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SATIZ CNG NEF Series Technical And Repair Manual

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CNG NEF SERIES
Vehicle application
N60
N60 ENT G
Technical and Repair manual

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Summary of Contents for SATIZ CNG NEF Series

  • Page 1 CNG NEF SERIES Vehicle application N60 ENT G Technical and Repair manual...
  • Page 2 This publication describes the characteristics, data and correct methods for repair operations on each component of the ve- hicle. If the instructions provided are followed and the specified equipment is used, correct repair operations in the pro- grammed time will be ensured, safeguarding against possible accidents.
  • Page 3 CNG NEF ENGINES CNG NEF ENGINES Part 1 F4B Engines...
  • Page 4 CNG NEF ENGINES...
  • Page 5 CNG NEF ENGINES SPECIAL REMARKS Where possible, the same sequence of procedures has been followed for easy reference. Diagrams and symbols have been widely used to give a clearer and more immediate illustration of the subject being dealt with, (see next page) instead of giving descriptions of some operations or procedures.
  • Page 6 CNG NEF ENGINES PRELIMINARY REMARKS Manuals for repairs are split into Sections, each one of which is marked by a numeral; the contents of these sections are indicated in the general table of contents. Each section is generally dedicated to a main Unit (e.g.: engine, gearbox, electric system, etc.). Sections with mechanical contents include technical data, tightening torque collections, tool lists, connections —...
  • Page 7 CNG NEF ENGINES Graph and symbols Removal Intake Disconnection Refitting Exhaust Connection Removal Operation Disassembly Fitting in place ρ Compression ratio Assembly Tolerance Tighten to torque Weight difference Tighten to torque + angle value Rolling torque α Replacement Press or caulk Original spare parts Regulation Rotation...
  • Page 8 CNG NEF ENGINES...
  • Page 9 CNG NEF ENGINES Part 1 F4B ENGINES Section General specifications Fuel General overhaul Tools Appendix Safety prescriptions PREFACE TO USER’S GUIDELINE MANUAL Section 1 describes the F4B engine illustrating its features and working in general. Section 2 describes the type of fuel feed. Section 3 relates to the specific duty and is divided in four sepa- rate parts: 1.
  • Page 10 CNG NEF ENGINES...
  • Page 11 CNG NEF ENGINES UPDATING Section Description Page Date of revision...
  • Page 12 CNG NEF ENGINES...

  • Page 13: Table Of Contents

    CNG NEF ENGINES SECTION 1 - GENERAL SPECIFICATIONS SECTION 1 General specifications Page CORRESPONDENCE BETWEEN TECHNICAL CODE AND COMMERCIAL CODE ... . . LUBRICATION ......OIL VAPOUR RECIRCULATING SYSTEM .
  • Page 14 SECTION 1 - GENERAL SPECIFICATIONS CNG NEF ENGINES...

  • Page 15: Correspondence Between Technical Code And Commercial Code

    CNG NEF ENGINES SECTION 1 - GENERAL SPECIFICATIONS CORRESPONDENCE BETWEEN TECHNICAL CODE AND COMMERCIAL CODE Technical Code Commercial Code F4BE0641A*G102 N60 ENT G F4BE0641A*G103 N60 ENT G F4BE0641A*G105 N60 ENT G...
  • Page 16 SECTION 1 - GENERAL SPECIFICATIONS CNG NEF ENGINES...

  • Page 17: Lubrication

    CNG NEF ENGINES SECTION 1 - GENERAL SPECIFICATIONS Lubrication involves the heat exchanger (2,3), the LUBRICATION turboblower for turbocompressed versions, and for any Lubrication by forced circulation is achieved through oil rotary compressed air system. expansion pump, placed in the front part of the basement, All these components may often vary according to the specific driven by the straight-tooth gear splined to the shaft’s bar hold.

  • Page 18: Oil Vapour Recirculating System

    SECTION 1 - GENERAL SPECIFICATIONS CNG NEF ENGINES OIL VAPOUR RECIRCULATING SYSTEM Figure 2 3240t 1. Valve - 2. Breather pipe - 3. Tappet Cap. On the tappet cap (3) there is a valve (1) whose duty is to condense oil vapour inducing these to fall down because of gravity, to the Tappet cap underneath.

  • Page 19: Cooling System

    CNG NEF ENGINES SECTION 1 - GENERAL SPECIFICATIONS - Visc pusher fan, having the duty to increase the heat COOLING SYSTEM dissipating power of the radiator. This component as well The engine cooling system, closed circuit forced circulation will be specifically equipped based on the engine’s type, generally incorporates the following components: development.

  • Page 20: Air Induction Boost Diagram

    SECTION 1 - GENERAL SPECIFICATIONS CNG NEF ENGINES AIR INDUCTION BOOST DIAGRAM Figure 4 TURBOCHARGER AIR FILTER EXHAUST RADIATOR 74195 Description The turbocharger is equipped with a transforming valve to regulate the pressure , that is located on the exhaust collector The turbocharger is composed by the following main parts: before the turbine and connected by piping to the induction one turbine, one transforming valve to regulate the boost...
  • Page 21 CNG NEF ENGINES SECTION 2 - FUEL SECTION 2 Fuel Page CHEMICAL COMPOSITION OF NATURAL GAS (CNG) ....ADVANTAGES OF METHANE GAS UTILIZATION IN AUTOMOTIVE ..... - Motor advantages of methane gas utilization - Disadvantages of methane utilization in engines - Torque and power typical curves -...
  • Page 22 SECTION 2 - FUEL CNG NEF ENGINES...

  • Page 23: Chemical Composition Of Natural Gas (Cng)

    CNG NEF ENGINES SECTION 2 - FUEL CHEMICAL COMPOSITION OF NATURAL GAS (CNG) Natural gas is a mixture of gases, mainly composed of methane gas, the percentage of which, as the one of the other components, may vary from each field. In gas of domestic production and imported gas as well, main characteristics are though included in an almost limited range of tolerance.

  • Page 24: Motor Advantages Of Methane Gas Utilization

    SECTION 2 - FUEL CNG NEF ENGINES Motor advantages of methane gas utilization The gaseous status and the high antiknock power make methane a suitable fuel for the feed of engines with firing control driven by high compression volumetric ratio. (up to 13:1). The high octane value (120-130) confers to methane significant resistance to detonation, featuring the super fuels.

  • Page 25: Torque And Power Typical Curves - F4Be0641A Engines

    CNG NEF ENGINES SECTION 2 - FUEL Torque and power typical curves - F4BE0641A engines Figure 1 87772 A. Power - B. Torque. Performances (ECE 88/185/195 after 50 hours of operation - Tolerance ± 5%) Max power 147 kW (200 CV) Max power rpm 2500 - 2700 rpm Piston average speed...

