The process of boring a motorcycle cylinder in the form of instructions, tips on boring in the video

Hi all. Every owner of gasoline equipment has encountered (or will encounter in the future) a problem - cylinder wear. Here they do everything they can - either buy a new cylinder and piston, or buy a new piston and go to a turner. Grandmas pay him, but he is bored... Many turners love blue (alcohol) and the straightforwardness of some leaves much to be desired... I suggest boring the cylinder yourself! It's pretty simple.

General provisions and safety precautions:

The author is not responsible for injuries, accidents during repetition, for “jambs” and defects obtained when trying to repeat the contents of this article.

If you are under 16 years old, work should be carried out with adults (preferably a male assistant).
Remember, you are working with rotating parts, do not wear gloves! Work with bare hands. There should be no sleeves on work clothes. Even if there is, roll up your sleeves to at least the elbow.
What is in the photographs is the author’s work process.
ANY cylinder can be sharpened using THIS method. The first one that came to hand was taken.
For the sake of writing this article, a cylinder from the D-6 engine was taken.
For boring you will need a drill with a power of at least 350 watts. In this article I used a 1050 watt drill.
The lower the speed, the better. I have 550 rpm.

Please remember that you are working with electrical appliances. Do not allow exposed wires or other defects in the cable network. It is advisable to carry out work outdoors. If the workshop allows it, then you can do it there.

I hope everyone has checked the wires, the condition of the sockets, their workplace, and are ready to continue.

The principle of boring: a guide must pass along the entire length of the cylinder - also known as a “mill” (shaft, cylindrical body). It should be a perfect cylindrical shape. BUT it must be smaller than the current piston that was on the engine. “Rolling” sandpaper onto this shaft will give us a certain “grip” of grinding the metal. That is, the longer the blade, the more the cylinder “eats” from us. Exactly what is needed! To attach the paper to the shaft, we need to make a groove. And fix our sanding cloth in it.

Cylinder boring at home

Hi all. Every owner of gasoline equipment has encountered (or will encounter in the future) a problem - cylinder wear. Here they do everything they can - either buy a new cylinder and piston, or buy a new piston and go to a turner. Grandmas pay him, but he is miserable. Many turners love blue (alcohol) and the straightforwardness of some leaves much to be desired. I suggest boring the cylinder yourself! It's pretty simple.

General provisions and safety precautions:

The author is not responsible for injuries, accidents during repetition, for “jambs” and defects obtained when trying to repeat the contents of this article.

If you are under 16 years old, work should be carried out with adults (preferably a male assistant).
Remember, you are working with rotating parts, do not wear gloves! Work with bare hands. There should be no sleeves on work clothes. Even if there is, roll up your sleeves to at least the elbow.
What is in the photographs is the author’s work process.
ANY cylinder can be sharpened using THIS method. The first one that came to hand was taken.
For the sake of writing this article, a cylinder from the D-6 engine was taken.
For boring you will need a drill with a power of at least 350 watts. In this article I used a 1050 watt drill.
The lower the speed, the better. I have 550 rpm.

I hope everyone has checked the wires, the condition of the sockets, their workplace, and are ready to continue.

Making a “cutter”

In this operation we will need: a birch log, calipers, a marker, a chisel, a saw, a cylinder (the one we are going to sharpen), a piston (new and old), a rasp (you can use a file), a drill, a long bolt with a nut or a hairpin with two nuts , sandpaper sheets “10”, “6”, “5” and “0” (on a fabric basis - not suitable on paper). There are a few caveats - the stud or bolt must be at least 8mm in diameter. The best solution would be 12mm. Sandpaper is selected independently, depending on the type of boring. It is advisable to go through the “rough process” and bring it “to clean water”, and not to drive the rough one until you are blue in the face. Then fix the finishing one, and buy and select a new piston.

Let's start - measure the sleeve with a caliper:

Let's take an allowance of 10mm and measure it on the already trimmed log:

Let's outline approximately where we have “more meat”, and set some simple markings there and drill:

Immediately take a larger chisel and chop off the excess “meat”. Shape it into a cylinder.

But the shape of a cylinder will not work, it will turn out something like an oval:

The next step is to tighten the resulting cylinder onto the stud/bolt. Tighten until your teeth creak. When inserted into the drill, tighten until your teeth creak - it will unwind with a bang. If you tighten it harder, it won’t run away. Now secure the drill, make a stop for the chisel, and unwind the cylinder by pressing the gas on the drill. Take technology breaks more often. During breaks, tighten all nuts. If it comes loose, the results could be disastrous.

By substituting a chisel (smoothly substituting a chisel!) we ensure that we first get an oval:

Then the shape will remind us of a cylindrical object:

Later you will get a natural, perfect cylinder. I think there is no need to explain that the fine-tuning was no longer carried out with a chisel, but with a rasp, and later even with a file.

You should now have a long wooden piston for the cylinder.

. Only well weakened. Somewhere by 0.3-0.6 mm.

Something like that:

This is an example of relaxation.

Next, we will make a technological cut in a wooden blank:

And you need to make a “latch” for it, that is, a latch. So that the sandpaper does not run away from us somewhere far away. Here I honestly admit that I stepped in the wrong place.

I made it wooden:

And it looked like this:

But when I started refilling, I realized that it didn’t hold well. The answer did not take long to arrive - a 3mm welding electrode worked perfectly as a clamp.

Make a fastener for the drill - it tends to run away from you!

Now let's see how we will have a working area:

Well, we have made our workplace. We can start taking measurements.

