UMZ 421 - UAZ engine: Technical characteristics

Taking into account the growing needs of the modern market, the Volzhskie Motors production enterprise in the city of Ulyanovsk began producing new internal combustion engines with increased traction and speed characteristics. Compared to analogues produced earlier, the 421 engine has increased torque (22.5 kgf) and increased maximum power (112 hp). The new generation UMZ 421 engine remains interchangeable with previous models and can be installed on earlier production vehicles without additional modifications.

Engine UMZ 421 - Technical characteristics

This power unit is considered the basic design, installed on UAZ-Hunter, UAZ-3303, 2206 vehicles. The 421 UAZ engine runs on A 76 gasoline, has a displacement of 2.89 liters, and a compression ratio of 7.0. Fuel supply type – carburetor. The permissible temperature range of motor operation is from – 50 to + 50 ° C.

A distinctive feature of the new modifications of ZMZ engines is the original design of the cylinder block made of aluminum alloy, in which thin-walled cast iron liners are cast. The new design block contains cylinders with an increased diameter (100 instead of the usual 92 mm), while the distance between them has not changed. The service life of the updated piston group has been significantly increased against the backdrop of reduced lubricant consumption. Thanks to maintaining the inter-cylinder distance, a large number of working units and parts are interchangeable with engines from previous batches.

Technical characteristics of the UAZ 421 engine:

1. Number of cylinders – 4 pcs.
2. Type of arrangement – ​​in-line.
3. The working volume of the cylinders is 2.89 liters.
4. The number of crankshaft revolutions is 4000 rpm.
5. Power 84.4 - 98 l. With.
6. Engine weight – 170 kg.
7. Recommended motor oil by viscosity coefficient is 15W40, 5W40, 10W30, 10W40, 20W40.
8. By brand - Rosneft, LukOil, Liqui Moly.
9. In terms of chemical composition - semi-synthetic - in the summer months, synthetic - in cold weather.
10. The declared service life of the UMZ 421 engine is 250,000 km.

Technical characteristics of UMZ 421 2.9 l/98 – 125 l. With.

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, replacing the cylinder head gasket did not help, so the manufacturer impregnated the block with resin using aircraft manufacturing technology, changed the shape of the intake tract, and named the engine 421.10.

To increase low-end torque and overall power, 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. The engines left the factory with 100 mm cylinders, which initially provided high torque and power. The manual of the automaker GAZ recommends them for installation on the Gazelle, which requires minor modifications:

• the Gazelle radiator is located lower than in UAZs;
• the fan needs to be moved;
• a drive with a separate belt appears.

The power supply system and gas removal from the crankcase have been additionally improved; the motor is designated 4215.10-30. If the oil consumption of the 421 family models is the same, then different fuels can be used.

To reduce the operating budget of a truck and minibus, the GAZ manufacturer switched many Gazelles and Sobols to A-76 gasoline. A similar modification of the UMZ engine for low-octane gasoline was designated 4215.10-10.

Then an injection version was required, but for all-wheel drive UAZs - minibuses, SUVs, trucks and utility vehicles. This 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 series 421 was the last from the UMP manufacturer with a lower camshaft. Already for the next generation of 429.10 high-speed internal combustion engines, the camshaft was moved inside the cylinder head, that is, located on top.

The table contains the main technical characteristics of the UMZ 421 motor:

