Any car decays and wears out over time, and this applies not only to the body or interior elements. Much more trouble for car owners is caused by malfunctions of the engine and other car systems that have arisen as a result of long-term operation of the vehicle.

Sooner or later, every driver is faced with the need to overhaul the power unit, which involves replacing most of the components of the cylinder-piston group and the crank mechanism. The result is an engine updated almost to its original state, which at first must be run in by analogy with a completely new car.

Of course, there are some differences, and we will definitely tell about them in our review.

Why is the engine running in

Engine repairs, even with the use of expensive equipment, cannot be compared with factory production; therefore, there are almost always microscopic irregularities and deviations from ideal geometry on the surfaces to be treated. Therefore, lapping the power unit is necessary so that such extremely minor defects (typical, by the way, for new engines) do not develop into significant ones. And the risk of more serious troubles increases many times, if at first the car is not operated in a sparing mode.

Until the rubbing parts are worn in, overheating of the motor must not be allowed - this can lead to further deformation of the motor elements. Running in the engine after capitalization assumes that the car owner will drive, adhering to the recommended one, for about 3 thousand kilometers after the overhaul. However, the complete rubbing of rubbing surfaces, in which all irregularities are smoothed out, occurs, as practice shows, after a collision of 10,000-15,000 kilometers. Over the specified period of time, the likelihood of significant scoring, as well as melting of rubbing parts, is significantly reduced.

Regardless of whether the engine parts were processed in a handicraft way, or new factory-made units were installed, you cannot do without running in, and here's why:

• you carry out the assembly of the engine yourself or in a workshop. It is not necessary to talk about observing exact tolerances for quite understandable reasons;
• since you do not change the entire engine, there are always old components and parts that, due to natural wear and tear, will no longer correspond to new ones;
• since new parts are produced using a cutting tool, even after finishing, there are always at least areas that do not fully correspond to the original ones in geometry.

The first start of the power unit

Assembling the motor is an extremely critical stage. Any mistake can have very serious negative consequences. The first start of the engine after the completion of the repair work is no less important. We can say that how successful the subsequent running-in of the motor will be depends largely on observing the correct sequence of actions.

Here is the algorithm for the first one after overhaul:

• make sure that the battery is fully charged - due to the presence of irregularities, all its power may be needed to crank the crankshaft;
• great importance should be given to engine oil: it should not only correspond to the recommended for a given engine, but be of high quality. Filling with MM should be carried out up to the upper boundary mark of the dipstick - after 15 minutes, part of the oil will drain into the sump, and it may need to be topped up, but this time not reaching the MAX mark. It is not recommended to pour lubricant into the oil filter - inept performance of this operation can lead to the formation of an air lock in the oil line;
• for diesel and carburetor power units, manually supply fuel to the system;
• if all the preparatory manipulations have been made, you can start starting the motor. When doing this, be sure to check the oil pressure lamp. Compared to a normal start, it should burn for a few seconds longer, but if after 5-7 seconds it does not go out, you should immediately turn off the engine and begin to find out the reason why the oil pressure was not brought back to normal;
• when starting the engine with a starter, do not help it with the accelerator - the increased load here is not just inappropriate, but unacceptable. But the squeezed clutch will be very useful;
• if the light has gone out, it should be at idle speed, without gassing, warm up the engine to 85-92 ° C. While the engine is warming up, you can look into the engine compartment and under the car to make sure that there is no oil and antifreeze. Remember that the appearance of a burning smell during the first start after the capital is a normal phenomenon, this is the result of burnout of the lubricants applied during the assembly of the motor. After the power unit reaches the operating temperature, there will be a slight drop in MM pressure in the system, since the hot liquid becomes more liquid. A pressure in the range of 0.4-0.85 kg / cm 2 is considered acceptable. If it is less, it means that there are problems that appeared either as a result of assembly errors, or due to the use of poor-quality lubricating fluid;
• after warming up, the engine must be turned off and started back only after it cools down to 40 degrees. Such cycles of starting / stopping the motor should be carried out about one and a half dozen, after which you can let the motor run at higher speeds (the first three minutes - at a thousand rpm, then for four to five minutes - at one and a half thousand rpm, after which Let the engine run at 2 thousand revolutions for 5 minutes).

Duration and features of engine running-in after capital

The first three thousand kilometers are considered the most important period for the restored engine. During this period, it is extremely important to unquestioningly observe the recommended driving mode, especially until the vehicle reaches a mileage of a thousand kilometers. Let's list the general rules for running in:

• driving at high speeds is unacceptable, trips at reduced speeds in relation to the nominal speed are also undesirable;
• a gentle driving mode does not mean that you have to move at a constant speed and revs - the driving rhythm must be changed, but within acceptable limits;
• it is highly undesirable to load the car for the running-in period, and even more so to use a trailer;
• you should avoid sudden acceleration / deceleration and completely abandon the habit.