We buy a new piston, one repair size larger (usually 1 unit) and see how and where it fits (if it doesn’t fit, then there’s still more to come

We push in different directions to understand where and what is in the way. If the cylinder worked in risky modes, it means it has a huge output. Mine worked with too early ignition, a slightly lean mixture, which gave quite high revolutions.

The cylinder mirror is excellent, but here's the breakdown:

What you see on the cylinder liner is dirt. That is, a lubricant that once was. After removing it, I preserved it for some reason. I don’t know why.

Having measured the piston (even if it goes inside, it jams right in the middle), I realized that it needs to sharpen just a little. If the piston doesn’t fit at all, then yes, let’s see how much grinding needs to be done. Usually in such situations they sharpen 0.1-0.15 mm. I sharpened 0.01-0.07. It is advisable to choose a piston in the store so that it barely enters. Then boring will turn out better because you can pick up the piston even larger and bore it again. In the pictures there is simply a worn-out cylinder that seems to have served its useful life during this repair.

You've been waiting for this for so long, let's start the process.

What is it for?

The very concept of “block boring” implies the process of restoring the geometry of the power unit cylinders using special machines. The main prerequisite for block boring is a major overhaul of the engine, but now the procedure is mainly carried out to increase its power.

It is necessary to bore cylinders during a major overhaul because the pistons in them, under the influence of high temperatures, pressure and other constant loads, cause a violation of the geometric shape of the cylinders. To put it simply, due to constant friction and high loads, the cylinder, instead of a perfectly round shape, takes on the shape of an ellipse. Because of this, the piston can no longer fully adhere to its walls, resulting in a significant gap through which exhaust gases or fuel penetrate into the crankcase, and engine oil into the combustion chamber.

Naturally, because of all this, the power unit significantly loses its power, fuel and oil consumption increases. One of the sure signs indicating the need for engine boring is increased engine oil consumption

In addition, you should pay attention to the color of the exhaust gases. If bluish-blue smoke begins to appear from the exhaust pipe, a major overhaul of the power unit is not far off.

Just a few decades ago it was impossible to find good quality motor oil or coolant, which caused frequent overheating of engines. It even got to the point where it was necessary to overhaul the engine of a new car after 30-50 thousand kilometers. And units on trucks and special vehicles had to be restored much more often.

Today the situation has changed dramatically. Modern lubricants and coolants can significantly increase the service life of a car engine. Now the average mileage before major repairs is approximately 200-250 thousand km, and not every motorist drives even 12-15 thousand km in a year. It turns out that this resource of the power unit should be enough for more than 15 years of operation. Not every vehicle can withstand that much.

Block boring has recently been extremely rarely used as a necessary repair measure. This procedure is mainly used for tuning to increase engine volume and power. But, in the second case, boring is carried out only when the condition of the cylinder walls allows it to be performed. In this case, it is necessary to install pistons with a larger diameter. Also, to ensure correct operation of the power unit, a larger amount of fuel mixture will be required, since its volume will increase, and accordingly, the power will increase.

MY MOTORCYCLE

How long did you have before me? In millimeters, or better to the nearest hundredth. The size of the cylinder, bored out for the “second repair,” was not surprising: the motorcycle has a lot of mileage, but there is still “meat” on the walls. We'll cut it off!

The engine in the Tru Motor workshop decided to assemble a modern one, which means that modern spare parts are needed. The main stumbling block was the crankshaft from Ural for the 2015 model year, the installation of which entailed a number of changes. Tolerances, workmanship and safety margins are unprecedented for a Soviet motorcycle. One problem: you can’t just push it into the old, lower-valve crankcase: the modern crankshaft is not mounted on 207 bearings, as before, but on larger, more reliable 208 bearings.

With the rear main bearing everything is more or less simple; it, along with the rear crankcase cover and oil seal, is supplied from the same new Ural, and the modern flywheel is also from it. But for the front bearing the shaft will have to be re-sharpened - the journal diameter will have to be reduced from 40 mm to 35 mm (Fig. 1). The work is complex and requires special equipment. You can’t clamp a shaft into a regular lathe or grinding machine; the non-removable connecting rods need to be fixed somehow, otherwise they will destroy the entire workshop, so we resorted to the help of a friendly workshop that remakes such crankshafts in small batches, and bought a ready-made shaft.

We were able to find spare parts for the new Urals from the official Plamen dealer, who provided us not only with a rear crankcase cover with a bearing and oil seal, but also a new oil pump, Avtotekhnologiya forged pistons with a diameter of 79 mm, a new flywheel and timing gears. And we managed to find spare parts for the “lower valve” in the oldest Moscow store MOTO99, where they dug up for us a new Soviet-made K-750 camshaft, a set of oil seals, Japanese bearings, as well as a complete set of gaskets, including even such scarce things as aluminum gaskets heads (although they can be made at home - there would be a sheet of aluminum, or even better, copper 0.5 mm thick).

In addition, we found a tray with advanced fins that provide better cooling. They didn’t skimp on lubricants either, deciding to pamper the engine with Motul 300V Competition 15W50 synthetic. Don't be surprised: car oil is much more appropriate in an engine with a dry clutch than motorcycle oil.

All that's left to do is to bore the worn out cylinders (photo 1) for new pistons and repair the valves. We went to solve this problem, which happily agreed to help us, and most importantly, show us the whole process from the inside.

