Two-stroke or four-stroke outboard motor? Two-stroke and four-stroke internal combustion engine.

Which outboard motor choose? (comparison of two and four-stroke motors.)

The age-old dispute, which motor is better than a two-stroke or four, now and then flares up again and again on different fishing resources. Foaming water motors alone prove that a two-stroke is “just what the doctor ordered!” Others, on the contrary, argue that it cannot be better than a four-stroke!

I will say right away that both types of motors have their advantages and disadvantages, and when buying a PLA, you need to proceed from what you need for your conditions of use. That is, after comparing 2 and 4-strokes, the choice should be yours. And I, in turn, will try to give strong arguments "for" and "against" both designs.

Environmental friendliness.

A two-stroke outboard motor is designed in such a way that the oil that lubricates the crankshaft inevitably enters the combustion chamber. Ideally, it should burn there along with gasoline and burnt out as exhaust gas. But, as they say, there is nothing perfect in the world, and designers are also people, so in reality everything is a little different. The new fuel enters the combustion chamber at almost the same time as the exhaust gases are expelled. This then leads to the entry into the exhaust gas of a working or incompletely burned mixture, which ultimately ends up in a reservoir.

Regarding the norms of the law in the USA and the countries of the European Union, it seems like the sale and use of two-stroke engines is prohibited due to increased pollution standards environment. So if you buy a motor and want to go all over Europe under it, then definitely take a four-stroke. In Russia, there are no prerequisites for the adoption of such norms and laws yet, our government is more interested in winter - summer time and any other crap, ecology and a ban on the sale of networks are not included in their plans, like many other aspects of improving the environment and raising the standard of living of the population. It follows that we can safely walk with two-stroke engines. There is one more important point left, if you are an ardent environmentalist, then you have already received the answer which motor is better.

Motor weight

In four-stroke engines, every fourth stroke is a working one. For two-stroke engines, accordingly, every second will be a worker. Ideally, it should be that two stroke motors twice as powerful as four-stroke ones (with the same volumes of combustion chambers). In fact, everything is a little different. Design flaws, such as, for example, the ingress of a used and fresh mixture into the exhaust into the working mixture, lowers this figure by about 1.7 times. But, one way or another, it turns out that in order to achieve the same power on the shaft (namely, it is interesting to us), we need two stroke engine smaller than a four stroke. And if the size is smaller, then the motor is lighter. That is, if the main criterion when choosing a motor is its weight, then you should be inclined to buy a two-stroke motor. Where is the weight really important? In the event that your boat is at the boat station or in the garage on a trailer in the assembled state, and you hung the motor on the transom, forgetting about it until the time of service or repair ... In this case, does the weight of the motor matter? I think no!

But if you inflate the boat every time on the shore, each time installing the motor on the transom, and take it off after fishing or walking, and even store the kit on the balcony ... then, I think everyone will agree that weight matters.

The shorter the boat, the greater the role of weight at the stern, in which case you will have to constantly load the bow in order to safely approach the engine or get into planing mode.

If you use a large PVC boat and you have to assemble - disassemble it on the shore, and at the same time hang 15 mares on the transom, then a thirty-kilogram (two-stroke) motor can still be picked up alone, and it will not be easy to screw a 50kg (four-stroke) one without assistance, unless you are a bodybuilder or a heavyweight weightlifter.

Saving

For the same power, four-stroke outboard motors are more expensive than their two-stroke counterparts. The price difference can be up to 50%. All this is due design features four stroke.

Fuel

It is no secret that the efficiency of a four-stroke engine is higher, it eats less gasoline and oil. Again, it's all about the design of the motors. How important it is for you, decide for yourself. If you go to the pond a couple of times a month, then perhaps your grandchildren will pay off the price difference, but if you go out on the water every day and the engine rests only during the freeze-up period, then the fuel costs will be tangible and then you need to think about which engine is better.

There is an opinion that a four-stroke engine has a much longer resource than a two-stroke competitor. In fact, these statements are solid theory. Let's assume that the motor resource of the engine is declared at 2000 m.h. To establish this in practice, it is necessary to walk around the pond back and forth throughout the entire season of “liquid water”, moreover, around the clock. Despite the rest and weather. Or ride three seasons, every day, eight hours a day. For completeness of the data, it is necessary to use several outboard motors. What will be the cost of such a check, it is even difficult to imagine. In fact, if there were any tests, they are too conditional, since they were most likely sponsored by the manufacturer of the PLM, which means it is difficult to judge the reliability of the data. So it is difficult to judge the motor resource of outboard motors, since they were most likely calculated only on a computer or paper. In this regard, it is very problematic to say with certainty which motor is better.

