Cruze

Engine Component Description

The cylinder hollow frame structured in-line 4 cylinder. The block has 5 crankshaft bearings with the thrust bearing located on the third bearing from the front of the engine.

The crankshaft is a steel crankshaft. It is supported in 5 main journals with main bearings which have oil clearance for lubrication. The 3rd bearing is the thrust bearing which controls the proper axial end play of the crankshaft. A harmonic damper is used to control torsional vibration.

The engine is equipped with a variable oil pump. The oil pump is integrated into the engine front cover and provides different oil pressure values depending on the engine speed.

The sump is a structural aluminium sump with transmission attachment points. The oil suction gallery for the oil pump is integrated into the sump.

The pistons are aluminium pistons. The connecting rods are made of fractured steel. The piston pin is floating in piston bore and shrinked in connecting rod.

This cylinder head is a double over head camshaft (DOHC) type and has 2 camshafts that open 4 valves per cylinder with hydraulic valve clearance adjusters and hydraulic valve clearance adjuster arms. The cylinder head is made of cast aluminium alloy for better strength and hardness while remaining light weight. The combustion chamber of the cylinder head is designed for increasing of squish and swirl efficiency to help maximise petrol combustion efficiency.

A timing chain is used for camshaft drive. There is a tensioner to control the tension of the chain. The engine is equipped with a variable camshaft timing system. The camshaft adjuster will readjust itself depending on the engine speed. The valve timing readjusts to reduce fuel consumption and provide optimal power and torque.

The inlet manifold provides the air flow passage to the combustion chambers through the throttle body. The inlet manifold along with the throttle body have an effect on engine torque, power, noise, drivability, emission, fuel economy and performance. The inlet manifold is made of plastic for better strength while maintaining light weight.

The turbocharger consists of turbine and compressor on a common shaft. The shaft bearing is constructed to higher rotation speed and lubricated by engine oil. The turbocharger is water cooled for improved durability. The turbine wheel is driven by exhaust emissions. The compressor wheel compresses the intake air. A bypass valve (Wastegate) regulates the charging pressure for generating a high pressure at low speed as well. At a defined charging pressure it regulates the way of the exhaust emission on bypassing the turbine wheel. The Wastegate valve is controlled pneumatic and electric from the pressure in the intake manifold. The pressure of exhaust emission is reduced by opening the Wastegate thereby reducing the intake pressure.

The crankcase ventilation system is used to consume crankcase vapours in the combustion process instead of venting vapours to the atmosphere. Fresh air from the intake system is supplied to the crankcase, mixed with blow-by gases and then passed through a calibrated orifice into the intake manifold. The primary control is through the positive crankcase ventilation (PCV) orifice which meters the flow at a rate depending on inlet vacuum. The PCV orifice is an integral part of the camshaft cover. If abnormal operating conditions occur, the system is designed to allow excessive amounts of blow-by gases to back flow through the crankcase vent into the inlet system to be consumed by normal combustion.