To begin, the cylinder is clamped on the boring machine bed and centered relative to the cutter (photo 2). Having measured the internal diameter, adjust the spread of the cutters (photo 3) and begin boring (photo 4). The cutter removes a rather thin layer of metal, so after each pass it is removed and the expansion in the cutters is increased (photo 5), repeating the procedure until the diameter of the hole is equal to the diameter of the piston (in our case 79 mm). In fact, the piston diameter may differ from the stated 79 mm and range from 78.93 to 78.94 mm, so it is always better to bore according to the actual size of the pistons.

After this, the cylinder is sent for honing, where inclined marks are applied to its inner surface to retain oil. At the same time, its diameter also increases slightly. The gap we need between the cylinder and the piston is 0.12 mm. Would you say it's too much? Not at all! The coefficient of thermal expansion of forged pistons is slightly higher than usual, the “air” engine is much hotter than its “liquid” counterparts, therefore it is impossible to bore less, and we decided to provide a small margin. But you don’t have to worry about break-in and you can safely load the engine, for example, at races.

Honing takes place in three stages using three special bars of different hardness (photo 6), but before that it is necessary to accurately measure the diameter of the piston in its widest part - one and a half centimeters from the edge of the lower skirt, perpendicular to the hole for the piston pin (photo 7). First, a rough hone is applied, which removes 0.08 mm from the cylinder walls in just a few passes, after which the rough bars are replaced with medium ones, which remove much less, and the gap increases to 0.12 mm. After each pass, the master checks the diameter of the cylinder using a bore gauge (photo and, most importantly, checks that the cylinder is bored evenly, without turning into a cone.

Honing is a type of abrasive processing of materials using honing heads (honing heads). It is mainly used for processing internal cylindrical surfaces by combining the rotational and reciprocating movement of the hone with sliding abrasive bars attached to it with abundant irrigation of the treated surface with a cutting fluid. One of the types of finishing and finishing processing by cutting. Allows you to obtain a hole with a deviation from cylindricity of up to 5 microns and surface roughness Ra=0.63÷0.04.

Honing of external surfaces is carried out on specialized machines (horizontal honing) or modernized (grinding, horizontal boring), the productivity is 2-4 times higher compared to superfinishing due to the larger number of bars and higher pressures.

If you look at a honed cylinder under a microscope, it turns out that seemingly shallow scratches actually look like huge ditches with burrs, metal sastrugi and shavings. They are smoothed at the third stage of honing (photo 9). Then the cylinders are sent to a special washing chamber, where they are washed from chips, oil and other contaminants with a special shampoo under high pressure and temperature (photo 10). Usually this is where the repair ends, but we need to sort out the valves.

Previously, motorcyclists had to pour kerosene or diesel fuel into the combustion chambers to check their tightness, but modern technology saves time and hydrocarbons by checking the tightness with a vacuum compressor (photo 11). Sucking air? Disorder! In our case, all the valves were leaking: on the right cylinder it was barely noticeable, on the left - with a whistle. The piston, which was trying to split into atoms and get free, seriously damaged the chamfers and stuck to the valve seats (photo 12). In addition, the ends of the valve stems were also tired, so everything had to be repaired. It’s good that you don’t change it: wear on the valve seats and stems is almost unnoticeable, and there is no indication for replacing them. But if the wear of the valve stem exceeds 0.15 mm and its diameter approaches 8.85 mm or becomes smaller, as well as if the wear of the seat exceeds 0.25 mm and reaches 9.25 mm, both the valves and the cylinder need to be changed. There are no guide bushings in the cylinders; the valve seat is made directly into the cast iron casting of the cylinder. Other indications for cylinder replacement are chipping and cracks on the seats.

First, the valve is clamped in a special end-cutting machine (photo 13), where the broken end of the stem is ground off and chamfered (photo 14). After this, chamfer the plate (photos 15 and 16). Using special cutters centered on the valve guide, the chamfer on the seat is restored (photo 17). It is important to get an even contact zone between the valve and the seat (its width - approximately 1-2 mm - is very important to ensure tightness, cooling and ultimately the longevity of the parts). After processing with a milling cutter, there is no need to grind the valves, the tightness is absolute! It’s good that the bushings weren’t broken either (the easiest way to assess the gap is to slightly extend the valve and rock it in different planes).

Of course, broken cooling fins worsen the heat transfer of an already hot cylinder, but the loss of up to 20% of the fins is acceptable and has virtually no effect on the operation of the motor. Cooling is worsened by flakes of rust and dirt that clog the entire space between the fins, so sandblasting the cylinders more than compensates for a couple of broken corners of the fins.

If the cylinder requires serious repairs, it is easier not to mess with it and look for another one. For a slightly worn cylinder from a lower valve they ask about five hundred rubles, cheaper than for any other motorcycle.

So, the geometry is restored. But it’s too early to install the cylinders on a motorcycle: dirt and rust on the cooling fins will interfere with normal cooling, so it is advisable to clean the fins with coarse sandpaper, or better yet, sandblast them. At Pesochka.ru, all the husks were blown off our “pots” in literally ten minutes, completely removing the layer of sewage that had stuck for decades. After this, all that remains is to paint the cylinders with heat-resistant paint - and you can begin assembling the engine, which we will talk about in the next issue.

Issue: MOTO Magazine - June 2015

Author: Dmitry FEDOTOV, photo by the author and Konstantin YAKUBOV

Manual cylinder boring process

The boring process itself is simple, but long and tedious, but if you have the desire and desire, then everything will work out.

