Compact ZiD 4.5 engine for a variety of applications

Engine purpose

The ZiD internal combustion engine is a single-cylinder, air-cooled, four-stroke gasoline engine. It was produced at the Degtyarev plant in the city of Kovrov from the mid-60s until almost the 90s of the last century. For its time, it was the most common motor for use in various agricultural units, such as pumps, crushers, various machine tools, circular saws, mini-tractors, conveyors, etc.

The ZiD 4.5 engine has become widespread due to its main advantages:

compactness;
simplicity of design;
reliability;
maintainability;
high technical parameters;
efficiency.

In addition, an important factor should be considered the ability of the engine to run on low-quality fuel, which is important for rural regions.

Among the shortcomings of the motor, it should be noted increased vibration, characteristic of all single-cylinder engines, which had to be taken into account when installing and fastening the unit.

Description

One of the features of this power unit is the presence of forced air cooling, which in turn prevents overheating of the engine when driving at low speeds.

This is a four-stroke single-cylinder power unit that has a power of 4.5 horsepower. Such power figures are achieved at 2000 rpm. This power unit has an extremely simple design and magneto ignition.

In fact, the ZiD 4.5 engine is an analogue of the German DKW power unit, which was manufactured in pre-war times. This development was distinguished by its reliability, so the Degtyarev plant took as a basis and actually copied such a durable and extremely easy to maintain single-cylinder four-stroke engine with a displacement of 520 cubic centimeters.

One of the distinctive features of the ZiD engine is its efficiency. Such an engine consumes approximately one and a half liters of fuel per hour of operation. At the same time, it easily runs on low-octane fuel, to which it is recommended to add a small amount of oil for additional lubrication of the power unit.

At the same time, certain disadvantages must be taken into account, including the poor balance of the single-cylinder engine. As a result, such a motor has significant vibration, and it must be correctly mounted on a walk-behind tractor or light tractor.

The carburetor system (ZID 12 type K-12ZH) of this power unit was also not reliable, so the car owner needed to open the carburetor quite often and check the float chamber.

Engine device

The design of the ZiD engine consisted of the following main units:

cylinder with block head;
crankshaft;
piston with connecting rod;
crankcase;
pallet;
valve box;
spark plugs with high-voltage wire;
oil pump with filter;
fuel tank;
flywheel;
gearbox;
fan with casing;
carburetor;
muffler;
air purifier;
racks for fastening.

The engine was equipped with a special two-stage reduction gearbox for removing and converting energy. In this case, a special pulley installed on the flywheel side was used for the belt drive. In addition, with the help of a pulley and cord, the engine was started, and at any gearbox speed. To operate the motor in stationary conditions, a special transmission sprocket was provided on the gearbox side.

It should be noted that aluminum was widely used in the production of engine components. The crankcase body, cylinder head and piston are made from an alloy of this metal.

Engine ZID 4.5-Device

This power unit was installed on self-propelled machines, as well as on stationary devices in order to mechanize manual labor when performing agricultural work of varying severity. ZID 4.5 engines were made in various configurations, depending on the purpose and characteristics of the landing gear and the technical characteristics of the base device.

List of main engine components:

Carter made of aluminum alloy.
Working cylinder, piston, connecting rod.
Crankshaft.
Aluminum cylinder head.
Spark plug.
Oil pan.
Oil filter.
Pump.
Fuel tank.
Carburetor.
Muffler.
Air purifier.

The ZID 4 5 engine also includes: a special two-stage reduction gearbox, a pulley, and a belt drive. The gearbox has a gear ratio of 1:6; 1:2, 91; to reduce the number of crankshaft revolutions.

The ZID engine is put into operation using a special device in the form of a cord. This cord wraps around the engine pulley and jerks sharply. The engine can be started immediately from the first or second gear of the reduction gearbox.

It also provides for starting the engine using the starting handle through the gearbox shaft. However, this method is not used often, since its promotion requires considerable effort.

Important: If the gearbox is installed in second gear, less force must be applied than when it is in first position. This is explained by the fact that the torque of the handle is transmitted to the crankshaft of the internal combustion engine directly through the gears of the gearbox.

Engine ZID 4 5 technical characteristics

Technical specifications

The operational and technical characteristics of the ZiD engine are:

type – petrol;
number of cylinders – 1 pc.;
volume – 520 cm3;
working process – 4-stroke;
cooling option - forced, air;
power – 4.5 l. With.;
speed at maximum power – 2000 rpm;
idle speed – 700 rpm;
fuel system – ZiD 12 carburetor;
gas tank capacity – 8.0 l;
fuel supply method – top gravity flow from the fuel tank;
fuel grade – gasoline A-72, A-76;
lubrication method - spraying, supplying oil to the tray using a plunger pump;
oil consumption – up to 20 g/hour;
oil system capacity – 1.6 l;
gas distribution - valve;
number of valves – 2 pcs.;
engine weight (dry) – 60 kg;
dimensions:
length – 0.63 m,
width – 0.58 m,
height – 0.73 m,

Standard operating time before major overhaul is 500 hours.

Modifications of ZID engines

Depending on the purpose, installation location and type of work performed, manufacturers produced these motors in various designs. For example, ZID-4.5 DU-M; ZID-4.5 VN-M.

The DU-M model is designed for water lift drives. It is equipped with a single-stage reduction gearbox, its gear ratio is 1:6. The VN-M motor drives the vacuum pump of the UDS-1-2S milking machines. A single-stage reduction gearbox with a gear ratio of 1:2.91 is used here. In these designs, a transmission sprocket of the chain mechanism is not provided.

For the convenience of choosing the appropriate model layout, the engines are equipped with special nameplates with the appropriate markings: “DU”, “VN”.

