The type of power equipment is critical when choosing. Today, there are two options - a 4-stroke engine and a 2-stroke.
Features
Power equipment operates on the basis of gas expansion during heating, which occurs when ignition of fuel entering the inner part of the cylinder. Many are of the opinion that the 4-stroke Briggs Stratton engine has better performance. To get a definite answer, it’s worth understanding the features of both types of work.
The crank design and the mechanism responsible for the distribution of gas are the main components, no less important systems that provide lubrication of elements, ignition and power.
A crank device transfers the necessary effects of expanding gases, while the mechanism that distributes them delivers gasoline to the cylinder space.
The 4-stroke engine is characterized by economical fuel consumption, the absence of combustible mixtures in the exhaust, a lower level of reproducible noise, as well as environmental friendliness, due to which it has become widespread in many car manufacturing companies.
How a two-stroke engine works
The whole process is based on work progress and compression.
The piston is mainly in two positions - these are the lower and upper dead points. When moving from one to another, the purge and outlet openings overlap, then the gas present in the cylinder begins to compress. At this time, the combustible mixture exits the inlet window and enters the chamber of the crank mechanism, it will subsequently be compressed.
After the vapor of air and gasoline reaches the maximum degree of compression, an electric spark coming from the candle ignites them. At this time, pressure is generated that promotes the movement of the piston to a lower point due to a sharp increase in gas volume and temperature of the mixture. During the movement, the outlet opens and combustion products exit. The mixture is compressed as the piston moves and ends up in the combustion chamber, while the purge window opens.
Positive and negative sides
The mechanism is characterized by a sufficient number of disadvantages, including high fuel consumption, while most of it is wasted. This is caused by a partial discharge of the vapor mixture during the simultaneous opening of the outlet and purge windows. It should also be noted the continuous consumption of oil, as it is part of the mixture and without it the engine is impossible. Another negative side is the continuous preparation of the fuel mixture.
The two-stroke mechanism has a small weight and dimensions, which a 4-stroke engine cannot boast of. But during the operation of the car, it causes more problems, which is why this option is common in the field of modeling, where every extra kilogram is given special importance.
How a four-stroke engine works
It is completely different from its lighter counterpart. The principle of a 4-stroke engine is a cycle consisting of a sequential intake, compression, stroke and exhaust, due to which the valve system has found its application.
The piston opens the inlet by moving down, then the combustible mixture enters the cylinder, at the same time a working mixture is created after mixing with the residues from the used composition.
Processes that are systematically repeated, in the established sequence, represent a working cycle, they occur in all cylinders and provide mechanical work due to energy conversion.
Advantages
The motor in an ordinary car operates on the basis of a four-stage cycle, it occurs during four movements of the piston or two revolutions of the crankshaft.
A 4-stroke diesel engine has a completely different method of igniting the working mixture and its formation, compared with the carburetor option. The main difference in the intake stroke is that air heated to high temperature values enters the diesel cylinder, and the fuel atomized to the smallest particles ignites under the influence of the temperature level.
The 4-stroke engine has an oil sump in its design, this part is responsible for lubricants, more precisely, for a constant stay at a set level. The oil pump transfers material to the lubrication system and distributes it on the walls of the inside of the cylinder. As a result, the piston friction is reduced due to the oil thin film. Oil scraper special ring elements prevent the ingress of oil into the combustion chamber through the return. The oil pump is used, as a rule, in engines with a capacity of more than 5 l / s. In other cases, the lubricant is distributed by oil mist, the creation of which is ensured by the crankshaft.
A 4-stroke engine has a lower degree of load, due to this, the oil flows systematically in the required volume, thereby increasing the life of the mechanism.
Only one lubricant change is needed per season. It is worth noting that you need to periodically check the oil level, although it can not suddenly disappear. Today, manufacturers have simplified the task for drivers and equipped modern models with special sensors that monitor the level of lubricant and report the need for its replacement.
The main difference
As noted above, the two types of motor have a fundamental difference, which is the lubrication of push-pull mechanisms, a mixture of gasoline and oil, which subsequently burns. Some of them have a special system that delivers oil to the crankcase, but the meaning remains the same - gasoline burns with the oil. While the Chinese 4-stroke engine “Lifan”, like any other similar plan, is equipped with devices for returning oil to a special compartment.
Lubricants
Due to the differences between the engines, automobile oils must meet different requirements:
- oil for a four-stroke mechanism should have high lubricating properties that remain the same for a long time;
- for another type, maximum combustion of the lubricant is necessary with minimal residual effects in the form of soot and ash.
At the dawn of the existence of engines, conventional distillation of petroleum products was used to produce grease. The composition was the same for both options. The need to create new oils did not arise due to the fact that the 4-stroke engine had low power, and as a result, low wear and light loads on the constituent elements. Later, the reserve of trains was exhausted by a gradual increase in speed during operation and general parameters. This problem was solved by the use of additives - special additives for automotive oils. Today, they significantly increase the characteristics of the lubricant.
Power
There is an opinion that 2T engines are more powerful due to the full use of fuel energy for two revolutions of the shaft. This is not entirely true, because in this embodiment, the cylinder, unlike a different type of engine, has an incomplete design, and part of it falls on the exhaust and inlet openings, respectively, a smaller amount of fuel burns.
The simplicity of the 2T mechanism caused the use of a mixture of gasoline and oil as a lubricant. A lubricant-containing working mixture has a lower energy release. Also, design features have led to an empty flow of the combustible mixture, which accounts for a fairly significant part. At the same time, the 4-stroke Chinese engine has a more complex design, and as a result, a small amount of non-combustible fuel. That is, 2T motors are more powerful only in a fairly narrow range.