Maintenance and repair

Any mechanism needs repair over time. And here I think it is clear that the greater the cost of the motor, the more expensive the spare parts for it. If your hands grow from where you need to, and you are able to understand the mechanisms yourself, maintain and repair the engine, then it is preferable to stop at buying a two-stroke engine. These motors are simple, there are more specialists on them, they are longer taken out of production. There are craftsmen who can perfectly tune two-strokes right on the water.

Other nuances

Motor noise. The noise level of two-stroke engines is higher than that of their four-stroke counterparts. This is especially noticeable at full and very low speed. Therefore, if you are going to troll, then it would be preferable four stroke motor. The two-stroke also smokes more, due to the presence of oil in the mixture, which turns trolling with a tailwind into an uncomfortable pastime. Here you will quickly decide on the choice of outboard motor, if weight is not of key importance.

Oil. A two-stroke engine uses a mixture of gasoline and oil, while a four-stroke engine runs on pure gasoline. And some, when choosing a motor, see some great difficulties in mixing oil with gasoline. To break in the PLM, the proportions are 1 to 25, and after the break-in is 1 to 50. Who has problems with arithmetic so much that they cannot divide a liter by 25 or 50. Many immediately pour at the gas station required amount oil into a canister, and while they get to the reservoir, gasoline mixes with oil, and when moving through the reservoir, the mixture continues to slosh. And now those oils that are produced for two-stroke engines are self-mixing.

Transportation. Four-stroke motors must be transported in a certain position, while two-stroke engines can be transported as your heart desires, even upside down. This is due to the fact that in four-stroke engines there is oil in the crankcase and, if transported incorrectly, it can leak out. Many two-stroke supporters mention this fact as very significant when choosing a motor, although in fact it does not affect the speed or power of the motor, and I don’t remember at all who was so inconvenienced by transporting a four-stroke motor that it was worth focusing on this .

Planing. To get on the glide, you need the “right boat”, designed not for quiet walks in displacement mode. Trying to bring such a boat into planing mode will not lead to anything good.

Also, the output to the planing mode depends on the weight of the boat with all its contents and the number of horses under the hood. The calculation is approximately such that 25-30 kg of weight should fall on one mare. Since the weight of the motor is also taken into account when calculating the exit to planing mode, the smaller its weight, the more likely it is to go on planing. The other side of the coin is that the less weight, the less horses. Approximately, you can say this - if you have a small PVC boat with a transom, then it is better to take a five in 2 cycles, with it it is more likely to go on a gliding than with a 4-stroke. If we are talking about ten mares or fifteen, then in this case the weight does not play a big role, and if in other respects the weight is not important to you, then there is no point in bothering.

I hope the article turned out to be useful to you and many questions about choosing a PLM have disappeared.

Sincerely, Mamba!

Engine internal combustion works on well-established principles. We will consider piston engines, since rotary and other exotic units that convert combustion energy into kinetic energy are not so common.

For a better understanding of the process, let's define the technical terms:

• Engine duty cycle - a chain of alternating processes, as a result of which the energy of fuel combustion is transformed into the rotation of the wheels (when used in a vehicle)
• Intake - filling the cylinder with a mixture of gasoline and air vapors (in gasoline engines) or air in diesel engines
• Compression - pressing fuel mixture in a cylinder
• Working stroke - expanding gases, after igniting the combustible mixture, rapidly drive the piston down
• Release - ventilation of the cylinder cavity from a portion of exhaust gases.

During the work cycle, the processes follow in a strictly defined order. Each of them is called a beat. From a mechanical point of view, a stroke is the movement of a piston from one dead center to the second. Depending on the design of the motor, there may be two or four cycles.

What is a two-stroke engine - video

What is the difference between a two stroke engine and a four stroke engine?

For each rotation of the crankshaft 180 °, two cycles are performed (different, depending on the type of engine). Process development two-stroke internal combustion engine is carried out in one revolution, and a four-stroke - in two revolutions of the crankshaft. Unclear? Let's consider the issue in more detail.

Important! There are passive and active clocks. More precisely, there is only one active cycle - the working stroke. The remaining movements of the cylinder occur due to the inertia of the flywheel mounted on the motor axis. This applies to a single-cylinder engine, each subsequent cylinder works out of phase, and a heavy flywheel is no longer needed. Therefore, its role is played by the gear, which the starter clings to.

