Power unit. Gas distribution mechanism. Valves.

Adjusting the valves on a Ural or Dnepr motorcycle is carried out infrequently, but this procedure is mandatory and allows you to keep the engine in full working condition. Despite the fact that the presented Soviet heavy motorcycles have different engines, their principle and adjustment scheme are the same.

What is thermal valve clearance?

Thermal valve clearance is the distance from the upper end of the valve stem to the pressure part of the rocker arm. This gap is necessary so that when the engine reaches high operating temperatures, with subsequent expansion of the metal, the optimal valve opening function is maintained. Of course, when cold, the engine may run unevenly or not at full power, fortunately, air-cooled engines quickly reach operating temperature and the valves begin to work as expected. Different units have different clearances, this is due to the materials from which they are made. For example, in the Dnepr K-750 motorcycle there is a gap of 0.1 mm, while more modern models of Soviet heavy motorcycles received a gap of only 0.05 mm. This means that the older K-750 was made of metal subject to a high degree of thermal expansion, while modern models are made of a more stable metal. To control gaps, special probes are used. They are made of steel plates of various thicknesses. Each probe indicates its thickness, and the degree of deviation with the indicated value is so small that under the operating conditions of these engines the error can be neglected.

Why is valve adjustment done on Ural motorcycles?

The valves have mobility in both directions, along their axis, which means the gap can increase or decrease. First, let's consider what happens if the gap decreases, right up to the contact with the pusher. First of all, power is reduced due to loss of compression. The engine heated up, the metal expanded, and the valve began to not close completely, making less contact with the seat, due to constant contact with the pusher. This can be determined by several signs - the engine has become harder to start, there is a noticeable loss of power when warming up, you can also hear the knocking of valves when hot and notice popping noises in the carburetor. Here you can find out details about setting up carburetors on a Ural motorcycle. On the other hand, if the gap becomes larger than required, then the valves will not open completely, the combustion chamber will become less filled with the fuel-air mixture and will be less cleared of exhaust gases. In both cases, the engine will perform noticeably worse, and in the most advanced cases, the engine will simply be impossible to start. By the way, the ignition in the Urals must also be adjusted.

Messages [17]

1↑ Topic from Yurets13 04/27/2015 08:39:19

• Yurets13
• Experienced
• Inactive
• Name: Yuri

• From: Nizhny Novgorod
• Registered: 04-04-2015
• Messages: 303
• Reputation: 31
• Motorcycle: Dnepr 10 (died), Dnepr 11 (I’m using it now), Planet 5 (a fairy tale and not a motorcycle), IZH 56 (I had experience)

Topic: I propose a new topic “INTERCHANGEABILITY and ANALOGUES”

Hi all. Due to serious problems with finding and purchasing good spare parts for Dnepr motorcycles (I think the Urals have the same problem, less pronounced, but still there). I propose to create a new topic - “Interchangeability and analogues”.

Despite the fact that I am new to the forum and have not been involved in heavy motorcycles for so long, I have already been able to draw conclusions about the very high price of what is sold for motorcycles. Automotive spare parts are many times cheaper! Sometimes the price differs by 10 times. Visiting stores and looking at shop windows, and even reading the forum, we can conclude that there are a lot of spare parts, components and even assemblies that come from cars. Many auto parts fit without problems, buying/getting them is much easier than for motorcycles and, most importantly, the price. The turn relay burned out, for a motorcycle it cost 380 rubles, I bought it from 8 to 110. I was looking for a guide for the Dnieper, but I couldn’t find it. I came to the service center, they found a VAZ for me and did it. And this is just yesterday! ))) In general, the price of motorcycle parts is unreasonably high! A fuel hose was offered at the motor market for 170 rubles

, I bought a reinforced VAZ 2101 at an auto parts store for 25. I hope there is no such topic, and I’m sure it will be useful, especially for beginners.

Edited by Yurets13 (04/27/2015 09:10:13)

Source

Messages [16]

1↑ Topic from Sibiryak 29-11-2012 16:45:02

• Siberian
• Pro
• Inactive
• Name: Siberian

• From: Novosibirsk
• Registered: 03-03-2012
• Messages: 879
• Reputation: 84
• Motorcycle: Ural IMZ 8.103.10

Topic: What kind of car will the valve fit into the Ural head? springs too

from which springs with valves will also fit crackers.