The mandrel is done, all that remains is to purchase sandpaper, it is advisable to buy sandpaper with coarse grain and moisture-resistant, and one or two sheets of fine sandpaper for stuffing the mirror. Now that you have everything purchased, proceed to the actual boring of the cylinder, insert the sandpaper into the groove and wrap it around the mandrel, generously lubricate the sandpaper with oil, insert it into the cylinder, and begin to rotate the mandrel with the sandpaper in the cylinder.

Rice. Block boring mandrel

And now the most important thing is how to correctly bore the cylinder to the repair size, wrap the mandrel with sandpaper, try to insert it into the cylinder, if the mandrel with sandpaper easily fits into the cylinder, then place paper under the sandpaper, make sure that the mandrel with sandpaper fits tightly into the cylinder using rotation. But do not forget to generously lubricate the sandpaper with oil; with oil, the cylinder bores well and the sandpaper does not clog. As the mandrel with sandpaper begins to rotate easily, place more paper under the sandpaper. As you bore the cylinder, try inserting the repair piston, and as soon as the piston begins to fit tightly into the cylinder, take a fine-grain sandpaper and fill the mirror.

If you are boring a cylinder for a car, then it is desirable that the piston in the cylinder does not move very tightly, but stands in the cylinder and does not move under its own weight.

When boring a motorcycle cylinder, bore the cylinder so that the piston in the cylinder does not dangle, but also moves easily, since in a motorcycle there is air cooling and the cylinder heats up much more, and if the cylinder is bored tightly, the piston will jam when heated, running in the motorcycle will turn into torture.

I hope my experience in cylinder boring will help you bore the cylinder yourself.

Why do you need to bore the cylinder block?

The change in shape can only be determined using special measuring tools. You need to understand that it is only in theory that the piston moves in the cylinder along an ideal trajectory. In fact, this is far from the case. And the greater the deviation from the ideal trajectory, the faster wear occurs on both the cylinders and pistons.

The irregularity of the piston trajectory is associated with many factors, primarily of a structural nature. For example, this may be misalignment and non-perpendicularity of the position of the mating parts. In addition, premature wear is affected by too large dimensional tolerances, which allow the piston to move not only parallel to the cylinder axis, but also with a certain horizontal deviation.

And all this leads to the fact that the cylinder gradually loses its shape, and this may occur unevenly. And over time, the profile of the cylinder becomes not perfectly round, but elliptical.

In addition, the cylinder walls are exposed to high temperatures and combustion products are exposed, which gradually destroy the cylinder walls and at the same time the piston surface. And, it would seem, you can simply replace the piston, and everything will be fine. But this won't happen. If the geometry of the new piston is ideal, then the geometry of the cylinder is already broken, and no amount of replacing the piston without boring the cylinder block will help in this situation.

Cylinders must be bored if they are worn. But it should be understood that not all cylinders wear out, despite prolonged use. Some engines normally live out their life without any boring or repairs.

In order to determine the degree of cylinder wear, a system for assessing two cylinder dimensional parameters is used:

The first parameter is a change in the original dimensions by 0.05 mm at top dead center. But not the piston itself, but the upper ring of the piston.
The second parameter is a change in size by 0.03 mm at the point of contact of the piston skirt with the cylinder wall.

That is, if the parameters change by such values, repairs are already required. But the situation can be even worse when a defect appears in the upper part of the cylinder in the form of a step. It is this step that accelerates the breaking of not only the piston rings, but also the seats on the piston for the rings. Impacts occur, and very noticeable ones at that.

The engine begins to operate with strong vibrations. In addition, due to the resulting ellipse, the fit of the piston rings to the cylinder walls is disrupted. And this is fraught with a breakthrough of gases from the cylinder into the crankcase, compression in the engine is disrupted, and significant excess consumption of oil and fuel begins.

In the end, it may turn out that the rings simply fall apart from constant shock loads. In this case, the cylinder walls are damaged so that no boring can eliminate the resulting defect.

Boring of the cylinder block is needed in order to restore the geometric parameters of this part of the engine. But restoring the cylinder block concerns not only the geometric parameters of the cylinder themselves, but also the restoration of the normal position of the mating parts relative to each other.

Those. if you only achieve the normal geometry of the cylinder itself, this will not be enough to restore normal alignment and the normal location of all base surfaces. And if the base surfaces are not coaxial and parallel, then the cylinders will continue to break as the engine operates. And not just cylinders.

The stress and excess friction that occurs due to incorrect alignment will also affect other components of the piston group. Those. all moving parts involved in engine operation, included in the piston group, will experience additional bending, compression, etc. loads.

How to bore a cylinder at home on a scooter

In this article I wanted to explain to many, based on many years of experience, that boring a scooter cylinder and honing it (or, as people more simply call it, grinding) are two different processes, and doing only one of them is in 100% cases money down the drain.
Unfortunately, a lot of workshops that repair scooters do not even delve into the essence of these processes; as a rule, they either have a makeshift grinding machine or an old USSR machine with grinding bars. Or do people simply hand over the cylinder for grinding without even asking what they will do? how will they do it? on what equipment, etc.