  • Page 26: Gas Emissions

    SECTION 2 - FUEL CNG NEF ENGINES GAS EMISSIONS 1999/96/EC European Regulation for heavy engines introduced a new test cycle called ETC for methane gas feed engines and states the limits for the emissions, lower Euro 3 and Euro 4, for the EEV vehicle segment with minimum impact to the environment. LIMIT VALUES PRESCRIBED BY 1999/96/EC REGULATION WITH ETC TEST CYCLE (CO) (NMHC)
  • Page 27 CNG NEF ENGINES SECTION 2 - FUEL Emissions of Iveco CNG engine compared to ETC cycle emissions - gas of reference: G20 and G25 Figure 2 87893 Figure 3 87894...

  • Page 28: Ignition And Injection Integrated System

    SECTION 2 - FUEL CNG NEF ENGINES IGNITION AND INJECTION INTEGRATED SYSTEM Characteristics Metafuel 3 system belongs to the category of the electronic ignition and injection integrated systems of sequential and timed type. The central unit electronically controls air flow rate through motorised throttle (driven by VDO EGAS2), controls the turboblower through special solenoid valve, regulates fuel injection in such a way that (air/fuel) ratio is always ranging within optimal value and calculates ignition lead.

  • Page 29: Electric Injectors

    CNG NEF ENGINES SECTION 2 - FUEL ELECTRIC INJECTORS Figure 5 87776 The electric injectors are specific for methane engines. The methane jets at 9-bar pressure come out of the injector upstream the suction valves. The operating logic is of ”phase sequence” type. The six injectors are controlled according to the suction sequence of the engine cylinder, while the fuel supply can be started for each cylinder already at the expansion stage until reaching the suction phase already started.

  • Page 30: Air Suction Circuit

    SECTION 2 - FUEL CNG NEF ENGINES AIR SUCTION CIRCUIT The air suction circuit consists of the following components: Air filter Debimeter (air flow sensor) Air temperature sensor Suction manifold pressure sensor Turbocharger pressure sensor Turbocharger Throttle valve and position sensor Suction manifold Engine idling speed actuator Debimeter (Air flow sensor)

  • Page 31: Pressure Reducer

    CNG NEF ENGINES SECTION 2 - FUEL PRESSURE REDUCER The TARTARINI META pressure reducer is installed in the engine compartment and its task is to reduce the gas pressure from the value on the cylinder to the injector supply value and keep it under control at any operating conditions. The pressure reducer is also fitted with an hydraulic connection to the engine water cooling circuit which supplies the right amount of heat to the gas.
  • Page 32 SECTION 2 - FUEL CNG NEF ENGINES Installation note You are recommended to position the reducer in areas without dust and humidity. Actions on components Given the high technology and precision required at assembly, it is not permitted to carry out operations on the reducer inner parts.
  • Page 33 CNG NEF ENGINES SECTION 2 - FUEL Safety valve The device is fitted with a safety or overpressure valve. This valve makes it possible to discharge the overpressure generated by faulty capacities of the first stage outside. Exchanger It is a pipe completely separated from the gas circuit, whose function is to heat the methane which tends to cool down after the expansion due to the pressure reduction occurred at the first stage.

  • Page 34: Steel Hose

    SECTION 2 - FUEL CNG NEF ENGINES To change the reducer proceed as follows: - Use a wrench to slacken slightly the reducer inlet pipe union so that the pressure inside the pipe gets out in the atmosphere. - Then slacken completely the pipe union. - Remove the fastons from the coil by taking off all the electrical connections.

  • Page 35: Oxygen Sensor

    CNG NEF ENGINES SECTION 2 - FUEL OXYGEN SENSOR The oxygen sensor is made up of a zirconium dioxide-based ceramic body coated with a this layer of platinum enclosed at one end, placed into a protective tube, and housed in a metal body that ensure extra protection and allows the ceramic body to be fitted to the exhaust manifold.
  • Page 36 SECTION 2 - FUEL CNG NEF ENGINES...
  • Page 37 CNG NEF ENGINES SECTION 3 - USE SECTION 3 Page GENERAL SPECIFICATIONS ....GENERAL PROPERTIES ....PART ONE - MECHANICAL COMPONENTS ENGINE OVERHAUL .
  • Page 38 SECTION 3 - USE CNG NEF ENGINES Page Page - Acceleration deactivation (option) ..VEHICLE FUNCTIONS APPLIED BY CONTROL - Self-diagnosis ......UNIT MF3 .

  • Page 39: General Specifications

    CNG NEF ENGINES SECTION 3 - USE GENERAL SPECIFICATIONS Figure 1 102602 102603 The NEF F4BE0641A engines are characterized by a boosted The section herein described is composed or four sections: Otto cycle with 6 cylinders and 2 valves per cylinder. - Section of mechanical overhaul prescribed in accordance They are powered by indirect injection and common rail, and to the engine’s specific duty, illustrating all necessary...

  • Page 40: General Properties

    SECTION 3 - USE CNG NEF ENGINES GENERAL PROPERTIES F4BE0641A*G F4BE0641A*G... Type Max. output (HP) (200) 2700 Max. torque (kgm) (66) 1250 Loadless engine idling Loadless engine 2900 peak TURBOCHARGING with intercooler Turbocharger type HOLSET HX 38 G Forced by gear pump, relief valve single action LUBRICATION oil filter Oil pressure (warm engine)

  • Page 41: Part One - Mechanical Components

    CNG NEF ENGINES SECTION 3 - USE DIAGNOSI PART ONE - MECHANICAL COMPONENTS...
  • Page 42 SECTION 3 - USE CNG NEF ENGINES...

  • Page 43: Engine Overhaul

    CNG NEF ENGINES SECTION 3 - USE ENGINE OVERHAUL Figure 3 Preface Part of the operations illustrated within this section can be partially executed while the engine is assembled on the vehicle, depending on the room available for access to the engine and on the equipment application as well.
  • Page 44 SECTION 3 - USE CNG NEF ENGINES Figure 5 Figure 8 87513 87510 Remove the heat guard (2) by slackening the screws (1). Remove the exhaust manifold (2) by slackening the fastening screws (1). Figure 9 Figure 6 87514 87511 Remove the engine cable fastening plate (2) by slackening the Slacken the screws (1) and remove the six coils (2).
  • Page 45 CNG NEF ENGINES SECTION 3 - USE Figure 10 Figure 13 87552 87515 Remove the screws (2) and disconnect the injectors (1). Slacken the fastening nut (2) of the tie rod (1) for the throttle Disconnect the feeding pipes (3) and remove the rail (5) valve control.