Manufacturer	UMP
Engine brand	421
Years of production	1993 – …
Volume	2890 cm3 (2.9 l)
Power	72 – 92 kW (91 – 125 hp)
Torque moment	220 Nm (at 4200 rpm)
Weight	170 kg
Compression ratio	8,2 (7)
Nutrition	carburetor/injector
Motor type	in-line petrol
Ignition	switching, contactless
Number of cylinders	4
Location of the first cylinder	TVE
Number of valves on each cylinder	2
Cylinder head material	aluminum alloy
Intake manifold	duralumin
An exhaust manifold	combined with resonator and exhaust pipe
Camshaft	lower, OHV circuit
Cylinder block material	resin impregnated aluminum alloy
Cylinder diameter	100 mm
Pistons	the groove in the form of a truncated cone is part of the combustion chamber
Crankshaft	steel, then cast iron
Piston stroke	92 mm
Fuel	AI-92/A-76
Environmental standards	Euro-0 (Euro-4)
Fuel consumption	highway – 8.8 l/100 km combined cycle 11 l/100 km city ​​– 12.5 l/100 km
Oil consumption	maximum 0.3 l/1000 km
What kind of oil to pour into the engine by viscosity	15W40, 5W40, 10W30, 10W40, 20W40
Which engine oil is best by manufacturer	Liqui Moly, LukOil, Rosneft
Oil for UMZ 421 by composition	synthetic in winter, semi-synthetic in summer
Engine oil volume	6 l
Operating temperature	90°
ICE resource	declared 250,000 km actual 350,000 km
Adjustment of valves	nuts
Cooling system	forced, antifreeze
Coolant volume	10.7 l
water pump	with plastic impeller
Spark plugs for UMZ 421	Czech Brisk DR17YC/A
Spark plug gap	0.8 mm
Timing drive	gear
Cylinder operating order	1-3-4-2
Air filter	Nitto, Knecht, Fram, WIX, Hengst
Oil filter	removable with non-return valve full-turn
Flywheel	with clutch landing diameter 200 mm or 215 mm
Flywheel mounting bolts	M12x1.25 mm, length 26 mm
Compression	from 10 bar, difference in adjacent cylinders maximum 1 bar
XX speed	800 min-1
Tightening force of threaded connections	spark plug – 60 Nm flywheel – 70 – 88 Nm clutch bolt – 60 Nm Read also:  Density of diesel fuel and other characteristics - what is their role in determining the quality of fuel bearing cap – 120 Nm (main) and 60 Nm (rod) cylinder head – three stages 42 Nm, 106 Nm + 90°

The table provides a description of the parameters of the basic carburetor version 4218.10. Other engines use different attachments, the layout of the exhaust and intake tracts, and the injection systems have been changed.

Features of the UMZ 421 engine design

Unlike analogues of previous releases, the following changes have been made in the design of the 421st injection engine:

• use of dry type liners in the cylinder block;
• the piston pin is shifted upward by 7 mm (due to this, the load on the side walls is significantly reduced);
• the rear crankshaft support is sealed with a rubber seal instead of a cord gasket;
• The coolant is supplied directly to the cylinder block instead of the cylinder head.

Main modifications of UMZ engines

The UMZ 421 family consists of the following models:

Motor name	Brief description of the models' features
4218.10-10	Carburetor engine runs on AI 92 gasoline, compression ratio is 8.2. Generated power – 103 hp. With.
421.10; 421.10.30	Carburetor engines equipped with exhaust manifolds of improved design.
4213.10-40	The injection engine for UAZ complies with Euro-3 environmental requirements, the developed power is 117 hp. With.
4213.10-50	The injector, developed for UAZ cars, complies with international Euro-4 standards.
4215.10-10	Carburetor engine runs on A-76 gasoline.
4215.10-30	Carburetor, adapted for AI-92 fuel.
4216.10	Injection internal combustion engine, runs on AI-92, developed for Gazelles, supported by Euro-3 standards. The compression ratio is 8.8. Generated power – 123 hp. With.
42164.10	Injector, designed for Gazelle cars, engine power – 99 hp. With.
42164.10	The injection engine, designed for Gazelles, complies with Euro-4 standards. Maximum power is 125 hp. With. Equipped with a new camshaft design.
421647.10	Combined version, runs on both gasoline and gas. Power – 100 l. With.
· 42167.10	Gasoline engine, power is 123 hp. With.

The technical characteristics of the 421 engines on the UAZ do not differ from each other in terms of volume. All engines are equipped with a G 250 generator, a pre-heater, a fuel filter, and a shielding device for the P 132 sensor.

