Engine Description

WARNING: This page is about a different variant/trim than selected.

Engine Block

The cylinder block is constructed of aluminum alloy by high-pressure die casting with 4 cast-in-place iron cylinder liners arranged in-line. The block has 5 crankshaft bearings with the thrust bearing located on the second bearing from the rear of the engine. The cylinder block incorporates a bedplate design that forms an upper and lower crankcase. This design promotes cylinder block rigidity and reduced noise and vibration.

Crankshaft

The crankshaft is forged micro alloy steel. It is supported in 5 main journals with main bearings which have oil clearance for lubricating. The thrust bearing is located in the 4th position which controls proper crankshaft axial end play. The crankshaft is also comprised of 4 counterweights that have been scalloped for mass reduction and precise engine balance. A harmonic balancer is used to control torsional vibration.

Piston and Connecting Rod

The pistons are cast aluminum. The pistons use 2 compression rings and 1 oil control ring assembly. The piston is a low friction, lightweight design with a recessed top and barrel shaped skirt. The piston pins are chromium steel and are a full-floating design. The connecting rods are powdered metal. The connecting rods are fractured at the connecting rod journal and then machined for the proper clearance. All applications use a piston with a graphite coated skirt. The piston and pin are to be serviced as an assembly.

Lower Oil Pan

The oil pan is made of synthetic material. The oil pan is attached at the engine block lower structural extension.

Engine Block Lower Structural Extension

In the engine block structural extension is the oil pump and the balance shafts installed.

The balance shafts are driven by the balance chain. The chain is tensioned by a hydraulic tensioner that is supplied pressure by the engine oil pump. This design promotes the maximum effectiveness of the balance shaft system and reduces noise and vibration.

The oil pump assembly is fastened directly to the rear of the balancer shaft assembly and by the oil pump drive shaft. The oil pump assembly possesses variable flow capability which is made possible by a shift of the circular vane arrangement and the actuation of an oil control valve assembly guided by the ECM. The variable flow capability of the pump optimizes oil flow to the engine components when needed. During performance maneuvers and acceleration the oil pump operates in a steady high pressure state. However, during steady low load touring speeds on level terrain the oil pump operates in a steady low pressure state.

Cylinder Head

This cylinder head is double over head camshaft (DOHC) type. The cylinder head is made of cast aluminum alloy for better strength in hardness with light weight. The combustion chamber of the cylinder head is designed for increasing of squish and swirl efficiency and then this is maximized to gasoline combustion efficiency. The exhaust manifold is integrated into the cylinder head.

Valves

There are 2 intake and 2 exhaust valves per cylinder. Positive valve stem seals are used on all valves.

Valve Lash Adjusters

The valve train uses a roller finger follower acted on by a hydraulic lash adjuster. The roller finger follower reduces friction and noise.

Camshaft Carrier

In the camshaft carrier the two camshafts are. The camshaft carrier has mounting locations for the ignition system and the camshaft position actuator for the cylinder disconnection.

Camshaft

Two camshafts are used, one for all intake valves, the other for all exhaust valves. The camshafts are assembled with steel lobes.

The camshafts consist of several segments that are displaceable. As a result, two cylinders can be switched off. The movement of the segments of the camshaft is controlled by the camshaft position actuators in the camshaft carrier.

Camshaft Drive

A roller chain is used for camshaft drive. There is a tensioner and active guide used on the slack side of the chain to control chain motion and noise. The chain drive promotes long valve train life and low maintenance.

Intake Manifold

The intake manifold is the air flow passage to the cylinder combustion chamber through the throttle body and has an effect on engine torque, power, noise, driveability, emission, fuel economy and performance. It is made of composite plastic.

Turbocharger

The turbocharger is the device that supplies hot, compressed air, that is from the turbine/impeller created from the passing exhaust gas or ram air, to the engine to increase the power. Quick compressed air from this turbocharger expands with high temperature and causes decreasing of charging efficiency into the cylinder because density of oxygen gets lower. However charging efficiency into the cylinder increases as compressed hot air is cooled and density of air gets higher through the charge air cooler. It brings also higher fuel efficiency as well as lower CO2 emissions. Charge air cooler which is installed on top of radiator in front of car makes compressed hot air cool by airflow through the radiator grill. With the variable turbine geometry turbocharger the boost pressure is optimized in all engine conditions.

Fuel Injection System

The engine is equipped with a central direct injection system. The fuel system consists of 4 separate direct injection fuel injectors, one high pressure fuel rail, and a high pressure fuel feed pipe that connects the high pressure fuel pump to the fuel rail. The injectors are each seated into their individual bores in the cylinder head with two combustion seals to provide sealing. The high pressure fuel pump mounts to the rear of the cylinder head and is driven by the intake camshaft. Motion is transmitted to the pump from a quad-lobe on the rear of the camshaft through a hydraulic roller lifter. Due to the location of the central direct injection system injector location this provides an increase in fuel economy and performance.