  • Page 46: Cylinder Head Removal

    SECTION 3 - USE CNG NEF ENGINES Cylinder head removal Figure 19 Figure 16 87607 87580 Slacken the screws (2) of the breathing cover (1). Slacken the screws (2) and remove the breather (1). Remove the cover (1) by slackening the clamp (5) of the engine block connecting pipe.
  • Page 47 CNG NEF ENGINES SECTION 3 - USE Figure 22 Figure 24 70140 70143 Remove the screws (2) and disconnect the alternator support Use wrench 99355019 to remove the screws (1) and (3) and (3). disconnect the hydraulic power steering pump (2) together Use tool 99360076 to remove the oil filter (1).
  • Page 48 SECTION 3 - USE CNG NEF ENGINES Figure 26 Figure 28 70148 70146 Remove the screws (1) and remove the water pump (2). Remove the screws (3) and remove the roller (4). Apply the tool 99360351 (2) to the flywheel housing (1), to Remove the screws (5) and remove the rpm sensor (6).
  • Page 49 CNG NEF ENGINES SECTION 3 - USE Figure 31 Figure 34 70149 Remove the screws (1) and remove the front cover (2). 70152 NOTE Write down the screw (1) assembling position Screw two pins (2) exhibiting a proper length into the engine because they exhibit different lengths.
  • Page 50 SECTION 3 - USE CNG NEF ENGINES Figure 36 Figure 38 70153 87603 Remove the screws (1) and remove the oil suction rose (3). Remove the screws (1) and remove the rear cover (2). Remove the screws (2) and remove the stiffening plate (4). Figure 39 NOTE Write down the screw (1) assembling position...

  • Page 51: Installation Of Components

    CNG NEF ENGINES SECTION 3 - USE Installation of components Figure 42 Figure 41 70210 DIAGRAM FOR TIGHTENING THE REAR TIMING GEAR CASE FASTENING SCREWS 70209 Refit the case (1) to the engine block. Screw the fastening screws in the same position found at IVECO No.

  • Page 52: Mounting The Flywheel Housing

    SECTION 3 - USE CNG NEF ENGINES Clean accurately the flywheel housing (1) and timing gear case Figure 44 coupling surfaces. Perfect seal is only obtained by cleaning accurately the surface to seal. Smear housing (1) with IVECO No. 2992545 to obtain a bead of few mm diameter.

  • Page 53: Engine Flywheel

    CNG NEF ENGINES SECTION 3 - USE Figure 48 Figure 50 70216 87593 Apply tool 99346253 part (5) to the rear output shaft tang (6), Screw two pins (2) having suitable length into shaft holes (3) secure it by screws (4) and fit the new sealing ring (3). and remove the engine flywheel (1) using proper sling and Position part (1) on part (5), screw nut (2) until completing hoister.
  • Page 54 SECTION 3 - USE CNG NEF ENGINES Figure 52 Figure 54 α 70221 70219 Apply a new sealing ring (2) to the water pump (1). Tighten engine flywheel (2) fastening screws (1) in two stages: - 1st stage, tightening to 30 to 4 Nm torque with dynamometric wrench;...
  • Page 55 CNG NEF ENGINES SECTION 3 - USE Figure 57 Figure 59 70224 87603 Clean accurately the front cover (2) surface and refit it. Fit the plate (4), the suction rose (3), drive in the fastening Tighten the screws (1) to the specified torque. screws (1, 2) and tighten them to the prescribed torque.
  • Page 56 SECTION 3 - USE CNG NEF ENGINES Figure 61 Figure 63 70230 87600 Fit a new sealing ring on the speed sensor (3). Fit the oil sump (1) and apply the plate (3) to it. Fit the speed sensor (3) on the front cover (1) and tighten the Tighten the screws (2) to the specified torque.
  • Page 57 CNG NEF ENGINES SECTION 3 - USE Figure 65 Figure 67 87590 70232 Refit the alternator (1). Lubricate the sealing ring (2) with engine oil and set it on the Tighten the screw (2) to the specified torque. oil filter (3). Screw manually to seat the oil filter (3) on the support connection (1) and then screw again the oil filter (3) by ¾...

  • Page 58: Mounting The Cylinder Head

    SECTION 3 - USE CNG NEF ENGINES Mounting the cylinder head Figure 69 Figure 71 87601 84180 Lubricate the valve stem and insert into the respective valve guide according to the position marked upon disassembling. Refit the air compressor (3). Tighten the screws (2) and the Re-attach the thermostat assy (2) and brackets (1) and (3).
  • Page 59 CNG NEF ENGINES SECTION 3 - USE Figure 73 Figure 75 87585 84209 Prior to inserting the pushrods, verify their state of Verify that the cylinder head attaching plane and the crankcase preservation: the spherical seats in contact with the rocker attaching plane are both clean.
  • Page 60 SECTION 3 - USE CNG NEF ENGINES Figure 77 Figure 79 84198 84196 Fasten the head screws (1) according to the instructions given Figure 80. MAIN DATA OF ARBOUR-ROCKER ARM Verify that the arbour/rocker arm matching surfaces do not show excessive wear or damages. Figure 80 Figure 78 α...
  • Page 61 CNG NEF ENGINES SECTION 3 - USE Figure 81 Figure 83 84200 Ad just the play between the rocker arms and the valves by means of an Allen wrench (2), box wrench (3) and thickness gauge (1). 87607 The operation play is: Fit the breather (1) aside and tighten the fastening screws (2) - intake valves: 0.25 ±...

  • Page 62: Completion Of The Engine

    SECTION 3 - USE CNG NEF ENGINES Completion of the engine Figure 87 Figure 85 87552 87579 Drive in the fastening nut (2) of the throttle valve control tie rod (1) and make sure the axis centre between the articulated Reconnect the VDO control actuator (3) with the relevant joints is the pre-set x = 153 mm.
  • Page 63 CNG NEF ENGINES SECTION 3 - USE Figure 89 Figure 91 87513 Refit the heat guard (2) by tightening the screws (1) to the prescribed torque. 87515 Refit the rail (5), tighten the screws (2) to the prescribed Figure 92 torque, connect the injectors (1) and the feeding pipes (4).
  • Page 64 SECTION 3 - USE CNG NEF ENGINES Figure 94 87510 Refit the exhaust manifold (2) by tightening the fastening screws (1) to the prescribed torque. Figure 95 87509 Refit the engine cable (1) by connecting the connectors: injector wiring, spark plugs, gas pressure sensor, throttle valve body, VDO actuator, temperature sensor, compressor, coolant fluid temperature sensor, engine oil temperature/pressure sensor, engine rev sensor.

  • Page 65: Checks And Inspections

    CNG NEF ENGINES SECTION 3 - USE Checks and inspections Figure 96 The following tests shall be made after engine assembly to the vehicle. Start the engine, let it run at revolution regimen slightly higher than idling and wait that the cooling liquid temperature reaches the value enabling thermostat opening, then check that: - There is no water bleeding from the manifolds connecting...
  • Page 66 SECTION 3 - USE CNG NEF ENGINES...

  • Page 67: Part Two - Electrical Equipment

    CNG NEF ENGINES SECTION 3 - USE PART TWO - ELECTRICAL EQUIPMENT...
  • Page 68 SECTION 3 - USE CNG NEF ENGINES...

