Which engine on a Ural motorcycle is better. Specifications of the Ural motorcycle engine

Greetings to the owners of heavy domestic Ural or Dnepr motorcycles who are not satisfied with the standard factory power of the engines of these bikes - this article is for you. Here we will look at how to increase the power of the strangled engines of these motorcycles on our own, but I want to immediately warn you that without the acquaintances of a turner, borer, miller and thermist, it will be unrealistic to carry out the plan. Therefore, in advance, take a fancy to some kind of factory in your city or a well-equipped workshop and make an acquaintance there, since the completion of some details in an ordinary garage is not feasible.

In general, domestic boxer engines of these motorcycles have a good potential for boosting, since in these engines the piston stroke has a smaller distance than the piston diameter itself (the piston stroke is 68 mm and its diameter is 78 mm). That is, these motors can be quite resourceful (not like the Japanese, but still), but they are clearly strangled at the factory, and the quality of engine parts, to put it mildly, is poor compared to the Japanese or European motor industry.

And now, in general, parts of such basement "firms" have appeared on sale that factory Soviet parts seem to be the height of perfection. So before you start tuning your engine, as I will describe in this article, first do an overhaul of it (replace worn gears, shafts, etc.), but only from Soviet parts, which the local population still has plenty of in Russia and the CIS ( especially somewhere in the outback). And find Soviet pistons from the 6 volt Dnepr MT-9 (or K-650), with a spherical bottom - they will come in handy for raising the compression ratio of your motor. So let's get started.

Engine head.

The head of any motor is very important, because through it the engine cylinders are filled with a combustible mixture and exhaust gases are removed. And the more efficiently the cylinders are filled, and the exhaust gases are more efficiently removed, the greater the power of any engine.

The first thing we will start with is to bring the factory head of your boxer to a normal state. First dry the head valves and remove the valves. If you have a Ural motorcycle head, then it is more strangled than the Dnieper one, since the diameter of its valves is only 35 mm exhaust and 38 mm intake. Borrow native Ural saddles and press in their place normal Dnieper valve saddles with a diameter of 38 and 40 mm. What landing should be with the correct pressing of the saddles (the saddles must be made of durable malleable and heat-resistant cast iron), any minder in a car repair shop knows, so go there. In the same place, the Ural valve seats will be bored (removed) for you, and the enlarged Dnieper valve seats will be pressed in correctly.

Dnieper valves will now be required, but when buying, check the evenness of their rods (the left hand is enough), the straightness rate of which is up to 0.03 mm (you can check by rolling the valve stem over a piece of glass, and a probe thicker than 0.03 mm should not be inserted between the glass and the valve stem , and ideally even thinner). You won’t be able to check what the valves should be made of, but it’s still useful to know - an alloyed alloy of grade 40X9 for the intake valve and heat-resistant steel of grade EP303 for the exhaust valve. Soviet parts are made from these alloys.

Having bought the valves, measure their diameter with a micrometer and match them with new guide bushings made of cermet or bronze, but so that the gap between the valve stem and the bushing is no more than 0.04 mm. (by the way, when buying, immediately measure both bushings and valves). The inner diameter of the sleeve is measured with a small indicator. You can read how to press bushings using the example of automobile ones, because the principle of pressing is the same, only the fixture needs to be made specifically for your head (device and how to use it

I want to assure many oppositionists that 90% of all NEW heads for boxer engines are now sold with overpriced as much as 0.5 millimeters !!! clearance between the guide sleeve and the valve stem. Once again I repeat - NEW heads, so when you buy a new head, immediately crack the valves and change the bushings, or valves with thicker stems (to get a gap of 0.04 mm). By the way, I advise you to press in the Zhiguli factory bushings, since a special groove is made on them, on which a very useful valve seal is put on (see photo).

Also check on the valve plates all three necessary chamfers: at the seat inlet there should be a chamfer of 60 °, which will ensure maximum filling of the cylinder at the inlet; at the outlet of the seat there should be a chamfer of 30 °, which will give the outlet a minimum resistance; and a 45° chamfer that will make excellent contact with the valve disc, providing excellent sealing.

The next operation will be to replace the standard springs with springs from a foreign car, for example, from Avdotya (Audi 100). This must be done, since your engine speed will increase after tuning, and regular springs will not cope with the inertia of the valves and their pushers at higher speeds. And Audi springs are stiffer and this stiffness, as well as their progressive characteristic, will not allow the valves to hang at high crankshaft speeds.

Springs from Audi, spring plate and finalization of the valve crackers from Audi.
1 — springs from Audi, 2 — valve crackers from Audi and grooves on the valve for them.

To implement this idea, you will need to shorten the valve stems a little (up to 90 mm), and cut three grooves at the ends of the stems for the Audi spring locks (see photo). And the cut ends of the valve stems (at the point of contact with the rocker arms) will need to be hardened or cemented (whatever thermal you find at the factory, do it).

When assembling, do not forget to check that the rocker is pressing exactly into the center of the valve end, because on most factory heads this centering is broken. With the help of thin shims put on the axis of the rocker arm, make sure that the tip of the rocker arm presses exactly into the center of the valve end, this is important.

