fed with fossil fuels like natural gas or petroleum products such as gasoline, diesel fuel or fuel oil. There's a growing usage of renewable fuels like biodiesel for compression ignition engines and bio ethanol for spark ignition engines. Hydrogen is sometimes used, and can be made from either fossil fuels or renewable energy.
Engine Configurations:
Continuous combustion:
This is an animated computer drawing of one cylinder of the Wright
brothers' 1903 aircraft engine.
This engine powered the first, heavier than
air, self-propelled, maneuverable, piloted aircraft; the Wright
1903 Flyer.
The engine consisted of four
cylinders
like the one shown above, with
each piston connected to a common
crankshaft.
The crankshaft was connected to two counter-rotating
propellers
which produced the
thrust necessary to overcome the
drag of the aircraft.
The brothers' design is very simple by today's standards, so it is a good engine for students to study to learn the fundamentals of engine operation. This type of internal combustion engine is called a four-stroke engine because there are four movements, or strokes, of the piston before the entire engine firing sequence is repeated. The four strokes are described below with some still figures. In the animation and in all the figures, we have colored the fuel/air intake system red, the electrical system green, and the exhaust system blue. We also represent the fuel/air mixture and the exhaust gases by small colored balls to show how these gases move through the engine. Since we will be referring to the movement of various engine parts, here is a figure showing the names of the parts:
Intake Stroke
The engine cycle begins with the intake stroke as the piston is pulled towards the crankshaft (to the left in the figure).
The intake valve is open, and fuel and air are drawn past the valve
and into the combustion chamber and cylinder
from the intake manifold located on top of the combustion chamber.
The exhaust valve is closed and the electrical contact switch is open.
The fuel/air mixture is at a relatively low
pressure
(near atmospheric)
and is colored blue in this figure. At the end of the intake stroke, the
piston is located at the far left and begins to move back towards the
right.
The cylinder and combustion chamber are full of the low pressure fuel/air mixture
and, as the piston begins to move to the right, the intake valve closes.
Historical note - The opening and closing of the intake valve of the Wright 1903 engine was termed "automatic" by the brothers. It relies on the slightly lower pressure within in the cylinder during the intake stroke to overcome the strength of the spring holding the valve shut. Modern internal combustion engines do not work this way, but use cams and rocker arms like the brothers' exhaust system. Cams and rocker arms provide better control and timing of the opening and closing of the valves.
Compression Stroke
With both valves closed, the combination of the cylinder and combustion chamber form a completely closed vessel containing the fuel/air mixture. As the piston is pushed to the right, the volume is reduced and the fuel/air mixture is compressed during the compression stroke.
During the compression, no
heat
is transferred to the fuel/air mixture.
As the volume is decreased because of the piston's motion,
the pressure in the gas is
increased, as described by the laws of
thermodynamics.
In the figure, the mixture has been colored
yellow to denote a moderate increase in pressure.
To produce the increased pressure, we have to do
work
on the mixture, just
as you have to do work to inflate a bicycle tire using a pump.
During the compression stroke, the electrical contact is kept opened.
When the volume is the smallest,
and the pressure the highest as shown in the figure, the contact is closed, and
a current of
electricity flows through the plug.
Power Stroke
At the beginning of the power stroke, the electrical contact is opened. The sudden opening of the contact produces a spark in the combustion chamber which ignites the fuel/air mixture. Rapid combustion of the fuel releases heat, and produces exhaust gases in the combustion chamber.
Because the intake and exhaust valves are closed, the combustion of the
fuel takes place in a totally enclosed (and nearly constant volume) vessel. The
combustion increases the
temperature
of the exhaust gases, any residual air
in the combustion chamber, and the combustion chamber itself. From the
ideal gas law,
the increased temperature of the gases also produces an increased
pressure in the combustion chamber. We have colored the gases red in the figure
to denote the high pressure. The high pressure of the gases acting on the
face of the piston cause the piston to move to the left which initiates the
power stroke.
Unlike the compression stroke, the hot gas does work on the piston during the power stroke. The force
on the piston is transmitted by the piston rod to the crankshaft, where the linear
motion of the piston is converted to angular motion of the crankshaft. The work
done on the piston is then used to turn the shaft, and the propellers, and
to compress the gases in the neighboring cylinder's compression stroke. Having
produced the igniting spark, the electrical contact remains opened.
During the power stroke, the volume occupied by the gases is increased because of the piston motion and no heat is transferred to the fuel/air mixture. As the volume is increased because of the piston's motion, the pressure and temperature of the gas are decreased. We have colored the exhaust "molecules" yellow to denote a moderate amount of pressure at the end of the power stroke.