  • Page 69: General Items

    CNG NEF ENGINES SECTION 3 - USE GENERAL ITEMS Figure 98 87608 1. Debimeter - 2. Air filter - 3. Fresh air - 4. Turbocharger - 5. Catalyst - 6. Exhaust gas - 7. Exhaust gas temperature sensor - 8. Lambda sensor - 9. WASTE - GATE valve - 10. Oil temperature/pressure sensor - 11. Oil sump - 12.

  • Page 70: Mf3 - Ignition And Injection Integrated System

    SECTION 3 - USE CNG NEF ENGINES MF3 — IGNITION AND INJECTION INTEGRATED SYSTEM MF3 system characteristics Metafuel 3 system belongs to the category of the electronic ignition and injection integrated systems of sequential and timed type. The central unit electronically controls air flow rate through motorised throttle (driven by VDO EGAS2), controls the turboblower through special solenoid valve, regulates fuel injection in such a way that (air/fuel) ratio is always ranging within optimal value and calculates ignition lead.

  • Page 71: Fuel Cutoff In Release Step

    CNG NEF ENGINES SECTION 3 - USE Fuel cutoff in release step The central unit, on releasing accelerator pedal. - takes feed off electrical injectors if rotation speed is higher than 850 — 1000 rpm; - reactivates feed to electrical injectors under 850 — 1000 rpm. In lack of feed, rotation speed drop is more or less fast depending on vehicle ride conditions.

  • Page 72: Startup Management

    SECTION 3 - USE CNG NEF ENGINES Startup management Central unit MF3 directly manages starter control relay. When startup key is put to position AVV [startup], the central unit makes a set of safety checks (gearbox idle or clutch pressed, cab not tilted (for truck only), etc.) and, in case of positive tests, sends the electrical command enabling starter feed.

  • Page 73: Ignition Management

    CNG NEF ENGINES SECTION 3 - USE Idle rotation speed management The central unit detects idle rotation speed condition through throttle closing position. To control idle rotation speed depending on users entered (air-conditioner, automatic gearbox, etc.) and on brake and clutch pedals signals, the central unit drives additional air actuator position.

  • Page 74: Connection To Vehicle Through Can Line (To Gearbox And Dashboard Central Units)

    SECTION 3 - USE CNG NEF ENGINES Connection to vehicle through CAN line (to gearbox and dashboard central units) Connection to gearbox central unit Dialogue between injection-ignition central unit and automatic gearbox central unit is through both some dedicated lines and CAN line.

  • Page 75: Vehicle Functions Applied By Control Unit Mf3

    CNG NEF ENGINES SECTION 3 - USE VEHICLE FUNCTIONS APPLIED BY CONTROL UNIT MF3 Speed limit (OPTIONAL) This function is applied not to overcome the speed limit programmed for the vehicle. There is a second threshold available on the basis of the input switch. The speed limits are applied through the VDO E-GAS II control units. The two limits are: - Maximum speed limit - Variable speed limit The speed limit function uses a lower value if both speed limits are active.

  • Page 76: Mf3 Control Unit Installation

    SECTION 3 - USE CNG NEF ENGINES MF3 CONTROL UNIT INSTALLATION The control unit can be installed in vertical position (along axis z). Any other position is not advisable. The figure below (demonstration — utilization of buses) shown the vehicle axles and the recommended positions: Figure 99 Figure 101 87773...

  • Page 77: Mf3 Control Unit Wiring Diagram

    CNG NEF ENGINES SECTION 3 - USE MF3 CONTROL UNIT WIRING DIAGRAM (FIRST PART) Figure 102 0050078t...

  • Page 78: Mf3 Control Unit Wiring Diagram

    SECTION 3 - USE CNG NEF ENGINES MF3 CONTROL UNIT WIRING DIAGRAM (SECOND PART) Figure 103 0050079t...

  • Page 79: Key

    CNG NEF ENGINES SECTION 3 - USE Engine control unit MF3 Throttle valve control unit VDO E-Gas Tempostat Restyling dashboard (CAN network connection) Bosch debimeter Oil pressure and temperature sensor Throttle valve position sensor Heated Lambda sensor Monte Methane cylinder pressure sensor - Keller 30-pole round connector / Diagnosis outlet Supercharging pressure sensor Manifold air pressure and temperature sensor...

  • Page 80: Pin Out Mf3

    SECTION 3 - USE CNG NEF ENGINES PIN OUT MF3 Pin code Description Cylinder 1 coil control Injector 3 control on hot side Injector 2 control on hot side Injector 6 control on hot side Radiofrequency earth Engine oil temperature External sensor power supply Neg.
  • Page 81 CNG NEF ENGINES SECTION 3 - USE Pin code Description Injector 4 control on cold side Rail gas temperature A52 ÷ A54 Absolute pressure sensor signal Engine oil pressure A57 ÷ A59 External sensor earth Power supply Power earth Power supply Power earth Direct power supply from BATTERY (+ 30) Power earth...
  • Page 82 SECTION 3 - USE CNG NEF ENGINES Pin code Description Lamp control (MIL) Request of NC lamp control view/signal Starter relay control Air conditioning engagement control/consensus Throttle valve opening limit Repetition of processed SMOT signal Repetition of processed vehicle speed signal By-pass idling control B74 ÷...

  • Page 83: Components

    CNG NEF ENGINES SECTION 3 - USE COMPONENTS Electric injectors Figure 104 87776 The electric injectors are specific for methane engines. The methane jets at 9-bar pressure come out of the injector upstream the suction valves. The operating logic is of ”phase sequence” type. The six injectors are controlled according to the suction sequence of the engine cylinder, while the fuel supply can be started for each cylinder already at the expansion stage until reaching the suction phase already started.

  • Page 84: Air Suction Circuit

    SECTION 3 - USE CNG NEF ENGINES Air suction circuit The air suction circuit consists of the following components: - Air filter - Debimeter (air flow sensor) - Air temperature sensor 3A - Suction manifold pressure sensor 3B - Turbocharger pressure sensor - Turbocharger - Throttle valve and position sensor - Suction manifold...

  • Page 85: Throttle Valve Body

    CNG NEF ENGINES SECTION 3 - USE Throttle valve body The throttle valve body function is to dose the quantity of air supplied to the engine according to the driver’s request through the accelerator. The throttle valve body is fastened to the suction manifold. The throttle valve is opened by means of a levering system with different opening angles.

  • Page 86: Idling Actuator

    SECTION 3 - USE CNG NEF ENGINES Idling actuator This electric engine opens another air flowing passage parallel to the pipe and takes the valve air leaks (when the engine races) to the throttle valve to maintain the idling speed constant regardless of the engine load (accessories off or on, engine warm or cold, etc.).

  • Page 87: Fuel Cut-Off

    CNG NEF ENGINES SECTION 3 - USE Fuel cut-off When the valve is closed and the speed is above calibration, the fuel injection is cut off. Below this value the engine is at idling position. Before reaching idling, the engine fuel supply is reactivated and the air flow speed is controlled by the idling actuator according to a logic called ”soft approach”...