Often in practice, when replacing a piston or when changing piston rings, they work with so-called honing brushes or spring-loaded honing stones. However, this action has little in common with proper sprouting and honing. In this case, the more or less worn-out working surface of the scooter cylinder is only cleaned and made a little rough. This cannot improve the geometric characteristics of the cylinder. Due to the fact that the grinding tools are loaded with spring force, they precisely follow every deviation from roundness and every misalignment, but still without improving the geometry of the cylinder . Due to the lower contact pressure, it is unlikely that sufficient surface roughness can be achieved to improve lubrication. As a result, there is greater frictional resistance for the new piston rings, which wear into the cylinder wall a little faster. Thus, this wear on the cylinder surface cannot be prevented or reduced. If the piston rings are worn, then, based on experience, the cylinder wall is equally worn. The remarkable appearance of the internal bore after simple honing of the cylinder should not be misleading, since the ellipse of the cylinder remains the same.

Water container

Now you need to take another paint can, but of a smaller size. A hole with a diameter of 1 cm is drilled in the center of its lid. Two more holes are made on the side of the jar - one almost at the bottom, the second above, near the lid itself.

Take two crusts, in the center of which a hole is made with the diameter of a copper tube. 25 cm of plastic pipe is inserted into one cork, 10 cm into the other, so that their edge barely peeks out from the plugs. A korok with a long tube is inserted into the lower hole of a small jar, and a shorter tube into the upper hole. We place the smaller can on the larger can of paint so that the hole in the bottom is on the opposite side from the ventilation passages of the large can.

Aluminum block and sleeves

Guys, this is a VERY broad topic, perhaps I will write about it a little later. In the meantime, I’ll let you understand a few basic postulates.

Aluminum options are indeed often not recommended to be bored (although not all of them) and this is the point. First, let’s look at the manufacturing technology of modern blocks:

When casting, thin-walled thin cast iron sleeves are installed at the factory, the wall thickness is 2 - 3 mm. Such options are called “dry with cast iron sleeves.” Boring of this option is acceptable, and repair pistons and rings are produced for them. Installed on cars such as VOLVO, Land Rover, HONDA, SUBARU, NISSAN, SUZUKI and some others.

All-aluminum monoblocks using SILUMAL technology (developed by MAHLE). There is a cast aluminum body here, but the walls from the inside are subjected to complex chemical-thermal treatment, after which a high concentration of silicon is formed on the walls; this material prevents the rings and pistons from quickly wearing out the walls and the resource increases to 150 - 200,000 km. The layer is quite thick and can also be bored out a LITTLE; for such engines, repair kits are available that increase the cylinder size by 0.5 - 1 mm. Such options are installed on many models of Mercedes, BMW, AUDI, PORSCHE and some other cars.

NICASIL monoblock technology. Here, too, a durable coating of only a mixture of nickel and silicon carbide is applied to the surface of the cylinder walls. It is much thinner than its predecessor, and therefore cannot be repaired! The manufacturer has not provided repair capabilities and does not provide repair kits. Installed on some BMW models and others.

“Dry liners” and SILUMAL are quite repairable, that is, if your compression has dropped due to wear from high mileage, then you can easily remove 0.5 - 1 mm, install a repair piston group and continue riding. ALSO, for some SILUMAL variants, manufacturers produce ORIGINAL aluminum sleeves; they are needed when the bore is more than 1mm. True, their cost simply goes off scale, up to 200 EUROS per one, but there is an exceptional ratio of metals and the possibility of complete restoration (also in some cases you can buy one piece for one cylinder). The only EXCEPTION can be that the block wall is very badly damaged, to a depth greater than repair boring is possible. However, such blocks may not be saved by anything; fatal damage may occur, for example, the piston has turned.

NICASIL – it is virtually impossible to restore! That is, as the manufacturer assures, this is actually a disposable motor. As I wrote above, he does not have spare parts approved by the manufacturer. But in the country we live in, there are a lot of companies that make sleeves specifically for Nicasil, and cast iron with a small wall (2 - 3 mm), there are also craftsmen who can combine this whole thing! However, you need to remember about thermal expansion and various metals. Most likely, Uncle Vasya will not be able to do it efficiently in the garage. However, prices for new units, if you take top-end BMWs, can reach up to 5000 - 7000 EURO, force you to look for such masters.

This is such a large material, if it’s difficult to read, then watch the video version, it’s more detailed and simple.

I’ll end here, I think it was useful. SINCERELY YOUR AUTOBLOGGER

Why is boring necessary?

Boring is necessary to increase engine power. This procedure allows the engine to have the same size in the block and a symmetrical relationship of all the holes in it. An additional resource appears that increases the safety of all engine parts. The friction of the piston rings against the cylinder walls is also reduced, which has a positive effect on performance. This does not result in increased oil consumption.

On the road, the car will behave better, which will give the driver confidence. The cost of boring depends on the workshop and equipment. On average, the price for one cylinder is about 2000 rubles.

Causes of cylinder failure

The pistons, falling and rising inside the cylinder, are in constant friction with the walls of the cylinder, thereby leading to its wear. It is worth noting that a motorcycle cylinder can wear out completely unevenly, and therefore the cylinder becomes deformed, losing its original shape. Unfortunately, this defect is not immediately noticeable to the naked eye. However, the fact that the shape of the cylinder has undergone changes can be determined using special measuring tools.

It should be remembered that the piston moves inside the cylinder along the correct trajectory only theoretically; in practice it happens a little differently. The angle of deviation from the trajectory affects the wear rate of parts. Thus, the larger the angle, the faster the motor cylinders wear out.

The movement of pistons in cylinders along an incorrect trajectory is caused by several factors, one of which is the nature of the design (lack of axiality or perpendicularity in the position of the parts that are mating).

In addition, very large dimensional tolerances also contribute to rapid wear of pistons and cylinders, due to which the piston moves not only parallel to the cylinder axis, but also with a certain deviation from the horizontal.

