Relatively 2 stroke engine of same physical size with 4 stroke engine, produces higher amount of power than that by 4 stroke engine. But in term of thermal efficiency, 2 stroke engine are considered less thermal efficient than 4 stroke engine.
Why thermal efficiency of 4 stroke engine is more than 2 stroke engine?
Difference Between 2 Stroke and 4 Stroke Engine
|2 Stroke||4 Stroke|
|More power generation.||Less power generation.|
|Produces more heat so it requires greater cooling and lubrication.||Generates less heat.|
|Lower thermal efficiency||Higher thermal efficiency|
Which engine has higher thermal efficiency?
According to Popular Mechanics, the reason diesel engines have a higher thermal efficiency than gasoline engines is that of two factors: compression ratios and lean-burn combustion.
What is the thermal efficiency of 2 stroke engine?
The results showed that a maximum brake thermal efficiency of 47.2% can be achieved for the two-stroke BUSDIG engine with lean combustion and water injection.
Why thermal efficiency is lower in 2 stroke engine?
More mechanical efficiency due to less friction on a few parts. 7. More output due to full fresh charge intake and full burnt gases exhaust. Less output due to the mixing of fresh charge with the hot burnt gases.
What is the main difference between 2 stroke and 4-stroke engine?
In a 2-stroke engine, all five functions of the cycle are completed in only two strokes of the piston (or one revolution of the crankshaft). In a 4-stroke engine, the five functions require four strokes of the piston (or two revolutions of the crankshaft).
What is the difference between 4 stroke and 2-stroke engine?
The main difference between a 4-stroke engine and a 2-stroke engine is that a 4-stroke engine goes through four stages, or two complete revolutions, to complete one power stroke, while a 2-stroke engine goes through 2 stages, or one complete revolution, to complete one power stroke.
Is a 4 stroke engine a 4 cycle engine?
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. … Combustion: Also known as power or ignition.
Why is the efficiency of a 2 stroke SI engine less than that of a 4 stroke SI engine?
Hence, the compression ratio of this engine is lower than that of a four-stroke engine of the same dimensions. As the efficiency of an engine is directly proportional to its compression ratio, the efficiency of a two-stroke cycle engine is lower than that of a four-stroke cycle engine of the same size.
What is better a two stroke or four?
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.
How can you increase the efficiency of a 2 stroke engine?
First, an electric turbocharger allows for “variable compression ratio,” whereby the inlet pressure fed into the engine’s cylinders is varied to maximize efficiency. Second, an approach called asymmetrical port timing–opening the intake and exhaust ports at different times–helps improve the efficiency of gas exchange.