EN ISO 5164:2014

SLOVENSKI STANDARD
01-september-2014
1DGRPHãþD
SIST EN ISO 5164:2006
1DIWQLSURL]YRGL'RORþHYDQMHRNWDQVNHJDãWHYLODPRWRUQLKJRULY5D]LVNRYDOQD
PHWRGD,62
Petroleum products - Determination of knock characteristics of motor fuels - Research
method (ISO 5164:2014)
Mineralölerzeugnisse - Bestimmung der Klopffestigkeit von Ottokraftstoffen - Research-
Verfahren (ISO 5164:2014)
Produits pétroliers - Détermination des caractéristiques antidétonantes des carburants
pour moteurs - Méthode de recherche (ISO 5164:2014)
Ta slovenski standard je istoveten z: EN ISO 5164:2014
ICS:
75.160.20 7HNRþDJRULYD Liquid fuels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 5164
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2014
ICS 75.160.20 Supersedes EN ISO 5164:2005
English Version
Petroleum products - Determination of knock characteristics of
motor fuels - Research method (ISO 5164:2014)
Produits pétroliers - Détermination des caractéristiques Mineralölerzeugnisse - Bestimmung der Klopffestigkeit von
antidétonantes des carburants pour moteurs - Méthode de Ottokraftstoffen - Research-Verfahren (ISO 5164:2014)
recherche (ISO 5164:2014)
This European Standard was approved by CEN on 14 April 2014.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5164:2014 E
worldwide for CEN national Members.

Contents Page
Foreword .3
Foreword
This document (EN ISO 5164:2014) has been prepared by Technical Committee ISO/TC 28 "Petroleum
products and lubricants" in collaboration with Technical Committee CEN/TC 19 “Gaseous and liquid fuels,
lubricants and related products of petroleum, synthetic and biological origin” the secretariat of which is held by
NEN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2014, and conflicting national standards shall be withdrawn
at the latest by December 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 5164:2005.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 5164:2014 has been approved by CEN as EN ISO 5164:2014 without any modification.

INTERNATIONAL ISO
STANDARD 5164
Fourth edition
2014-06-01
Petroleum products — Determination
of knock characteristics of motor fuels
— Research method
Produits pétroliers — Détermination des caractéristiques
antidétonantes des carburants pour moteurs — Méthode de recherche
Reference number
ISO 5164:2014(E)
©
ISO 2014
ISO 5164:2014(E)
© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested 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 2014 – All rights reserved

ISO 5164:2014(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Reagents and reference materials . 3
6 Apparatus . 5
7 Sampling and sample preparation . 6
8 Basic engine and instrument settings and standard operating conditions .6
8.1 Installation of engine equipment and instrumentation . 6
8.2 Engine speed . 6
8.3 Valve timing . 7
8.4 Valve lift . 7
8.5 Intake valve shroud . 7
8.6 Carburettor venturi . 7
8.7 Direction of engine rotation . 7
8.8 Valve clearances . 7
8.9 Oil pressure . 7
8.10 Oil temperature . 8
8.11 Cylinder jacket coolant temperature . 8
8.12 Intake air temperature . 8
8.13 Intake air humidity . 8
8.14 Cylinder jacket coolant level. 8
8.15 Engine crankcase lubricating oil level. 9
8.16 Crankcase internal pressure . 9
8.17 Exhaust back-pressure . 9
8.18 Exhaust and crankcase breather system resonance . 9
8.19 Belt tension . 9
8.20 Rocker arm carrier support basic setting . 9
8.21 Rocker arm carrier basic setting . 9
8.22 Rocker arm and push rod length basic settings . 9
8.23 Basic spark setting .10
8.24 Basic ignition timer control arm setting .10
8.25 Basic ignition timer transducer to rotor vane gap setting .10
8.26 Spark-plug gap .10
8.27 Basic cylinder height setting .10
8.28 Fuel-air ratio .11
8.29 Carburettor cooling .12
8.30 Knockmeter reading limits .12
8.31 Detonation meter spread and time constant settings .12
9 Engine calibration and qualification .12
9.1 General .12
9.2 Engine fit-for-use qualification .12
9.3 Fit-for-use procedure in the 87,1 RON to 100,0 RON range .13
9.4 Fit-for-use procedure below 87,1 RON and above 100,0 RON .14
9.5 Checking performance on check fuels .14
10 Procedure.15
10.1 General .15
10.2 Start-up .15
ISO 5164:2014(E)
10.3 Calibration .15
10.4 Sample fuel .16
10.5 Primary reference fuel No. 1 .16
10.6 Primary reference fuel No. 2 .17
10.7 Additional measurement readings .17
10.8 Special instructions for ratings above 100,0 RON .17
11 Calculation .18
12 Expression of results .18
13 Precision .19
13.1 General .19
13.2 Repeatability, r . 19
13.3 Reproducibility, R . 19
13.4 Precision for ratings at barometric pressures below 94,6 kPa .19
13.5 Precision for fuels containing 15% to 25% (V/V) ethanol .20
14 Test report .20
Annex A (informative) Test variable characteristics .21
Bibliography .24
iv © ISO 2014 – All rights reserved