  • Page 88: Lambda Sensor

    SECTION 3 - USE CNG NEF ENGINES Lambda sensor When the oxygen sensor comes into contact with the exhaust gases, it generates an electric signal whose voltage depends on the concentration of oxygen contained in the gases. This voltage is linked to the mixture composition: rich or poor. When the sensor signals a low voltage (below 200 mV), the control unit recognizes that the mixture is poor and therefore increases the quantity of gas injected.

  • Page 89: Air Temperature-Pressure Sensor

    CNG NEF ENGINES SECTION 3 - USE Air temperature-pressure sensor The air temperature sensor is fitted downstream the debimeter on the suction manifold. It is a normal NTC (Negative Temperature Coefficient) Termistore, so that the sensor electric resistance decreases as the temperature increases. As a result, the ECU can, at any moment, evaluate the resistance variations through the voltage variations and therefore obtain the information concerning the sucked air temperature.

  • Page 90: Crankshaft Sensor

    SECTION 3 - USE CNG NEF ENGINES Crankshaft sensor It is an inductive sensor and is positioned on the engine front left-hand side. It generates the signals coming from the magnetic flow lines which close as a result of the phonic wheel opening on the crankshaft. The same signal is used to control the electronic revolution counter.

  • Page 91: Wastegate Solenoid Valve

    CNG NEF ENGINES SECTION 3 - USE Wastegate solenoid valve Figure 111 87778 The limiting valve (1) receives the air pressure form the pipe (D), reduces it by means of ECU MF3 and sends the correct pressure to the waste gate actuator by means of pipe (A), which opens the waste gate valve (3) integrated in the turbocharger (2). Without the electric control the pressure does not fall, the waste gate valve remains open thus preventing the turbocharger over-pressure.

  • Page 92: Tartarini Meta Pressure Reducer

    SECTION 3 - USE CNG NEF ENGINES TARTARINI META pressure reducer The pressure reducer is installed in the engine compartment and its task is to reduce the gas pressure from the value on the cylinder to the injector supply value and keep it under control at any operating conditions. The pressure reducer is also fitted with an hydraulic connection to the engine water cooling circuit which supplies the right amount of heat to the gas.
  • Page 93 CNG NEF ENGINES SECTION 3 - USE Installation note You are recommended to position the reducer in areas without dust and humidity. Actions on components Given the high technology and precision required at assembly, it is not permitted to carry out operations on the reducer inner parts.
  • Page 94 SECTION 3 - USE CNG NEF ENGINES Safety valve The device is fitted with a safety or overpressure valve. This valve makes it possible to discharge the overpressure generated by faulty capacities of the first stage outside. Exchanger It is a pipe completely separated from the gas circuit, whose function is to heat the methane which tends to cool down after the expansion due to the pressure reduction occurred at the first stage.

  • Page 95: Steel Hose

    CNG NEF ENGINES SECTION 3 - USE To change the reducer proceed as follows: - Use a wrench to slacken slightly the reducer inlet pipe union so that the pressure inside the pipe gets out in the atmosphere. - Then slacken completely the pipe union. - Remove the fastons from the coil by taking off all the electrical connections.

  • Page 96: Throttle Valve Setting At Idling

    SECTION 3 - USE CNG NEF ENGINES Throttle valve setting at idling - With the button in OFF position, remove the support between the valve and the actuator. - Position the ignition key to MAR (panel ON), then release the accelerator pedal: the VDO actuator will slightly move (mechanically) towards the electric ZERO.

  • Page 97: Part Three - Troubleshooting

    CNG NEF ENGINES SECTION 3 - USE PART THREE - TROUBLESHOOTING...
  • Page 98 SECTION 3 - USE CNG NEF ENGINES...

  • Page 99: Preface

    CNG NEF ENGINES SECTION 3 - USE Every time there is a breakdown claim and this breakdown is PREFACE actually detected, it is necessary to proceed inquiring the electronic unit in one of the ways indicated and then proceed A successful troubleshooting is carried out with the with the diagnostic research making trials and tests in order to competence acquired by years of experience and attending have a picture of the working conditions and identify the root...

  • Page 100: Blink-Code - General Information

    SECTION 3 - USE CNG NEF ENGINES Detectable failures BLINK-CODE - GENERAL INFORMATION Sensors: Anomaly warning led - ECU engine control unit — Atmospheric pressure continuously screening, complex auto-diagnosis routine procedures, its own working - E-Gas VDO control unit conditions as well as the conditions of the components - Air flow meter connected to, and of the engine.

  • Page 101: Self-Diagnosis

    CNG NEF ENGINES SECTION 3 - USE Self-diagnosis Central unit self-diagnosis system checks system correct operation and signals any faults by means of two warning lamps, located on board instrument panel, having different colour (red and orange). Warning lamps signal both engine management failures and the faults detected by diagnosis strategies. Red warning lamp going on of course signals that there are present errors having a greater seriousness than the ones making orange warning lamp go on.

  • Page 102: Vdo Egas2 Diagnosis System

    SECTION 3 - USE CNG NEF ENGINES VDO EGAS2 Diagnosis System The VDO control unit controls all input and output data which make it possible to identify the short circuit, the breaking or the inconsistency between signals. Failures are usually stored in the permanent memory and signalled through the dashboard warning light as follows: - Warning light OFF - NO ERROR - Warning light ON -...

  • Page 103: Troubleshooting By Means Of Blink-Codes

    CNG NEF ENGINES SECTION 3 - USE TROUBLESHOOTING BY MEANS OF BLINK-CODES For correct trouble shooting, always make a complete diagnosis through dedicated tools. These tools display, by means of a display screen, the sequential operations that are necessary for the selected diagnosis. It is also available a blink codes table and a collection of “research of failures based on signs”...
  • Page 104 SECTION 3 - USE CNG NEF ENGINES Fault Blink Description Type of error warning warning Notes Code light light GAS cylinder pressure sensor C. o. or s. c. at Gnd upstream reducer (high S. c. at Vbatt (8) pressure) CNG solenoid valve on pressure S.
  • Page 105 CNG NEF ENGINES SECTION 3 - USE Fault Blink Description Type of error warning warning Notes Code light light 1393 Starting coil 1 Overheating KON ER General error 1394 Starting coil 2 Overheating KON ER General error 1395 Starting coil 3 Overheating KON ER General error...
  • Page 106 SECTION 3 - USE CNG NEF ENGINES Fault Blink Description Type of error warning warning Notes Code light light 1448 Injector 5 S. c. hot side Vbatt KON ER S. c. cold side Vbatt S. c. hot side Gnd S. c. cold side Gnd S.
  • Page 107 CNG NEF ENGINES SECTION 3 - USE Fault Blink Description Type of error warning warning Notes Code light light VDO general error EGAS II fault Actuator position from EGAS Signal above max threshold KON ER Signal below min threshold 1081 Warning lamp/ blink code S.