It is also worth considering the temperature regime at which all this occurs, as well as the products produced. All this has a destructive effect on the cylinder walls and piston surface. Thus, as a result we can have not a round cylinder, but an elliptical one.

How to bore a motorcycle cylinder

The engine of any vehicle is its heart, which makes the wheels spin, thereby driving the vehicle, including a motorcycle. Thus, the greatest loads during engine operation fall on its cylinders and pistons. This is due to the harsh conditions of high temperature and pressure in which the motor operates.

Cylinder block boring advice

The best boring of a cylinder is done on a special boring machine; the cylinder will be perfectly bored, although this also depends on the skill of the boring machine. Manual boring may not produce a perfect cylinder, which is a waste of time. Therefore, it is better not to suffer by boring the cylinder by hand, but to find out where there is a cylinder boring workshop nearby.

How to bore a cylinder at home. Video.

Drivers are often faced with the question of how to bore a cylinder block at home? Is there any point in such a procedure? This is because block grinding is a rather complex process, and it is not always possible to do it yourself. Time and effort will likely be wasted. First of all, the quality of the work performed will raise doubts.

How to bore a cylinder block at home? It must be said right away that there is a real chance to do without a machine, but to use the so-called generally accepted methods. Experienced turners advise using specialized equipment. With it, it is possible to fit the cylinder perfectly, provided that a professional works. When boring a block by hand, you don’t always get the desired result. Of course, in the absence of a machine there is no other choice. This option is considered optimal for power units installed on motorcycles and mopeds.

How to bore a cylinder yourself

Today, many people want to learn how to bore a cylinder (cylinder block) at home. Thousands of views of video reviews are clear evidence of this. But, unfortunately, this is the lot of only those craftsmen who are able not only to do something, but to do it well. We do not see the advisability of carrying out this operation in their garage for those car enthusiasts who consider self-repair only one of a few hobbies. On the contrary, if you can easily cope with the repair of many engine components, then boring the cylinder block will be too tough for you.

Why do you need a boring?

Boring is the process of restoring the required geometry, as well as creating the required distance between the cylinder walls and the pistons.
As you know, the cylinder very rarely fails, but sometimes this can happen. Yes, not every cylinder wears out ahead of time, but still, anything can happen with technology. All worn cylinders can be bored. Boring a cylinder block means restoring the quality of the car engine. How to determine that they are worn out and that they need rehabilitation? The first sign of wear is a change in the original dimensions of the piston ring. In the case when the size changes by at least five hundredths of a millimeter, this is a sure sign that the cylinder urgently needs to be bored. The second parameter is the change in size at the points of contact of the piston skirt with the cylinder walls. In this case, even a deviation from the norm of three tenths of a millimeter is fraught with consequences. As mentioned above, these changes cannot be caught by eye. It is advisable to check the diagnostics and checking of pistons during a routine inspection using a special tool.

Thus, even with a change of seemingly such minuscule dimensions, it is necessary to resuscitate the system. But, more important, and at the same time dangerous, is the formation of a defect in the form of a step on the walls of the cylinder. It is this defect that accelerates wear not only of the pistons, but also of the ring seat on the piston, and the sound from friction/impact is very noticeable. As a result, vibrations occur in the operation of the machine engine. In addition, the formation of the piston into an elliptical shape prevents the rings from tightly abutting the walls. What can lead to compression failure in the engine, as well as excessive fuel and oil consumption? In the worst case, the rings can fall apart due to constant shock loads, which will lead to the cylinder walls being damaged to such an extent that no amount of boring will correct the defects that have appeared. This means that the cylinder, unfortunately, will have to be thrown away.

Traditional methods

So, closer to the topic. You can bore a cylinder block at home without special equipment using several traditional methods. They will require not only time, which goes without saying, but also patience.

On the other hand, most experts agree that you still need to use the machine. A boring machine will allow you to fit the cylinder perfectly accurately, although much will depend on the person’s skills. But compared to the manual boring method, the percentage of defects is minimized.

Although the method is “old-fashioned”, it also cannot do without a tool. A good electric drill set at low speed will work here. A worn piston with a gap in the liner (on the side) is also required. And you will also need a cylinder pin, as well as sandpaper with a different number of abrasive.

The piston in this case plays the role of the most significant element. It is the working fluid onto which the sandpaper is fixed. It is better to select an old piston that has expired, since after boring it will no longer be suitable for use.

In a car service, it is not paper that is used, but abrasive chips. Instead of a drill, as mentioned above, a special machine with a crank having the required diameter is used.

Repair process

A hole is drilled in the middle of the piston for the cylinder pin.
A nut is screwed onto the stud, and then the stud is inserted into the piston with its end up.
The pin is tightened tightly.
A cut is made on the piston with a metal hacksaw.
The sandpaper is inserted into the resulting hole and then wrapped around the piston.
This unique attachment is installed in the drill and tightened tightly.
The cylinder is secured against turning.
The drill turns on at low speed. Boring starts from top to bottom, and then from bottom to top.

Note. During this boring process, care must be taken to ensure that the skin does not come out of the piston. First, a large skin is used, then a finer one. At the final stage, grinding should be carried out with a zero.

Some experts also advise boring the cylinder block while using oil. Others do not agree with this opinion, because they believe that it bores well even dry. We are more impressed with the latter option, especially since you can feel the uniformity and smoothness with your hands if you have a certain skill.

A useful recommendation is: in order not to knock your hands off during grinding with an electric drill, it is recommended to firmly fix the cylinder, but try not to damage it in the process.

