Foreword

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This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 38, Motorcycles and mopeds.

This fifth edition cancels and replaces the fourth edition ( ISO 4106:2012 ), which has been technically revised.

The main changes are as follows:

the ranges of fuel temperature, engine inlet air temperature, and the applicable range of the correction factor have been expanded;
engine inlet depression and dry atmospheric pressure have been removed from required measurement items;
an example of the record form for test fuel specifications has been added;
transmission component efficiencies of helical and bevel gears have been changed.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

This fifth edition harmonizes some minor differences compared to the other measurement methods as much as possible to improve efficiency.

1 Scope

This document 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. 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. Particular specifications for the test of compression-ignition engines are specified in Annex A.

2 Normative references

3 Terms and definitions

4 Symbols

5 Standard reference conditions

6 Tests

6.1 General

6.2 Measuring equipment and instrument accuracy

6.3 Setting and test conditions

6.4 Test procedure

7 Torque, power and specific fuel consumption

7.1 Calculation of measured torque, measured power and specific fuel consumption

7.2 Net torque and net power

7.3 Corrected net torque and corrected net power

8 Test report

8.1 General

8.2 The description of test report

8.3 Statement of results

Bibliography