Engine ZMZ-4061 and 4063 carbureted, four-cylinder, in-line, four-stroke with four valves per cylinder and two camshafts in the block head

Cylinder firing order: 1–3–4–2.

The cylinder block is cast iron, the cylinders are bored directly in the block.

There are passages for coolant between the cylinders.

The drive of the coolant pump with a fan and the alternator is by a V-ribbed belt located in front of the engine.

The clutch housing is attached to the rear mating plane of the cylinder block.

ZMZ-40630 engine of GAZ-2705 car

The power unit is attached to the car body on three supports - two rubber cushions are placed on the right and left sides of the engine, the third support is installed under the rear gearbox housing.

Crankshaft - cast iron, cast, rotates in five main plain bearings. The axial movement of the shaft is limited by four thrust half rings.

Connecting rods - steel, forged, I-section, the lower (split) head they are connected to the crankshaft through connecting rod plain bearings, the upper head - with a piston pin.

The finger is a floating type, i.e. it rotates freely in the piston bosses and in the bronze bushing of the upper head of the connecting rod.

The axial movement of the piston pin is limited by two retaining rings installed in the grooves of the piston bosses.

Pistons are cast, made of aluminum alloy, with two compression and one oil scraper rings.

During operation, the pistons are cooled by a jet of oil through the holes in the upper heads of the connecting rods.

Cylinder head cast aluminum alloy with pressed cast iron seats and valve guides.

The valves are actuated through cylindrical hydraulic tappets, so the valve actuator does not need to adjust the clearances.

Camshafts - cast, cast iron, each rotates in five plain bearings.

They are kept from axial displacement by plastic half-rings installed in the grooves of the front covers and the grooves of the front bearing journals of the shafts.

Camshaft drive - chain, two-stage (through an intermediate shaft sprocket).

The tension of both chains is provided by automatic hydraulic tensioners powered by pressure in the lubrication system.

Engine lubrication system - combined: main and connecting rod bearings of the crankshaft, piston pins, camshaft bearings, bearings of the intermediate shaft and oil pump drive shaft, hydraulic pushers and helical gears are lubricated under pressure.

The rest of the parts are splashed.

Oil pump - gear, single-section driven by an intermediate shaft through a pair of helical gears.

An oil cooler and a full-flow filter are integrated into the lubrication system.

The crankcase ventilation system is closed, forced, with crankcase gases being removed through the oil separator to the intake system.

The engine has an exhaust gas recirculation system. It directs part of the exhaust gases into the intake manifold, thereby reducing toxicity.

Cooling system — liquid, closed type with forced circulation.

The coolant pump is a centrifugal type, driven from the crankshaft by a V-ribbed belt together with a fan. A thermostat is built into the cooling system.