You may also find this video about honing helpful.

In this case, a wooden mandrel will be used as the main tool. But you will have to contact a milling machine who will turn this very mandrel. The mandrel manufacturing technology is based on the following formula: if the cylinder being bored is 76, the bar mandrel should have a diameter of 74 mm. As for the length, it should be 200 mm larger than the size of the cylinder.

Preparing the fixture

A hole is drilled in the mandrel.
Using a hacksaw, a cut is cut along the mandrel, into which abrasive paper is inserted, as in the case described above.

Note. The approximate depth of the groove should be 10 mm. The skin, as in the first case, should be both large and small.

Motor types

A homemade engine can have several configurations. Among them:

Options with permanent magnet.
Combined synchronous model.
Variable motor.

The permanent magnet drive is equipped with a main element in the rotor part. The operation of such devices is based on the principle of attraction or repulsion between the stator and rotor of the device. This stepper motor is equipped with a rotor part made of iron. The principle of its operation is based on a fundamental basis, according to which the maximum permissible repulsion is produced with a minimum gap. This promotes the attraction of the rotor points to the stator poles. Combination devices combine both parameters.

Another option is two-phase stepper motors. The device has a simple design, can have two types of winding, and is easily installed in the required location.

Do-it-yourself VAZ 21011 engine tuning without high costs

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It’s time for a friend to overhaul his 11th engine, and at the same time he wants to modify it

what can we do with him?

1) 213 crankshaft 2) pistons 08 79.4 3) camshaft 213? or which one is better (preferably budget) 4) Benz, as I understand it, will 95 need to be poured? if he wants 92, then should he make a sandwich out of pads? 5) Hydraulics?

what else is possible, just without fanaticism, a city car is made more powerful than stock, and also, where does such a short-running car have a max. power and torque?

1) 213 crankshaft 2) pistons 08 79.4 3) camshaft 213? or which one is better (preferably budget) 4) Benz, as I understand it, 95 will need to be poured. 5) Hydraulics? . what else is possible, just without fanaticism

It’s time for a friend to overhaul his 11th engine, and at the same time he wants to modify it

what can we do with him?

what else is possible, just without fanaticism, a city car is made more powerful than stock, and also, where does such a short-running car have a max. power and torque?

Why piston 08? Add shortened connecting rods Take away the hydraulics (they are more trouble than good) The timing is better not 213 but “revolving”.

Look at the characteristics of the original “six” engine and you will get the characteristics of maximum power and torque (the engines are identical in stroke and diameter). From my own experience I will say this: the engine turned out to be high-torque both at the bottom and at the top (within reasonable limits, of course). From a standstill I do the 16-valve ten, but when the speed approaches 100 mph. then the 16-valve engine takes revenge in full. And the horseman on the dessiatine with 1500 eight-valve on the plain made him look like a puppy. From the wishes: I would like to add power at rpm (over 5000), so that at speeds above 130 there is a reserve, that’s why I recommend a high-speed camshaft. On some forum they advised me, I think “Estonian”, although I’m not sure, it’s better to check with the experts.

Source

How is cylinder block boring done?

The operation to restore the required gap between the cylinder walls and the pistons is not that difficult. It is enough to grind the cylinder to the required size on a boring machine, and the gap will appear by itself. Then all that remains is to install a new piston. Typically, a vertical boring machine is used for these operations to bore the cylinder block. And the correctness of boring depends on the condition of the equipment and the qualifications of the machine operator. However, this is not a complex technological operation.

But in order to remove the ellipse effect, you will have to tinker. Restoring the cylinder shape is the most difficult part of the process. The reason is that the deterioration of the internal surfaces of the cylinder can be very different at different places in the cylinder. Therefore, before starting boring, several measurements are taken using micrometric pointer instruments. And only after this a decision is made on how exactly the cylinder needs to be machined in order to achieve the desired surface geometry.

In addition to eliminating ellipse, boring the cylinder block aims to remove the taper of the cylinder. And this parameter should be no more than 0.01 mm. Along the entire length of the cylinder. Similar operations with such a minimal error can only be done on boring machines, whose grooving accuracy is even lower than 0.01 mm.

In addition, when boring a cylinder, high demands on the resulting cleanliness of the machined surfaces must be met. The cleaner the surface is processed during boring, the less time it will take to grind in new parts.

If the cleanliness of the processing is insufficient, problems will arise with premature wear of the piston rings, excessive oil consumption, and excessive fuel consumption. Plus, friction increases, especially during the break-in process; this is always associated with an excess amount of metal dust in the oil.

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Oil pump work

Due to the low engine efficiency and low wear resistance, mechanical tuning of the Niva 4x4 engine is almost mandatory. Such work is called work to change the geometry of the power plant. You should start modifying the power plant by upgrading the carburetor. We do the following:

We change jets with an indicator of 1 kam to a jet with an indicator of 2 kam;
Renewing the accelerator pump nozzle.

If you are the owner of an injection Niva, then independently modifying the injector is unacceptable. Only a professional with knowledge of software can perform such tuning of the Niva engine.

Lubricant supplied through the oil pump extends engine life. To improve the performance of the oil pump when tuning the Niva engine, you need to take another pump and cut off part of the housing with the parting plane from it. The thickness of this “pancake” should be about 11 cm. Using milling, cut off the excess and leave a thickness of 10 mm.