A modern motor is quite complex from an engineering point of view. Processes are provided by various auxiliary mechanisms, their work must be synchronized. In addition, the components of the engine have a certain mass, so there is inertia.

Friction parts are slowed down by resistance. This slows down the process and wastes extra power. All amendments must be taken into account when designing the motor.

It is difficult to program the control algorithm, operating conditions are constantly changing. If the cycle sequence fails, there will be a loss of power or engine shutdown. Therefore, for uninterrupted operation you need so many fixtures around the pair: piston, cylinder.

Two stroke or four stroke?

What is the best outboard motor for fishing?

In this article, we will select and study the types of outboard motors, taking into account their convenience for fishing. What should be an outboard boat motor for fishing? After all, you really want to catch a fish, relax on a pond, breathe clean air, and not just ride three hundred kilometers and stay with “zero”. The “classic phrase” for the beginning of an article usually sounds like this: 2-stroke outboard motors are simpler in their design and repair, and 4-stroke motors are more economical, but more expensive.

First, let's define terms

Reliability - the property of an object to keep in time within the established limits the values ​​of all parameters that characterize the ability to perform the required functions in specified modes and conditions of use, Maintenance, storage and transportation.

Maintainability is a property of an object, which consists in adaptability to maintaining and restoring a working state through maintenance and repair.

Simply put, we pay for modern car half a million is not to fix it every weekend, we want to use it as a means of transportation, and not like before, when every weekend was spent in the garage, adjusting the carburetor or "looking for a spark." Thus, one can also choose outboard motor- it should set the boat in motion and not break.

Yes, a 2-stroke motor is simpler in design, but this does not mean that it is more reliable. As I already mentioned, the motor resource is 4 stroke engine five times more than a two-stroke. Naturally, we compare the carburetor models of such engines. Where does such a difference come from?

I will not draw pictures from textbooks and explain what two or four bars are. We know the following: two-stroke outboard motors are filled with fuel consisting of a mixture of gasoline and oil, and four-stroke outboard motors are filled with just gasoline.

So the engines are different? Quite right! A mixture of gasoline with oil and air burns in the cylinder of a 2-stroke engine. Burns worse than a mixture of gasoline and air, because. oil in the fuel mixture reduces the energy released and this mixture is unstable in density - sometimes thick, sometimes empty. And this despite the fact that modern oils in most cases self-mixing, i.e. dances with shaking a tambourine (tank) do not need to be arranged.

Let's go back to the 4-stroke outboard engine. Even a schoolboy knows how to check the oil level in a car and knows that it should be there! This is where the "dog is buried." Unlike a two-stroke engine, in which lubrication of the crankshaft, crankshaft bearings, compression rings, piston, piston pin and cylinder is carried out by adding oil to the fuel, the crankshaft of a four-stroke engine is in an oil bath - crankcase. That is, the mechanisms of this type of engine are lubricated continuously and do not experience such “torn” loads as a two-stroke one. Moreover, than more revs we give the engine, (i.e. than more speed movement), the more oil is supplied to the rubbing parts. After all, 4-stroke outboard motors have an oil pump. But in a two-stroke engine, with an increase in oil speed, there may not be enough oil - “dry” wear will begin. This is where such a colossal difference in motor resource comes from.

Small four-stroke outboard motors up to 5 "horses" oil pump they do not, and lubrication is carried out by oil mist created by a rotating crankshaft, but they also have less load.

Destroying the myths about the four-stroke outboard motor

It's time to remember the myth about transporting a 2-stroke engine on "any side and in any position", and that a 4-stroke outboard motor can only be transported on a certain side so that oil does not leak out.

Yes, a four-stroke motor is transported on one side, which is indicated in the instructions for the motor. Yes, it always has oil in it. By the way, the oil will flow to the wrong place in only three hours. If you get to the reservoir for one hour, then nothing bad will happen.

Do you often carry your outboard motor upside down? So, in the motor there is a forward-neutral-back shift knob, and during my work there were a couple of cases of breakdowns of 2-stroke outboard motors right in the store, when the motors were put on the gear knob and that’s it - the crank handle ... For example , for a five-horsepower outboard motor, such a pen costs at least 4,000 rubles. Conclusion: you will have to carry motors of both types on the same side where this handle is not. The myth about the difficulty of transporting a 4-stroke outboard motor compared to a 2-stroke is busted.