Strictly speaking, running-in does not allow even short-term operation of the motor in heavy duty. You always need to start with very moderate loads, gradually increasing them. Long-term work at XX is undesirable (only to warm up the power unit), since idle speed for a car is also considered a heavy and difficult mode.

As in the case of a new car, after the first thousand kilometers, the engine oil should be changed. In this case, flushing the engine is unacceptable, as is the use of all kinds of additives and additives.

Consider the features of running in a power unit, depending on the scope of work being carried out as part of a major overhaul. Recovery is complete and partial. The complete reconstruction of the engine assumes that work has been carried out affecting all the main engine systems: CPG, KShM, timing. In this case, the recommended run-in mileage is at least 3000 kilometers. Partial repairs are associated with the replacement and restoration of individual engine components (piston rings, camshaft, valves), and in most cases it is enough to run over a thousand kilometers in a gentle mode to grind parts.

Since the full "capital" is more common, we give recommendations for running in just for this case:

• before setting off on the road, you should warm up the power unit at XX, but not too long (we already said that this is harmful) - it will warm up to operating temperature while driving;
• it is advisable to plan the route of travel in such a way as to minimize travel on steep slopes. Passengers are not encouraged to be in the cabin during the run-in;
• engine braking, fast acceleration and emergency braking are unacceptable;
• recommended - 60 km / h, regardless of the type and power of the engine. In this case, the revolutions should be kept short of 2500 rpm and dropped for a long time below 1500 rpm. Beware of the tightness of the operation of the power unit;
• a common mistake is the tendency to drive in one gear, keeping a constant speed. The dosage of the load on the motor should be smooth, deceleration / acceleration should be present, but the speed should always correspond to the selected gear. In this case, the engine runs at an average speed for this mode.

Moderate in every sense of the ride during break-in provides the piston rings with the opportunity to settle down, get comfortable in their places - piston grooves, the surface of the cylinders gradually acquires a mirror-like cleanliness, etc. That is, real driving allows you to smooth out all those inaccuracies that cannot be eliminated during grinding, even with the most modern equipment.

Note also that the specified run-in period of 3,000 kilometers is considered the minimum necessary for a complete overhaul, while a complete lapping of the moving elements of modern internal combustion engines occurs after a collision of 7,000-10,000 kilometers. In other words, the light run-in mode should last much longer. Maximum loads are permissible only after the above section.

Motor break-in methods

The algorithm described above is a classic natural run-in. But besides this, there are at least three more ways to grind parts of a restored power unit:

• cold rolling method, produced using a special stand;
• cold running in without a stand;
• method of hot lapping of engine parts.

Let's consider the features of each of the listed methods.

Run-in at the stand

Of course, the stand itself is very expensive equipment. Only large service stations can afford it, but thanks to its use, it is possible to gain complete control over all technological stages of running in.

In this case, the power unit is installed on the stand and is started by connecting to the cardan shaft, which, in turn, is driven by an electric motor, which is considered to be leading in relation to the car's motor.

A special device, called an encoder, monitors the rotational speed of the leading motor; a tachometer records a slightly less accurate reading. The bench equipment operates under the control of a microprogram, which regulates the parameters of the electric motor, based on the readings of the sensors.

The total duration of the operation of the master / slave motor pair is determined by the scope of work performed as part of the car overhaul. In particular, for normal lapping of a new cylinder-piston group, approximately three hours of continuous rotation of both engines are required.

The result of such a cold lapping suggests that the following indicators have been achieved:

• when the SA is operating at XX (at revolutions not exceeding 600 per minute), the revolutions are stabilized;
• pressing the accelerator pedal in the same mode does not lead to interruptions in the operation of the leading engine, and it should not stall.

Note that the purchase of an expensive stand for cold running is not enough - you also need a specialist who is well versed in the nuances of entering a certain mode, in unquestioning observance of the technology of grinding parts.

Standless cold run-in

It consists in towing the car in third gear, but with the engine off, for 2-3 hours. Before running-in, the car is filled with all the necessary technical fluids, including oil and antifreeze / antifreeze.

Although experts do not advise using this method, it has become widespread among garage repairmen.

Hot running

It is made directly on the car, but on the immobilized. It is characterized by the ability to control the quality of the assembly of the power unit after overhaul and leveling of minor defects made in the production of parts and assemblies installed instead of worn ones. What is good - this technology can be used in garage conditions. Cold run-in algorithm:

• we start the engine, set the speed at the level of the idle mode;
• let it run for about 3-4 minutes, turn off the engine for about the same time interval. We repeat the cycle 10-15 times. Stopping the engine is necessary in order to prevent local overheating of the power unit;
• start the engine again, set the speed to 1200 rpm, gradually increase it to about 50% of the maximum level. We calculate the increase in revolutions so that the total operating time of the power unit is 45-50 minutes.

During the last stage, we especially carefully monitor the engine temperature, if it rises uncontrollably - you should turn off the engine, let it cool down and only then start it again. If everything is normal, we check the levels of technical fluids and the presence / absence of their leaks, measure the compression of the cylinders. Finally, after the run-in is completed, we re-set the ignition and adjust the valve clearances.