The basic ZMZ 421 engine in its family has models intended for military equipment. The markings of modifications 4219.10 differ depending on the type of installed attachment:

4179.10-01	The motor is mounted with a 254 mm lever clutch.
· 4179.10-13	Equipped with power steering.
· 4179.10-05	Adapted for a diaphragm clutch with a diameter of 240 mm.
· 4179.10-25	Equipped with a power steering pump.

By special order of the Ministry of Defense, high-voltage equipment was installed for modifications of internal combustion engines 4219.10.

Engine Modifications

Trying to eliminate the shortcomings, the designers constantly refined and corrected the unit. As a consequence, fixation of changes led to the appearance of modifications of the model, the performance characteristics of which differed.

The base engine “4218.10”, which became the basis for the rest of the modifications, had a defect due to which coolant penetrated into the oil through aluminum pores. It was not possible to eliminate the defect by replacing seals and gaskets. The designers used the technology of impregnating the frame with resin, after which the defects disappeared, and the modification received the marking “421.10”.

In order to increase the impulse at lower speeds and the power of the unit, an improved resonator was supplied to the product and the compression ratio in the combustion chamber was increased. Modification “421.10-30” after modification is installed on the Gazelle car. The same engine with a modernized power supply and exhaust gas removal mechanism is marked as “4215.10-30”.

In order to reduce fuel costs, UAZ engines used for buses and trucks began to be converted to fuel with a lower octane number “A-76” (“4215.10-10”).

The appearance of the UAZ 421 engine injector, which was intended for installation on vehicles with all-wheel drive, led to the creation of a new modification “4213.10”. A special feature of the engine is the use of a cast iron camshaft, which made the modification stand out in comparison with a carburetor product. The same motor with a modified fan drive was installed on the Gazelle, product identifier “4216.10”.

Types of UAZ with carburetor (421...):

Designation	Explanation
…8.10	Base, A-76, compression 7, 98 horses, Euro-1;
…8.10-10	Analogue “...8 .10”, AI-92, compression 8.2, 103 horses;
….10	Analogous to “...8 .10”, with a modified release;
….10-30	Analogous to “...8.10-10”, with a modified release;
…3.10-40	Analogue “….10-30” with an injector, environmental standards “Euro-3”, 117 horses;
…3.10-50	Analogue “...3.10-40”;
…5.10-10	Analogous to “...8.10”;
…5.10-30	Analogue “...8.10-10”;
…6.10	Analogue “...5.10-30” injector, AI-92, compression 8.8, 123 horses, Euro-3;
…61.10	Analogue “...6.10”, 99 horses;
…64.10	Analogous to “…6.10”, different camshaft, 125 horses, “Euro-4”;
…647.10	Analogue “...64.10”, gas and gasoline, 100 horses;
…67.10	Analogue “...6.10”, gas and gasoline, 123 horses;
…61.10	Analogue “...6.10”, 99 horses.

Frequency of motor monitoring and adjustments

When calculating the power plant, the designers determined the operating life of the unit at the level of 250,000 km. To achieve the specified period, the following is configured and adjusted:

• 10,000 km: change the oil filter and engine lubrication;
• 15,000 km: valve adjustment 421 engine;
• 20,000 km: control and replacement of exhaust, pipes, belts, spark plugs, battery, etc.;
• 30,000 km: change the air filter, check the pan ventilation;
• 40,000 km: change the cooler and fuel filter;
• 60,000 km: oxygen sensor monitoring.

Replacing the oil filter:

The same deadlines for the work are observed after the overhaul, regardless of how many manipulations are performed. For engines running on gas and gasoline, seals are replaced more often. You can also read about the UAZ Patriot Razdatka.

Adjusting engine valves UAZ 421

The design of this engine provides for periodic adjustment of the valve clearances in the gas distribution mechanism. The valves must be adjusted after a travel distance of 5 thousand kilometers. If certain changes are noticed in the operation of the engine, the established period will have to be reduced. The main signs of violation of the clearance adjustments of the valve system of the gas distribution mechanism:

1. Reduced engine power.
2. You can hear the valves tapping.
3. The appearance of flashes inside a working carburetor.
4. Popping noises similar to the sounds of gunshots in the muffler area.