The purpose of the exhaust
stroke is to clear the cylinder of the spent exhaust in preparation for another
ignition cycle.
As the exhaust stroke begins, the cylinder and combustion chamber are full
of exhaust products at low pressure (colored blue on the figure above.)
Because the exhaust valve
is open, the exhaust gas is pushed past the valve and exits the engine.
The intake valve is closed and the electrical
contact is open during this movement of the piston.
At the end of the exhaust stroke, the exhaust valve is closed and the engine
begins another intake stroke.
2- STROKE ENGINE:
6- STROKE ENGINE:
The six-stroke engine is a type of internal combustion engine based on the four-stroke engine, but with additional complexity intended to make it more efficient and reduce emissions. Two types of six-stroke engine have been developed since the 1890s:
In the first approach, called the single piston design, the engine captures the heat lost from the four-stroke Otto cycle or Diesel cycle and uses it to power an additional power and exhaust stroke of the piston in the same cylinder. Designs use either steam or air as the working fluid for the additional power stroke. The pistons in this type of six-stroke engine go up and down three times for each injection of fuel. There are two power strokes: one with fuel, the other with steam or air.
The second approach , called the opposed piston design , uses a second opposed piston in each cylinder that moves at half the cyclical rate of the main piston, thus giving six piston movements per cycle. Functionally, the second piston replaces the valve mechanism of a conventional engine but also increases the compression ratio.
DIESEL ENGINE:
The diesel engine (also known as a compression-ignition engine) is an internal combustion engine that uses the heat of compression to initiate ignition and burn the fuel that has been injected into the combustion chamber. This contrasts with spark-ignition engines such as a petrol engine (gasoline engine) or gas engine (using a gaseous fuel as opposed to gasoline), which use a spark plug to ignite an air-fuel mixture.
The diesel engine has the highest thermal efficiency of any standard internal or external combustion engine due to its very high compression 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 unburnt 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 are manufactured in two-stroke and four-stroke versions. 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 USA increased. According to the British Society of Motor Manufacturing and Traders, the EU average for diesel cars account for 50% of the total sold, including 70% in France and 38% in the UK.
The world's largest diesel engine is currently a Wärtsilä-Sulzer RTA96-C Common Rail marine diesel of about 84.42 MW (113,210 hp) at 102 rpm output.
ATKINSON CYCLE ENGINE:
he clever arrangement of levers allows the Atkinson engine to cycle the
piston through all four strokes in only one revolution of the main
crankshaft, and allows the strokes to be different lengths.
The design eliminates the need for a separate cam shaft. The intake (if used), exhaust, and ignition cams are located on the main crank shaft. My illustration shows only an exhaust cam.
This illustration closely follows the dimensions of a model engine, described in the excellent book: Building the Atkinson Cycle Engine. In this design, the intake and exhaust strokes appear to be longer than the compression and power strokes. It’s not clear whether this was intentional; I suspect that the model designer was more interested in the linkage than the thermal cycle.
In a true Atkinson cycle, the power and exhaust strokes are longer than the intake and compression strokes.8 By starting with a small initial charge, and allowing it to expand to a larger volume than it originally occupied, a greater degree of fuel efficiency is realized.
Atkinson designed more than one engine to capitalize on this important property. I hope to have better animations of them all some day.
For more on the Atkinson and all internal combustion engines, I highly recommend Lyle Cummins’ Internal Fire.
It is possible to create the same effect as the Atkinson cycle by changing the valve timing on an otherwise ordinary Otto four stroke engine. I really should illustrate this, but in the meantime I hope the following explanation will suffice:
A cam is employed on both intake and exhaust valves (unlike my four stroke illustration). The intake valve cam is designed to hold the intake valve open for more than a single stroke:
The Atkinson cycle engine is a type of internal combustion engine invented by James Atkinson in 1882. The Atkinson cycle is designed to provide efficiency at the expense of power density, and is used in some modern hybrid electric applications. Also called the Berta engine. (1884)
he clever arrangement of levers allows the Atkinson engine to cycle the piston through all four strokes in only one revolution of the main crankshaft, and allows the strokes to be different lengths.
The design eliminates the need for a separate cam shaft. The intake (if used), exhaust, and ignition cams are located on the main crank shaft. My illustration shows only an exhaust cam.
This illustration closely follows the dimensions of a model engine, described in the excellent book: Building the Atkinson Cycle Engine. In this design, the intake and exhaust strokes appear to be longer than the compression and power strokes. It’s not clear whether this was intentional; I suspect that the model designer was more interested in the linkage than the thermal cycle.