  • Page 108: Vdo Diagnosis

    SECTION 3 - USE CNG NEF ENGINES VDO DIAGNOSIS The failure warning light comes on to signal failures only when the key is in the ON position. The warning light will indicated the following: a) warning light OFF = no error found b) warning light ON = errors found c) warning light blinking = serious errors found Blink-code reading...

  • Page 109: Vdo Egas2 System Diagnosis

    CNG NEF ENGINES SECTION 3 - USE VDO EGAS2 system diagnosis FAILURE BLINK DESCRIPTION ECU PIN POSSIBLE CAUSES SYSTEM RESPONSE WARNING CODE LIGHT VEHICLE SPEED SIGNAL Pin 11 interruption or Max. engine speed: 1,600 short-circuit r.p.m. ENGINE SPEED SIGNAL Pin 42 short-circuit to P.T.O.

  • Page 110: Troubleshooting By Symptoms

    SECTION 3 - USE CNG NEF ENGINES TROUBLESHOOTING BY SYMPTOMS THE ENGINE DOES NOT START Connections to the battery terminals in good working Clean, check, and tighten the terminal nuts, or replace order them. Batteries in good working order Carry out the checks described in the “Electric system”...
  • Page 111 CNG NEF ENGINES SECTION 3 - USE Injectors Check the injector opening/closing by means of active diagnosis Ignition system in good working order Check the spark plugs, spark plug cables, and ignition coils Stepper motor in good working order Verify whether it is connected or defective; replace, if necessary Driving electronic control unit in good working order Replace...
  • Page 112 SECTION 3 - USE CNG NEF ENGINES Pressure regulator in good working order Check or replace Connect a pressure gauge downstream the reducer (9 ± 0.5 bar) Spark advance all right Check and adjust, if necessary Turbocharger in good working order Check the Waste Gate valve Boost control unit in good working order Check or adjust...
  • Page 113 CNG NEF ENGINES SECTION 3 - USE THE MOTOR SHOWS SIGNS OF ABNORMAL KNOCKING Knock located in the drive shaft. Check journal play and out-of-round condition, engine flywheel and bed support screw fastening, and oil pressure. Replace the parts or overhaul the engine. Knock found on connecting rods.
  • Page 114 SECTION 3 - USE CNG NEF ENGINES THE ENGINE STOPS Fuel bottles fill-up (natural gas pressure) Fill up Ignition system in good working order Check and adjust or replace, if necessary, the parts Adjust the idle speed Check the idle running valves, oxygen sensors or control units.
  • Page 115 CNG NEF ENGINES SECTION 3 - USE OIL PRESSURE TOO HIGH OR TOO LOW Pressure control valve in good working order Check and replace, if necessary Both oil pump and delivery pipes in good working Check and replace, if necessary order Main bearings and connecting rod bearings in good Replace the bearings and grind, if necessary, the drive...
  • Page 116 SECTION 3 - USE CNG NEF ENGINES Water pump in good working order Overhaul or replace the unit Thermostat in good working order Replace Radiator in good working order Wash thoroughly; check for leaks, replace the part, if necessary Both circuit piping and air filter in good working order Clean or replace defective parts...

  • Page 117: Part Four - Maintenance Planning

    CNG NEF ENGINES SECTION 3 - USE PART FOUR - MAINTENANCE PLANNING...
  • Page 118 SECTION 3 - USE CNG NEF ENGINES...

  • Page 119: Recovery

    CNG NEF ENGINES SECTION 3 - USE MAINTENANCE PLANNING Recovery To ensure optimised working conditions, in the following pages we are providing instructions for the overhaul control interventions, checks and setting operations that must be performed on the engine at due planned dates. The frequency of the maintenance operations is just an indication since the use of the engine is the main characteristic to determine and evaluate replacements and checks.

  • Page 120: Checks Not Included In Maintenance Planning-Daily Checks

    SECTION 3 - USE CNG NEF ENGINES Checks not included in maintenance planning-daily checks It is a good habit to execute, before engine start, a series of simple checks that might represent a valid warranty to avoid inconveniences, even serious, during engine running. Such checks are usually up to the operators and to the vehicle’s drivers. - Level controls and checks of any eventual leakage from the fuel, cooling and lubricating circuits.

  • Page 121: Check Of Fuel System

    CNG NEF ENGINES SECTION 3 - USE Check of fuel system Checking/replacing the blow-by filter The check must be executed both when the engine disconnected and when it is running. Figure 115 The check is carried out by observing the fuel pipes running from the tanks to the pressure reducer, from the reducer to the rail, and from the rail to the injectors.

  • Page 122: Check Of Drive Belt Tensioning

    SECTION 3 - USE CNG NEF ENGINES Check of drive belt tensioning In order to more quickly perform the operating Some applications are equipped with an automatic tensioner clearance adjustment for rocker arms — valves, that provides correcting belt tensioning. proceed as follows: Check of belt’s tear and wear status Carefully verify the belt’s surface in order to detect any sign of...

  • Page 123: Changing The Engine Oil And Oil Filter

    CNG NEF ENGINES SECTION 3 - USE Changing the engine oil and oil filter Warning: the oil filter contains inside a quantity of oil of about 1 kg. Warning: We recommend to wear proper protec- tions because of high motor service temperature. Place properly a container for the liquid.