Natural engine break-in

We have already given the sequence of the classical running-in. It is worth noting that regardless of the complexity and composition of the restoration work, the running-in should be carried out exclusively in a gentle mode, even if you limited yourself only to replacing the chain (of course, the total mileage in this case will be minimal, about 500 kilometers).

Driving in fifth gear should be avoided, and you should drive off very smoothly. We have already discussed the importance of filling with quality engine oil, but it is equally important to use good fuel - at least until the end of the break-in period.

What not to do

We partially mentioned what it is extremely undesirable to do, we will give for better memorization the list of forbidden actions in full and in full:

• it is impossible to increase the speed in excess of the value of 2000 rpm;
• sharp acceleration / deceleration, especially by the engine, is unacceptable;
• run-in should be done in a lightweight version, without passengers and cargo;
• it is forbidden to include direct transmission, as well as to move on a low one for a long time. In this case, the speed limit should be varied, which will have a positive effect on fuel consumption and the smoothness of the vehicle;
• do not run-in on busy highways, both in and out of the city - in this case, you will not be able to comply with the recommended regime. The ideal place is a deserted track, the ideal time is evening or early morning.

During the first start, it is advisable to listen to the operation of the power unit in order to identify extraneous sounds that may indicate problems in the operation of the restored engine.

Oil selection, replacement intervals

Lapping rubbing surfaces is a process that is accompanied by intensive formation of metal shavings and other products of friction and combustion. Therefore, in the ideal case, replacing the MM after overhaul should be done three, or even better four times. Each time you perform this procedure, you can make sure that the oil is heavily contaminated with products of accelerated wear, and heterogeneous fractions - from invisible to the naked eye to noticeable.

In theory, the first oil change (meaning the natural run-in mode) is made after 500 kilometers. The second - after hitting thousands of kilometers, the third - after another 2000 km. Use only greases recommended by the manufacturer (both in terms of viscosity and brand / model). The use of inexpensive products is undesirable, if only because they rarely include extreme pressure additives.

The last time we change the MM after the completion of the running-in. We have already partially answered the question of which oil to pour after the capital, but we will remind you of seasonality just in case: in summer it is recommended to use a lubricating fluid with a viscosity

15W40 / 10W40, in the cold season - 10W40 / 5W30.

The API standard requires lapping oils to be low viscosity, although high viscosity formulations help to remove surface roughness from lubricated engine parts.

In any case, before running in, you should carefully study the recommendations of the manufacturers - in some cases they do not recommend changing the oil at the initial stage, since branded fluids include an additive package that significantly accelerates the grinding of rubbing surfaces.

Each MM replacement must be accompanied by the following operations:

• replacing the oil filter (it usually clogs up first);
• high-quality test crimping of all threaded connections;
• valve adjustment;
• checking the belt tension with its tension if necessary;
• by adjusting the timing drive.

Any assembled internal combustion engine, regardless of whether it is assembled at the factory, in a car service or in your own garage, must pass a certain period of time in the mode of gentle operation. The plant recommends not to load the engine during the first 500-1000 kilometers, considering this mileage sufficient for running-in. Full engine running-in occurs after a run of about 3-5 thousand kilometers.

Running-in is also necessary after almost any opening of the engine, when any of its components were replaced. This can be a conventional replacement of piston, without replacing pistons, which is often practiced for rebuilding the cylinders of a power plant. In this case, mating parts such as new rings and cylinder walls must rub in.

The liners and support half rings of the crankshaft, intermediate shaft bushings and other things can also be replaced separately, everything that is done with an average engine repair.

Similar requirements apply to the repair of the block head, when the camshafts, guide bushings and valve seats and the valves themselves, pushers, springs, rockers, etc. are replaced.

What is meant by the term - running in?

Break-in is an important period of engine commissioning, which determines its reliability and durability.

The term "running-in" means that it is necessary to enable all rubbing pairs of the power plant in the initial period to work with a minimum load in conditions where they will operate for the entire further period of operation.

When the engine is first started, under the action of friction, the couples begin to rub against each other, taking on their finished shape, which changes will only slightly occur as natural wear and tear.

How is the running process going

The first hours of operation of the assembled motor are most important for its further operation. At this time, the process of grinding the piston rings begins, both to the piston grooves and to the cylinder mirror.

This is especially important when lapping rings and cylinder walls. The fact is that a special mesh, the so-called hon, is applied to the cylinder mirror, which is necessary for the engine oil to remain on the cylinder wall for as long as possible.

In the photo: pistons in the cylinder

On the piston rings, respectively, micro-cuts from the hone are also obtained, since they begin to contact the mesh, sliding along the cylinder body.

For the crankshaft, its connecting rod and main journals are "foreign" to the installed liners until they are lapped together.

The same can be said about the parts of the block head, where the camshafts and their liners begin to contact, valves in guide bushings and seats, compensators in their seats and with the body of rockers, springs to biscuit plates.

