Iveco Motors N67 MNT M28 Operating instructions

NEF ENGINE
N67 MNT M28
TECHNICAL AND REPAIR
MANUAL
OCTOBER 2005 EDITION
TECHNOLOGICAL EXCELLENCE

N67 MNT M28
1.2 OCTOBER 2005
FOREWORD
We strongly recommend that you carefully read the indi-
cations contained in this document: compliance with them
protects the engine against irregular operation and assures
its reliability, safeguarding sea-going and maintenance person-
nel against accident hazards.
The indications contained in this document pertain to the
N67 MNT M28 marine engine and complement the IVECO
MOTORS publication of “Marine Diesel Engines Installation
Handbook” that the reader should refer to for anything that
is not explained herein.
Technical engineers and fitters are required to comply with
safety regulations on work. They have to implement and
adopt the device required for individual personal safeguard
while carrying out maintenance or checks.
Safety rules are reported in Section 9 of this publication.
Regulations on handling engine are reported at the end of
Section 6 of this publication.
In order to start the engine, strictly follow the procedure
stated at the end of Section 5 of this publication.
To get the best possible performance out of the engine, it
is mandatory to conform with its intended mission profile.
The engine must not be used for purposes other than those
stated by the manufacturer.
IVECO MOTORS is available beforehand to examine requi-
rements for special installations, if any.
In particular
q Use of unsuitable fuels and oils may compromise the
engine’s regular operation, reducing its performance,
reliability and working life;
q Exclusive use of IVECO Original Parts is a necessary
condition to maintain the engine in its original integrity;
q Any tampering, modifications, or use of non-original
parts may jeopardize the safety of service personnel and
boat users.
To obtain spare parts, you must indicate:
- Commercial code, serial number and indications shown
on the engine tag;
- Part number of the spare as per spare part catalog.
The information provided below refer to engine characteri-
stics that are current as of the publication date.
IVECO MOTORS reserves the right to make modifications
at any time and without advance notice, to meet technical or
commercial requirements or to comply with local legal and
regulatory requirements.
We refuse all liability
for any errors and omissions.
The reader is reminded that the IVECO MOTORS Technical
Assistance Network is always at the Customer’s side with its
competence and professionalism.
Publication IVECO MOTORS edited by:
IVECO PowerTrain
Advertising & Promotion
Pregnana Milanese (MI)
www.ivecomotors.com
Printed P3D32N002 E - October 2005 Edition

N67 MNT M28 1.3 OCTOBER 2005
SECTION CONTENTS
Section Page
1. OVERVIEW 5
2. TECHNICAL DATA 31
3. ELECTRICAL EQUIPMENT 37
4. DIAGNOSTICS 53
5. MAINTENANCE 63
6. SERVICING OPERATIONS
ON INSTALLED ENGINE 69
7. TOOLS 81
8. OVERHAUL 89
9. SAFETY REGULATIONS 147
Indications for consultation
Sections 1-2-3 are intended for sales personnel, to provide
them with exact knowledge of the product’s characteri-
stics and enable them to meet the Customer’s demands
with precision.
The remaining sections are meant for personnel in charge of
carrying out ordinary and extraordinary maintenance; with
an attentive consultation of the chapter devoted to diagno-
sing, they will also be able to provide an effective technical
assistance service.

N67 MNT M28
1.4 OCTOBER 2005

N67 MNT M28OVERVIEW 1.5 OCTOBER 2005
SECTION 1
OVERVIEW
Page
IDENTIFYING DATA 7
COMMERCIAL CODE 8
PRODUCT MODEL NUMBER 9
ENGINE PARTS AND COMPONENTS 10
ENGINE ARCHITECTURE 12
Crankcase 12
Crankshaft 13
Connecting Rods 13
Pistons 14
Timing system driving gear 14
Cylinder head 16
Valves and valve seats 17
Ancillary machine parts drive 17
COMBUSTION AIR INTAKE AND EXHAUST SYSTEM 18
Comburent air filter 19
Turbocompressor 19
Air / sea-water heat exchanger 19
COOLING FRESH WATER CLOSED-LOOP 20
Exhaust manifold cooling 21
Thermostatic valve 22
Water pump 22
Additional expansion tank 22
SEA-WATER OPEN COOLING LOOP 23
Sea-water pump 24
Sea-water/coolant heat exchanger 24

N67 MNT M28 OVERVIEW
1.6 OCTOBER 2005
Page
ENGINE OIL LUBRICATION LOOP 25
Gear pump 26
Filter bracket 26
Oil vapour recirculation 26
FUEL LINE 27
Fuel supply system scheme 28
Fuel pre-filter 29
Fuel filter 29

