Four Stroke Engine Basics
- Piston completes four complete separate strokes in this cycle. If you don’t know about strokes, a stroke means the piston travels along with the cylinder.
- These 4-stroke engines are used in almost every commercial as vehicles. ...
- An operating process requires two revolutions (720°) of the crankshaft. ...
What is a 4 stroke engine used for?
Four-stroke engines are most commonly used in heavy applications such as trucks, buses, dirt bikes, vans, tractors, and other heavy vehicles. Which engine produces less pollution, 2-stroke or 4-stroke?
What are the different types of four-stroke engines?
The common four stroke engine used,are the power stroke,exhaust stroke,intake stroke and the compress stroke…..these pattern used for the internal combustion engines…and it was perform with the two cycle power,it makes more sufficient rather than other method,,,as far as big engines the more factor strokes could be undertaken….
What is a 2 stroke diesel engine used for?
2 stroke diesel engines are among the most efficient engines available which is why they are used to power locomotives, ships and as standby power plants, but they are low speed engines. Their peak power is achieved in between 100-500 rpm and hence they are coupled with an alternator and used as hybrids.
How many piston strokes does a hydraulic engine have?
This type of engine utilizes four distinct piston strokes in order to effectively run. Whether you’re currently working in the field or are considering becoming a technician, it’s important to understand exactly how this process works.
Where are two-stroke and four-stroke engines used?
Summarizing the Difference between Two-stroke and Four-stroke EngineTwo-Stroke EngineFour-Stroke EngineVery noisy.Produces less noise.Two-stroke engines are used in scooters, motorcycles, military tanks, and also in ship propulsion.Four-stroke engines are used in cars, motorboats, modern bikes, and aircraft.12 more rows
Is four-stroke engine used in bike?
Motorcycle engines are typically two-stroke or four-stroke internal combustion engines, but other engine types, such as Wankels and electric motors, have been used.
Where are 2-stroke engines used?
Two-stroke engines are still found in a variety of small propulsion applications, such as outboard motors, small on- and off-road motorcycles, mopeds, scooters, tuk-tuks, snowmobiles, go-karts, ultralight and model airplanes.
What is a 4-stroke good for?
Although a 4-stroke motor uses four piston strokes to generate one revolution of crankshaft power, it makes for a smoother-running engine that happily runs on idle or on low RPM without misfiring. It also generates more torque, making 4-stroke outboards perfect for heavier boats.
Which engine is used in cars?
Modern cars use IC (Internal Combustion) engines. A petrol engine features a spark-ignition system, whereas a diesel engine uses a compression ignition system. Which is the most common engine configuration used in modern cars? Inline 4-cylinder is one of the most common engine configurations used in modern cars.
Is a bullet a 4-stroke?
The Bullet has evolved from a four-stroke engine with exposed valve-gear to the latest all-alloy unit construction engine with electronic fuel-injection.
Are cars 4-stroke engines?
These days, all cars and light trucks use four-stroke piston engines, whether burning gasoline or diesel. This means that the crankshaft must go around twice, and each piston moves up and down two times, to produce one pulse of power.
Are 4-strokes better than 2 strokes?
Because 2-stroke engines are designed to run at a higher RPM, they also tend to wear out faster; a 4-stroke engine is generally more durable. That being said, 2-stroke engines are more powerful. Two-stroke engines are a much simpler design, making them easier to fix. They do not have valves, but rather ports.
Why is a 4-stroke engine more efficient?
Four-stroke engines are more efficient due to less demand for fuel. Fuel is consumed once every four strokes versus two. Four-stroke engines are better for the environment due to reduced emissions. A two-stroke engine releases burnt oil into the air in addition to the exhaust produced.
Are 4-stroke engines quieter?
4-stroke engines also run quieter as they offer a different power delivery. The general rule is that a 4-stroke engine always develops much more torque at lower engine RPMs. This means 4-stroke engines require less throttle to produce the same amount of power.
Why marine engines have 2stroke?
A two-stroke engine can burn low-grade fuel oil and hence reduce the running cost of the ship.