General rules for running in

The engine before driving, when driving uphill, engage a lower gear, keep the speed limit no more than 90-100 km / h, excluding aggressive driving style.

During the break-in period do not raise the speed above 3000 rpm and not more than 2500 rpm for diesel engines (from engine type from 1200 to 2500 rpm).

If possible, avoid traffic jams during rush hours, using the morning and evening hours for running in, or driving in the countryside in highway mode.

For the first 500 kilometers, it is recommended to drive evenly so as not to put stress on the power unit and transmission. So on the first 50 kilometers, you need to move at a speed of 40-50 km / h in 3rd gear. Then move at a speed of up to 70 km / h, switch to 4th gear, passing the next 100-150 km.

After every new 100 km of run, you can increase the speed by 10 km / h by moving in 4th gear.

On the second 500 km of running-in, it is advisable to go in the track mode using an increased 5th or 6th gear, raising the motor to 3000 rpm, including a lowered one on long ascents.

Also, avoid long engine idling, since in this mode there is no stable pressure in the oil line and friction couples can "starve", which is not permissible until they get used to each other.

Running in a new car engine

It is believed that the motors of the new cars have already passed the bench run-in at the factory and do not require any restrictions. However, as mentioned above, the full run-in cycle ends after a run of 3-5 thousand kilometers.

On the factory engine, metal microparticles also appear from mutual friction against each other, when the parts have just begun to rub against each other.

Adding fresh engine oil

If the engine oil is not replaced after the specified break-in periods, then metal microparticles will get into the working part of the liners, under the piston rings, into the oil pump elements, and other friction pairs, which will significantly reduce their service life.

Engine after "capital"

Especially carefully it is necessary to run in the engine after repair in non-factory conditions, since even a large car service does not have all the capacities and necessary conditions for a full restoration of engines, as in a factory.

So after boring and honing of the cylinder block liners, part of the emulsion remains in its channels, which is fed by the machine to the cutter to cool it and microchips from the block processing, and all this will "come out" after the engine starts.

Photo: cylinder block honing

It is considered necessary to rinse the cylinder block after boring in a hot bath with a special solution in order to remove traces of microchips from the cylinder bore and in open channels. In car services, this procedure is almost never performed.

On such engines, you can drain the oil and replace the oil filter after the first hundreds of kilometers in order to get rid of traces of wear after boring and lapping from all pairs of friction.

Cold running

If it is possible to use running water, the motor after a major overhaul can be run in cold. To do this, the coolant drain plug is unscrewed from the cylinder block, the water hose is inserted into the radiator or expansion tank. The engine starts. Water will constantly circulate in the block cooling system with a constant temperature, preventing the block and piston parts from heating up.

Taking into account the water consumption, it is possible to run the engine on a cold one within 1.5-2 hours.

A few more words

Do not test the engine of a new car for its maximum until it passes the minimum grinding period, as this can lead to an increase, knocking of the crankshaft liners and in the cylinder-piston group.

Since the running-in process is not visually visible or audible, some simply ignore this period, considering it insignificant. However, even if the brake pads are replaced, their effectiveness will not be 100% until they are rubbed onto the plane of the brake disc, that is, they have passed the same running-in period.

Therefore, do not force the engine for at least the first 1000 kilometers, and it will answer you for this with a period of long and reliable operation.

Most often, the happy owners of a newly purchased car literally blow off dust particles from it, but special attention should be paid to the "heart" of the car. A new engine, or a motor that has recently undergone a major overhaul, needs gentle operation. and only after running-in can they be used in standard mode with all the required loads.

What is engine break-in

It is customary to call a motor running-in the process of grinding in parts that constantly interact with each other, working at high temperatures. In fact, all mechanisms that have mating moving parts must undergo running-in, because this is the only way, having worked under a light load, they will be able to “prepare” for the conditions in which they will have to work throughout their entire service life. Simply put, the moderate friction generated helps the parts to take their final shape, and in the future it should not change significantly.

The first and most important stage of running-in the power unit takes place within a few hours after its installation on the vehicle. So, in the process of the first start-up, the compression and oil scraper rings are lapped, which are in contact with the cylinder wall. We do not have a special name to define this process, while English-speaking countries use two different terms at once. The first stage is called "Engine break-in" (can be translated as "commissioning"), and the subsequent final processing is called "engine run-in", which, in fact, provides for the direct running-in of moving parts.

It should be noted that there is no universal instruction that would explain exactly how the engine should be run-in. Moreover, most car owners do not need to deal with this process on their own, since all the necessary manipulations are performed by specialists at the factory, and the car arrives at the buyer with an already run-in engine and filled with oil. However, a certain amount of information is still available. In particular, on the issue of the degree of load during the engine running-in period, the opinions of experts from various manufacturers differ somewhat. Oddly enough, the lack of agreement here is due to a general increase in productivity over the past few years.