The second "advantage of 2-strokes" is that they bring the boat to the glider faster. Yes, two-stroke engines have better accelerating dynamics and bring the boat to the glider faster - by as much as 5 seconds - did we come fishing to arrange races or are we in a hurry somewhere?

Let's talk about the beautiful - that is, about fishing

What is a boat motor for fishing - it's a track and casting.

I have never seen such a picture myself, at my favorite “point” they try to catch perch from a boat without turning off the outboard motor! Throw, more, more - the result is one okushka. They go further with their 13 kg 2-stroke engine. I'm coming in five minutes at 4 stroke motor also 13 kg - a dozen perches! This is explained simply - at low speeds, a 2-stroke outboard motor is twice as noisy as a four-stroke one. And this is a perch, which, in general, is not afraid of noise, but even goes out to it.

On weekends, when there are a lot of boats with large motors on the pond, the bite is worse. The outboard motor has an exhaust into the water, which is good for us as helmsmen, but very bad for us as anglers. Due to the peculiarities of their work and design, two-stroke outboard motors are an order of magnitude noisier than four-stroke ones.

A trail with a tailwind is a special attraction. The exhaust from the engine is directed into the water, but the gases will go to the surface and into our lungs ... Four-stroke engines produce much cleaner exhaust, since a mixture of only two components burns in the cylinders - gasoline and air - and its combustion is easier to control than mixture of gasoline, air and oil. In a two-stroke outboard motor, unburned oil enters the water, prevents gasoline from completely burning out, degrades exhaust quality and - you breathe nasty stuff when fishing on the track.

The most interesting thing begins when two liters of gasoline or one and a half liters remain in a 12-liter tank, you can’t make out by eye. But the tank needs to be refueled, and yesterday we celebrated the capture of a pike or celebrated Bastille Day ... We begin to remember the proportions. How many two-stroke outboard motors have been ruined by drinking ... and you can’t count. And I topped up clean gasoline at a gas station and that's it - one less problem.

Given all of the above, we can confidently say that it is 4-stroke outboard motors that are most suitable for fishing, and besides, they are more reliable than 2-stroke ones and will require less money for their maintenance.

As I have hinted more than once in my articles about outboard motors up to 5 hp, you need to buy four-stroke motors. Their difference in weight and price is minimal.

Low-power outboard motors over 5hp

Immediately pay attention to the outboard motor power. 20 HP Why? The thing is that a 4-meter boat is ideally combined with such a motor. Mobile collapsible boat limit. In Ladoga on an inflatable boat less than 4 meters and you should not meddle. And since the boat is 4 meters, then the motor is 15-20 "horses". You can still load things into such an inflatable boat for a trip for three days, if you do not take a comfortable air mattress ...

The lightest 4-stroke "tag" weighs 43 kg, and 2-stroke 36 kg. One and 36 kg is a lot, and together and 43 kg is not much.

Among the “tens”, the weight advantage is still on the side of the 2-stroke ones.

The price of a boat motor or what you should not save on

Yes, two-stroke motors are cheaper, but four-stroke motors are more convenient and reliable in operation, due to which they allow us to save a lot of time that can be spent on fishing. And time is the most precious thing in the world.

With motor fishing greetings Vlad Bagrov

Created 10 Feb 2012

Dear friend, today we will talk about what it means four stroke engine. About the history of its invention, the principle of operation, features, technical specifications and areas of application.

Of course, if you have driver's license, then you at least heard this term when you studied at a driving school. But it is unlikely that then they began to delve into all the subtleties, so now is the time to figure out what is happening there under the hood of your iron horse.

There were already engines in the 19th century, but they were mostly large machines powered by steam. Of course, they partially provided for the developing industry, but had many shortcomings.

They were heavy, had low efficiency, large dimensions, it took a long time to start and stop, skilled workers were needed for operation.

The industrialists needed new unit without these shortcomings, they already understood what a four-stroke engine means. And how, under certain conditions, it can be used to increase profits.

It was developed by the inventor Eugene-Alphonse Beau de Rocha, and in 1867 Nikolaus August Otto embodied it in metal.

At the time, it was a marvel of technology. The internal combustion engine was characterized by low operating costs, small size and did not require the constant presence of maintenance personnel.

The device worked according to a special algorithm, which is now called the "Otto cycle". 8 years later, after the launch of the first instance, the Otto company has already produced more than 600 power plants a year.

Very quickly, due to autonomy and compactness, internal combustion engines became widespread.

