312000273 - INTRODUCTION - ENGINE

GLOSSARY

Hardened and tempered steel

Heat treatment applied to special steels to improve their mechanical properties: involves hardening followed by tempering to make the material much stronger.Tempering: consists of heating at temperatures < 720°C followed by slow cooling in order to lessen the effects of the tempering without removing them.In this way, the material returns to conditions that are closer to a stable chemical and physical balance.Hardening: this is achieved when the metal structure is at a high temperature, when it is harder and more resistant than when cold.

CONTROL AREA NETWORK (CAN)

The CAN is a communication network that allows the transmission of data between the ECU and other vehicle system computers.The advantage of this system lies in the fact that the need for long wiring is contained and the number of sensors reduced (because, from the moment the computers are connected by the data transmission system, the information supplied by a sensor can be used simultaneously by various devices).The CAN also allows improvement in the fault diagnosis system capacities, faster transmission of signals and electrical/magnetic compatibility of components (relationship between various electrical and electronic circuits on the vehicle and interaction between the vehicle and surrounding conditions).The circuit that connects the ECU with the other terminals is an integrated circuit known as a CAN interface. It has the function of converting the messages received via the data transmission system into the appropriate format.

Condensation

This is the change of a substance from a vapour to a liquid state, the opposite of evaporation; it takes place through compression or cooling.

DUCTILE CAST IRON

Ductile cast iron is cast iron that, through the addition of cerium and magnesium, contains globules or balls of carbon in a graphite state in a predominantly ferrous matrix with the consequent improvement of all mechanical and technological properties. It can therefore be forged, welded and worked with tools.It is used very extensively also because, unlike normal cast iron, it has high resistance and percentage extension values.

Evaporation

The phenomenon, also known as vaporisation, when a body changes from a liquid state to a gaseous state,occurs at any temperature but, everything else being equal, the lower the temperature, the slower the change.

PWM MODULATION OPERATING CYCLE

This is an impulse frequency and modulated width fixed voltage produced by the ECU for the operation of the solenoids. A PWM voltage supply consists of a series of single polarity square waves whose duration is altered by the ECU in response to demand.
A. OffB. OnC. Low resulting currentD. Average resulting currentE. Maximum resulting currentThe PWM modulation resulting current varies in proportion to the Wave-Space ratio. The Wave-Space ratio is the relationship between periods of "supply - on" and "supply - off". This ratio can be considered as a percentage and, in fact, this is the form of measurement for the Operating Cycle.

Sensor

It is a system that reacts when subject to any form of energy by changing its state, i.e. one or more of its properties (resistance, volume, temperature etc.).For example, a sensor is a material which undergoes conductivity changes when submerged in a magnetic field.New-generation sensors are solid-state devices produced using microelectronic processes that can take environmental readings and produce responses in the form of electrical signals for subsequent processing and so that final checks can be conducted.Sensors are therefore able to measure force, acceleration, pressure and temperature of gases, liquids and solids, concentration of gases such as nitrogen oxides, oxygen, etc.

Viscosity

Material property whereby the particles in a body encounter resistance as they slide over one another.The resistance value or internal friction depends on the nature of the body: large in solids, very small in viscous liquids, nil in gases.In liquids, viscosity drops rapidly as temperature rises.

SPECIFICATIONS

4 cylinder in line, 16 valve 1368 cc engine with TOHC with a Bosch ME 7.9.10 electronic injection/ignition system.POWER - 74 kW -100 bhp EEC at 6000 rpmTORQUE - 13.1 daNm - 13.2 kgm EEC at 4250 rpmCYLINDER ARRANGEMENT - 4 in lineBORE - 72 mmSTROKE - 84 mmCYLINDER CAPACITY - 1368 ccCYLINDER HEAD - aluminiumCRANKCASE - cast ironCRANKSHAFT - ductile cast iron with 8 counter-weights and 5 main bearings with torsional damperTIMING SYSTEM - two overhead camshafts, with drive transmission through gears with clearance recovery by intake and exhaust shafts, hydraulic tappets, 4 valves per cylinderFUEL SYSTEM - returnless system with phased sequential Bosch injectionIGNITION - completely electronic with individual coils (pencil coils)POLLUTION-CONTROL DEVICES - three-way catalytic converterLUBRICATION - forced with lobe geared pumpCOOLING - liquid with forced circulation via centrifugal pump and sealed circuit; radiator and supplementary expansion tank

COMPOSITION

The systems involved in the operation of the engine are:

  • fuel supply system
  • air supply system
  • exhaust system with catalytic converter
  • fuel vapour recirculation system
  • engine cooling system.
The operation of these systems is optimised by an electronic control system governed by a control unit.    See descriptions 1056 PETROL INJECTION SYSTEM

Assembly view

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1. Engine and power unit2. Fuel tank and pipes3. Pump(s) and supply circuit devices4. Engine air supply circuit5. Petrol fuel injection system6. Exhaust pipes and silencers7. Emission control system8. Engine lubrication9. Engine cooling

Fuel supply system

This is returnless with an electric fuel pump submerged in the tank and enclosed in a container together with the pressure regulator, the level gauge and the filter.    See descriptions 1040 FUEL TANK AND PIPES

Air supply system

Air supply system with plastic intake manifold and large air filter casing to limit intake noise.    See descriptions 1048 ENGINE AIR SUPPLY CIRCUIT

Exhaust system

The exhaust system has a post-treatment system for the exhaust gases with a Lambda sensor and catalytic converter fitted in the engine compartment    See descriptions 1076 EXHAUST PIPES AND SILENCERS

Emission control system

The following emission control systems are used on this model:

  • Exhaust emission control system with a three-way catalytic converter and two lambda sensors, one downstream and one upstream of the catalytic converter;
  • crankcase vapour/gas recirculation system;
  • fuel evaporation control system.
    See descriptions 1080 EMISSION CONTROL SYSTEM

Cooling system

Forced circulation with centrifugal vane pump.    See descriptions 1088 ENGINE COOLING