The fact is that the quality of engine parts has improved significantly, although the consequences of incorrect commissioning are still observed today. If an ordinary mechanic could find the cause of a breakdown on old power plants, then for good orientation in modern cases of engine damage due to incorrect running in, the specialist must have considerable knowledge in the field of physics.

The cars produced today differ from their ancestors by their high sensitivity to the quality of fuel and oil recommended by the manufacturer. Therefore, engine break-in should only be performed using the fluids specified in the vehicle's technical manual.

Interesting fact! The largest engines are marine. The diameter of their 14 cylinders corresponds to 960 mm, and the power of the installation reaches 108,920 hp.

What is engine break-in

To perform lapping of parts of a new or just repaired engine, it is best to use a special stand, which will help to obtain the most reliable data on the condition and activity of all units of the unit. However, this is not the only option for carrying out such a procedure, and the engine running-in can be performed in other ways (meaning after the overhaul of the power unit). But first things first.

Cold running, for which the stand is used, provides for connecting the engine to the electric motor using a coupling. The latter can change the speed, which allows the motor to be run in in a soft mode. The operation of this device is controlled by a special program installed on the stand computer. It also receives data from sensors, processes them and selects the rotation mode. These sensors take temperature readings, thereby preventing the engine from overheating.

Cold running-in of the engine using a stand is the most acceptable technology that allows you to get a high-quality result and good grinding in the parts of the power plant. However, you need to understand that for such a procedure you will have to pay a certain amount of money. If you do not have a desire to contact specialists who have the aforementioned equipment, then you can use another method of cold running (without a stand).

In this case, the rotation of the engine will occur due to the transmission from the side of the wheels of the car (the car is hooked to another vehicle and towed in third gear without turning on the engine). In addition, there must be sufficient oil in the system for effective break-in and coolant.

I must say that the described version of cold grinding is very far from ideal, since it is difficult to control the heating of the rubbing surfaces of the motor here. Hot-type engine running-in is often used (the car always stands in one place, but the engine continues to work). The same option is also used when working with the stand, only in this case hot lapping is performed on the removed motor. To begin with, the engine is allowed to idle (no more than 3 minutes), and then it is muffled and allowed to cool completely.

The procedure should be repeated several times, and after the completion of short-term cycles, the unit is started for a longer time (40-50 minutes) in idle mode. In this process, a prerequisite is the control of temperature indicators (should not exceed 80 ° C), and as soon as the temperature begins to rise, the engine is turned off. The increase in speed occurs gradually.

Note!The motor must always cool down, otherwise the constant exposure to high temperatures can lead to thermal deformation of the rubbing parts and a loss of oil viscosity.

The easiest way to break-in an engine is to naturally lap the parts. It should start with driving at a speed of no more than 40 km / h during the first 50 km of the journey, which is quite difficult in urban conditions (traffic lights and "traffic jams" are often encountered on the driver's path), which means it's best to run in outside the city, and no more than in third gear. After covering the specified distance, you can increase the speed to 60 km / h, having driven 200 km in this mode, and then increase the speed by 10 km / h after every 100 km of the vehicle's run. However, do not forget that until the car has covered 2000 km, it is not advised to raise the speed above 90 km / h.

Despite the seeming complexity of the process, you should not have a question “why is engine running-in needed and whether it is needed at all”, since by performing this procedure, you will provide your engine with a long “life”.

When to run in

A car engine is run-in in two cases: after installing a new engine on a vehicle and after overhauling an old power unit.

On a new car

The "primary" running-in is performed by the specialists of the car manufacturer, and the further "well-being" of the car largely depends on the thoroughness of this procedure. However, there are cases when the manufacturer declares that there is no need to run-in the released vehicle.

Most likely, in this case, the experts calculated that the harm from the non-optimal operating mode of the new car is so insignificant that it is not worth informing the buyer about it. Of course, you can heed these recommendations, but it will be better if you still take care of your vehicle, at least in the initial stages of operation.

Note! Despite the widespread opinion, a new engine should not be run in by prolonged operation at the same speed. This procedure will lead to highly specialized lapping of parts, therefore, when you start operating the car in normal mode, it will be re-run in, which is fraught with additional wear of the elements.

When running in the engine, you should also avoid sudden accelerations and its operation at maximum speed or close to them. You will find the permissible speed value for a particular model in its operating instructions.

After engine overhaul

Any part of the power plant that has recently undergone a major overhaul (it does not matter whether the cylinders were bored, holes or the shaft surfaces were ground) needs a certain time to run in the mates.

Often, the initial run-in for most automobile friction pairs is performed during the first 2-3 thousand km of run, which, however, is not the end of this procedure, but is only considered the starting point for a smooth increase in the load. Depending on the quality of the replaced parts and the repair itself, the final running-in usually takes place up to 10-15 thousand kilometers. Only after this figure it is possible to demand the maximum performance from the motor.

It should be noted that the running-in of rubbing pairs is always accompanied by increased heating, which explains the need for running in a new or repaired engine at reduced crankshaft speeds (up to 60% of the nominal values). Also a prerequisite is the use of fuels and lubricants recommended by the manufacturer. An improperly run-in power unit often has a resource that does not exceed 30% of the design value laid down in its design by the manufacturer.