2↑ Reply from EVGEN1 29-11-2012 17:03:17

• EVGEN1
• Newbie
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• Registered: 02-07-2012
• Messages: 19

Re: What kind of car will the valve fit in the Ural head? springs too

springs from VAZ 2101

3↑ Reply from Sibiryak 29-11-2012 17:06:23

• Siberian
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• Name: Siberian

• From: Novosibirsk
• Registered: 03-03-2012
• Messages: 879
• Reputation: 84
• Motorcycle: Ural IMZ 8.103.10

Re: What kind of car will the valve fit in the Ural head? springs too

I just read on opposite.ru that the plates and springs will fit from the VAZ2108 and from the Muscovite 406. Now the question is about the valves themselves, what are they suitable for?!

4↑ Reply from mexanik62 29-11-2012 18:47:00

• mexanik62
• Mechanic from the 30s.
• Inactive
• Name: Uncle Vitya

• From: Evpatoria
• Registered: 03-08-2011
• Messages: 10 831
• Reputation: 1 137
• Motorcycle: 12-volt K-750, ZAZ Sens Hatchback

Re: What kind of car will the valve fit in the Ural head? springs too

Not only will they come from the Zaporozhian Cossacks The topic about valves was The valves are only original, the rest need to be modified

5↑ Reply from Sibiryak 11/30/2012 04:53:17

• Siberian
• Pro
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• Name: Siberian

• From: Novosibirsk
• Registered: 03-03-2012
• Messages: 879
• Reputation: 84
• Motorcycle: Ural IMZ 8.103.10

Re: What kind of car will the valve fit in the Ural head? springs too

and if you pick up some kind of valve from the car, but without modifying the legs there’s no way of course)

6↑ Reply from mexanik62 30-11-2012 09:33:03

• mexanik62
• Mechanic from the 30s.
• Inactive
• Name: Uncle Vitya

• From: Evpatoria
• Registered: 03-08-2011
• Messages: 10 831
• Reputation: 1 137
• Motorcycle: 12-volt K-750, ZAZ Sens Hatchback

Re: What kind of car will the valve fit in the Ural head? springs too

Look carefully there is such a topic!

7↑ Reply from Sibiryak 11/30/2012 15:06:47

• Siberian
• Pro
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• Name: Siberian

• From: Novosibirsk
• Registered: 03-03-2012
• Messages: 879
• Reputation: 84
• Motorcycle: Ural IMZ 8.103.10

Re: What kind of car will the valve fit in the Ural head? springs too

Mechanic62, I couldn’t find it.

8↑ Reply from PATRIOT 11/30/2012 15:11:49

• PATRIOT
• Patriot IMZ
• Inactive
• Name: Ilya

• From: Krasnodar region, Krasnodar
• Registered: 18-02-2011
• Messages: 3 148
• Reputation: 176
• Motorcycle: No. Next will be the K750!

Re: What kind of car will the valve fit in the Ural head? springs too

why do you need this at all?

9↑ Reply from Sibiryak 11/30/2012 16:36:43

• Siberian
• Pro
• Inactive
• Name: Siberian

• From: Novosibirsk
• Registered: 03-03-2012
• Messages: 879
• Reputation: 84
• Motorcycle: Ural IMZ 8.103.10

Re: What kind of car will the valve fit in the Ural head? springs too

I want to completely repair the head, it was like it was from scratch and improve it a little) well, I was thinking, I’ll probably leave the Ural valves) but I’ll change the springs with plates)

10↑ Reply from PATRIOT 30-11-2012 16:54:47

• PATRIOT
• Patriot IMZ
• Inactive
• Name: Ilya

• From: Krasnodar region, Krasnodar
• Registered: 18-02-2011
• Messages: 3 148
• Reputation: 176
• Motorcycle: No. Next will be the K750!

Re: What kind of car will the valve fit in the Ural head? springs too

Well, I already said that there is no point in meddling with boxer engines with your own improvements. The way they were made at the factory by knowledgeable people is how they should remain. Any implementation will reduce the service life! You are not motorcycle racers for whom it is important to take first place in the race no matter what. - So they tune the engines, get maximum efficiency and power from it for a certain period of time, and then continue to tinker with repairs. It is important for you and me that a conventional engine lasts as long as possible, works, and helps. to climb into it and repair it as little as possible.

Added: 30-11-2012 16:54:47

As for the springs and their components - yes, they fit from a figure eight! I won’t say anything, but I’ve heard a lot of bad reviews about the fact that they are too elastic for a Ural engine. the rods seem to not hold up and bend a little, which is not good

Analogue valves Moto Dnepr

Dnepr/Ural. Instead of a collar seal, there is a hub seal from Grand Vitara (art. no. 19016629B). The crankcase was modified (the photo shows my modified crankcase), the seat was machined to 59mm. Here is the article: https://oppozit.ru/article85909.html

Kia piston pin 21x66 mm (art. no. 2341233000) fits boxer. In the photo on the left is the original one (worn out), on the right is the new one.

Analogue of the crankshaft oil seal Dnepr. Corteco (art. no. 12011334B). The outer surface is steel. I haven’t installed it yet, but I estimate it will work. Original size 60x85x12, replacement 60x85x10.

List of possible valves for alteration (with estimated cost for autumn 2013):

-intake 38.5mm AE V91144 121r -intake 39mm AE V91198 183r -intake 39.5mm AE V91306 145r -intake 40mm AE V91146 168r -intake 41mm AE V91292 207r -intake 42mm AE V9013 2 205r - inlet 42mm AE V90178 148r - inlet 43.9mm AE V90371 153r -intake 44mm AE V91308 220r -intake 46mm AE V91445 200r

-issue 35.1mm AE V35040 331r -issue 35.8mm AE V91994 240r -issue 36mm AE V34499 200r -issue 36mm AE V91172 263r -issue 37mm AE V90134V1 261r -issue 37.9mm AE V 90439 KhZr - 38mm edition AE V95004 400r - 38.1mm edition AE V91494 585r - release of 38mm AE V91309 325r 02.02.16

Source

MY MOTORCYCLE

Irbit “Ural” and Kiev (“Dnepr”) are among the most popular motorcycles of the Soviet era of motorcycle construction, which never caught up with other motorcycle giants of the world. But that's not what we're talking about now. So, these two opposites can be found everywhere and the most interesting thing is that even though, like, different models are still very little different from each other. And they have the same ancestor. And the question often arises, especially for beginners: are the parts interchangeable?!

This is where a discrepancy arises - there is no need to talk about complete interchangeability of parts. Unless you move the motors from one frame to another. Here everything is adjusted and fits.

Let’s look at what is more or less suitable below:

Analogue valves Moto Dnepr

Mersedes valve k750 m72 for shortening, (rod +3 weave 8.98, original plate 38mm, United Motors 20VX408)

Valve k750 m72 for shortening (rod stock 8.95, original plate 38 Stellox 8124626SX)

Rusk k750 m72 under 3 grooves free rotation mk9h

Guides Ural Dnepr Guide 14.05 Metelli 01-1913 or Freccia G2070 Guide 14.15 Metelli 01-1915 Guide 14.25 Freccia G2781 or Metelli 01-1916 Guide 15.07 Freccia G3110

Dnepr intake Freccia R4643/SCR without modifications, on old saddle, on new saddle R4641/scr

Dnepr release without modifications AE v91338

Ural intake without modifications Freccia R4641/SCR

Ural release for regrinding plates from 38 to 35 AE v91338 Ural release for shortening Stellox 0124074SX Freccia R4293/RCR

Camshaft bearing (1 piece) (SKF, NSK, NTN, Koyo) 6205 (ZZ-closed) C3 - required

Crankshaft bearing (2 pcs) (SKF, NSK, NTN, Koyo) 6207 (ZZ-closed) C3 - required

Needle shank bearing 874901

Double-row shank bearing 3086304L3304DMA

Piston pin Hyundai / KIA 23412 33000

Rings for forging 79mm for 1 cylinder Kolbenschmidt 800013611000 4 times cheaper for 4 cylinders, no worse in quality, but you need to set the gaps United motors 24p2g02000

Bushing for breather KAMAZ DZV 740100602602

Official manufacturer of forged pistons AUTOTECHNOLOGY https://www.nppavto.ru work via mail

Thick washers, for head bolts k750 m 72 21120 1003265 00

Source

Required Tools

Before you start adjusting the valves, you should prepare the necessary tools.
First of all, you will need a set of keys. In practice, you will only need one, but it is better to have everything on hand. The motorcycle valves are directly adjusted using feeler gauges. Depending on the motor model, different probes may be needed. On the M 72 Ural, a thickness of 0.1 mm will be required; for newer engines, for example, IMZ, it is better to use 0.05 mm. In fact, these are very conditional indicators. There is a small tolerance during adjustment, but under operating conditions of the power unit this does not affect its performance.

You will need to stock up on a small container to catch the oil; it can sometimes spill. Also, a rag will not be superfluous; it can be used to clean the engine from dirt. Let's see how to properly perform this repair.

Valves - bushings for Dnepr (MT10-36) analogues

As they say when opening a new topic, I didn’t find it:

Maybe there is something somewhere separately, BUT I would like to see it in one topic.

It is clear that the issue regarding bushings is not very critical, because both for the Urals and for the Dnieper are the same. Although I wanted to know reviews about Metelli bushings, no one has used them? It’s also interesting about metalceramics (manufacturers).

And the pressing question is the analogues of the valves for the Dnepr MT10-36, the price is not critical (the TAZ valves need not be discussed here), but the dimensions are critical (so as not to resharpen anything) and the ability to obtain them relatively quickly (1-2 weeks at best).

I didn’t place the topic in the BUYS section, because in 30 days it will be destroyed, but I think the topic will be useful for the Dneprovods.

Z.Y. I actually need valves, but I don’t want to install regular ones, I would buy them from someone (suggestions for gears, so as not to clutter the topic)

Z.Y.2 let’s make no guesses, but specifically, from what, number, article, etc.

Kydelka, On Dnepromoto everything is described in detail with articles, pictures and other things.

true biker, so they need to be modified, are there really no valves in our world that could be made without redistribution?

It’s written there that it’s not necessary to modify the valves. Anything that still needs to be done can be done at home, with a file, in an hour or two.

All of them (not counting ours) have a length exceeding a hundred (again, not counting the Audi, but the stem of this valve is 7). On the knee, with a file and under breadcrumbs... well, well And do this crap every 2 years (less lucky).

Volkswagen 40x8x91.3 crackers are worthless. on Dnepromoto everything is in shambles

Kydelka, Both valves from Volkswagen fit 40mm into the Dnieper with VAZ crackers without modifications, bronze bushings from BMW, or PEUGEOT -406 also without modifications. or do you need a 37 release valve?

yes, we still need an exhaust valve (even first of all, an exhaust valve, a transverse risk appeared on it from somewhere, maybe not because of this, but my guide sleeve on this valve was eaten away). Graduation 37? I have 37 in my book on boxers, and 38 on dnepromoto.

By the way, where did you find it on the Dnieper? I just found this about analogues in the topic of enlarged valves https://dnepromoto.com/dvigatel/golovki-cilindrov/uvelichennye-klapana/

Kydelka, you need to look in the forum (motor section). There are no analogues for 37 (38), so use 40mm, it’s easier to process the saddle for it.

Source

Checking and adjusting the valve clearances of the diesel engine of the Ural car

To adjust (check) the clearances, set the crankshaft to position I, corresponding to the start of fuel injection into the 1st cylinder, while turning off the fuel supply by completely repressing the idle speed handle.

Place the flywheel lock (Fig. 2, a) in the lower position, as shown in Fig. 2, b.

Remove the front hatch cover 1 of the clutch housing (Fig. 5).

Inserting a crowbar into holes 2 on the flywheel, turn the crankshaft as it rotates until the latch, under the action of the spring, engages with the flywheel.

In this case, the position of the marks on the end of the fuel injection advance clutch housing and the flange of the drive coupling half of the high-pressure fuel pump drive (Fig. 3) must coincide and be in the upper position.

If the marks are not in the upper position, disengage the lock and rotate the crankshaft one turn until the crankshaft is locked again.

Set the lock to the upper fixed position.

Rotate the crankshaft in the direction of rotation (counterclockwise, when viewed from the flywheel side) through an angle of 60° (turning the flywheel through the distance between two adjacent holes corresponds to turning the crankshaft by 30°), i.e., to position I.

In this position of the crankshaft, the clearance in the valves of cylinders 1 and 5 is checked (the valves are closed, the valve rods can be easily turned by hand).

Using a torque wrench, check the tightening torque of the nuts securing the rocker arms of the adjustable valves (Mkr = 4.2 ÷ 5.4 kgcm).

Using a feeler gauge, measure the gap between the toes of the rocker arms and the ends of the valve stems of the 1st and 5th cylinders.

With correctly adjusted gaps, a feeler gauge 0.20 mm thick for the intake valve and 0.30 mm thick for the exhaust valve should fit in freely, and a feeler gauge 0.25 mm thick for the intake valve and 0.35 mm thick for the exhaust valve should fit in with force.

If necessary, set the required gap as follows:

— using a device for adjusting valves or a wrench and a screwdriver, loosen nut 2 (Fig. 4) of adjusting screw 1;

— insert a feeler gauge of the required thickness and, turning the screw with a screwdriver, set the required gap;

— holding the screw with a screwdriver, tighten the nut and check the size of the gap.

The tightening torque of the adjusting screw nut should be 4.2. 5.4 kgf-m.

To check the clearances in the remaining valves, install the crankshaft in positions II, III and IV, to do this, rotate it 180°, 260°, 540° respectively relative to the first position of the crankshaft, while checking valves 4 and 2, 6 and 3, 7 and 8 cylinders.

Reinstall the clutch housing and cylinder head covers.