N67 MNT M28OVERVIEW 1.7 OCTOBER 2005
IDENTIFYING DATA
Viale dell'Industria, 15/17 - 20010 Pregnana Mil.se MI - ITALY
ENGINE TYPE
ENGINE DWG
ENGINE S/N
COMMERC. TYPE / VERSION
POWER SET CODE
HOMOLOGATION N°
ENGINE FAMILY
POWER (KW)
AND SPEED (RPM)
YEAR OF BUILD
S. p. A.
04_002_N
Figure 1
Figure 2
The engine identification data are stenciled on a tag located on a side of the engine coolant tank.
04_306_N

N67 MNT M28 OVERVIEW
1.8 OCTOBER 2005
COMMERCIAL CODE
The purpose of the commercial code is to make the characteristics of the product easier to understand, categorizing the engi-
nes according to their family, origins and intended application. The commercial code, therefore, cannot be used for the technical
purpose of recognizing the engine’s components, which is served by the “ENGINE S/N”.
N 67 M N T M 28 . 1 0
ENGINE FAMILY IDENTIFIER: N = NEF
DISPLACEMENT: 67 = 6700 cc NOMINAL
FUEL SUPPLY: M = MECHANICAL INJECTION PUMP
BASE: N = NON STRUCTURAL
AIR INTAKE: T = INTERCOOLED SUPERCHARGED
APPLICATION: M = MARINE
MAXIMUM PERFORMANCE LEVEL ACHIEVABLE
28 = 280 HP
VERSION:
TURBOCHARGED:
1 = COOLED
2 = NOT COOLED
VERSION

N67 MNT M28OVERVIEW 1.9 OCTOBER 2005
PRODUCT MODEL NUMBER
The model number is assigned by the manufacturer; it is used to identify the main characteristics of the engine, and to characte-
rize its application and power output level. It is stamped on a side of crank-case, close to oil filter.
F 4 G E 0 6 8 6 A *E 6 0 1
ENGINE FAMILY IDENTIFIER
DESIGN ITERATION
ENGINE
NO. OF STROKES AND CYLINDER DISPOSITION (0 = 4 STROKES, VERTICAL)
NO. OF CYLINDERS
FUEL + INJECTION (8 = DIESEL, TCA, DIRECT INJECTION)
INTENDED USE (6 = MARINE)
POWER RANGE:
A = MAXIMUM POWER 280 HP
E = EMISSION FOR
MARINE APPLICATION
VARIANTS TO
BASIC ENGINE

N67 MNT M28 OVERVIEW
1.10 OCTOBER 2005
ENGINE PARTS AND COMPONENTS
Figure 3
1. Engine coolant discharge cap - 2. Electric starter motor - 3. Tube bundle engine coolant / sea-water heat exchanger - 4.-Location
of sacrificial anode - 5. Cooled exhaust manifold - 6. Exhaust gas and sea-water discharge pipeline - 7. Lifting eyebolt - 8. Rocker arm
covers - 9. Oil refill cap - 10. Location of thermostatic valve - 11. Cap for engine coolant outlet to sanitary water heating system
- 12. Coolant refill cap - 13. Fuel intake fitting - 14. Fuel filter - 15. Engine coolant tank - 16.-Auxiliary belt automatic tensioner -
17. Alternator - 18. Cap for engine coolant discharge and recirculation from sanitary water heating system - 19. Oil filter.
19
2
3
4
5
69
8
17 16
1
04_303_N
7
10 11 1312
15
14
18

N67 MNT M28OVERVIEW 1.11 OCTOBER 2005
ENGINE PARTS AND COMPONENTS
Figure 4
1. Combustion air filter - 2. Sea-water inlet - 3. Sea-water pump - 4. Throttle lever lever on injection pump - 5. Rubber holder
junction for fuel outflow to the tank - 6. Sacrificial anode - 7. Wiring connectors - 8. Combustion air / sea-water heat exchanger -
9. Location of sea-water discharge cap - 10. Manual lubricating oil extraction pump - 11. Oil dipstick - 12. Lifting eyebolt -
13. Oil separator - 14. Air filter clogging sensor - 15. Cooled turbocompressor - 16. Sea-water junction pipe from after-cooler to
engine coolant / sea-water heat exchanger (Oil gearbox heat exchanger, on request)
1234
11 13 14 15
16
5
7
04_304_N
6
9
8
10 12