Before assembly, it is advisable to bore the inlet and outlet channels of both heads a little (about 1.2 - 2 mm) with a cutter, and then polish their walls to a mirror finish - this will improve filling, the motor will breathe better and this will increase power. Do not forget then to thoroughly wash the entire head from the processed products.

Well, another improvement to the head. Futorki should be made and screwed in under the longer threads of modern ones, because all normal (for example) spark plugs have a long thread. And it's time to introduce, which are designed for as much as 200 thousand kilometers, into our boxer engines. It is better, of course, to make two futors, as I did on my Dnieper, in order to install two candles for each cylinder in the future. You can see it here, and there you will see the easiest way to install home-made electronic ignition on a boxer domestic engine.

Who wants to go even further, in the endless path of tuning, then you can install hydraulic valve lifters from a foreign car on (the Dnieper has more oil pressure than the Urals, since the oil pump is more productive). This will allow you to forget about frequent adjustment of valve clearances. To carry out this undertaking, you first need to select the hydraulic lifters themselves during disassembly (we move their diameter as fashionably closer to the diameter of the standard pushers in order to remove less aluminum when boring standard holes in the crankcase), and valve springs from the same machine.

Having measured the exact diameter of the compensators, it is necessary, based on this diameter, to bore the holes (in which the regular valve lifters move) in the Dnieper crankcase, so that the hydraulic compensators move in the bored holes with a gap of 0.04 mm.

And in order for them to work (compensating for valve clearances), they need to be supplied with oil under pressure from the lubrication system of the Dnieper engine. It is easiest to supply oil to the hydraulic compensators from the standard oil pressure sensor (we connect the fitting to the sensor, which is shown in the blue photo on the left, only it will need to be welded to the steel tube, and the clamp is not needed) and further along the steel tubes, and from the tubes into the crankcase are screwed T-shaped fittings, through which oil is supplied directly to the hydraulic lifters in the crankcase (see photo below).

But the main thing in this alteration is to install valve springs from the same machine as the hydraulic lifters. Since the compensators are heavier than the regular Dnieper pushers and the regular Dnieper springs do not have enough elasticity to cope with the inertia of heavier compensators (at speeds above 4 thousand), and there will be interruptions in the engine.

The last thing that is tedious to do here is to drill a hole in the bottom of the compensator (in all four), into which the regular dural rod will rest, which pushes the valve (more precisely, the steel tip of the rod).

Camshaft.

An engine with a modified head will "breathe" even deeper and more efficiently at high speeds, if the valve opening stroke is slightly (by 1.5 - 2 mm) increased. And for this you need to weld metal on the camshaft cams, increasing the profile of the cams. By the way, on the Dneprov MT-1036 model, a camshaft with a higher cam profile (than other models) was already installed at the factory, so it makes sense to look for this shaft. If possible (a normal factory or a workshop with good specialists), then you can order a new camshaft to be made, but with a 2 mm larger cam profile, made of 20X steel, followed by carburizing.

Welding should be done better with an apparatus, slightly fusing metal to the top of the cam, and at the same time the entire camshaft should be immersed in a bath of cold water (add cold water as it heats up). This is mandatory, otherwise the shaft will lead when heated. Having welded a little metal on all 4 tops of the cam, we process them and constantly check the profile with a template made of cardboard in advance.

The profile of all four cams should be exactly the same both in height and in the shape of the "egg", and after you achieve this, the cams should be polished to a mirror finish. After polishing, it is desirable to harden the cams to a hardness of HRC 43-48 (it is better to contact a familiar thermist). By the way, you can increase the resource of the camshaft by modifying it a little, but here's how to do it, we read.

After finalizing the camshaft, no matter how hard we tried, it could still lead, and not only from welding, but most likely from hardening. It is necessary and important to check this if you lay the shaft in two prisms, and bring to it in different places (where there are no cams) a clock-type spout. We check the shaft by scrolling it in prisms and following the indicator arrow. And if there is curvature, then you can fix the problem if you drop a drop of metal in the middle of the shaft by electric welding (where there is no cam) and you will immediately see that the shaft will bend a little in the opposite direction.

So you can completely remove the curvature, constantly checking the shaft with an indicator, after each drop of welding (at the end we grind off a drop). Just practice first on some kind of unnecessary roller, or metal rod.

I want to warn you that it is pointless to carry out painstaking revision of the camshaft if you do not replace all the bearings, especially the crankshaft bearings, with high-quality Japanese ones. Also the piston and crankshaft must be new. And the most important thing I want to say is that with an increase in the profile of the cams, the engine power will increase only at high speeds, and on the contrary, it will drop at medium and low speeds.

Why this happens cannot be explained in a nutshell, and I strongly advise you to read more about this here, after reading which you will understand that the revision of the camshaft, as described above, is in most cases not justified. After that, you will have to constantly twist the engine and work twice as often with the gearshift foot, which is not solid for a chopper - its motor must pull from the bottom. If you are building a motorcycle in the style of a cafe racer or streetfighter, then it makes sense to bother, but again, let me remind you that your engine must be brought to the ideal (start, as I already said, with replacing bearings with branded ones, replacing carburetor jets with 40% larger ones, replacing outlet for forward flow, etc.).