In a true Atkinson cycle, the power and exhaust strokes are longer than the intake and compression strokes.8 By starting with a small initial charge, and allowing it to expand to a larger volume than it originally occupied, a greater degree of fuel efficiency is realized.
Atkinson designed more than one engine to capitalize on this important property. I hope to have better animations of them all some day.
For more on the Atkinson and all internal combustion engines, I highly recommend Lyle Cummins’ Internal Fire.
It is possible to create the same effect as the Atkinson cycle by changing the valve timing on an otherwise ordinary Otto four stroke engine. I really should illustrate this, but in the meantime I hope the following explanation will suffice:
A cam is employed on both intake and exhaust valves (unlike my four stroke illustration). The intake valve cam is designed to hold the intake valve open for more than a single stroke:
MILLER CYCLE ENGINE:
In engineering, the Miller cycle is a thermodynamic cycle used in a type of internal combustion engine. The Miller cycle was patented by Ralph Miller, an American engineer, US patent 2817322 dated Dec 24, 1957. The engine may be two-stroke or four stroke and may be run on diesel fuel, gas fuel or dual fuel.[1]
This type of engine was first used in ships and stationary power-generating plants, and is now used for some railway locomotives such as the GE PowerHaul. It was adapted by Mazda for their KJ-ZEM V6, used in the Millenia sedan, and in their Eunos 800 sedan (Australia) luxury cars. More recently, Subaru has combined a Miller cycle flat-4 with a hybrid drive line for their concept "Turbo Parallel Hybrid" car, known as the Subaru B5-TPH.
How Car Engine Works:
An internal combustion engine (ICE) is an engine where the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine the expansion of the high-temperature and high-pressure gases produced by combustion apply direct force to some component of the engine. The force is applied typically to pistons, turbine blades, or a nozzle. This force moves the component over a distance, transforming chemical energy into useful mechanical energy. The first commercially successful internal combustion engine was created by Étienne Lenoir around 1859.The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the six-stroke piston engine and the Wankel rotary engine. A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.Firearms are also a form of internal combustion engine.Internal combustion engines are quite different from external combustion engines, such as steam or Stirling engines, in which the energy is delivered to a working fluid not consisting of, mixed with, or contaminated by combustion products. Working fluids can be air, hot water, pressurized water or even liquid sodium, heated in a boiler. ICEs are usually powered by energy-dense fuels such as gasoline or diesel, liquids derived from fossil fuels. While there are many stationary applications, most ICEs are used in mobile applications and are the dominant power supply for cars, aircraft, and boats.Typically an ICE is fed with fossil fuels like natural gas or petroleum products such as gasoline, diesel fuel or fuel oil. There's a growing usage of renewable fuels like biodiesel for compression ignition engines and bio ethanol for spark ignition engines. Hydrogen is sometimes used, and can be made from either fossil fuels or renewable energy.
Engine Configurations:
- Two-stroke engine
- Four-stroke engine (Otto cycle)
- Six-stroke engine
- Diesel engine
- Atkinson cycle
- Miller cycle
Continuous combustion:
- Gas turbine
- Jet engine (including turbojet, turbofan, ramjet, rocket, etc.)
The brothers' design is very simple by today's standards, so it is a good engine for students to study to learn the fundamentals of engine operation. This type of internal combustion engine is called a four-stroke engine because there are four movements, or strokes, of the piston before the entire engine firing sequence is repeated. The four strokes are described below with some still figures. In the animation and in all the figures, we have colored the fuel/air intake system red, the electrical system green, and the exhaust system blue. We also represent the fuel/air mixture and the exhaust gases by small colored balls to show how these gases move through the engine. Since we will be referring to the movement of various engine parts, here is a figure showing the names of the parts:
The engine cycle begins with the intake stroke as the piston is pulled towards the crankshaft (to the left in the figure).
Historical note - The opening and closing of the intake valve of the Wright 1903 engine was termed "automatic" by the brothers. It relies on the slightly lower pressure within in the cylinder during the intake stroke to overcome the strength of the spring holding the valve shut. Modern internal combustion engines do not work this way, but use cams and rocker arms like the brothers' exhaust system. Cams and rocker arms provide better control and timing of the opening and closing of the valves.
Compression Stroke
With both valves closed, the combination of the cylinder and combustion chamber form a completely closed vessel containing the fuel/air mixture. As the piston is pushed to the right, the volume is reduced and the fuel/air mixture is compressed during the compression stroke.