  • Page 124: Alternator Belt - Water Pump Replacement

    SECTION 3 - USE CNG NEF ENGINES Alternator belt - water pump replacement Figure 118 (Demonstration) 77839 To remove and fit the belt (1) back on, you need to use an appropriate tool on the tightener (2) in the direction shown by the arrow.
  • Page 125 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL SECTION 4 General overhaul Page GENERAL SPECIFICATIONS ....CLEARANCE DATA ..... . ENGINE OVERHAUL .
  • Page 126 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Page Page - Piston pins - Checking piston protrusion ......
  • Page 127 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL GENERAL SPECIFICATIONS Type F4BE0641A Cycle Eight-stroke diesel engine Power Supercharged Injection Number of cylinders 6 in-line ∅ Bore Stroke +.. = Total displacement 5900 ρ Compression ratio 11 : 1 TIMING start before T.D.C. -9º...
  • Page 128 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES CLEARANCE DATA Type F4BE0641A CYLINDER UNIT AND CRANKSHAFT COMPONENTS ∅ 1 102.009 to 102.031 ∅1 Cylinder barrels Spare pistons ∅ 1 type: Size 60.5 ∅ 1 Outside diameter 101.781 to 101.799 ∅ 2 Pin housing 40.008 to 40.014 ∅...
  • Page 129 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Type F4BE0641A CYLINDER UNIT AND CRANKSHAFT COMPONENTS 2.705 to 2.735 Split ring slots 2.420 to 2.440 4.020 to 4.040 S 1* 2.560 to 2.605 Split rings 2.350 to 2.380 3.975 to 4.000 * measured on 99 mm ∅...
  • Page 130 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Type F4BE0641A CYLINDER UNIT AND CRANKSHAFT COMPONENTS Size Max. tolerance on connecting rod axis alignment ∅ ∅ ∅ 1 Journals 82.993 to 83.013 ∅ 2 Crankpins 68.987 to 69.013 Main half bearings 2.456 to 2.464 Big end half bearings 1.955 to 1.968...
  • Page 131 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Type F4BE0641A CYLINDER HEAD — TIMING SYSTEM ∅ 1 Valve guide seats on ∅ 1 cylinder head 8.019 to 8.039 ∅ Valves: ∅ 4 7.96 to 7.98 α ∅ 4 7.96 to 7.98 α...
  • Page 132 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Type F4BE0641A CYLINDER HEAD — TIMING SYSTEM Valve spring height: free spring 63.5 under a load equal to: 49.02 38.20 Injector protrusion not adjustable Camshaft bush housings No. 1-7 59.222 to 59.248 Camshaft housings ∅...
  • Page 133 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Type F4BE0641A CYLINDER HEAD — TIMING SYSTEM ∅ 1 Tappet cap housing ∅ 1 16,000 ÷ 16,030 on block ∅ 2 Tappet cap outside ∅ ∅ 2 diameter: 15.929 to 15.959 ∅ 3 15.965 to 15.980 ∅...

  • Page 134: Engine Overhaul

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES ENGINE OVERHAUL Figure 3 ENGINE REMOVAL AT THE BENCH Figure 1 70160 The second-last-bench cap (1) and its relevant support have the half-bearing (2) equipped with shoulder. 70158 NOTE Write down the upper and lower half-bearing Remove the connecting rod cap (2) fixing screws (1) and assembling position, in the event of use, they should remove them.

  • Page 135: Repair Interventions

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL REPAIR INTERVENTIONS Figure 6 CYLINDER GROUP Controls and measurements Figure 9 70163 Remove the screws (1) and remove the camshaft (3) check plate (2). NOTE Write down the plate (2) assembling position. 70166 Carefully clean the cylinder-block group, when performed the engine disassembly.
  • Page 136 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Figure 10 Figure 11 ± 70167 The measurements must be performed for each individual cylinder at three different heights from the barrel and on two perpendicular surfaces: one parallel to the longitudinal engine axis (A) and the other one perpendicular (B);...

  • Page 137: Head Face Check On The Cylinder Group

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Check that the head face, on the cylinder group, does not Head face check on the cylinder group present deformations. This check can be carried out, after a previous grains (4) Figure 12 extraction by means of a calibrated ruler (2) and feeler gauge (3).

  • Page 138: Cam Lift Check And Pin Alignment Check

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Cam lift check and pin alignment check BUSHES Position the shaft on counterpoints and, by means of a Figure 15 centesimal gauge, located on the central support, check that the alignment error is not higher than 0.04 mm: on the contrary, replace the shaft.

  • Page 139: Bush Replacement

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Bush replacement Fitting tappets - camshaft Figure 17 Figure 19 70176 Lubricate the tappets (1) and fit them into the relevant 70174 housings on the engine block. To replace front and rear bushes (1), use for their removal and refitting the tool 99360362 (2) and handgrip 99370006 (3).

  • Page 140: Output Shaft

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES OUTPUT SHAFT Figure 22 Measuring journals and crankpins Figure 24 70179 Check camshaft end float (1). It shall be 0.23 ± 0.13 mm. 70182 Grind journals and crankpins if seizing, scoring or excessive ovalisation are found.
  • Page 141 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Figure 25 70514 FILL THIS TABLE WITH OUTPUT SHAFT JOURNAL AND CRANKPIN MEASURED VALUES * Rated value Figure 26 Measured on a radius greater than 45.5 mm ↗ 0.500 between adjacent journals 70577 OUTPUT SHAFT MAIN TOLERANCES...
  • Page 142 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES TOLERANCES TOLERANCE CHARACTERISTIC GRAPHIC SYMBOL ○ Roundness SHAPE SHAPE Cilindricity /○/ Parallelism Verticality DIRECTION Straightness POSITION Concentricity or coaxiality Circular oscillation Total oscillation OSCILLATION Taper LEVELS OF IMPORTANCE FOR PRODUCT CHARACTERISTICS GRAPHIC SYMBOL ©...

  • Page 143: Replacing Oil Pump Control Gear

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Replacing oil pump control gear Finding journal clearance Figure 30 Figure 28 84086 70184 Check that gear toothing (1) is not damaged or worn, Refit the output shaft (2). otherwise remove it using the proper puller (3). Check the backlash between output shaft main journals and When fitting the new gear, heat it to 180 °C for 10 minutes the relevant bearings as follows:...

  • Page 144: Checking Output Shaft Shoulder Clearance

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Figure 32 Figure 34 70189 70187 - Remove caps from supports. Tighten the pre-lubricated screws (1) in the following three successive stages: The backlash between the main bearings and the pins is found stage, with dynamometric wrench to 50 ±...
  • Page 145 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL CONNECTING ROD - PISTON ASSEMBLY Figure 38 Figure 36 32613 Remove split rings (1) from piston (2) using pliers 99360183 70191 (3). Figure 39 CONNECTING ROD — PISTON ASSEMBLY COMPONENTS 1. Stop rings - 2. Pin - 3. Piston - 4. Split rings - 5. Screws - 6.

  • Page 146: Pistons

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Pistons Conditions for proper pin-piston coupling Measuring piston diameter Figure 40 Figure 43 32615 32619 Lubricate the pin (1) and its seat on piston hubs with engine Using a micrometer (2), measure the diameter of the piston oil;...
  • Page 147 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Connecting rods Figure 46 Figure 48 39.9938 40.0002 41104 DIAGRAM FOR MEASURING THE CLEARANCE X BETWEEN THE FIRST PISTON SLOT AND THE TRAPEZOIDAL RING Since the first sealing ring section is trapezoidal, the clearance between the slot and the ring shall be measured as follows: make the piston (1) protrude from the engine block so that the ring (2) protrudes half-way from the cylinder barrel (3).

  • Page 148: Connecting Rods

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Bushes Figure 49 Check that the bush in the connecting rod small end is free from scoring or seizing and that it is not loosen. Otherwise replace. Removal and refitting shall be performed using the proper beater.

  • Page 149: Checking Torsion

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Checking torsion Position the vertical support (1) of the dial gauge (2) to rest the latter on pin (3), point C. Figure 51 Move the connecting rod forwards and backwards to find pin top position, then in this condition reset the dial gauge (2).