Piston group.

When finalizing the pistons, we will take into account two main circumstances. The first is to increase the compression ratio, and the second is to make sure that the pistons do not meet at the top with the valves, but at the bottom with the cheeks of the crankshaft. And as I said at the beginning, in order to raise the compression ratio, the Urals will need MT-9 pistons with a convex bottom, which is already 6 mm higher than the Ural one, and therefore it will provide an increase in the compression ratio.

1 - excess aluminum was removed from the piston skirt, 2 - a copper tube that pours oil on the bottom inside the piston, 3 - a sample of 12 by 12 mm.

But the catch is that it is impossible to rotate the Ural crankshaft with MT-9 pistons, since the cheeks of the crankshaft will rest against the lower edge of the piston skirt. To eliminate this, you need to sharpen the Dnieper pistons so that only 3 mm of aluminum remains on the side of the piston skirt (where the number 1 is in the photo) to the lower oil scraper ring. (see photo).

Pistons and crankshaft after such refinement will no longer interfere with each other. But when the piston goes to the bottom dead center, check that there is a gap of at least 1 mm between the worn part of the piston skirt and the crankshaft cheek (so that as the pistons wear and they are shifted, the parts do not meet during operation, well, plus a thermal gap).

You should also cut out window 3 (see photo) in the skirts of both pistons, 12 mm wide and 12 mm high. This is necessary so that the piston does not cling to the oil supply pipe on the bottom of the piston during operation (but more on that later). On the cylinder, you will also need to cut the same window 12 by 12 mm (see photo below).

After all the grinding and fitting, ensure that both pistons have exactly the same weight in grams. Next, assemble the piston and install the heads, then bringing the pistons to TDC, fill in engine oil through the candle hole to check (in turn) the compression ratio. To do this, you need to divide the larger amount of fluid that will fit in the cylinder at BDC by the smaller amount of fluid that will fit in the combustion chamber at TDC. It should be about 9.0 - 9.2. (for standard engines, the compression ratio is 6.5 - 7).

When turning the crankshaft of a Ural engine with Dnieper pistons by hand, make sure that the piston does not meet the valves (this will immediately prevent the crankshaft from being turned by hand). And you should also make sure that there is a gap of at least 1 mm between the valve that is fully open and the piston. This can be checked by sticking plasticine or window putty on the bottom of the piston, a couple of millimeters thick.

The valves will leave a distinct imprint in the plasticine. If the piston touches an open valve (or two), then you should make a cut on the piston with a cutter. Such samples are made on more modern Dnieper pistons (and on a piston from a foreign car too).

By the way, you can raise the compression ratio on a Dnepr motorcycle without changing the standard piston if you grind off the mating plane of the engine head, but how much to grind? It depends on the degree of compression you want to achieve, as well as the thickness of the bottom of the pistons. After all, after you grind (end) the head, for example, by 2 mm, you should select the same 2 mm with a cutter for sampling under the valve, otherwise the piston and valves will touch each other and prevent the crankshaft from scrolling (do not forget about the gap of 1 mm between piston bottom and open valves).

Cooling and lubrication system.

After the alterations described above, the antediluvian air cooling system (if you can call it that) should be improved. This is especially true of Ural motorcycles, whose ancient cast-iron cylinders barely manage to keep the engine from overheating, even with a standard compression ratio of 6.5. And what can we say, if we raised the compression to 9, then overheating is guaranteed without modifications.

By the way, KMZ factory engineers have long taken into account that cast-iron cylinders are the Stone Age, and after the notorious lower-valve cacique (K-750), they began to install aluminum cylinders with a cast-iron sleeve on all upper-valve motors of subsequent Dnieper models, which are cooled much more efficiently.

It is a pity that the Irbit engineers riveted cast iron cylinders (cast iron cylinders) that constantly overheated in the heat until the end of the 90s, until the more advanced Ural Voyage appeared, and then the Wolf, on which they finally repeated the cylinders like those of the Dnieper, making them aluminum , and fastening them with the help of through studs (probably after a few years, enlightenment came to the heads of the engineers of the Urals).

So, what am I for? And besides, ideally, you need to install cylinders from the Wolf on older Ural motorcycles. But before that, they should be shortened by as much as 10 mm (and their fastening should be redone with through studs, as on the Dnieper), since the Wolf has a piston stroke 10 mm longer than that of a conventional Ural. But it’s better, of course, not to spoil Volkov’s cylinders, but also to install a crankshaft from Volk, and then the engine volume will also increase to 750 cubic meters, but this is a topic for a separate article. In general, to be honest, for me the Dnepr motorcycle is much more pleasant and easier to tune than the Urals, no offense to the owners of the Urals, of course.

1 - the copper tube is screwed into the pump housing, 2 - the tube outlet is sealed with a sealant.