Power Stroke
At the beginning of the power stroke, the electrical contact is opened. The sudden opening of the contact produces a spark in the combustion chamber which ignites the fuel/air mixture. Rapid combustion of the fuel releases heat, and produces exhaust gases in the combustion chamber.
During the power stroke, the volume occupied by the gases is increased because of the piston motion and no heat is transferred to the fuel/air mixture. As the volume is increased because of the piston's motion, the pressure and temperature of the gas are decreased. We have colored the exhaust "molecules" yellow to denote a moderate amount of pressure at the end of the power stroke.
2- STROKE ENGINE:
— but it's one inefficient, dirty little machine.
Simplicity and its drawbacks
With an upstroke and a downstroke, the engine completes one cycle of
internal combustion; hence the name. Automobile engines require four
strokes to complete a cycle and are much heavier because they require
extra systems and components, which make them cleaner and more
efficient.
Two-cycle engines use metal fins to
radiate heat from the motor. The fuel is a mixture of gasoline and oil,
which lubricates the engine.
Exhaust is pushed out
of the combustion chamber by fresh fuel, some of which escapes with the
exhaust, giving two-stroke engines their characteristic oily, aromatic
odor.
A greener option
Electric motors are a quieter, cleaner alternative, but they are less
powerful and require recharging or extension cords. Although emissions
are released by the coal-fired power plants that generate electricity,
these gases are much less polluting than those from a two-stroke engine.
Exhaust outlet
Fuel intake for air/fuel mixture
On the downstroke, the piston compresses the air-fuel mixture in the crank case, forcing it through the transfer port into the combustion chamber.
As the crankshaft rotates, it powers fans, mower blades, wheels or propellers.
As the crankshaft rotates, it powers fans, mower blades, wheels or propellers.
Exhaust pollutes the air with carbon monoxide, acid-rain-forming nitrogen oxides, particulate matter and unignited fuel.
The six-stroke engine is a type of internal combustion engine based on the four-stroke engine, but with additional complexity intended to make it more efficient and reduce emissions. Two types of six-stroke engine have been developed since the 1890s:
In the first approach, called the single piston design, the engine captures the heat lost from the four-stroke Otto cycle or Diesel cycle and uses it to power an additional power and exhaust stroke of the piston in the same cylinder. Designs use either steam or air as the working fluid for the additional power stroke. The pistons in this type of six-stroke engine go up and down three times for each injection of fuel. There are two power strokes: one with fuel, the other with steam or air.
The second approach , called the opposed piston design , uses a second opposed piston in each cylinder that moves at half the cyclical rate of the main piston, thus giving six piston movements per cycle. Functionally, the second piston replaces the valve mechanism of a conventional engine but also increases the compression ratio.
DIESEL ENGINE:
The diesel engine (also known as a compression-ignition engine) is an internal combustion engine that uses the heat of compression to initiate ignition and burn the fuel that has been injected into the combustion chamber. This contrasts with spark-ignition engines such as a petrol engine (gasoline engine) or gas engine (using a gaseous fuel as opposed to gasoline), which use a spark plug to ignite an air-fuel mixture.
The diesel engine has the highest thermal efficiency of any standard internal or external combustion engine due to its very high compression 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 unburnt 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 are manufactured in two-stroke and four-stroke versions. 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 USA increased. According to the British Society of Motor Manufacturing and Traders, the EU average for diesel cars account for 50% of the total sold, including 70% in France and 38% in the UK.
The world's largest diesel engine is currently a Wärtsilä-Sulzer RTA96-C Common Rail marine diesel of about 84.42 MW (113,210 hp) at 102 rpm output.
ATKINSON CYCLE ENGINE:
The design eliminates the need for a separate cam shaft. The intake (if used), exhaust, and ignition cams are located on the main crank shaft. My illustration shows only an exhaust cam.
Deviation from proper Atkinson cycle
Since this page was first published, I’ve learned a great deal about the Atkinson engine. Visitors to this site originally clued me in, which prompted me to do a bit more reading.This illustration closely follows the dimensions of a model engine, described in the excellent book: Building the Atkinson Cycle Engine. In this design, the intake and exhaust strokes appear to be longer than the compression and power strokes. It’s not clear whether this was intentional; I suspect that the model designer was more interested in the linkage than the thermal cycle.
In a true Atkinson cycle, the power and exhaust strokes are longer than the intake and compression strokes.8 By starting with a small initial charge, and allowing it to expand to a larger volume than it originally occupied, a greater degree of fuel efficiency is realized.
Atkinson designed more than one engine to capitalize on this important property. I hope to have better animations of them all some day.
For more on the Atkinson and all internal combustion engines, I highly recommend Lyle Cummins’ Internal Fire.