What is the engine made of?

To understand the principle of operation, let's get acquainted with the main components of the engine:

• (includes crankshaft, pistons, connecting rods) - it is necessary to convert the reciprocating movements of the piston into rotational movement of the crankshaft;
• the head of the block along with the gas distribution mechanism, which opens the intake and exhaust valves in order to receive working mixture and exhaust gases are released. The timing may include one or more camshafts, which consist of cams for pushing the valves, the valves themselves, and valve springs. For stable operation four-stroke engine, there are a number of auxiliary systems:
• ignition system - for igniting the combustible mixture in the cylinders;
• intake system - for supplying air and working mixture to the cylinder;
• fuel system - for continuous supply of fuel, obtaining a mixture of air and fuel;
• lubrication system - for lubrication of rubbing parts, as well as the simultaneous removal of wear products;
• exhaust system - to remove exhaust gases from the cylinders, reduce exhaust toxicity;
• cooling system - to maintain the optimum temperature of the engine.

What does a four-stroke engine mean and why four strokes

1. Now that you have more or less an idea of ​​​​the design of a four-stroke engine, you can consider the workflow.
   It consists of the following stages: inlet - the piston moves down, the cylinder is filled combustible mixture from the carburetor through inlet valve, which are opened by the camshaft cam. When the piston moves down, a negative pressure is created in the cylinder, thereby sucking in the working mixture, namely air with fuel vapor. The intake continues until the piston reaches BDC (bottom dead center). At this point, the intake valve closes;
2. compression or compression - after the BDC is reached, it begins to move up to the TDC (top dead center). When the piston moves up, compression occurs, the working fuel-air mixture compresses, the pressure inside the cylinder increases. Inlet and outlet valve closed;
3. power stroke or expansion - at the end of the compression cycle (at TDC), the working mixture is ignited by a spark in the spark plug. The piston from the microexplosion rushes to the BDC. During the movement of the piston from the TDC to the BDC, the mixture burns out, and the gases increasing in volume push the piston, performing useful work. It is for this reason that the movement of the piston in this cycle is called the working stroke. Inlet and outlet valve closed;
4. release exhaust gases- in the final fourth stroke, the exhaust valve opens, the piston rises in top point and pushes the products of combustion out of the cylinder exhaust system passing through the muffler, they enter the atmosphere. After the piston reaches TDC, the exhaust valve closes, then the cycle repeats. These four cycles represent the duty cycle of the motor. The stroke is also called the movement of the piston up or down. One turn crankshaft corresponds to two measures, and two revolutions corresponds to 4 measures. Hence the name of the four-stroke engine.

What determines the power of a four-stroke internal combustion engine

Everything seems to be clear here - power piston engine basically defined:

1. cylinder volume;
2. the degree of compression of the working mixture;
3. rotation frequency.

You can also increase the power of a four-stroke engine by increasing throughput intake and exhaust strokes by increasing the diameter of the valves (especially intake).

Also maximum power is obtained with the maximum filling of the cylinders; for this, turbines are used for forced air pumping into the cylinder. As a result, the pressure in the cylinder increases and, accordingly, Engine efficiency increases significantly.

Current Application

Four-stroke engines are either petrol or diesel. These engines are used in transport or stationary power plants. It is recommended to use such an engine in cases where it is possible to adjust the ratio of speed, power and torque.

For example, if the engine is paired with an electric generator, then you need to maintain the desired speed range. And when using intermediate gears, a four-stroke engine can be adapted to loads within a fairly wide range. That is to use in cars.

Let's go back to the origins of its creation. A very talented engineer Gottlieb Daimler worked in the group of the inventor Otto, he understood what a four-stroke engine means, its development prospects, and proposed to build a car based on a four-stroke engine. But the chief did not consider it necessary to change something in the engine, and Daimler, carried away by his idea, left the master.

And after some time, together with another enthusiast Karl Benz in 1889, they created a car that was driven precisely by the gasoline four-stroke internal combustion engine of the inventor Otto.

This technology is still successfully used today. In cases where power point works on transient modes or modes with partial power removal - it is indispensable, as it ensures stable stability of the process.

Now, dear friend, are you in in general terms know what a four-stroke engine means, where it is used. Now you are head and shoulders above. But do not be stingy with the information received, share it with your friends. Social media buttons are at your service.