Okay, enough philosophy; no matter what cylinders are on your opponent, you still need to do the following: first, you need to bring additional coolness to the bottoms of the pistons - the zone of the highest temperatures. To do this, to the standard Ural oil pump, through an adapter and an elongated roller, we connect another Ural oil pump, and preferably a more efficient Dnieper oil pump (see photo).

And connect a separate oil line to it, which is connected further through the oil cooler (in series), then bifurcates and pumps oil precisely to the bottoms of the pistons from the inside. Check that both oil supply pipes are directed precisely to the bottoms of the pistons from the inside (bring the piston to the BDC and bend the tube, directing it to the bottom of the piston from the inside, but so that it does not touch the piston skirt).

An oil cooler can be found at dismantling motorcycles of foreign cars, since many road Japanese motorcycles have air-oil cooling, and the worse our opponent is. The radiator can be fitted even from Zaporozhets - even it has air = oil cooling. And in the crankcase itself, the volume of oil should be increased to 3 liters, using a higher aluminum oil pan (see photo below), they are now on sale. The additional volume of oil will have a good effect on the temperature regime of the engine, along with the radiator.

Oversized aluminum oil pan.

Power and ignition.

It remains to install electronic ignition on your boxer, as described in the article about its installation (link above in the text), as well as normal ones from a Japanese motorcycle, which will add power. Just remember to switch to a higher octane gasoline, since the compression ratio is no longer a seven, but a nine! The engine speed will increase to 7500, and new opportunities will open up for the boxer engine and the motorcycle in general. And since the speed has increased, then some standard bearings may not be able to cope with the speed. Therefore, as they wear out, I advise you to replace them with branded ones, and how to choose a bearing and recognize its markings, I advise you to read.

And of course, it does not hurt to install third and fourth gear tuning gears in the gearbox in order to reduce their gear ratios (from 1.7 to 1.55 - third gear, and from 1.3 to 1.09 - fourth gear). And also install the tenth pair of gears in the rear axle gearbox (read how to do it correctly). This will allow you to move at speeds over a hundred without twisting the engine.

If you do tuning engine motorcycle Ural or Dnepr as described in this article, your bike will be much more capable than stock factory bikes, and you will enjoy a sharper start and increased top speed, and the bike is made for fun; good luck to everyone!

It has become popular, at the same time expensive, to have a high-quality and powerful motorcycle from well-known global suppliers. But our bike is a motorcycle Ural not far removed from foreign motorcycles, if you look at the prices, you will go crazy, the price is like a car. Therefore, little is bought on the domestic market for new Urals, although they are supplied for the Armed Forces of the Russian Federation and other law enforcement agencies, but abroad they are in some, albeit small, but definite demand. Most of the motorcycles of obsolete models available to the population, released in the last century, the prices in those days were affordable. Speaking about the Ural motorcycle, the first thing that comes to mind is what kind of engine it is. IMZ-8.103-10 (IMZ-8.103-30, M-67-36), are there flaws And weak spots because it is the qualities and characteristics engine underlie the characteristics motorcycle Ural.

Characteristics motorcycle modification engines Ural	M62	M63	M66	M67	M67-36	IMZ-8-103
Type engine	4-stroke, carburetor, 2-cylinder, opposed, air-cooled, combined lubrication system
Wed gasoline consumption per 100 km, l
Working volume, cm 3
Cylinder diameter, mm
Piston stroke, mm
The degree of compression of the combustible mixture
Max. power, l. With
Max. power, kWt
Rotational frequency crankshaft at max. power, rpm
Max. torque, Nm
Carburetor brand (2 pcs.)
Air cleaner type	Combined inertial contact-oil filter with two-stage cleaning

Characteristics of transmissions of modifications of motorcycles Ural	M62	M63	M66	M67	M67-36	IMZ-8-103
clutch type	Dry 2-disc driven discs with overlays on both sides
Cardan type	With cardan shaft and flexible coupling and needle bearing joint
Main gear type	With 2 bevel wheels with helical teeth, gear ratio -4.62
Gearbox type	4-speed, has gear ratios in I, II, III, IV gears 3.6; 2.28; 1.7; 1.3 respectively

Refueling volumes of gasoline and oils of modifications of Ural motorcycles, in liters	M62	M63	M66	M67	M67-36	IMZ-8-103
In the fuel tank, (gasoline A-80)
In the crankcase
In the crankcase
In the main gear housing
In the air cleaner

Weak points of the engine IMZ-8.103-10 (IMZ-8.103-30, M-67-36) of the Ural motorcycle

• Kick starter (kickstarter);
• Gas and clutch cables;
• Generator;
• carburetors;
• cylinder heads;
• Reverse gear (gearbox).

In more detail about the weak points of the motor ...

Kick starter (kickstarter)

The foot starter of the IMZ-8.103-10 engine is a weak point due to the pawl slipping. The malfunction is eliminated after dismantling the gearbox and disassembling it with rearrangement of the pawl by the other side or its replacement. I have an assumption that the metal of the dog with low hardness. On the other hand, if the pawl is made harder, then the gear will fail. You need to choose the golden mean.