N67 MNT M28 OVERVIEW
1.12 OCTOBER 2005
NEF engines are the highest expression of design and engi-
neering efficiency that IVECO MOTORS makes available on
the market place. They are highly innovative engines designed
to be able to comply now with the regulations on fumes and
acoustic emissions that will be enforced in the near future.
Designed with innovative techniques and manufactured with
advanced working processes, they are the result of hundreds
of years of design and engineering tradition as well as of an
important international cooperation.
The excellent performance of NEF engines originates from
induction and exhaust ducts of new design where, by impro-
ving the gas exchange phases, the intaken air turbolence is
improved, thus enabling the complete exploitation of the
new injection system capacity.
The new criteria chosen in defining the parameters setting
the combustion conditions, metering and injection, enable
to obtain new balance between high performance and
consumption reduction. NEF engines can be fitted with a
mechanical pump or a total electronic controlled “Common
Rail” fuel supply system.
Every technical solution has been accurately devised so as
to assure qualitative product perfection. The configuration
of the engine itself has been designed in such a way as to
facilitate access to each individual part thus reducing main-
tenance time.
Cylinder head fitted with two valves per cylinder, rear timing
control, new design connecting rods and aluminum-nickel
pistons are components of an engine fitted with 40% less
elements than an engine of equivalent performance.
Moreover, within the cast iron crankcase, coolant circula-
tion grooves, ducts for lubrication loops for the various
machine parts and the seat for push rod bushings have
been grooved in. The backing plate (6) applied to the
lower part makes the crankcase tougher and improves
resistance to stress.
Crankcase
04_011_N
7
81
3
6
5
4
2
1. Reconditionable integral cylinder barrels - 2. Water pump seat - 3. Camshaft bushing seat - 4. Oil pump seat - 5.-Main bearings - 6.
Crankcase backing plate - 7. Oil cooler (water/oil) seat - 8. Product model number location.
ENGINE ARCHITECTURE
Figure 5

N67 MNT M28OVERVIEW 1.13 OCTOBER 2005
The crankshaft is made in steel hardened by induction and
rests on seven mountings; inside the hollow shaft are the
ducts for the lubrication oil circulation.
On the front tang, the oil pump driving gear, the phonic
wheel, the flywheel connecting hub and the driving pulley of
the ancillary components are keyed on.
On the rear tang the camshaft driving gear and the coupling
flange to the engine flywheel are keyed on.
The bench half bearings are in cast babbitt lining steel and
the 6th is fitted with a shoulder ring to contain the end play
of the driving shaft.
Details 1 and 2 in the figure, assembled by negative
allowance on the rear tang, are not replaceable. The front
and rear retaining rings are of the slide type with radial
seal and require special fixtures to be assembled and
disassembled.
Connecting Rods
They are made in steel, manufactured by pressing, with small
end oblique edged and cap separation obtained by fracture
splitting technique.
The connecting rod half bearings are cast babbitt lining
steel.
Every connecting rod is marked on the body and on the cap
by a number that identifies their coupling and the cylinder
into which it is to be assembled; moreover, a letter is impres-
sed on the body stating its weight class.
In case a replacement were necessary, only one type of
connecting rod is available as spare part of an intermediate
class weight that can be used to replace any other. Therefo-
re, connecting rods that are still efficient, do not need to be
replaced even if they are of a different class weight.
Crankshaft
1. Timing system driving gear - 2. Flywheel connecting hub - 3. Oil pump driving gear.
04_013_N
Figure 7
Figure 6
04_012_N
3
1
2

N67 MNT M28 OVERVIEW
1.14 OCTOBER 2005
Pistons
The pistons integrate the high swirl combustion chamber;
the annular chambers inside the junk ring enable an effective
heat elimination obtained by circulating the lubrication oil
delivered by the spray nozzles mounted on the crankcase.
On the piston skirt the are three seats for the retaining rings;
the first one of these is obtained by a special trapezoidal
section cast iron insert.
The piston rings have different functions and different geo-
metry.
- The 1st piston ring has a trapezoidal section and ceramic
chrome plating;
- The 2nd piston ring has a a torsional conical rectangular
seal;
- The 3rd piston ring has a double oil scraper with internal
spring.
Timing system driving gear
The timing system driving gear machine is a push rods
and rockers type, with a camshaft (1) that is located in the
crankcase and set into rotation directly by the crankshaft.
1. Positioning reference - 2. Crankshaft - 3. Camshaft.
The figure illustrates the position that the toothed wheel has
to have to set the correct timing strokes.
Figure 8 Figure 9
04_014_N
04_015_N
Figure 10
04_317_N
1
2
3
1

N67 MNT M28OVERVIEW 1.15 OCTOBER 2005
The timing camshaft rests on seven mountings; the mounting
points at front and rear end, are fitted with cast babbitt lining
steel bushings, assembled by negative allowance.
The timing camshaft is set into rotation by the crankshaft
with direct coupling to a straight toothed wheel.
1. Rocker - 2. Rocker support - 3. Adjuster screw - 4. Rod - 5. Cotters - 6. Cup - 7. Spring - 8. Tappet - 9. Camshaft.
Figure 11
04_316_N
7
8
3
4
1
6
5
2
9