Toyota Prius and the Atkinson cycle
A number of visitors have arrived at this page after reading somewhere that Toyota’s popular hybrid car, the Prius, uses an Atkinson cycle engine. I do not know where this claim originated, but I doubt that the Prius engine uses the linkage illustrated above.It is possible to create the same effect as the Atkinson cycle by changing the valve timing on an otherwise ordinary Otto four stroke engine. I really should illustrate this, but in the meantime I hope the following explanation will suffice:
A cam is employed on both intake and exhaust valves (unlike my four stroke illustration). The intake valve cam is designed to hold the intake valve open for more than a single stroke:
- The intake stroke begins as usual, initially drawing a full cylinder of fuel-air mixture.
- When the piston begins its upward travel, the intake valve remains open. The piston pumps some of the fresh fuel mixture back out the intake port. The net effect is exactly the same as if the intake stroke were shortened.
- The intake valve closes after the piston has moved some predetermined portion of this stroke. Compression does not actually begin until this point, effectively shortening the compression stroke to match the shortened intake stroke.
- The power and exhaust strokes remain as in the four stroke, employing almost the entire length of the piston travel.
The Atkinson cycle engine is a type of internal combustion engine invented by James Atkinson in 1882. The Atkinson cycle is designed to provide efficiency at the expense of power density, and is used in some modern hybrid electric applications. Also called the Berta engine. (1884)
he clever arrangement of levers allows the Atkinson engine to cycle the piston through all four strokes in only one revolution of the main crankshaft, and allows the strokes to be different lengths.
The design eliminates the need for a separate cam shaft. The intake (if used), exhaust, and ignition cams are located on the main crank shaft. My illustration shows only an exhaust cam.
Deviation from proper Atkinson cycle
Since this page was first published, I’ve learned a great deal about the Atkinson engine. Visitors to this site originally clued me in, which prompted me to do a bit more reading.This illustration closely follows the dimensions of a model engine, described in the excellent book: Building the Atkinson Cycle Engine. In this design, the intake and exhaust strokes appear to be longer than the compression and power strokes. It’s not clear whether this was intentional; I suspect that the model designer was more interested in the linkage than the thermal cycle.
In a true Atkinson cycle, the power and exhaust strokes are longer than the intake and compression strokes.8 By starting with a small initial charge, and allowing it to expand to a larger volume than it originally occupied, a greater degree of fuel efficiency is realized.
Atkinson designed more than one engine to capitalize on this important property. I hope to have better animations of them all some day.
For more on the Atkinson and all internal combustion engines, I highly recommend Lyle Cummins’ Internal Fire.
Toyota Prius and the Atkinson cycle
A number of visitors have arrived at this page after reading somewhere that Toyota’s popular hybrid car, the Prius, uses an Atkinson cycle engine. I do not know where this claim originated, but I doubt that the Prius engine uses the linkage illustrated above.It is possible to create the same effect as the Atkinson cycle by changing the valve timing on an otherwise ordinary Otto four stroke engine. I really should illustrate this, but in the meantime I hope the following explanation will suffice:
A cam is employed on both intake and exhaust valves (unlike my four stroke illustration). The intake valve cam is designed to hold the intake valve open for more than a single stroke:
- The intake stroke begins as usual, initially drawing a full cylinder of fuel-air mixture.
- When the piston begins its upward travel, the intake valve remains open. The piston pumps some of the fresh fuel mixture back out the intake port. The net effect is exactly the same as if the intake stroke were shortened.
- The intake valve closes after the piston has moved some predetermined portion of this stroke. Compression does not actually begin until this point, effectively shortening the compression stroke to match the shortened intake stroke.
- The power and exhaust strokes remain as in the four stroke, employing almost the entire length of the piston travel.
MILLER CYCLE ENGINE:
In engineering, the Miller cycle is a thermodynamic cycle used in a type of internal combustion engine. The Miller cycle was patented by Ralph Miller, an American engineer, US patent 2817322 dated Dec 24, 1957. The engine may be two-stroke or four stroke and may be run on diesel fuel, gas fuel or dual fuel.[1]
This type of engine was first used in ships and stationary power-generating plants, and is now used for some railway locomotives such as the GE PowerHaul. It was adapted by Mazda for their KJ-ZEM V6, used in the Millenia sedan, and in their Eunos 800 sedan (Australia) luxury cars. More recently, Subaru has combined a Miller cycle flat-4 with a hybrid drive line for their concept "Turbo Parallel Hybrid" car, known as the Subaru B5-TPH.
How Car Engine Works: