In detail: do-it-yourself uaz 421 engine repair from a real master for the site my.housecope.com.
When I was buying my UAZ-31601, I noticed that the engine (UMP-421) was shaking violently. There is an imbalance. Since I was still going to sort out the engine (my nature is like this: I can not safely drive until I am sure that everything is in order inside), I did not attach much importance to this, but indicated to the seller.
He said that in my place he did not do this, since the engine was being sorted out by experienced mechanics, who, among other things, prepare engines for athletes.
Indeed, it started up with half a turn, pulled well, ate moderately. But the sausage was not childish. Having traveled a little in the summer, in the fall I began to carry out my plan - to sort out the engine and put 5 tbsp. Checkpoint. So that, then, once again do not remove and put the unit.
Resolved. Car to the garage. Outward slider. I took it off, scattered it:
Inside, in fact, everything is cultural, everything is decent.
There is tuning: duralumin valve spring plates and titanium pusher rods.
Weigh the pistons, connecting rods separately. Strange: the difference is no more than 1 g.
It is not clear why he was shaking so?
Let's take a closer look:
Here it is - the first ambush. The mechanics who went through the engine were not only experienced, but also “stupid”. Apparently, for the sake of laughter, they put one finger “simple”, and not “reinforced”, as it should be for 3 liters. engine. "Reinforced" has thicker walls and is naturally heavier (weighed, it turned out to be 12 g). To distinguish it, the “simple” has a step in the middle inside. According to the book, the difference in the weight of the pistons assembled with connecting rods installed in one engine should not exceed 8 g. The difference of 12 g due to the old-style finger could not give such a strong vibration as it was on my engine. He shook it so that the bell (scientifically - the clutch housing) burst in two places. Replacing the bell is a separate song, more on that below.
Video (click to play). |
We look further ShPG.
The repairmen adjusted the connecting rods by weight, grinding off the tide on the lower head. But the connecting rod is called the connecting rod because it performs complex reciprocating and rotational movements in the engine. Those. its upper head moves linearly up and down in place with the piston, and the lower one rotates together with the crankshaft connecting rod journal. It is obvious that the inertial forces of the ShPG were balanced, not only the same mass of the connecting rods plays a role, but also the position of the center of mass of the connecting rod. If, while adjusting the weight of the connecting rod, remove metal only in one place, for example, from the cover of the lower head, then the center of mass will shift towards the upper head. Roughly speaking, we add mass to the piston by facilitating the crankshaft connecting rod journal. Obviously, the most important for balancing is the uniformity of the position of the center of mass of each connecting rod along the axis of symmetry. The theory is now clear. How to find this very center of mass in practice?
Three connecting rods gave a delta in the region of 1 mm, and the fourth deviated by 5 mm. This is the second ambush. Further, everything is simple: we lighten the connecting rods, removing the metal from the tides on the heads, trying to bring the center of mass of each to the uniformity. Those. if the upper head outweighs, then from it, and vice versa.We remove a little, each time checking the mass of the connecting rod and its balancing. It took me about 3 hours with all the sloppiness.
To weigh the connecting rods (and pistons), I used a beam balance, preserved from the times when, being carried away by photography, I myself made up the developer-fixer. It is difficult to determine “exactly how many in grams” a connecting rod or piston weighs on these scales, but the weight can be compared with sufficient accuracy. It is only necessary to bend the corresponding hooks from the same length of steel wires.Weighed the pistons together with the fingers, the connecting rods - assembled, with tightened bolt nuts. He adjusted the weight of the pistons by removing the metal from the bosses with a cutter.
At the end, I washed everything so that there was no sawdust left. The crankshaft complete with a flywheel and a basket was taken to the “Mechanics” for balancing. The book says that the clutch must be assembled with the driven disc. This should not be done, because it is difficult to accurately center the driven disc, and during operation it takes an arbitrary position. The crankshaft brought back was checked statically at two corners set in level. “Mechanics” did excellently - the crankshaft did not budge!
The installation of the new bell was well described on the “UAZbook” of blessed memory of Makhno.
I was looking forward to the moment when it would be possible to start the engine.
Started up! Doesn't tremble. Hooray!
Not a trace of the old dance was left.
Vibrations on the move are more noticeable from the drivetrain, but that's another story.
About titanium push rods. Weighed - they are lighter than duralumin. I noticed one feature - the knock of the timing belt with warming up does not decrease, but rather the opposite. I looked in the “Metalworker's Handbook” - the coefficient of linear expansion of titanium is about three times lower. Those. with warming up, the rods do not reduce the gap, but rather vice versa. Reduced thermal gaps to 0.2 mm, less scary. The knock is still loud enough.
(February 2004)
All parts of the connecting rod-piston group are divided into categories and selected individually to each other.
Using the letter painted on the block, we select the piston to the cylinder.
The designation "421" on the piston indicates that it is intended for the UMZ-4218 engine.
When repairing with cylinder bore, the required clearances are ensured in the process of boring and honing for previously purchased pistons of the same repair size.
The diameters of the holes in the piston bosses, the connecting rod head and the outer diameters of the piston pin are divided into four groups, marked with paint: I - white, II - green, III - yellow, IV - red.
On the fingers, the group number is marked with paint on the inner surface or ends. It must match the group indicated on the piston.
On the connecting rod, the group number is also indicated by paint. It must either match or be adjacent to the group's finger.
A finger lubricated with engine oil should move with little force in the connecting rod head, but not fall out of it.
Liner locks must be located on one side of the connecting rod, ...
... and the projection on the connecting rod cover align in the direction with the inscription "FRONT" on the piston.
We heat the piston to a temperature of 60–80 ° С. It is allowed to heat the piston in hot water. We insert the connecting rod head between the piston bosses and quickly press in the piston pin greased with engine oil.
If there is no device, you can press the pin in with a copper or ordinary hammer through a soft metal mandrel, holding the piston in weight.
We fix the piston pin on both sides with retaining rings.
We check the piston rings, for this ..
... alternately install the piston rings into the cylinder to a depth of 20–30 mm from the upper edge and measure the gaps with a set of feelers. Compression rings should have a gap in the lock of 0.3–0.5 mm, oil scraper rings - 0.5–1 mm.
We put the rings on the piston, starting with the oil scraper ring.
Having opened the lock of the radial expander, we install it in the lower groove.
Having opened the lock of the radial expander, we install it in the lower groove.
... axial expander and upper annular disc.
The oil scraper ring discs are interchangeable.
We put on two compression rings in succession so that.
... the chamfer on the outer diameter of the lower compression ring faces towards the piston skirt, ...
... and the chamfer on the inner side of the upper compression ring is towards the piston crown.
The pairing of the wearing parts in the cylinder block of the UMZ-421 engine is carried out mainly by replaceable parts, which allows the cylinder block to be repaired by regrinding and replacing the pistons with replacing the crankshaft main bearing shells.
The cylinder block of the UMZ-421 engine with holes in the cylinder walls, water jacket and crankcase or with cracks in the upper plane and ribs supporting the main bearings must be replaced.
Since 1996, camshafts have been installed in the cylinder block of the UMZ-421 engine without intermediate bushings. To restore worn camshaft bearings, the supports are bored to the following dimensions:
Support 1 - 55.5 +0.018 mm.
Support 2 - 54.5 +0.018 mm.
Support 3 - 53.5 +0.018 mm.
Support 4 - 52.5 +0.018 mm.
Support 5 - 51.5 +0.018 mm.
Semi-finished bushings are pressed into the bored supports, followed by their boring to fit the dimensions of the camshaft bearing journals. Restoration of the pair's performance: cylinder block bore - pusher, due to slight wear on the cylinder block, is reduced to replacing the pushers.
As a result of wear, the cylinders of the block acquire the shape of an irregular cone along the length and an oval shape around the circumference. The wear reaches the greatest value in the upper part of the cylinders in the area of the upper compression ring, when the piston is at TDC: the smallest is in the lower part, when the piston is at BDC.
An increase in the out-of-roundness and non-cylindricality of the sleeves up to 0.08-0.1 mm., Can be corrected by honing, without the use of boring, for a repair diameter of 100.1 mm. For the indicated size, repair pistons are produced, having the designation 421.10004015-P1, broken down into five size groups with the same tolerances as pistons of the nominal size.
With greater out-of-roundness and non-cylindricality of the liners, as well as wear of liners in diameter by more than 0.1 mm, it is necessary to bore them with subsequent honing to a repair diameter of 100.5 mm for the existing pistons of the corresponding size group, taking into account the provision of a gap between the skirt and the liner within 0.03 -0.06 mm.
If a limited number of pistons are available for repair, it is recommended to calculate the bore deviations for each cylinder based on the actual size of the diameter of the piston skirt intended for the given cylinder, and bore the cylinder to these dimensions. Deviations in the shape of the cylinders must be located in the tolerance field of the dimensional group for the cylinder diameter.
Damage to threaded holes in the form of nicks or thread stripping of less than two threads is repaired with a tap to the nominal size.
Threaded holes with wear or thread breakdowns of more than two threads are restored by cutting threads of an increased repair size, setting threaded screw drivers with subsequent cutting of a thread of nominal size in them or installing threaded spiral inserts. The latter method is the most efficient and less time consuming.
UAZ cars are very popular in Russia, and in Soviet times the UAZ was out of competition - foreign SUVs were extremely rare in the Soviet Union at that time. But since the machines are often operated in difficult conditions, it is necessary to regularly repair components and assemblies, and repairing the UAZ engine is a relevant topic that interests many.
- motors are not complex;
- spare parts are available and are in stock at many auto dealerships;
- engine parts are inexpensive.
The engines of the Ulyanovsk plant have their own characteristic "diseases", and not all car owners leave their "native" engine - they put internal combustion engines from other car models.In this article, we will consider the features of UAZ engine repair, typical engine malfunctions, as well as possible options for replacing UAZoav power units.
UMP begins its history in 1944, when a joint-stock company was created by the order of the People's Commissar. At first, the plant produced small-displacement engines for charging batteries and mobile power plants, and the first automobile internal combustion engine rolled off the assembly line in 1969.
The motor was named UMZ 451, and had a lot in common with the power unit of the Volga GAZ 21. Since 1971, the ICE 451 was modernized, and it received the 451M index, this engine was awarded the “Quality Mark”. In the late 70s and early 80s of the last century, the UMZ-414 ICE was installed on the UAZ 469 ("goat") and UAZ 452 ("loaf") cars, and since 1989, the UMP 417 with a capacity of 90 liters has been produced. With.
Until the mid-90s, all Ulyanovsk engines had a volume of 2.445 liters and a cylinder diameter of 92 mm. In 1996, the production of the UMZ-421 ICE began, this power unit was distinguished by a cylinder diameter increased to 100 mm and a large volume (2.89 liters). Since 1997, the Ulyanovsk plant has been supplying power units for GAZ vehicles, and these are models:
- 4215;
- 4213;
- 4216 in various modifications;
- Evotech 2.7.
The engine of the Ulyanovsk plant, model 417, is produced in various modifications, has an aluminum block and a cylinder head, 4 cylinders in one row, 2 valves per cylinder. "417th" engines have a carburetor fuel system:
- a single-chamber carburetor is installed on modification 417;
- UMZ-4178 is equipped with a two-chamber carburetor.
The technical characteristics of the UMZ-417 are as follows:
- volume - 2445 cm³;
- power - 90 liters. With.;
- piston diameter - 92 mm;
- compression ratio (compression in cylinders) - 7.1;
- piston stroke - 92 mm;
- type of fuel used - gasoline A-76.
The UMZ-417 internal combustion engine, in addition to 4178, also has other modifications:
- 4175 - an engine designed to use AI-92 gasoline (98 hp, compression ratio - 8.2);
- 10-10 - ICE with a block head from model 421 and with a rubber rear oil seal.
The UMZ-421 engine has been produced since 1996, it is installed on Ulyanovsk models:
Instead of stuffing box packing, this motor uses a rubber oil seal as the rear crankshaft seal. This motor has the following characteristics:
- volume - 2890 cm³;
- power - 98 liters. With.;
- piston diameter - 100 mm;
- compression ratio (compression in cylinders) - 8.2;
- piston stroke - 92 mm;
- the type of fuel used is AI-92 gasoline.
There is also a version of the internal combustion engine designed for A-76 gasoline fuel, the power of such a power unit is 91 liters. With. (respectively, the compression ratio is 7.0). UMZ-421 motors are equipped with K-151E carburetors.
The UAZ Patriot, which is widely popular in Russia, has been produced since 2005, but unlike all other Ulyanovsk-made cars, this model has no "native" engines - the SUV is equipped with ZMZ and Iveco engines. Only one type of gasoline engines is installed on the Patriot as standard - 3MZ 409.10 with a volume of 2.7 liters and a capacity of 128 liters. With. This engine has taken root so well on the UAZ that it is sometimes called the UAZ 409.
The engines of the Ulyanovsk Motor Plant are distinguished by their simplicity of design and high maintainability, and since UMP engines are simple, many drivers repair UAZ engines with their own hands. Overhaul is always carried out with the removal and installation of the power unit, disassembly and assembly of the internal combustion engine, so that the engine works for a long time after repair, it is necessary to correctly troubleshoot.
What to consider when doing self-repair:
We disassemble the removed engine as follows (consider the example of the UMZ-417 engine):
- disconnect the manifold assembly with the carburetor from the block head. The two inner nuts are most difficult to crawl, so you should use a socket wrench (standard nuts are usually 14 mm);
- remove the valve cover (6 screws or bolts);
- dismantle the distributor drive, remove the two side covers of the pushers;
- unscrew the nuts securing the rocker arm axle (4 pcs.), remove the axle.We take out the rods (there are 8 of them), and then the pushers (also 8 pcs.);
- we unscrew the cylinder head fastening nuts, dismantle the block head. The head can sit tightly, but you do not need to apply much effort to remove it, and when removing it, you should try not to damage the surface of the cylinder head;
- why do we remove the crankshaft pulley, turn off the ratchet. It can be unscrewed with sharp hammer blows in a counterclockwise direction;
- then the hub should be dismantled; to remove it, you must use a special factory or homemade puller. When dismantling, it is necessary to secure the crankshaft from rotation;
- the next step is to remove the pallet (oil sump). After unscrewing all the nuts, gently knock on the pallet with a hammer, and if the crankcase does not come off, you can pry it with a screwdriver, pushing it between the block and the plane of the pallet. You should not regret the gasket (it is still a replacement), the main thing is not to damage the surfaces of the parts;
- remove the oil pump, it is supported by four nuts;
- dismantle the camshaft cover (unscrew 7 nuts);
- we turn off the connecting rod nuts, dismantle the connecting rod caps, take out the pistons together with the connecting rods. It is necessary to dismantle one connecting rod at a time and immediately bait the covers in place - the covers should not be confused with each other, they are not interchangeable;
- we unscrew the nuts of the main covers, dismantle the covers, take out the crankshaft assembly with the gear, flywheel and clutch;
- we turn the camshaft so that bolts appear under the holes in the camshaft. With a socket wrench, unscrew the two bolts by 12, dismantle the camshaft together with the gear.
Now it remains to disassemble the details:
- disconnect the manifold from the block head;
- dry out the valve;
- remove the clutch, gear and flywheel from the crankshaft;
- dismantle the gear from the camshaft;
- disconnect the pistons from the connecting rods.