ISO 5164:2014(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
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. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT), see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 28, Petroleum products and lubricants.
This fourth edition cancels and replaces the third edition (ISO 5164:2005). Besides improving the
understanding of some of the procedures, the main revision lays in the introduction of the so-called
digital detonation meter. The revision includes allowances both measurement systems:
a) the knock measurement system based on analogue technology, and
b) the XCP digital technology used in the digital detonation meter.
ISO 5164:2014(E)
Introduction
The purpose of this International Standard is to accord ISO status to a test procedure that is already used
in a standardized form all over the world. The procedure in question is published by ASTM International
as Standard Test Method D 2699-12.
By publishing this International Standard, ISO recognizes that this method is used in its original text in
many member countries and that the standard equipment and many of the accessories and materials
required for the method are obtainable only from specific manufacturers or suppliers. To carry out
the procedure in every detail requires reference to annexes and appendices of ASTM D 2699-12. The
annexes detail the specific equipment and instrumentation required, the critical component settings and
adjustments, and include the working tables of referenced settings. The appendices provide background
and additional insight about auxiliary equipment, operational techniques and the concepts relative to
proper maintenance of the engine and instrumentation items.
The accumulated motor fuel data relating to knock characteristics determined in many countries has,
for many years, been based on the use of the CFR engine and the ASTM octane test methods. Accepted
worldwide, petroleum industry octane number requirements for motor fuels are defined by the research
1)
method and associated CFR F-1 Octane Rating Unit , which emphasizes the need for this method and
test equipment to be standardized. The initiation of studies to use a different engine for ISO purposes
has therefore been considered an unnecessary duplication of effort.
For these reasons, it has been considered desirable by ISO Technical Committee 28, Petroleum products
and lubricants, to adopt the ASTM D 2699 standard procedures. However, this International Standard
refers to annexes and appendices of ASTM D 2699 without change because of their extensive detail.
These annexes and appendices are not included in this International Standard because they are available
from ASTM International.
Due to identified component obsolescence issues, the original, analogue control panel has been replaced
by the manufacturer by new digital panel as of 2011. Service parts availability for the analogue system
[5]
will be phased out in the future. Research work was executed by ASTM International to check
whether there was statistically observable systemic bias between the 501C and the new digital knock
measurement system.
With respect to precision ISO and ASTM technical committees concluded that there was numerically
comparable precision for repeatability between the 501C and new panel knock measurement systems,
and no statistically observable difference for reproducibility between the 501C and new panel knock
measurement systems. This means that the new CFR octane panel could be included in the test method.
1) The sole manufacturer of the Model CFR F-1 Octane Rating Unit is Waukesha Engine, Dresser Waukesha,
Inc., 1000 West St. Paul Avenue, Waukesha, WI 53188, USA.
vi © ISO 2014 – All rights reserved