Throttle and clutch cables

Clutch control and fuel supply cables are a weak point due to the short period of use. To put it simply, they are torn, and before that they are stretched, which makes it necessary to adjust the timing of the fuel mixture supply, as well as the clutch.

The generator does not run for a long time.

Gasoline enters the floats, after which it fills the cylinder with gasoline. In addition, carburetors are not matched to these engines, half of the fuel flies into the wind, which is not economical. It would not be bad if one carburetor was put on the engine instead of two.

cylinder heads

You can not overtighten the candles on the heads, the threads break quite easily. It is impossible to overheat the engine, the result will be clearly visible on the heads, the studs are pulled out, leading the landing plane of the heads. If it was not possible to avoid breaking the thread for the spark plug, contact a familiar turner; he will be happy to repair it for a modest fee and install a steel threaded bushing. I can recommend the same for wear on valve seats and chamfers. It is much cheaper to repair heads than to buy new ones, a good turner can do this, just spit.

Reverse gear (gearbox)

Reverse gear does not work for a long time due to rapid wear of the reverse gear in the gearbox.

Disadvantages of the engine IMZ-8.103-10 (IMZ-8.103-30, M-67-36) of the Ural motorcycle

• Small resource;
• Difficulty starting or not starting at all
• In hot weather, in lower gears, it gets very hot;
• Interruptions in the operation of the cylinders;
• knocking;
• High fuel consumption;
• There are a sufficient number of cases of inaccuracies in the manufacture of the engine crankcase at the points of attachment of the cylinders;
• Oil is leaking at the joints.

More about the disadvantages...

small resource

In contrast to the engines of analog imported motorcycles, the resource of the IMZ-8.103-10 engine before repair is small from 20 to 45 thousand km, which is explained by the increased wear of parts of the crank and piston group. Increased wear is a consequence of insufficient air cooling, as well as from not very good quality parts (material, manufacturing accuracy).

Hard to start or won't start at all

For the most part, starting the IMZ-8.103-10 engine is difficult when the ignition, fuel supply and gaps in the valves of the gas distribution mechanism (between the rods and rocker arms) are not adjusted. The reason may be low compression in the cylinders, clogged carburetor jets, water in the carburetors, candles do not work, the condenser is out of order, a lean fuel mixture coming from the carburetors (a lot of fuel).

In hot weather, in lower gears, it gets very hot

Unfortunately, air cooling adversely affects the engine when operating in hot weather. Therefore, in the heat when driving in lower gears, overheating should not be allowed, so it is necessary to stop more often to cool the engine. If the engine is new, then you can easily overheat.

Interruptions in the work of cylinders

To a greater extent, interruptions in the operation of the cylinders are caused by the lack of synchronous operation of the cylinders due to the different amount of the supply of combustible mixture, but by a violation in the adjustment of the valves.

The cause of engine knocking may be: earlier ignition; overheat; wear of pistons, rings, fingers; wear of the crankshaft main bearings; valve adjustment is broken.

High fuel consumption

Carburettors are simple and uneconomical, the consumption is even according to the instruction manual, like that of a Zhiguli, but in reality it is even more. In Soviet times, they didn’t think about efficiency, and drivers poured gasoline into the ground, there was nowhere to put it. These days, for a motorcycle, such fuel costs are too high.

There are a sufficient number of cases of inaccuracies in the manufacture of the engine crankcase at the points of attachment of the cylinders

This leads to overheating of the cylinder due to the difference in size until the upper plane of the pistons at the top dead center coincides with the upper edge of the cylinders. In the event that one of the cylinders overheats and nothing can be cured, as an option, it is necessary to check whether the piston at its highest point reaches the upper plane of the cylinder, if not, then this is the problem. To eliminate overheating, it is necessary to bring the symmetry of dimensions, for which, gaskets are removed from under one of the cylinders, and a heat-resistant sealant is used in its place when mounting the cylinder. It is possible to install a thin gasket.

Oil leaks at joints

This disease does not affect the operation of the engine, the leaks are small. But the engine, littered with dust adhering to the oil, has to be washed. Tightening the head covers, oil pan does not help. After replacing the seals after some time, the oil starts to leak again. It also leaks along the seals of the valve stem guide bushings.

In conclusion, many probably thought that the IMZ-8.103-10 engine is just a bucket of bolts ... Well, what can you do, we are used to digging into motorcycles since childhood, or rather repairing them. Therefore, many people miss the bulkhead of the engine with their own hands. This is a joke, of course, but there is some truth in every joke. In general, if you properly monitor the engine, carry out maintenance in a timely manner, then of course you can take it. With a high flow rate, the problem is solved by installing one carburetor from the car. The engine is very simple and very easy to repair. The engine, like the Ural motorcycle itself, is well suited for tuning.