  • Page 150: Fitting Split Rings

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Fitting split rings Figure 54 Figure 56 70199 Connect piston (2) to connecting rod (4) with pin (3) so that 32613 the reference arrow (1) for fitting the piston (2) into the cylinder barrel and the numbers (5) marked on the Use pliers 99360183 (3) to fit the split rings (1) on the piston connecting rod (4) are read as shown in the figure.

  • Page 151: Fitting Connecting Rod-Piston Assembly Into Cylinder Barrels

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Fitting connecting rod-piston assembly into Finding crankpin clearance cylinder barrels Figure 60 Figure 58 70201 70203 Lubricate accurately the pistons, including the split rings and the cylinder barrel inside. To measure the clearance proceed as follows: Use band 99360605 (2) to fit the connecting rod-piston - clean the parts accurately and remove any trace of oil;...

  • Page 152: Checking Piston Protrusion

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Figure 62 Before the final fitting of the connecting rod cap fastening screws, check that their diameter measured at the centre of the thread length is not α < 0.1 mm than the diameter measured at approx. 10 mm from screw end.

  • Page 153: Cylinder Head

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL CYLINDER HEAD Figure 68 Removing the valves Figure 66 87588 Remove the thermostat unit (2) and brackets (1) and (3). 84179 Valves can be removed by means of tool 99360268 (1) by pressing slightly on collar (3) so that lock cones (2) can be removed by compressing springs (4).

  • Page 154: Checking The Cylinder Head Water Seal

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Checking the cylinder head water seal VALVES Check the water seal by means of suitable equipment. Use a pump to feed water heated to ~ 90 ˚C at a pressure Figure 71 of 2 to 3 bar.

  • Page 155: Checking The Play Between The Valve Stem, Valve Guide And Valve Centring

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL VALVE GUIDE Figure 73 Figure 75 84187 Use a micrometer (2) to measure valve stem (1), which must be equal to 7.96 to 7.98. INTAKE EXHAUST 84046 Use a bore gauge to measure the valve guide inner diameter, which must be equal to the value shown in the figure.
  • Page 156 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES Figure 77 INTAKE EXHAUST 87586 VALVE SEAT DIMENSIONS Figure 78 INTAKE EXHAUST 87587 VALVE SEAT HOUSING DIMENSIONS If the valve seats cannot be restored by simply reconditioning them, they can be replaced with spare parts. By using the same tool 99305019 and taking care not to indent the cylinder head, remove as much material as possible from the valve seats until the latter can be taken off the cylinder head by means of a punch.

  • Page 157: Valve Springs

    CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL Figure 79 84192 After the reconditioning operations, verify, by means of base 99370415 (2) and comparator 99395603 (1), that valve hollow (3) corresponds to the specified value. VALVE SPRINGS Figure 80 84193 MAIN DATA FOR INTAKE AND EXHAUST VALVE SPRING CHECK Prior to mounting, check the valve spring flexibility by means...

  • Page 158: Tightening Torques

    SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES TIGHTENING TORQUES TORQUE COMPONENT COMPONENT 15 ± 3 1.5 ± 0.3 M8 fastening screw for cylinder barrel lubricating nozzles 50 ± 6 5 ± 0.6 M12 fastening screw for crankshaft caps stage 80 ±...
  • Page 159 CNG NEF ENGINES SECTION 4 - GENERAL OVERHAUL TORQUE COMPONENT COMPONENT 85 ± 10 8.5 ± 1 M10 fastening screw for flywheel case 4.9 ± 0.5 49 ± 5 M12 fastening screw for flywheel case 10 ± 2 1 ± 0.2 M6 fastening screw for control unit heat exchanger 2.4 ±...
  • Page 160 SECTION 4 - GENERAL OVERHAUL CNG NEF ENGINES...
  • Page 161 CNG NEF ENGINES SECTION 5 - TOOLS SECTION 5 Tools Page TOOLS ....... .
  • Page 162 SECTION 5 - TOOLS CNG NEF ENGINES...
  • Page 163 CNG NEF ENGINES SECTION 5 - TOOLS TOOLS TOOL NO. DESCRIPTION 99305019 Tool box for valve seat grinding 99305047 Tool for spring load check Rotating stand for unit overhaul (capacity 1000 daN, torque 120 99322205 daNm) 99340055 Tool for extraction of crankshaft front gasket 99340056 Tool for extraction of crankshaft rear gasket 99341001...
  • Page 164 SECTION 5 - TOOLS CNG NEF ENGINES TOOLS TOOL NO. DESCRIPTION 99341009 Pair of brackets 99346252 Tool for fitting of crankshaft front gasket 99346253 Tool for fitting of crankshaft rear gasket Wrench (10 mm) for fastening screw of hydraulic power steering 99355019 pump 99358024...
  • Page 165 CNG NEF ENGINES SECTION 5 - TOOLS TOOLS TOOL NO. DESCRIPTION 99360163 Tool for gas pressure test 99360183 Pliers for piston snap ring assembly and disassembly (65 - 110 mm) 99360268 Tool for engine valve assembly and disassembly 99360330 Tool for engine flywheel rotation 99360351 Tool for engine flywheel fastening Beater for camshaft bush assembly and disassembly (to be used with...
  • Page 166 SECTION 5 - TOOLS CNG NEF ENGINES TOOLS TOOL NO. DESCRIPTION 99360500 Tool for crankshaft lifting 99360595 Rocker arm for engine removal and refitting 99360605 Clamp for piston fitting in cylinder barrel (60 125 mm) 99361037 Engine retaining brackets on rotating stand 99322205 99363204 Tool for gasket extraction 99370006...
  • Page 167 CNG NEF ENGINES SECTION 5 - TOOLS TOOLS TOOL NO. DESCRIPTION Dial gauge base for different measurements (to be used with 99370415 99395603) Pair for gauges for angle tightening with square coupling by 1/2” and 99395216 3/4” 99395220 Universal goniometer/ dip compass 99395363 Complete square for connecting rod squaring check 99395603...
  • Page 168 SECTION 5 - TOOLS CNG NEF ENGINES...
  • Page 169 CNG NEF ENGINES APPENDIX Appendix Page SAFETY PRESCRIPTIONS ....- Standard safety prescriptions ....- Prevention of injury .
  • Page 170 APPENDIX CNG NEF ENGINES...
  • Page 171 CNG NEF ENGINES APPENDIX - Do not execute any intervention if not provided with SAFETY PRESCRIPTIONS Standard safety prescriptions necessary instructions. - Do not use any tool or equipment for any different Particular attention shall be drawn on some precautions that operation from the ones they’ve been designed and must be followed absolutely in a standard working area and provided for: serious injury may occur.
  • Page 172 APPENDIX CNG NEF ENGINES - Avoid incorrect tightening or out of couple. Danger: Respect of the Environment incorrect tightening may seriously damage engine’s - Respect of the Environment shall be of primary components, affecting engine’s duration. importance: all necessary precautions to ensure - Avoid priming from fuel tanks made out of copper alloys personnel’s safety and health shall be adopted.

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