A common problem when running in an engine after a major overhaul is the placement of new rings in worn piston grooves. If they are badly broken, the likelihood of ring breakage the first time the engine is started increases significantly.

The groove wear is assessed visually by simply examining the old ring.If the lower part of it turns out to be glossy, plays a little in the sun with waviness, and when you slide your finger over it, you will feel the steps of wear, then the pistons will have to be changed without fail. In most cases, the grooves in the pistons wear out so that their bottom surface slopes slightly downward. For this reason, the bearing surface of the old ring will wear at the same angle. When a new ring is installed, it will begin to twist and, most often, it will quickly fail.

Do you know? The piston shape is not as strictly cylindrical as it might seem at first glance. If you look at the detail from the side, you will notice that it is more barrel-shaped, and if you look at it from above, it will most likely resemble an oval. During operation, the piston heats up and takes on the correct shape.

How to run in a motor correctly

There are few rules for running a motor. The first and foremost of them is not to load the car. You do not need to drive at high speeds or carry an excessive amount of cargo (passengers) in the vehicle, slow down suddenly and move in low gears. These rules should be observed up to 1500-2000 kilometers.

In case of poor-quality operation of the power plant, you will face a lot of trouble. These include: oil entering the air cleaner, increased fuel fluid consumption, problems with starting the engine, etc. Therefore, if you recently purchased a car or made a major overhaul of the motor, be sure to follow the specified rules.

A new or overhauled engine cannot be used to its fullest right away. A cold run-in of the engine is required for the parts to rub against each other. How does it happen, how long does it take, and how far must the car travel before it can be accelerated at maximum speed?

What is running-in for?

Running-in is recommended for any mechanisms in which there are moving parts experiencing mutual friction. This helps them gradually, without unnecessary stress, to take the ideal position, to take the correct shape.

All cars undergo the very first engine run-in at the factory. Dealers of many modern models declare that car owners do not need to do chipping and additional checks. The procedure is performed by specialists, and the buyer receives a car completely ready for any driving conditions.

However, if you look at the instructions for some prestigious German cars, you can find in them recommendations for observing the driving regime for the first 1.5-2 thousand km. But this is nothing more than a run-in.

The very first stage of lapping in the factory is called engine break-in. And the last stage is called the engine run-in.

It is not only the engine of a new car that recently rolled off the assembly line that requires running-in. After any intervention in the engine device, it must first be run in.

This requirement is easy to explain. All parts have microscopic irregularities. In the process of friction at high temperatures, these irregularities are erased, the smallest particles of metal get into the oil, negatively affecting the operation of the motor. Compression and oil rings are in contact with the cylinder wall. There is a high load on them, and after running in, they rub against the surface, take a more streamlined shape.

Gentle break-in allows parts to bounce back, reducing the load on the car engine. After the procedure, the run-in motor will last as long as it was laid down by the engineers, and the car owner will be able to use its full potential.

Run-in at the stand

Cold run-in at the stand is carried out in a professional auto repair shop after an engine overhaul. It means that parts of the engine are moving while the engine does not start itself. The procedure is suitable for gasoline and diesel units.

• The engine is placed on a special run-in stand.
• The crankshaft is connected to an external electric motor.
• Fill in oil and coolant.
• An electric motor is started to rotate the crankshaft.

The speed of rotation of the electric motor can be changed, which allows you to start running in at low speed. The process is controlled by a computer program. Sensors are connected to the main nodes, which transmit data to a computer. In accordance with the indicators, the speed of the electric motor is reduced or increased.

The control helps to maintain the optimum engine temperature, does not allow it to overheat. Therefore, the run-in was called "cold".

Towing

Break-in of a new car, as well as a car after repair, can be done by towing. Hitching to the towing vehicle must be rigid and carried out in third gear. Unscrew the candles from the machine being rolled in and turn off the gears. Towing takes about an hour. During this time, forces are transferred through the wheels to other parts of the car, which leads to their gradual lapping.

Experienced drivers say that after a major overhaul, the engine must burn the fuel tank at idle speed. Towing is not an ideal break-in option because it is difficult to control how hot the engine is.

Hot running

Instead of cold, hot running is sometimes used. The car is parked with the engine running and running continuously. Hot running-in is also used at the stand, when the motor is removed, connected to the stand and allowed to run for 3 minutes. After that, it should cool down. This is repeated 3-4 times, after which it is turned on for 40 minutes.

The surface of the engine to be run in should not heat more than 80 ° C. Cooling of the engine is the main requirement of the procedure. As a result of overheating, parts can deform, which, instead of running in parts, will lead to the failure of the entire system.

Cautious driving

In order not to bother with towing and not to spend money on running a new engine at the stand, you can choose the most common option. It consists in careful driving, during which the parts are rubbed in naturally. There are several rules for doing this.

