Engine structure (Chevrolet Lanos T150)

The engine is gasoline, four-stroke, four-cylinder, in-line, eight-valve, with an overhead camshaft. It is located transversely in the engine compartment. The firing order of the cylinders is 1-3-4-2, counting from the auxiliary drive pulley.

Fuel system - phased distributed fuel injection (euro-3 toxicity standards). The engine with the gearbox and clutch form a power unit - a single block, fixed in the engine compartment on three elastic rubber-metal supports. The right support is attached to the bracket located on the front wall of the cylinder block, and the left and rear ones - to the brackets of the gearbox housing.



On the right side of the engine (in the direction of the vehicle's movement) located: timing drive and coolant pump (toothed belt), generator and power steering pump drive (poly V-belt), air conditioning compressor drive (v-belt), oil pump, thermostat, crankshaft position sensor.

On the left are located: ignition coil and coolant temperature sensor.

Front: Exhaust manifold, oil filter, oil level indicator, spark plugs, air conditioning compressor (bottom right).

Rear: intake manifold with throttle assembly, fuel rail with injectors, exhaust gas recirculation valve, generator, starter, low oil pressure sensor, purge valve of the adsorber, phase sensor, knock sensor, coolant pump supply pipe, coolant temperature gauge sensor.











The cylinder block is cast from cast iron, the cylinders are bored directly in the block. The cooling jacket and oil channels are made in the body of the cylinder block.

At the bottom of the cylinder block there are five main bearing supports of the crankshaft with removable covers, which are attached to the block with special bolts. The holes in the cylinder block for the bearings are processed with the covers installed, therefore the covers are not interchangeable and are marked on the outer surface with numbers (timing pulley count).

The crankshaft is made of high-strength cast iron, with five main and four connecting rod journals. The shaft is equipped with eight counterweights, cast integrally with it. The liners of the main and connecting rod bearings of the crankshaft are steel, thin-walled, with an antifriction coating. The main and connecting rod journals of the crankshaft connect the channels located in the shaft body. The axial movement of the crankshaft is limited by two liners with thrust flanges of the third main bearing. At the front end (nose) of the crankshaft are installed: a toothed pulley of the timing mechanism (GRM) drive and a pulley of the auxiliary units drive. The flywheel is attached to the crankshaft flange with six bolts. It is cast from cast iron and has a pressed-on steel toothed ring for starting the engine with a starter.

Connecting rods are forged steel, I-section. The connecting rods are connected with their lower heads through liners to the crankshaft connecting rod journals, and with their upper heads through piston pins to the pistons.



The pistons are made of aluminum alloy. The hole for the piston pin is offset relative to the axis of symmetry of the piston by 0.7 mm toward the rear wall of the cylinder block. Three grooves for piston rings are machined in the upper part of the piston. The two upper piston rings are compression rings, and the lower one is an oil scraper ring.

Piston pins are steel, tubular in section. In the piston holes the pins are installed with a gap, and in the upper heads of the connecting rods - with tension (pressed in).

The cylinder head is cast from an aluminum alloy and is common to all four cylinders.

The head is centered on the block with two bushings and secured with ten bolts.

A sealing gasket is installed between the block and the cylinder head. The exhaust ports are located on the front side of the cylinder head, and the intake ports are located on the rear side. The spark plugs are screwed into the threaded holes of the cylinder head.

The valve seats and guide bushings are pressed into the cylinder head. The valve is closed by one spring. Its lower end rests on a washer, and its upper end rests on a plate held by two crackers. The crackers, when folded together, have the shape of a truncated cone, and on their inner surface there are flanges that fit into grooves on the valve stem. The valves are driven by a camshaft. The camshaft is cast iron and rotates on five supports (bearings) in an aluminum bearing housing that is attached to the top of the cylinder head. The camshaft is driven by a toothed belt from the crankshaft.



The valves are actuated by the camshaft cams through pressure levers, which with one shoulder rest on the hydraulic clearance compensators, and with the other through the guide washers - on the valve stems. The use of hydraulic compensators in the valve drive reduces the noise of the valve timing mechanism, and also eliminates its maintenance.

The engine lubrication is combined. Under pressure, oil is supplied to the main and connecting rod bearings of the crankshaft, the "support - camshaft journal" pairs and hydraulic compensators. The pressure in the system is created by an oil pump with internal gears and a pressure-reducing valve. The oil pump is attached to the cylinder block on the right side. The pump drive gear is mounted on two flats of the crankshaft nose. The pump takes oil from the oil pan through the oil receiver and supplies it through the oil filter to the main line of the cylinder block, from which oil channels go to the main bearings of the crankshaft and the oil supply channel to the cylinder head.

The oil filter is full-flow, non-separable, equipped with bypass and anti-drain valves. Splashing oil is supplied to the pistons, cylinder walls and camshaft cams. Excess oil flows through the cylinder head channels into the oil pan.

The crankcase ventilation system is a forced, closed type. The system is designed to reduce the emission of harmful substances from the engine crankcase into the atmosphere. Due to the vacuum in the intake manifold, gases from the engine crankcase enter the cylinder head cover through the ventilation hose. After passing through the oil separator located in the cylinder head cover, crankcase gases are cleaned of oil particles and enter the engine intake tract through the hoses of two circuits: the main circuit and the idle circuit, and then into the cylinders. Through the main circuit hose, crankcase gases are discharged in partial and full engine load modes into the space in front of the throttle valve. Through the idle circuit hose, gases are discharged into the space behind the throttle valve, both in partial and full load modes, and in idle mode.

The engine management, fuel supply, cooling and exhaust systems are described in the relevant chapters.

Reference

Counterweights. They are made on the continuation of the engine crankshaft cheeks. Counterweights are designed to balance the forces and moments of inertia that arise during the movement of the crank mechanism during engine operation.

Channels. They are made in the body of the crankshaft. They serve not only to supply oil from the main to the connecting rod bearings of the shaft, but also for centrifugal cleaning of engine oil from solid particles and deposits when the crankshaft rotates.

Flywheel. Provides removal of engine pistons from the top and bottom dead centers and more uniform rotation of the crankshaft in idle mode. Facilitates engine starting and its operation when the car starts moving.

Piston rings. Compression rings prevent gases from breaking through from the cylinder into the engine crankcase and help remove heat from the piston to the cylinder. The oil scraper ring removes excess oil from the cylinder walls when the piston moves.

Hydraulic compensator. It selects the gap between the camshaft cam and the valve pressure lever by moving the hydraulic compensator plunger under the action of its spring and supplying engine oil under pressure when the engine is running.

[The article was borrowed from the website: ChevyMan]