Does a 4-stroke engine need oil?
A two-stroke engine oil must be able to mix well with fuel and burn well in the combustion chamber of the engine, whereas a four-stroke engine oil needs to protect the valve train against wear and keep the engine as clean as possible.
What is a Four-Stroke Engine?
A 4-stroke engine is an IC engine that uses four strokes of the piston to complete a working cycle. It converts the thermal energy of the fuel into useful mechanical work due to the upward and downward movement of the piston. Therefore, it belongs to the category of the reciprocating engine.
How does a 4-Stroke Engine work?
As the piston reciprocates toward BCD from TDC (downward), a vacuum starts producing inside the compression chamber (cylinder).
PV diagram of the Four-Stroke Engine
The following PV diagram represents the working cycle of the 4-stroke engine. A four-stroke engine completes a working cycle in the following steps:
History
In 1882, James Atkinson designed the Atkinson cycle engine. It was a single-stroke IC engine.
Four-stroke Engine Power Output Limitations
The output power of the engine depends on the amount of air drawn in. The performance of a piston engine (whether it is a 4-stroke engine or a 2-stroke engine) depends on the speed (RPM), the calorific value of the fuel, loss, air-fuel ratio, volumetric efficiency, oxygen content in fuel-air mixture and combustion chamber size.
Components of 4-stroke Diesel Engine
The piston in the 4-stroke diesel engine produces reciprocating movement. It connects with the crankshaft via a connecting rod. It transfers its motion to the crankshaft via a connecting rod. The piston moves downwards and upwards inside the cylinder of the engine.
Advantages and Disadvantages of 4-Stroke Engines
Reliability: These types of diesel engines are more reliable and efficient.
How many events does a 4-stroke engine go through?
During engine operation, pistons go through 4 events to achieve each power cycle. The definition of an event is an up or down piston motion. Upon completion of the 4 events, the cycle is complete and ready to begin again. 4-stroke engines deliver a good balance of power, reliability and efficiency.
How does a 4 stroke engine reduce emissions?
When it comes to emissions, 4-strokes separate each event mechanically, which reduces unburned fuel emissions. It also separates oil from fuel, which significantly reduces carbon monoxide emissions. This combination of desirable traits has earned the 4-stroke the top spot in passenger vehicles today.
How does a piston move?
Piston moves up the cylinder bore from bottom dead center to top dead center. The momentum caused by the power stroke is what continues the crankshaft movement and the other 3 strokes consecutively. Intake valve is closed, the exhaust valve is open. This final stroke forces the spent gasses/exhaust out of the cylinder.
What is the difference between intake stroke and compression stroke?
Intake stroke: The intake valve (on the top left of each image) is open and as the piston travels downward, this suction pulls the air/fuel mixture into the cylinder. Compression stroke : Both valves are now closed and the piston compresses the air fuel into a much smaller volume, preparing the mixture for ignition.
What is a 2 stroke engine?
A 2-stroke engine is still an internal combustion gasoline powered engine , but they differ from 4-strokes in their design.
Why do 2 stroke engines burn oil?
Either way, 2-stroke engines burn oil to provide lubrication to moving parts. Power Twice as Often. The final major differentiating characteristic of a 2-stroke engine is its ability to complete each engine cycle and have a power pulse twice as often as 4-strokes.
Do Wankel engines have strokes?
Wankel and Rotary engines are internal combustion engines, but they do not have “strokes” in the same sense that a 2 or 4-stroke engine has. We will cover Wankel and Rotary engines in more detail in another blog post.