INTERNATIONAL STANDARD ISO 5164:2014(E)
Petroleum products — Determination of knock
characteristics of motor fuels — Research method
WARNING — The use of this International Standard may involve hazardous materials, operations
and equipment. This International Standard does not purport to address of the safety problems
associated with its use. It is the responsibility of the user of this International Standard to
establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1 Scope
This International Standard establishes the rating of liquid spark-ignition engine fuel in terms of
an arbitrary scale of octane numbers using a standard single-cylinder, four-stroke cycle, variable
compression ratio, carburetted, CFR engine operated at constant speed. Research octane number
(RON) provides a measure of the knock characteristics of motor fuels in automotive engines under mild
conditions of operation.
This International Standard is applicable for the entire scale range from 0 RON to 120 RON, but the
working range is 40 RON to 120 RON. Typical motor fuel testing is in the range of 88 RON to 101 RON.
This International Standard is applicable for oxygenate-containing fuels containing up to 4,0 % (m/m)
oxygen and for gasoline containing up to 25 %(V/V) ethanol.
NOTE 1 Although 25 % (V/V) of ethanol corresponds to approximately 9 % (m/m) oxygen, full applicability of
this test method for that oxygen range has only been checked for gasoline type of fuels.
NOTE 2 Work is under way to check the possibility to use the method up to and including 85 %(V/V) ethanol.
NOTE 3 This International Standard specifies operating conditions in SI units but engine measurements may
be specified in inch-pound units because these were the units used in the manufacture of the equipment, and thus
some references in this International Standard include these units in parenthesis.
NOTE 4 For the purposes of this standard, the terms “% (m/m)” and “% (V/V)” are used to represent the mass
fraction, µ, and the volume fraction, φ, of a material respectively.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3170, Petroleum liquids — Manual sampling
ISO 3171, Petroleum liquids — Automatic pipeline sampling
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 4787, Laboratory glassware — Volumetric instruments — Methods for testing of capacity and for use
ASTM D2699-12, Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO 5164:2014(E)
3.1
accepted reference value
ARV
value that serves as an agreed-upon reference for comparison, and which is derived as: a theoretical or
established value, based on scientific principles, an assigned or certified value, based on experimental
work of some national or international organization, or a consensus or certified value, based on
collaborative experimental work under the auspices of a scientific or engineering group
3.2
check fuel
fuel of selected characteristics that has a RON accepted reference value determined by round-robin
testing by multiple engines in different locations
3.3
cylinder height
relative vertical position of the CFR engine cylinder with respect to the piston at top dead center (t.d.c.)
or the top machined surface of the crankcase
3.4
dial indicator reading
numerical indication of cylinder height, indexed to a basic setting when the engine is motored with the
compression ratio set to produce a specified compression pressure
Note 1 to entry: The dial indicator reading is expressed in thousandths of an inch.
3.5
digital counter reading
numerical indication of cylinder height, indexed to a basic setting when the engine is motored with the
compression ratio set to produce a specified compression pressure
3.6
detonation meter
knock signal conditioning instrumentation that accepts the electrical signal from the detonation pickup
and produces an output signal for display
Note 1 to entry: The meter is either analogue or digital.
3.7
detonation pickup
magnetostrictive-type transducer that threads into the engine cylinder to sense combustion-chamber
pressure and provide an electrical signal proportional to the rate-of-change of that cylinder pressure
3.8
firing
engine operation with fuel and ignition
3.9
fuel-air ratio for maximum knock intensity
proportion of fuel to air that produces the highest knock intensity for each fuel
3.10
guide table
tabulation of the specific relationship between cylinder height and octane number for the CFR engine
operated at standard knock intensity and a specified barometric pressure
3.11
knock
abnormal combustion, often producing an audible sound, caused by auto-ignition of the air-fuel mixture
2 © ISO 2014 – All rights reserved