1. The car drives the first 50 km at a speed of 40-50 km / h evenly without jerks in 3rd gear.
2. The next 200 km can be driven at 60 km / h in 4th gear.
3. After that, every 100 km, the speed increases by 10 km / h until it reaches 90 km / h.
4. The next 500 km you can shift to 5th gear (just not uphill) and move at a speed of 100-120 km / h,
5. The procedure lasts until the car has traveled 1000-2000 km.
6. Wheel slip, heavy baggage are not allowed, gear changes must be timely.

Since it is problematic to comply with all conditions in the city, the run-in is carried out on a suburban highway. They leave, for example, early in the morning, when there are still no traffic jams in the city. Avoid sudden acceleration and deceleration, driving at high speeds. The permissible number of revolutions is indicated in the instructions for any car brand. The first 500 km are considered the most important. When going uphill, downshift and decelerate so as not to strain the engine.

Be sure to run in the car in which any engine repairs were carried out. 2000 km is considered the minimum mileage for grinding parts. Often the running-in is continued up to 5-10 thousand kilometers with a gradual increase in speed.

There is an opinion that the new motor can be run in at the same speed. However, this practice should be abandoned. In this case, a narrowly directed grinding of parts occurs. When you change the mode, the details will start to rub in differently. Their additional wear will occur, which is not the best way to affect the service life of the engine.

During the running-in process, metal microparticles enter the oil and clog the filter. Therefore, after 1–2 thousand km of run, it must be changed.

If the dealer has filled in his oil before selling, then the car is first run in on it, and then they are replaced. Pour in a quality brand recommended by the manufacturer.

There is a slight difference in break-in between automatic and manual vehicles. The automatic transmission must be warmed up before starting, the kickdown must not be touched and the neutral gear must not be allowed to operate while driving. Otherwise, there are no differences.

Why engine

Why does the engine require running in? Parts of the running gear and steering do not require lapping, because they begin to wear out during the first kilometers of driving. The components of the transmission are adjusted to each other even during test runs of the car, and it is recommended to change gears smoothly regardless of the mileage.

The brake pads rub in quickly. The only thing is that it is recommended to gently brake at the first kilometers of the run.

The heart of the car remains - its engine, in which the pistons, crankshaft and connecting rod parts move. The movement takes place under pressure and at high speeds. The inner walls of cylinders, compression rings, bearings and other parts constantly experience friction and heat up.

Significant heating can be not only at high speeds. This happens when the car is driving uphill in 5th or 4th gear at a relatively low speed with a strong gas supply. .

The quality of car parts is getting better every year. This applies to prestigious brands and inexpensive models. The situation is explained by the fact that technologies, precision engineering are improving. The use of computer-aided design, laser processing, modern materials makes the final product more perfect, more demanding on the quality of fuel and oil. However, this does not cancel the run-in.

Precaution never hurts, as experienced drivers believe. Buying a new car, which you have dreamed of for a long time, giving a significant amount of money for it, you try to treat it with care. For this, running-in is needed in order to extend the service life, to prevent premature breakdown of the most important part of the car - the engine.

Many car enthusiasts are well aware that after purchasing a new car or overhauling, the engine must be run in correctly. Immediately, we note that a well-executed running-in allows 15-20% to increase its throttle response and efficiency.

There are several types of break-in, among which the most common are "cold" and "hot". In the first case, an electric motor is connected to the engine, which rotates the unit without starting it. This is a cold run-in. As for the second type, the engine is run in directly on the car, that is, in motion.

As a rule, overhaul of the engine in many services does not imply cold running-in, since not all service stations have special stands for carrying out this procedure. This means that the car owner himself will have to run in the power unit. To do this, you need to know how to run in the engine after a major overhaul.

Read in this article

Features of the correct running-in of the motor

To begin with, do not confuse the concepts of overhaul and engine bulkheads. Bulkhead only involves certain narrow operations (eg valves, gaskets, etc.).

Overhaul means that a complete disassembly, washing, troubleshooting and replacement of all worn out elements is performed, as well as adjustment to factory parameters. The list of operations usually includes replacing pistons and piston rings, installing new ones, and much more.

Such repairs are expensive and carried out exclusively by specialized specialists. As a result, the owner receives a completely remanufactured engine, which approaches in most of its characteristics to a new unit.

It becomes clear that both in the case of new and "powered" internal combustion engines, the rules for running in will be very similar. The fact is that the installation of new, as well as restored parts after grinding and surface treatment also requires the obligatory grinding of all elements for the normal and well-coordinated operation of the unit under loads.

How much to run in the engine after overhaul and how to do it

So, the first 3 thousand km can be considered the most important. During this period, especially in the first thousand, it is necessary to observe the optimal driving mode for the motor, that is, careful operation with gentle loads is assumed. The general rules are as follows:

• driving with high or too low rpm is prohibited;
• you must not allow driving at a constant speed and the same speed;
• you should refuse to transport goods or tow a trailer;
• you cannot use the engine braking technique, practice sharp accelerations and stops;

In other words, during the running-in, it is necessary to exclude heavy operating conditions for the internal combustion engine, the load on the unit should be moderate, and increase gradually. Also, during this period, it is very undesirable to let the engine idle for a long time (except for warming up), since XX is considered a heavy operation of the internal combustion engine.