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When buying a new scooter, people often ask questions like " Which is better 2 stroke or 4 stroke". There is no single answer to this question. Each motorist will find both disadvantages and advantages in both types of engines. To figure it out for yourself which scooter is better 2 stroke or 4 stroke, you should first find out What is the difference between 2 stroke and 4 stroke engine.

The difference between a two-stroke and a four-stroke

Main differences between two-stroke and four-stroke engines is due to the difference in their gas exchange devices - the supply of a fuel-air mixture to the cylinder and the removal of exhaust gases. IN 4t engine the processes of cleaning and filling the cylinder are carried out using a special gas distribution mechanism (GRM), which closes and opens the intake and exhaust valves. IN engine 2t filling and cleaning of the cylinder are carried out in parallel with the compression and expansion strokes - at a time when the piston is located near BDC (bottom dead center). To do this, there are two holes in the walls of the cylinder - inlet (purge) and outlet, through which the fuel mixture is supplied and the exhaust gases are released. The two-stroke engine does not have a valve timing mechanism, which makes it much lighter and simpler.

Which engine is more powerful 2 stroke or 4 stroke

Unlike a 4 ton engine, in which one stroke occurs for two revolutions of the crankshaft, in a 2 ton engine, a stroke occurs with each revolution of the crankshaft. This means that a two-stroke engine must have (in theory) twice as much liter capacity (the ratio of power to engine volume) as a four-stroke. But in practice, the predominance is only 1.5 - 1.8 times. This happens due to inadequate use of the piston stroke during expansion, the worst mechanism for ridding the cylinder of exhaust gases, the cost of a share of power for purge and other phenomena associated with hallmarks gas exchange of 2 stroke engines.

Fuel consumption 2t and 4t

Surpassing the four-stroke engine in liter and power density, two stroke engine inferior to him in economy. The expulsion of exhaust gases is performed in it fuel-air mixture arriving in the cylinder from the crank chamber. In this case, part of the fuel mixture ends up in the exhaust channels, being removed together with the exhaust gases and not producing useful work.

Grease 4 t and 2 t

Two-stroke and four-stroke engines have a different design and principle of operation of the engine lubrication system. In 2 stroke scooters it is carried out by mixing in established proportions (usually 1:25 ... 1:50) engine oil with fuel. The fuel-air-oil mixture, circulating in the crank and piston chambers, lubricates the connecting rod and crankshaft bearings, as well as the cylinder mirror. When the fuel mixture ignites, the oil burns together with gasoline. The products of its combustion are removed together with the exhaust gases.

There are 2 methods of mixing oil with gasoline. Conventional mixing before pouring fuel into the tank and a separate supply, in which the fuel-oil mixture is formed in the inlet pipe located between the carburetor and the cylinder.

Separate lubrication system for two-stroke engine

1. oil tank
2. carburetor
3. throttle cable separator
4. throttle stick
5. oil control cable
6. plunger dosing pump
7. oil inlet hose

All modern 2t scooters use separate oil supply(we fill in 2t oil separately from gasoline). IN two stroke scooter the engine has an oil tank, the pipeline of which is connected to an oil pump that supplies oil to the inlet pipe in the amount that is necessary depending on the amount of air-gasoline mixture. The productivity of the pump depends on the position of the "gas" knob. The more fuel is supplied, the more oil is supplied, and vice versa. A separate lubrication system for two-stroke engines is considered more flawless. With it, the ratio of oil to gasoline at light loads can reach 1:200, which leads to a reduction in smoke, a decrease in carbon deposits and oil consumption. This design is used on modern scooters with two-stroke engines.

In a four stroke engine oil does not mix with fuel and served separately. To do this, the engines are equipped traditional system lubrication, consisting of an oil pump, filter, valves, pipelines. The role of the oil tank can be performed by the engine crankcase (wet sump lubrication system) or a separate tank (dry sump system).

Lubrication system of a four-stroke engine with a wet and dry sump

1. sump
2. oil intake
3. oil pump
4. oil filter
5. safety valve

When lubricating with a “wet” crankcase, pump 3 takes oil from the sump, pumps it into the outlet cavity and then delivers it through the channels to the crankshaft bearings, crankshaft and timing parts. When lubricating with a “dry” sump, oil is poured into the tank, from where it is pumped to the rubbing planes. That part of the oil that flows into the crankcase is pumped out by an auxiliary pump, which gives it back to the reservoir. There is a filter to clean the oil from wear products of engine parts. If necessary, a cooling radiator is also installed, since during operation the oil temperature can rise to high temperatures.