Tip: To avoid distractions when adjusting valve clearances yourself, it is recommended to purchase a new part called a “valve cover gasket” in advance.

In the process of adjusting the gaps between the valves and adjacent parts - rocker arms, the ignition timing is set. The distances between adjustable parts should be:

• 0.3 – 0.35 mm – for valves of cylinders I and IV;
• 0.35 – 0.4 mm – for the rest.

Description of the valve adjustment process on the ZMZ 421 engine

The work is performed in the following order:

1. When the piston of cylinder I is at the top point of TDC, align the crankshaft mark (2) with the pin (1) located on the camshaft gear cover.
2. Ensure that the distributor spark is directed to the spark plug of cylinder I. The location of the distributor resembles the hands of a clock showing the time 10:00.
3. Set a gap of 0.35 mm between the valves and the corresponding rocker arms using a special feeler gauge.
4. Turn the crankshaft.
5. Adjust the distances between the following paired parts.

Gap adjustment:

• insert the dipstick into the gap with some force;
• loosen the tightening torque of the locknut (5);
• use the adjusting screw (4) to decrease/increase the gap.

Advantages and disadvantages of UMZ 421 engines

Like all mechanisms that have a complex structure, these engines have both a large number of advantages and some disadvantages.

Main advantages:

• The performance characteristics of power units have been significantly improved, thanks to improvements - boring of the cylinder walls.
• The exhaust system has been modernized.
• It is possible to carry out repair and restoration work with your own hands in a garage.
• The intake system has been modernized, which has led to an increase in power performance.
• A rear crankshaft bearing seal made of high quality rubber is installed.
• The service life of the engine has been increased (not less than 250 thousand km).

List of disadvantages:

• Due to poor-quality metalworking, numerous leaks of working fluids of internal combustion engine systems often occur: coolant, engine oil.
• Mixing oil with gasoline and antifreeze.
• High consumption of fuel and lubricants.
• The need for frequent valve clearance adjustments.

Installation

Car owners often do the work themselves using garage tools. After the owner has decided which carburetor is better for the 421 UAZ engine, the device is installed. The carburetor on the UMZ 421 is no exception, especially since replacing the standard device will not be difficult. For a smooth ride, it is necessary to make the gas pedal mechanism a cable mechanism, and also redo the choke rod.

Modifications to DAAZ will require more intervention. The mounting holes do not line up with the studs on the intake manifold, which makes installation very difficult for inexperienced technicians. The accelerator and choke mechanism also need to be redone; there are ready-made options for auto analysis.

Before installing a used carburetor on the UMZ 421, you must thoroughly rinse the body and internal parts and replace all seals. It is not recommended to install jets from a repair kit; it is best to select the size after installation on the motor. There are many types of fuel mixture supply systems from Solex

Not all models are suitable for the parameters of the UAZ; it is important to study the design features before installation and the compatibility of components

Cars with engines of the ZMZ 421 family

Most power units produced at the Ulyanovsk Motor Plant are popular among well-known automakers. The UMZ 421 engine is no exception. SUVs equipped with engines of the 421 family

UAZ Hunter;

• Leopard;
• Patriot;
• 3160;
• 3161;
• Tiger 2330;
• Simbir 3162.

Trucks:

• Cargo;
• Pickup;
• 39095.

List of internal combustion engine modifications

Traditionally, for the Ulyanovsk Motor Plant, management develops motors in series. The main engine was 4218.10 with Euro-1 characteristics, power 98 hp. s., compression ratio 7 units. The UMZ 421 engine family includes several modifications:

• 4218.10-10 – carburetor, to adapt to AI-92 gasoline, the compression ratio is increased to 8.2, power is increased to 103 hp. With.;
• 421.10 – carburetor, new exhaust tract design;
• 421.10-30 – carburetor, exhaust manifold of a different design;
• 4213.10-40 – injector for UAZ, Euro-3, power 117 hp. With.;
• 4213.10-50 – injector for UAZ, Euro-4;
• 4215.10-10 – carburetor for A-76;
• 4215.10-30 – carburetor, for AI-92;
• 4216.10 – injection, for AI-92 for Gazelles, Euro-3, compression ratio 8.8, power 123 hp. With.;
• 42164.10 – injector for Gazelle, power 99 l. With.;
• 42164.10 – injection, for Gazelle, Euro-4, power 125 hp. p., new camshaft;
• 421647.10 – gas-gasoline version with a capacity of 100 hp. With.;
• 42167.10 – gas-gasoline version with a capacity of 123 hp. With.