The truck produced by the Ural Automobile Plant has a universal purpose. It is designed both for the transportation of people and for the transportation of goods. TTX "Ural-4320" allow you to overcome impassable places at full load. This factor contributed to the widespread use of the machine in the army and in regions with difficult climatic conditions. The first model of the vehicle in question was released in 1977. In fact, the car is an improved copy of the Ural-375 car, which was produced for military needs.

Exterior

According to the TTX "Ural-4320", it is equipped with a body made of a metal platform and a tailgate. The car is equipped with benches, an awning and arches of a removable type. There are also additional lattice boards. The standard equipment includes a three-seater cabin, assembled from thick-walled sheet metal, made by stamping. Sophisticated glazing and rear-view mirrors make it possible to fully monitor the situation on the road and increase visibility.

Structurally, the body is made in the form of short overhangs, which improves the cross-country ability. The curb weight of the truck is 8.2 tons. The weight of the transported cargo is up to 67.8 tons with the possibility of towing 11 tons.

TTX "Ural-4320" military with YaMZ engine

One of the variations of the power plants on the truck in question was the YaMZ engine in various modifications. It is a four-stroke engine with an electric torch starter. A feature of the power unit is the moment that before the final completion of work, it must work at idle for a couple of minutes.

The motor fully meets European standards (Euro-3). The capacity of the fuel tank is about three hundred liters (some models are equipped with additional tanks of 60 liters). Diesel fuel consumption per hundred kilometers is from 30 to 40 liters, depending on the speed of movement and the presence of a towing device. The maximum speed of the car is 85 kilometers per hour.

Other power plant options

Developing the performance characteristics of the Ural-4320 engine, manufacturers have provided for the possibility of installing several types of motors. These include the following variations:

• Installation KAMAZ-740.10 - with a capacity of 230 horsepower, a volume of 10.85 liters, has 8 cylinders, operates on diesel fuel;
• YaMZ-226 - runs on diesel fuel, power is 180 horses;
• YaMZ-236 NE2 has a volume of 11.15 liters, a power of 230 horses, turbocharging, four cycles;
• In addition, modifications with indices 238-M2, 236-BE2, 7601 were mounted. They differ in horsepower (240, 250 and 300, respectively).

In addition, the performance characteristics of the Ural-4320 with the YaMZ engine provide for the installation of a hydraulic booster, preheating and engine compliance with the Euro 3 standard.

Technical indicators

The brake assembly includes a main dual-circuit system and a spare unit with a single circuit. The auxiliary brake is actuated by a pneumatic drive from the exhaust gases. This mechanical type assembly with a drum placed on the transfer case (RK) is very effective. Parking brake - drum, mounted on the output shaft of the RK.

TTX "Ural-4320" are designed for the wheel formula 6 * 6. High cross-country ability is provided by single wheels equipped with automatic pumping of air chambers. The front suspension is dependent, has shock absorbers and semi-ellipse springs. The rear assembly is also of a dependent type with springs and torque rods. The truck in question has three axles, they are all leading, the front wheels are equipped with CV joints. The clutch unit has a friction drive, a pneumatic booster, a disk with a diaphragm exhaust spring.

Cabin and dimensions

The presented truck is equipped with a two-door cab, it is made entirely of metal and is designed for three people. The driver's seat is adjustable, there is a ventilation system, modernized variations are equipped with a sleeping bag. After 2009, the working conditions of the driver have improved significantly. The new cabin has increased comfort, a fiberglass hood and an original design style.

Below are the main overall dimensions that provide for the TTX "Ural-4320":

• Length / width / height (m) - 7.36 / 2.5 / 2.71, the height of the tent is 2.87 meters.
• Net weight (t) - 8.57.
• The maximum mass of the towing device (t) is 7.0.
• Wheel track (m) - 2.0.
• Ground clearance (cm) - 40.
• The number of seats on the platform is 24.

It is worth noting that the truck has a solid power reserve, which allows you to overcome more than one hundred kilometers without refueling.

Tactical indicators

TTX "Ural-4320" military tactically have the following capabilities:

• Overcoming the reservoir wade (depth) - one and a half meters.
• Crossing swampy terrain - similarly.
• Ditches and trenches (depth) - up to 2 meters.
• The maximum lifting height is 60 °.
• The minimum turning radius is 11.4 meters.
• The maximum height above sea level for normal operation is 4,650 meters.

Structurally, a powerful truck is made in such a way as to protect the cab and the driver from dirt when driving off-road (the power plant is located in front, the hood is raised up, and wide flat wings are installed on the sides).

TTX "Ural-4320" allow you to operate it in harsh climatic conditions with a maximum humidity of 98 °. The temperature range is from + to -50 degrees. Garage-free storage of the car is allowed. The sustained maximum wind force is 20 meters per second, and the dust content is 1.5 cubic meters.