Now let's take a closer look at the process of running in an engine after a major overhaul. First of all, you need to understand that a motor after a major overhaul needs all the parts and assemblies to fit well to each other.

If we talk about fully restored internal combustion engines, then the work usually affects the complex,. This means that it is necessary to run in such a unit at least 3 thousand km. If the repair only affected the timing (replacement, etc.), then 1,000 km is enough. Let's dwell on the more common first option.

1. Before the trip, the engine needs to be slightly warmed up at XX, after which the unit heats up to operating temperature in motion.
2. It is optimal to plan the route in advance so that the road is level (without frequent ups and downs). It is also desirable that only the driver is in the car.
3. During driving, sharp acceleration and deceleration, jerking, and also prohibited.
4. It is recommended not to accelerate more than 60 km / h, switch to higher gears and raise the crankshaft speed above 2.5 thousand rpm.
5. You should also avoid driving in tightness, constant movement at low speeds (1000-1500 rpm).
6. Avoid movements with the same load on the motor. Otherwise, you do not need to drive at a constant speed in one gear all the time. It is optimal to smoothly dose the loads, periodically decelerating and accelerating, however, it is important to select the right gear so that the unit works within the medium speed range.

In simple words, this approach allows the piston rings to "settle" in the piston grooves, the mirror in the cylinders gradually begins to "fill up", etc. The fact is that even the most thorough grinding does not allow you to perfectly smooth out all the irregularities that are leveled by running in.

We also add that the generally accepted figure is 3 thousand km. is minimal. It should be remembered that a complete grinding of all parts and assemblies on many internal combustion engines occurs at 8-10 thousand km. mileage. It turns out that it is also advisable to adhere to the running-in regime throughout this period, although not so strictly. Only at the end of the specified segment can the engine be loaded, gradually and smoothly raising the load from medium to high and then maximum.

Oil change after engine overhaul

It should be understood that the obligatory result of grinding parts (especially in the first hundreds of kilometers) in the engine is metal shavings. These chips enter the engine oil and accumulate in the oil filter. It is quite obvious that these shavings need to be removed from the internal combustion engine.

This means that you need to use the material recommended by the engine manufacturer. The lubricant must meet all API and ACE codes, requirements and approvals, and must be suitable for SAE viscosity, taking into account seasonality and other regional considerations.

It is also necessary to take into account separately that after boring the cylinder block into overhaul sizes for repair pistons, in some cases, experts recommend using a more viscous oil compared to that which is poured into a similar new engine.

The information that is given below will be useful to those who do engine overhaul with their own hands or are directly involved in this process.

• Before the first start and during running-in, special attention should be paid to the condition. Keep in mind that during the first start, cranking the crankshaft is the most difficult, so the battery should be.
• Some precautions should be taken when filling with oil and installing the oil filter before the first start. The main task is to eliminate the formation of air congestion so that the unit does not experience at the time of start-up.
• Grease and other fluids must be filled. The fact is that exceeding the recommended volume can lead to leaks and other malfunctions.
• After the first start, the oil pressure should return to normal within a few seconds during operation on the XX. It is forbidden to gas if. If the oil pressure at idle is low, the power unit must be shut off immediately.
• Then it is restarted. If the situation does not change, then a malfunction is evident. Any problems with the oil supply, air congestion, improper operation of the oil pump, and other reasons may lead to the need to re-repair the internal combustion engine.
• In the event that the lubricant pressure at idle is normal, you can warm up the engine. As the temperature rises, the lubricant liquefies,. However, it should not fall below 0.4-0.8 kg / cm2.
• While the engine is warming up, you need to carefully inspect the power unit for oil leaks and other technical fluids. If a leak is noticeable, the engine is immediately shut off, after which the problem should be immediately localized and eliminated.
• If the pressure in the lubrication system is normal, the unit is dry and runs smoothly, then it is also recommended to be careful. There should be no extraneous noise or knocking.

The normal and stable operation of the internal combustion engine suggests that you can start running the engine under load. Take a short test drive while observing the oil pressure light in the lubrication system and the temperature of the internal combustion engine on the instrument panel. After 2-3 km. stop the car and again inspect the engine for leaks of technical fluids.

Then turn off the power unit, wait about 15 minutes and check the engine oil level. The fact is that it may fall a little. This will require adding grease. It is necessary to add oil so that the level is exactly in the middle between the “min” and “max” marks.

Stable operation of the engine and all its systems will indicate that the engine, after overhaul, is ready for further running-in. To obtain the best results and prolong the life of the motor, you must adhere to the break-in modes and follow the recommendations indicated above.

Read also

Engine speed and service life. Disadvantages of driving at low and high revs. What is the best number of engine revolutions to drive? Advice and recommendations.