Next, do the following to remove chamfers on the edges of the teeth:

We compress, that is, remove, the drive gears.
We trim one of the gears by 0.75 mm on each side.
We cut the second gear to 11.5 mm (after trimming).
We repeat the operation with the remaining gears (driven).

Let's start working on the body. To do this we do the following:

We release the driven gear axis from the housing.
We form a longer axis from the drive roller.
We insert the resulting axle into the body.
We press the narrow gear onto the second drive shaft.
Press on the wide gear.
We fix the wide driven gear in the housing.
We install a narrow gear into the housing.

This sequence will prevent the gears from turning relative to each other. You can also improve the oil receiver of the Vase by cutting it a centimeter from the bottom. After this, we adjust the end gap and connect the entire structure with bolts.

Boring will help increase the compression of the cylinder block

Video instructions, as a rule, clearly show this event, but the viewer misses the most important thing - the specifics of the event. It seems to him that everything is simple and easy, and he can handle it, but we must not forget that in the video a pro is boring the block

Most of all, cylinder block boring is of interest to car owners concerned about compression. Watching a lot of videos becomes a revelation for many. They understand that dealing with this matter correctly at home will be extremely difficult.

As you know, if the cylinder compression is insufficient, the internal combustion engine cannot produce the required power, and the car’s dynamics decrease. Boring helps to significantly increase power by increasing the compression area on the cylinders.

Despite the fact that many experts recommend performing the operation in a car service center, there are more and more people who want to master the nuances of the operation. And this is not limited to video views alone. In search of useful information, an interested car enthusiast spams forums and websites, trying to find easy-to-understand instructions, but in most cases in vain.

How to bore a cylinder yourself

How to do boring with your own hands

At home, you can carry out major engine repairs only if you have such a machine. No other tool will provide such precision. In addition, there are many nuances that are worth considering. For example, strictly parallel installation of the engine on the frame (the role of which can be played by an ordinary table) and the machine. At the slightest discrepancy, which is not even noticeable to the naked eye, boring the cylinder block will not bring the expected result: the service life will be increased not by 99%, but by hardly 50, so that after a short time, “capital” will be required again. This is impractical and stupid, so we will try to avoid such mistakes as much as possible.

In addition, an important point in boring a cylinder block with your own hands is eliminating the taper of the cylinder. If the piston stroke was uneven, the cylinder will lose its shape, and if this is not corrected, the overhaul will be incomplete and will not bring any result.

So, first, calibrate the machine. Its procedure depends on the specific model, but, in essence, it is a banal check of parts for tightness and movement. After that, install the engine. Well, the main stage is actually boring the cylinders. To be honest, the process is not the most complicated and depends entirely on the equipment, but even here there is room for the human factor, so you need to be very careful. The spindle shaft with a cutter set to the required size is lowered into the cylinder hole and, rotating, aligns it to the same diameter. The new machines are controlled by a computer, so we are waiting for the program to complete. If the machine is older, its controls are manual. The main thing is to take your time. The metal of the cylinder is very dense and cannot be leveled in 1-2 passes.

The last stage is honing. In simple terms, this is polishing the surface of the cylinder walls; Using a grinding tool, the master achieves a perfectly smooth and round hole

Honing is important, of course you can do without it, but you shouldn’t skimp on such an important part as a car engine

Traditional methods

In a car service, it is not paper that is used, but abrasive chips. Instead of a drill, as mentioned above, a special machine with a crank having the required diameter is used.

Repair process

A hole is drilled in the middle of the piston for the cylinder pin.
A nut is screwed onto the stud, and then the stud is inserted into the piston with its end up.
The pin is tightened tightly.
A cut is made on the piston with a metal hacksaw.
The sandpaper is inserted into the resulting hole and then wrapped around the piston.
This unique attachment is installed in the drill and tightened tightly.
The cylinder is secured against turning.
The drill turns on at low speed. Boring starts from top to bottom, and then from bottom to top.

A useful recommendation is: in order not to knock your hands off during grinding with an electric drill, it is recommended to firmly fix the cylinder, but try not to damage it in the process.

You may also find this video about honing helpful.

Preparing the fixture

A hole is drilled in the mandrel.
Using a hacksaw, a cut is cut along the mandrel, into which abrasive paper is inserted, as in the case described above.

Note. The approximate depth of the groove should be 10 mm. The skin, as in the first case, should be both large and small.

Let's get started

The abrasive paper is wrapped around the mandrel.
The skin is generously moistened with oil.
The cylinder is bored by a mandrel. It is necessary to rotate the mandrel inside the cylinder with a large piece of sandpaper, trying to achieve free movement along the surface. Then change the paper to fine paper and continue.

The best grinders in the world are the Japanese. Their secret is great patience. It's the same here. You have to be patient, otherwise nothing will really work out. There is no need to rush in the process of boring cylinders.

Simple tips

The ideal option for boring cylinders that contain a car engine block:

The piston should sit tightly inside and not move downward due to its own weight.

The ideal option for boring cylinders that contain a motorcycle engine block:

The piston inside the cylinder should move easily, but not hang out too much, since when heated it will jam due to physical expansion.

Having learned how to carry out boring with your own hands correctly, you will no longer be concerned about the problem that arises for most owners of used cars. It is hardly possible to avoid low compression of internal combustion engines on used cars, but theoretically anyone can bore and increase compression.

Of course, as at the beginning of the article, we warn the reader. Most likely, it will not be possible to carry out boring correctly without the appropriate knowledge, but desire can overcome all doubts. Be sure to watch a few video instructions, study our recommendations and go ahead!