Engine Maintenance

Correct and timely maintenance of the power unit preserves the proper operation of the engine, extends the period of trouble-free operation, and allows you to maintain the specified technical characteristics of the ZiD 4.5. When servicing, you must perform the following simple operations:

Before starting the engine, be sure to check the presence and quantity of oil. If necessary, top up to the required volume.
After 40 hours of operation, perform a complete change of engine oil.
Inspect the air purifier every 5 hours of operation. Change oil and clean as needed.
Fill gasoline into the fuel tank through a special filter.
Flush the fuel tank sump every 50 hours of operation.
After 20 hours of operation, check and, if necessary, tighten the threaded connections.
As necessary, but no more than after 25 hours of operation, clean the cooling air fins of the cylinder body to prevent overheating.
In winter, drain the oil from the crankcase after finishing work and after a long break. Before starting the engine again, fill in oil heated to a temperature of 70˚C.

Use of ZID engines in mini tractors

The excellent technical data of the ZID 4 5 engine allow, in addition to stationary installations, to include them in the design of small vehicles - mini tractors. Most often it is a mini tractor with a ZID engine or a do-it-yourself walk-behind tractor with a ZID engine, made by skilled innovators.

In addition to single-cylinder stationary devices, in order to build a homemade mini tractor with a ZID engine, mechanics also dismantle two-cylinder engines from the following units:

motorized strollers;
motorcycles;
small passenger cars, etc.

A strong frame made using welding equipment is used as a strong basis for the mini tractor. The power unit and mechanical transmission are installed and securely mounted on such a frame. Homemade agricultural machinery copes with agricultural work in private areas. They have become widespread among numerous land owners, thanks to:

Relatively low material costs for maintenance and operation.
Easy to clean and maintain.
Compactness, relatively small dimensions, weight.
Economical.
Ease of operation.
Operating on low quality gasoline.
Excellent technical and operational characteristics of the ZID 4.5 engine.

In addition to tractors, the ZID engine is used in stationary mechanisms for individual use as indispensable assistants in the household:

pumps;
grains;
crushers;
machine tools (woodworking, metal-cutting, drilling, etc.);
circular saws;
walk-behind mowers;
conveyors.

Important: Among the few shortcomings of the ZID 4.5 engine, there is an increased tendency to vibration, inherent in single-cylinder designs. This factor is taken into account when installing and fixing power units on bases and frames.

In order to minimize engine vibration forces, during installation it is recommended to comply with the following requirements specified in the operating instructions:

The frame material is profiled steel.
The thickness of the installation shelf is not less than 7 mm.
The distance between the engine supports is no more than 500 mm.
It is not allowed to place the motor on separate pieces of metal of inappropriate rigidity.

Engine repair

The ZiD engine has a simple design, so if necessary, almost anyone familiar with the equipment can carry out repairs. To reduce the possibility of problems occurring in the power unit, it is imperative to observe the frequency and completeness of maintenance. In addition, every 300 hours of operation it is necessary to partially disassemble the ZiD engine. In this case, it is necessary to tighten the connecting rod bearing, grind the valves, clean the piston, valves, valve box, cylinder head from carbon deposits and clean the breaker contacts while simultaneously adjusting the gaps.

Malfunctions

FAULT	CAUSE
The motor has a significant drop in power.	First of all, you need to check the presence of ignition and, if possible, replace the spark plug. Next, we make sure that there is a high-quality fuel supply to the engine. Quite often it is necessary to open the engine and carry out diagnostics and eliminate the identified problems.
Significant vibrations are observed during engine operation.	As mentioned above, the engine is unbalanced and such vibration is a design feature. If you use this motor for various walk-behind tractors and agricultural tractors, you can make an additional wooden base that will absorb the vibration of the power unit.
The engine loses oil quickly.	If the engine actively consumes oil, but no traces of leaks are noted, then the cause is the rings through which the lubricant enters the cylinders and quickly burns out. This indicates a tired ZiD engine that requires expensive overhaul.
The engine refuses to start.	The cause of such a breakdown is problems with the carburetor and fuel system. It is necessary to ensure that fuel enters the cylinders by removing the supply line. It will also be necessary to clean the carburetor, which will solve starting problems.

Features of mini tractors with ZiD engine

Despite the fact that the power unit, by its design, was primarily a stationary source of energy, very often rural innovators made homemade mini tractors with a ZiD 4.5 engine.

As elements and components of such tractors, units and parts from a wide variety of motorcycles, sidecars, cars and trucks, and sometimes from serial tractors were used. But the basis of any design was a strong welded frame, which ensured installation and reliable fastening of the motor.

Manufactured homemade tractors with a ZiD engine ensured the performance of a variety of agricultural work in small areas. The low operating costs of such equipment were confirmed by the efficiency, reliability and ease of maintenance of the power unit.

Tuning

Among the possible tuning of ZiD engines, we can note the installation of a carburetor from a scooter and a unit with more power. This will make the mixture entering the cylinder richer, and power figures can increase to 5 - 5.5 horsepower.

Such tuning in no way affects the reliability of the power unit. There is no need to replace the oil pump or other attachments. There are no further opportunities to increase the power of this power unit.

Modifications of the UD-2 engine

During the production of this legendary domestic engine, the Ulyanovsk plant produced 4 main modifications. They differ from each other in power indicators, as well as design features:

UD2S-M1 - equipped with a RO-1 gearbox;
UD2T-M1 - distinguished by the presence of an 8-liter fuel tank;
UD2ST-M1 - provides for the presence of a gearbox and a fuel tank.

Be sure to read: Tractor MTZ 920 Belarus

It is necessary to mention the modification UD2-1MS, which was distinguished by the presence of an electric starter. It made it possible to make the engine start much more confident, thanks to which this modification was used in army equipment.