Current modifications

During the release of the truck in question from the Ural manufacturers, several modifications were developed, the main difference between which is the power of the power plant. The most popular are the following models:

1. "Ural-4320-01" - has an improved cabin, platform and checkpoint. Year of release - 1986.
2. Similar modifications with the YaMZ engine, with a capacity of 180 horses, as well as a truck with an increased wheelbase and cross-country performance.
3. TTX "Ural-4320-31" differ from its predecessor in the presence of an eight-cylinder power unit (YaMZ) with a capacity of 240 horses and an improved indicator of specific power. The car was released in 1994.
4. Model 4320-41 - YaMZ-236NE2 engine (230 hp), year of manufacture - 2002, compliance with Euro 2 standards.
5. Option 4320-40 is a version of the previous car, equipped with an extended base.
6. Modification 4320-44 - a cabin of improved comfort appeared (year of production - 2009).
7. Long base "Ural-4320-45".
8. Variation designed for installation of special equipment (4320-48).

Conclusion

There are several points that popularized the truck in question, both in the army and for civilian purposes. Firstly, the Ural-4320 is not afraid of absolutely no off-road, it has a high cross-country ability and carrying capacity. Secondly, it is unpretentious in maintenance, operation and repair. In addition, this vehicle is universal, capable of transporting military, civilian cargo, heavy trailers and about 30-35 people.

It is worth noting that manufacturers are constantly working on improving the Urals. An army vehicle is considered an efficient and productive vehicle. In addition to the fact that the truck has great power, armored variations are designed to protect personnel from being hit by charges from light and medium small arms (the third category of protection). In civilian use, the machine is indispensable for the northern regions and areas with difficult soils.

What owner of a domestic motorcycle did not think about tuning the Ural motorcycle engine? This burning question worries many fans of domestic Ural motorcycles! The fact is that the standard Ural engine has many inaccuracies in manufacturing and is technically imperfect. Depending on the model and year of manufacture, the power of the Ural motorcycle varies from 32 to 36 horsepower, which in our time is considered a low figure for an engine size of 650 cubic centimeters. In this article, we will look at how to increase the power of a standard outdated engine. I want to note right away that a lot of turning work will be required, find a workshop in advance that will agree to help you in this matter.

The Ural boxer engine has great potential for tuning, thanks to a piston diameter of 78mm and a stroke of 68mm. With this configuration, the engine could be revving, unfortunately the workmanship of the parts, and the purpose of the motorcycle does not allow this. In the article we will consider the solution to this problem, due to which it is possible to achieve impressive results from the operation of such an engine, namely:

• Engine head tuning
• Camshaft tuning
• Cylinders and pistons
• Carburettors and ignition

Engine head tuning

Through the channels of the engine heads, the cylinders are filled with a fuel mixture, and the exhaust gases are released. The more efficiently the cylinders are filled and the exhaust gases exit more easily, the greater the engine power. To tune the Ural engine heads, you will need to remove the valves. The diameter of the native valves of the Urals is only 38mm inlet and 35mm exhaust, which affects the suffocation of the engine. Along with the valves, you need to press out the old valve seats and guides. Seats for saddles should be bored to fit the size of the Dnieper saddles. New enlarged saddles will allow you to install valves of a larger diameter 40mm inlet and 38mm outlet from the Dnieper. The best alternative to Dnieper valves will be valves from Audi. The quality of automotive spare parts is much higher, and thanks to the fixation with new type of crackers, it is possible to significantly increase the resource of the heads. We recommend using bronze valve guides from VAZ 2101-2107.

Internal serrations improve valve stem lubrication. The movement of valves in them is the most efficient with minimal friction losses, and the service life is much longer. Bronze perfectly removes heat from the valve, which will positively affect the stability of valve clearances.

It is important to know: when choosing valves, do not run into a fake. Exhaust valves made of heat resistant steel must not be magnetized. Bronze guides are also not magnetic.

Please note that the gap between the guide and the valve stem is required from 0.04 to 0.06mm. The valve must move freely in the sleeve, while not hanging out in it. By the way, we want to note that the car guides have a seat for the valve stem seal. We strongly do not recommend installing it, since lubrication occurs by spraying oil, and not under pressure, as in cars. After installing new valve guides, pay attention to cutting the valve seats. It is necessary to cut the seat along three chamfers: 60,30 and 45 degrees, of which 45 degrees are working, which comes into contact with the valve disc, providing a snug fit. You will also have to replace the standard valve springs with automobile ones from the VAZ 2108. They are somewhat stiffer than the native ones, and are able to ensure the precise operation of the valves at high speeds. But keep in mind that with such springs, the camshaft is subject to accelerated wear - tuning a motorcycle engine requires sacrifice. The final procedure for tuning the heads is boring the inlet and outlet channels with a cutter a couple of millimeters larger in diameter. At the same time, it will be possible to get rid of casting influxes and ensure better engine breathing. The outlet channel should be polished to a mirror, and the inlet channel should be left slightly rough matte to prevent fuel condensation on the walls. After tuning the heads, do not forget to blow out all the channels and hard-to-reach places with compressed air, and grind the new valves. Lapping must be done manually with a two-component lapping paste. Never use a drill. A hose is put on the opposite end of the valve stem, thus turning the valve with your palms to achieve a matte belt on the valve seat and valve plate with a thickness of 1.2-1.6 mm. Check the tightness of the valve by pouring kerasin into the channels for 1-2 minutes.