UMZ 4213.10

UMZ 4215.10

UMZ 4216.10

Gasoline UMZ 421647.10
A distinctive feature of the 421 engine family is the availability of version 4219 for military equipment. Depending on what attachments are used in the internal combustion engine configuration, there are several options for 4219.10:

• 4179.10-01 – for a 254 mm lever type clutch;
• 4179.10-13 – power steering added;
• 4179.10-05 – for diaphragm clutch with a diameter of 240 mm;
• 4179.10-25 – power steering pump added.

Military version 4219.10

Features of maintenance of 421 engines

In the list of technical characteristics of this engine there is an item indicating an operational life of 250 thousand kilometers. This mileage is possible subject to compliance with the maintenance regulations. The list of works includes the following items:

Name of components, parts, consumables to be replaced	Recommended deadlines for completing work
Engine oil	10 thousand km
Oil filter	10 t. km
An exhaust manifold	20 t. km
Fuel rail, fuel line, spark plugs	20 t. km
Attachment Belt	20 t. km
Air filter	30 t. km
Fuel filter	40 t. km
Coolant (antifreeze, antifreeze)	40 t. km
Oxygen sensor	60 t. km
Adjusting valve clearances	15 t. km

Engines running on combined fuel (gasoline, gas) require maintenance much more often. The data shown in the table is not suitable for them.

Technical characteristics of the UAZ-421 engine

UAZ 421 engine technical characteristics:

Explanation	Meaning
Using the motor	“Loaf”, “Bars”, “Hunter”, etc.
The motor is produced	1993 to today
Engine fuel	A-76(92)
Motor, environmental standards	"Euro 0-4"
Ticks, (number)	«4»
Engine volume, (l)	2,890
UAZ frame, (alloy)	aluminum
Number of cameras, (pcs.)	"four"
Motor chamber, (location)	row, vertical
Valves, (pcs.)	"eight"
Spark plugs for 421 UAZ engine, potassium number	11/14/17
Camera operation, (order)	«1243»
Chamber cross-section, (m)	0,1
Gap between the extreme points of the displacer, (m)	0,092
Compression	«7», «8,2», «8,8»
Motor power, (hp)	98-125
Torque turning the shaft, (Nm)	220
Unit weight, (kg)	170
Motor operating time, (km)	250000
Engine mixture formation	carburetor/injector
Fuel consumption: highway*mixed (l/100)	10*11
Lubrication supply	pressure + steam
Lubricant volume, (l)	5,8
Engine lubricant	5(10)W-30 (40), 15(20)W-40
Lubrication loss, (l/thousand km)	0,1
Reducing engine temperature	Liquid, closed, fan

Being the successor to the UAZ-417, the new modification received a larger volume and, as a result, larger exhaust valves (39mm). It is noteworthy that the injector began to be installed on cars relatively recently, due to which fuel efficiency, in comparison with a carburetor, has improved. The disadvantage of the model is the lack of hydraulic compensators, so the valve clearance of the UAZ 421 engine requires adjustment every 10,000 km.

UAZ camshaft (cast iron):

Description of the most common problems with 421 engines

Special grooves in the pistons of new engines help protect the valves from possible deformations. The list of main defects in the operation of 421 engines includes the following items:

1. Coolant leakage into cylinder cavities and lubrication system.
2. Unstable idle speed.
3. Reduced power.
4. Knocks in the crankshaft bearings.

To identify the locations of engine breakdowns, computer diagnostics are carried out in service centers. To eliminate identified defects, it is necessary to replace worn components and parts, as well as adjust the temperature clearances of the valves.