Overview
Design and engineering principles
The maximum amount of power generated by an engine is determined by the maximum amount of air ingested. The amount of power generated by a piston engine is related to its size (cylinder volume), whether it is a two-stroke engine or four-stroke design, volumetric efficiency, losses, air-to-fuel ratio, the calorific value of the fuel, oxygen content of the air and speed (RPM). The speed is ulti…
History
Nikolaus August Otto was a traveling salesman for a grocery concern. In his travels, he encountered the internal combustion engine built in Paris by Belgian expatriate Jean Joseph Etienne Lenoir. In 1860, Lenoir successfully created a double-acting engine that ran on illuminating gas at 4% efficiency. The 18 litre Lenoir Engine produced only 2 horsepower. The Lenoir engine ran on illuminati…
Thermodynamic analysis
The thermodynamic analysis of the actual four-stroke and two-stroke cycles is not a simple task. However, the analysis can be simplified significantly if air standard assumptions are utilized. The resulting cycle, which closely resembles the actual operating conditions, is the Otto cycle.
During normal operation of the engine, as the air/fuel mixture is being compres…
Fuel considerations
A problem with compressed charge engines is that the temperature rise of the compressed charge can cause pre-ignition. If this occurs at the wrong time and is too energetic, it can damage the engine. Different fractions of petroleum have widely varying flash points (the temperatures at which the fuel may self-ignite). This must be taken into account in engine and fuel design.
The tendency for the compressed fuel mixture to ignite early is limited by the chemical composit…
See also
• Atkinson cycle
• Miller cycle
• Humphrey pump
• Desmodromic valve
• History of the internal combustion engine
General sources
• Hardenberg, Horst O. (1999). The Middle Ages of the Internal combustion Engine. Society of Automotive Engineers (SAE). ISBN 978-0-7680-0391-8.
• scienceworld.wolfram.com/physics/OttoCycle.html
• Cengel, Yunus A; Michael A Boles; Yaling He (2009). Thermodynamics An Engineering Approach. N.p. The McGraw Hill Companies. ISBN 978-7-121-08478-2.
External links
• U.S. Patent 194,047
• Four stroke engine animation
• Detailed Engine Animations
• How Car Engines Work
What Is A Four-Stroke engine?
How Does A 4-Stroke Engine Work?
- A four-stroke engine works in the following steps: 1. Intake Process 2. Compression Process 3. Power Process 4. Exhaust Process 1) Intake stroke 1. As the piston reciprocates toward BCD from TDC (downward), a vacuum starts producing inside the compression chamber (cylinder). 2. When the vacuum produces inside the compression chamber, the exhaust valve closes, and the …
PV Diagram of The Four-Stroke Engine
- The following PV diagram represents the working cycle of the 4-stroke engine. A four-strokeengine completes a working cycle in the following steps: 1. Isobaric Process (0 to 1):In the isobaric process, the piston moves downward and generates a vacuum inside the combustion chamber. During vacuum creation, a pressure difference generates between the atmospheric pr…
History
- Atkinson Cycle
1. In 1882, James Atkinson designed the Atkinson cycle engine. It was a single-stroke IC engine. 2. This cycle was invented for the provision of efficiency at the expenditure of power density. Nowadays, the Atkinson cycle engine is utilized in some latest hybrid electrical applications. 3. T… - Diesel Cycle
1. A diesel engine is a practical advancement of the Otto enginefrom 1876. 2. In 1861, Otto felt that engine productivity could be improved by compressing the air-fuel mixture before ignition, and Rudolf Diesel desired to make a more efficient engine that can run heavier Fuels. 3. Due to t…
Four-Stroke Engine Power Output Limitations
- The output power of the engine depends on the amount of air drawn in. The performance of a piston engine(whether it is a 4-stroke engine or a 2-stroke engine) depends on the speed (RPM), the calorific value of the fuel, loss, air-fuel ratio, volumetric efficiency, oxygen content in fuel-air mixture and combustion chamber size. Ultimately, the speed of the engine controls through lubri…
Components of 4-Stroke Diesel Engine
- The four-stroke engine has the following major components: 1. Fuel injector 2. Piston 3. Inlet Valve 4. Exhaust Valve 5. Crankshaft 6. Connecting rod 7. Engine block 8. Flywheel The piston in the 4-stroke diesel engine produces reciprocating movement. It connects with the crankshaft via a connecting rod. It transfers its motion to the crankshaft via a connecting rod. The piston moves …