ISO 4106:2004

INTERNATIONAL ISO
STANDARD 4106
Third edition
2004-08-01

Motorcycles — Engine test code — Net
power
Motocycles — Code d'essai des moteurs — Puissance nette




Reference number
ISO 4106:2004(E)
©
ISO 2004

---------------------- Page: 1 ----------------------
ISO 4106:2004(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2004
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2004 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 4106:2004(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 1
4 Symbols . 2
5 Standard reference conditions . 2
6 Test method. 2
7 Method of power correction. 5
8 Measurement and correction of smoke value for compression-ignition (diesel) engines. 6
9 Test report. 7
Annex A (informative) Example for record form of test fuel specifications . 10
Bibliography . 11

© ISO 2004 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 4106:2004(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 4106 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 22,
Motorcycles.
This third edition cancels and replaces the second edition (ISO 4106:1993), which has been technically
revised.
iv © ISO 2004 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 4106:2004(E)
Introduction
The third edition of ISO 4106 has been prepared in the framework of ISO engine power measurement
standards. By applying this framework, the disadvantages of the existence of many similar, but different, ISO
standards for the definition and determination of engine power can be avoided.
This framework uses the “Core” and “Satellite” approach. The “Core” standard contains the requirements that
are common to all engine applications described in the scope and the “Satellite” standards contain those
requirements that are necessary to tailor power measurement and declaration to suit a particular engine
application. ISO 4106 is a “Satellite” standard and is only applicable in conjunction with the “Core” standard, in
order to completely specify the requirements for the particular engine application — in this case, motorcycle
engines. The “Core” standard therefore, is not a document that can stand alone but only represents addenda
to the particular “Satellite” standard, used to create a complete standard together with the said “Satellite”
standard.
The advantage of this approach is that the use of standards for the same or similar engines used in different
applications will be rationalized and the harmonization of standards in the course of revision or development
will be ensured.
ISO 15550 is the “Core” standard. It was prepared in order to serve as the “Core” standard for making engine
power measurements. It was drafted in close co-operation between ISO/TC 70, Internal combustion engines,
and ISO/TC 22, Road vehicles, ISO/TC 23, Tractors and machinery for agriculture and forestry, ISO/TC 127,
Earth-moving machinery and ISO/TC 188, Small craft. The prerequisite for any future modification of
ISO 15550 will be the formal approval of all the above technical committees. Together with the “Satellite”
standard for each engine application, the “Core” standard serves as the basis for engine power declaration
and measurement. Each technical committee is fully responsible for the administration of its own “Satellite”
standard(s).

© ISO 2004 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 4106:2004(E)

Motorcycles — Engine test code — Net power
1 Scope
This International Standard specifies methods for evaluating the performance of engines designed for
motorcycles as defined in ISO 3833, in particular with a view to the presentation of power curves and specific
fuel consumption at full load as a function of engine speed, for net power assessment. Used in conjunction
with ISO 15550, it is applicable to reciprocating internal combustion engines (spark-ignition or compression-
ignition) — excluding free-piston engines — and rotary piston engines, either naturally aspirated or pressure-
charged and equipped with either mechanical pressure-charger or turbocharger.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 2710-1:2000, Reciprocating internal combustion engines ― Vocabulary ― Part 1: Terms for engine
design and operation
ISO 3833, Road vehicles ― Types ― Terms and definitions
ISO 15550:2002, Internal combustion engines ― Determination and method for the measurement of engine
power ― General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2710-1, ISO 15550 and the
following apply.
3.1
net power
power obtained on a test bed at the end of the crankshaft or its equivalent at the corresponding engine speed
with the equipment and auxiliaries listed in column 2 and required in column 3 (fitted for engine net power test)
of ISO 15500:2002, Table 1
NOTE Adapted from ISO 15550:2002.
3.2
net torque
torque transmitted on a test bed at the end of the crankshaft or its equivalent at the corresponding engine
speed with the equipment and auxiliaries listed in column 2 and required in column 3 (fitted for engine net
power test) of ISO 15500:2002, Table 1
NOTE Adapted from ISO15550:2002.
© ISO 2004 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 4106:2004(E)
3.3
specific fuel consumption
amount of fuel consumed by an engine per unit of power and time
NOTE 1 The amount of lubricants for 2-stoke cycle engines is excluded.
NOTE 2 Adapted from ISO15550:2002.
3.4
auxiliaries
equipment and devices necessary to make the engine acceptable for service in the intended application
4 Symbols
The symbols and their subscripts according to ISO 15550:2002, Tables 2 and 3, apply, except for the
following:
1)
T temperature of air inducted into the engine .
y
5 Standard reference conditions
The standard reference conditions shall be according to ISO 15550:2002, Clause 5.
6 Test method
6.1 General
This test method is used for verifying the net power of an engine type with the declared values. It presents
engine performance at full power/torque as a function of engine speed by generating curves of power and fuel
consumption.
6.2 Measuring equipment and instrument accuracy
6.2.1 Torque
The dynamometer torque-measuring system shall have an accuracy of ± 1 % in the range of scale values
required for the test.
The torque-measuring system shall be calibrated to take into account friction losses. The accuracy may be
± 2 % for measurements carried out at a power less than 50 % of maximum power.
6.2.2 Engine speed
The engine-speed measuring system shall have an accuracy according to ISO 15550:2002, 6.3.2.2.
6.2.3 Fuel flow
The fuel-flow measuring system shall have an accuracy according to ISO 15550:2002, 6.3.2.3.

1) In ISO 15550, this symbol is instead used to designate “ambient air thermodynamic temperature during test”.
2 © ISO 2004 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 4106:2004(E)
6.2.4 Fuel temperature
The fuel-temperature measuring system shall have an accuracy according to ISO 15550:2002, 6.3.2.4.
6.2.5 Engine inlet air temperature
The air-temperature measuring system shall have an accuracy of ± 1 K.
6.2.6 Barometric pressure
The barometric-pressure measuring system shall have an accuracy of ± 70 Pa.
6.2.7 Back pressure in exhaust system
The system used to measure the back pressure in the exhaust system shall have an accuracy of ± 25 Pa.
6.2.8 Test-room humidity
The test-room-humidity measuring system shall have an accuracy of ± 11 % in relative humidity.
NOTE A relative humidity measurement accuracy of ± 11 % corresponds to a wet and dry bulb thermometer
measurement accuracy of ± 1 K.
6.3 Setting and test conditions
6.3.1 Equipment and auxiliaries
During the test, the auxiliaries shall be installed on the test bench in accordance with Table 1, and according
to ISO 15550:2002, Table 1, as far as possible in the same position as in the intended application.
Table 1 — Equipment and auxiliaries
No. Equipment and auxiliaries To be fitted during the test
1 Inlet system
Yes, if SPE
Electro-control devices
2
Exhaust system
Yes, if SPE
Electro-control devices
3 Liquid-cooling equipment
No
Engine cowling
4 Oil cooler Yes, if SPE

6.3.2 Setting conditions
The setting conditions shall be according to ISO 15550:2002, 6.3.3.
© ISO 2004 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO 4106:2004(E)
6.3.3 Test conditions
...