Start the engine. If the clearances are correctly adjusted, there should be no knocking in the gas distribution mechanism.

Valve guides from vases on the Dnieper (Ural)

When I came to the conclusion that the valve guides were Khan, I came to the conclusion that the only alternative was the VAZ ones. Replacement did not cause problems 1- the head needs to be washed (after heating, you can wash off the horseradish) 2- Heat it up, I heated it in the oven of a gas stove (about 15 minutes), if there is an opportunity to find an electric one * (it’s easier with it) 3- Knock out the old bushings (you can buy a mandrel for knocking out, order a turner or make it yourself) a turner I know couldn’t turn it in time and couldn’t buy it (because it’s not available anywhere) so I did it myself )) with an angle grinder from the cylinder mounting stud (if you have a Ural, it won’t work), the main thing is don’t even think about knocking out the bushings when it’s cold. Anyone who says otherwise is simply not technically literate. (saw the consequences) only heating. knock out the bushings, not with strong blows, with proper heating it is not difficult (it is also not difficult to heat up) 4- VAZ bushings (short from the classics) will become like family ones, if possible, ask a turner to machine new grooves for the retaining rings (27mm from the end facing into the combustion chamber)

this is not necessary, but it greatly simplifies installation. The most important thing is that the bushings are sold as a set, long ones can be sharpened into short ones))) 5- Before installation, do not forget to soak the bushings for 2 hours in engine oil, heat the heads again (15-20 min) and press in new bushings, but not split the bushing (this happened to me) modify your homemade mandrel so that it does not damage the end of the bushing (if you are imaginative, there will be no problems) If you have retaining rings, then relax and hammer in all the way, if not - make a mark instead of them and carefully hammer in 6- After pressing, you definitely need to go through the bushings with an 8mm reamer and you will have to ream the seats, this is not difficult (I can explain in detail), but finding cutters (countersinks) is more difficult and they are expensive (although the process itself will take 30 minutes maximum), VAZ ones are suitable, 90,60,120 degrees, in the MT book it says 15,45,75, but this is the same (I’m shocked) 7- Grind in the valves, the easiest way is to apply paste to the valve, put a fuel hose on it (25cm is enough) and scroll the hose between your palms for a couple of minutes, periodically checking the seat (1-1.5mm should be ground in), if everything seems normal, wipe the paste from the valve and try again, then wipe the paste from the valve and seat and a couple more turn the valve once, if everything is normal, check the tightness of the valve by turning the combustion chamber to the light and look into the intake/exhaust channel, if you can see the light, repeat the procedure Wash the head so that no abrasive remains 8- Assemble the head, but place two paranitic ones under the springs rings (this will increase the preload of the springs and better tightness of the valves), feel free to install the seals on the valves and do not believe anyone who says that they will not hold up there and that the valves will not be lubricated. Ceramic metal is porous and oil seeps through the bushing in a volume sufficient for lubrication

What is thermal gap

The term thermal clearance refers to the distance between the rocker arm and the upper end of the valve. This allows for the inevitable thermal expansion of engine parts to ensure optimal operation of the valve mechanism. The disadvantage of having such a gap is the low stability of the engine when starting when cold, but it works great when fully warmed up.

It should be remembered that the gap must be appropriate for the engine model. On older models, the alloys are less stable, so it is recommended to set this indicator to 0.1 mm. On more modern engines, the gap can be set within 0.05 mm.

Weaknesses and shortcomings of the IMZ-8.103-10 engine

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

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

• Foot starter (kickstarter);
• Gas and clutch cables;
• Generator;
• Carburetors;
• Cylinder heads;
• Reverse gear (gearbox).

More details about the weak points of the motor...

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

The clutch control and fuel supply cables are a weak point due to their short service life. To put it simply, they tear, and before that they stretch, which makes it necessary to adjust the timing of the supply of the fuel mixture, as well as the clutch.

The generator does not run for a long time.

Gasoline gets into the floats, after which the cylinder is filled with gasoline. In addition, carburetors are not matched to these engines; half of the fuel goes to waste, which is not economical. It would be nice if the engine had one carburetor instead of two.

Do not overtighten the spark plug heads; the threads break off quite easily. You cannot overheat the engine, the result will be clearly visible on the heads, the studs are pulled out, leading to the landing plane of the heads. If you are unable to avoid breaking the spark plug thread, contact a familiar turner; he will be happy to repair it and install a steel threaded bushing for a modest fee. I can recommend the same for wear of valve seats and chamfers. It is much cheaper to repair heads than to buy new ones; a good turner can do this in no time.

Reverse gear (gearbox)

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