Camshaft tuning

This modification requires a very deliberate approach, as a rule, a new form of cams is created empirically and may not meet your expectations. A wide-phase camshaft will help to fully realize the capabilities of tuned cylinder heads. For moderate tuning, you can simply put it from the Ural model M 67-36. The photo below shows a wide-phase shaft on the left, a regular shaft on the right.

If you want to get the most out of the engine, then it is possible to increase the profile of the cams of the standard shaft. This can be done by welding metal with argon welding. By increasing the width and height of the cams by a couple of millimeters, it is possible to achieve a shift in torque to the region of high revolutions and an increase in power also by increasing the revolutions from the valve timing. Consider the fact that such an engine will lose traction at low revs and may even stall at idle. For this modification, we recommend finding a workshop or factory where the correct processing of the cam profile is possible, followed by carburizing. Then, it is important to make sure that the geometry of the shaft is even, it is likely that the shaft could have been led by a sharp temperature drop, the curvature is checked by an experienced turner with a dial indicator.

Cylinders and pistons

One of the most important parts in an engine is the pistons. They take on a huge load from expanding gases and temperature. Standard low-quality pistons do not withstand loads well, often have different weights, and piston rings cannot provide high compression due to outdated design, this significantly affects power, as well as the massiveness and number of rings make the piston very heavy, which prevents the motor from spinning. It is recommended to install forged pistons with imported rings. A good solution would be to install forged pistons from the Ural Wolf motorcycle, they have a convex surface that will increase the compression ratio and significantly increase engine power.

As for the cylinders, it is preferable to replace them with aluminum ones with a cast-iron sleeve. The thermal conductivity of aluminum is much higher, efficient heat dissipation is ensured. A significant improvement of the cylinders is re-sleeving. The standard inner diameter of the cylinder liner is 78mm, and if the volume of a standard engine of 650 cubic meters does not suit you, by replacing the native cylinder liners with liners from Moskvich 412 with an inner diameter of 82mm, it will be possible to significantly increase the volume and, accordingly, power. Accordingly, select the pistons for the new diameter.

To combat overheating, a cooling system will be useful in the form of installing an oil cooler and by forcibly spraying oil on the bottoms of the pistons. An additional oil pump is needed to connect the oil cooler, since the standard one is very weak. To drive oil through the radiator, it is advisable to install an oil pump from the Dnepr motorcycle. Drive the second pump through an adapter from the standard Ural one. In order for the additional pump to fit in the crankcase, an enlarged sump is required, which will also have a positive effect on cooling. Due to some increase in the amount of oil in the system, it will be possible to distribute the heat load, and the new aluminum pan will remove heat even better.

By connecting an oil line made of a copper or steel capillary tube to the new oil pump, which must first pass into the radiator, then cooled oil from it must enter the inside of the pistons. To do this, the line from the radiator enters back into the crankcase, bifurcates in such a way that the oil supply is directed to the piston bottom from the inside. An oil cooler can be purchased at the dismantling of Japanese motorcycles, as well as an automatic transmission radiator of the size you need from any car.

Carburettors and ignition

Tuning a Ural motorcycle engine affects all engine systems, including ignition and carburetors. It is recommended to read the information: how to do it right. The standard ignition is so outdated that it is not even suitable for everyday driving, let alone more. It is desirable to install a microprocessor ignition with the possibility of an automatic advance angle. this article will help you. In the ideal case, there will be an installation of such an ignition with a programmable controller with the possibility of adjusting the firmware. In such ignition systems, there is another useful feature - cut-off by speed. It will allow not to twist a strongly forced engine. Well, for maximum spark power in conjunction with a new ignition, you can use a coil from Oka or Gazelle. Branded high-voltage wires with silicone insulation and internal resistance are required, for example, Tesla from the VAZ 2108. They will provide an uninterrupted spark in any weather and eliminate the possibility of spark breakdown to ground. As for carburetors, it will require the installation of Japanese vacuum carburetors with diffuser diameters from 32 to 36 mm, followed by the selection of jets, synchronization and tuning with a gas analyzer. A dynamometer setup is highly desirable, where you can test different settings and ignition timings and get the most out of your bike tuning!

Additional engine upgrades

In addition to the above methods, the Urals have a few more secrets. It is possible to install a crankshaft from K 750 on the Ural engine, which will increase the cylinder stroke to 78mm.

Thus, it is possible to significantly increase the working volume of the Ural engine. Finding it is quite difficult, but worth it. Another problem with the bike is the tight throttle response and slow revs. This is due to the too heavy flywheel, the weight of which is designed for driving with a sidecar and for carrying heavy loads.

According to the drawing, it is possible to reduce its weight by a couple of kilograms. By reducing the weight, the inertia of the crankshaft will decrease, and the acceleration dynamics will increase significantly. To fully realize the power on the road, the gears of the gearbox must be replaced with 9 or 10 pairs. In conclusion, we want to note that tuning the Ural motorcycle engine justifies itself only for racing purposes; for everyday use, such a motor will have a small resource and significant fuel consumption.