Disassembly is complete, you can start troubleshooting parts.
Often on the old "UAZ" the engine completely depletes its resource, and then the car owners have a very reasonable question - how to replace the old engine. Installing an engine on the UAZ 402 is the most reasonable solution:
- the ZMZ-402 engine is more reliable than the "UAZ" one, and many such used engines in good enough condition are sold by hand;
- a minimum of alterations will be required for replacement - the Zavolzhsky ICE fits all mountings.
The "four hundred and second" engine has another very big plus - it will be the cheapest of all the proposed options that may exist when replacing the engine with a UAZ.
Installation of the ZMZ 406/405/409 engine on the UAZ will be somewhat more expensive. These motors are also suitable for mountings, but you will have to:
- deal with electrical wiring;
- adjust the front exhaust pipe.
In general, there are not many alterations either, but the 406 motors themselves are a little more expensive. There are UAZ car owners who install imported diesel engines on the car, but here you have to make a lot of changes to the design:
- remodel the exhaust system;
- digest motor and gearbox mountings;
- completely throw the wires;
- adjust the water connections in places.
The UMZ 421 engine incorporates the constructive solutions of the previous 417 series and the GAZ 21 engine. The prototype labeled 4218.10 was completed in 1983, but it was being finalized for another three years. After that, the designers took up the version 241.10 with the original form of the exhaust tract.
Then 8 more modifications were added with increased power, compression ratio, deformed, with a different camshaft, under Euro-4 standards and two gas-petrol options. As a result, the ICE 421 line is produced to this day, it is equipped with cargo and passenger Gazelles, Sobols, Barguzins and Hunter SUVs, cargo-passenger UAZ "Bukhanki".
Initially, in the engine of the first version 4218.10, antifreeze penetrated through the pores of the aluminum casting of the cylinder block into the oil. The leak was irreparable, the replacement of the cylinder head gasket did not help, so the manufacturer used the resin impregnation of the block using aircraft technology, the shape of the intake tract was changed, the engine was named 421.10.
To increase the torque at the bottom and power in general, the engine circuit received two additions:
- a resonator in the exhaust system, located after the muffler;
- increasing the compression ratio.
This version of the internal combustion engine is designated 421.10-30 and has its own repair manual. From the factory, the motors came out with 100 mm cylinders, which initially provided high torque and power. The manual of the automaker GAZ recommends them for installation on a Gazelle, which requires minor alterations:
- the Gazelle radiator is located lower than in UAZs;
- the fan must be displaced;
- a drive with a separate belt appears.
In addition, the power supply system, exhaust of gases from the crankcase has been improved, the engine is designated 4215.10-30. If 421 models have the same oil consumption, different fuels can be used.
To reduce the operating budget of the truck and minibus, many Gazelles and Soboli were converted by the GAZ manufacturer to A-76 gasoline. A similar modification of the UMP engine for low-octane gasoline was designated 4215.10-10.
Then an injection version was required, but already for all-wheel drive UAZ - minibuses, SUVs, trucks and utility vehicles. It was the 4213.10 engine. The camshaft here is cast iron, not steel, as in carburetor engines. For Gazelles, such an internal combustion engine was 4216.10 with a modified fan drive.
This 421 series was the last for the manufacturer UMP with a lower camshaft. Already for the next generation 429.10 high-speed internal combustion engines, the camshaft has been moved to the inside of the cylinder head, that is, it is located at the top.
The table contains the main technical characteristics of the UMZ 421 motor:
combined cycle 11 l / 100 km
bearing cover - 120 Nm (main) and 60 Nm (connecting rod)
cylinder head - three stages 42 Nm, 106 Nm + 90 °
The table contains a description of the parameters of the basic carburetor version 4218.10. In other engines, other attachments are used, the circuits of the exhaust and intake tracts, and the injection system have been changed.