ISO 5164:2014(E)
3.12
knock intensity
measure of engine knock
3.13
knockmeter
indicating meter with a division scale that displays the knock intensity signal from the detonation meter
Note 1 to entry: The meter is either analogue or digital.
3.14
motoring
engine operation without fuel and with the ignition shut off
3.15
research octane number
RON
numerical rating of knock resistance for a fuel obtained by comparing its knock intensity with that of
primary reference fuels of known research octane number when tested in a standardized CFR engine
operating under conditions specified in this document
3.16
oxygenate
oxygen-containing organic compound, such as various alcohols or ethers, used as a fuel or fuel supplement
3.17
primary reference fuel
PRF
2,2,4-trimethylpentane (iso-octane), n-heptane, volumetrically proportioned mixtures of iso-octane
with n-heptane, or blends of tetraethyl lead in iso-octane, which define the octane number scale
3.18
spread
sensitivity of the detonation meter expressed in knockmeter divisions per octane number
3.19
toluene standardization fuel
TSF
volumetrically proportioned blend that has RON accepted reference value and specified rating tolerances
4 Principle
A sample fuel, operating in a CFR engine at the fuel-air ratio that maximizes its knock, is compared to
primary reference fuel blends to determine that blend which, when operated at the fuel-air ratio that
maximizes its knock, would result in both fuels producing the same standard knock intensity when
tested at the same engine compression ratio. The volumetric composition of the primary reference fuel
blend defines both its octane number and that of the sample fuel.
5 Reagents and reference materials
5.1 Cylinder-jacket coolant, consisting of water conforming to grade 3 of ISO 3696. Water shall be used
in the cylinder jacket for laboratory locations where the resultant boiling temperature is 100 °C ± 1,5 °C
(212 °F ± 3 °F). Water with commercial glycol-based antifreeze added in sufficient quantity to meet the
boiling temperature requirement shall be used when laboratory altitude dictates.
A commercial multi-functional water treatment material should be used in the coolant to minimize
corrosion and mineral scale that can alter heat transfer and rating results.
ISO 5164:2014(E)
5.2 Carburettor coolant, if required (see 8.29), consisting of water or a water-antifreeze mixture,
chilled sufficiently to prevent fuel bubbling and excessive vaporization, but neither colder than 0,6 °C nor
warmer than 10 °C.
5.3 Engine crankcase-lubricating oil, comprising an SAE 30 viscosity grade oil meeting service
classification API SF/CE or better.
2 2
It shall contain a detergent additive and have a kinematic viscosity of 9,3 mm /s to 12,5 mm /s at 100 °C
(212 °F) and a viscosity index of not less than 85. Oils containing viscosity index improvers shall not be
used. Multi-grade lubricating oils shall not be used.
5.4 2,2,4-trimethylpentane (iso-octane) primary reference fuel, of minimum purity 99,75 % (V/V),
containing no more than 0,10 % (V/V) heptane and no more than 0,5 mg/l lead. This material shall be
1)
designated as 100 RON .
WARNING — iso-Octane is flammable and its vapours are harmful. Vapours may cause flash fire.
5.5 n-Heptane primary reference fuel, of minimum purity 99,75 % (V/V), containing no more than
2)
0,10 % (V/V) isooctane and no more than 0,5 mg/l lead. This material shall be designated as 0 RON .
WARNING — n-heptane is flammable and its vapours are harmful. Vapours may cause flash fire.
5.6 80-octane primary reference fuel blend, prepared using reference fuel grade iso-octane (5.4)
and n-heptane (5.5); this blend shall contain 80 % (V/V) ± 0,1 % (V/V) iso-octane.
NOTE ASTM D 2699–12, Annex A3 (Reference Fuel Blending Tables), provides information for preparation of
primary reference fuel blends to specific RON values.
5.7 Tetraethyl lead, dilute, (TEL dilute volume basis), consisting of a solution of aviation mix tetraethyl
lead antiknock compound in a hydrocarbon diluent of 70 % (V/V) xylene and 30 % (V/V) n-heptane.
WARNING —Tetraethyl lead is poisonous and flammable. It may be harmful or fatal if inhaled,
swallowed, or absorbed through the skin. May cause flash fire.
The anti-knock compound shall contain 18,23 % (m/m) ± 0,05 % (m/m) tetraethyl lead and have a relative
density at 15,6 °C/15,6 °C (60 °F/60 °F) of 0,957 to 0,967.
NOTE 1 The typical composition of the compound, excluding the tetraethyl lead, is as follows:
Ethylene dibromide (scavenger): 10,6 % (m/m)
Diluent:
xylene 52,5 % (m/m)
heptane 17,8 % (m/m)
Dye, antioxidant and inerts 0,87 % (m/m)
NOTE 2 Developments within ISO are under way in order to make less use of lead-containing PRFs.
5.8 Primary reference fuel blends for ratings over 100 RON, prepared by adding dilute tetraethyl
lead (5.7), in millilitre quantities, to a 400 ml volume of iso-octane (5.4). These blends define the RON
scale above 100.
1) PRFSs are commercially available, currently from Chevron Phillips Chemical Company LP., 1301 McKinney,
Suite 2130, Houston, TX 77010–3030, USA or Haltermann Products—Werk Hamburg, Zweigniederlassung der DOW
Olefinverbund GmbH, Schlengendeich 17, 21107 Hamburg, Germany.
4 © ISO 2014 – All rights reserved

ISO 5164:2014(E)
NOTE ASTM D 2699–12, Annex A3 (Reference Fuel Blending Tables), provides information on the RON values
for blends of tetraethyl lead in isooctane.
5.9 Methylbenzene (toluene), reference fuel grade, with a minimum purity of 99,5 % (V/V) as
determined by chromatographic analysis, a peroxide number not exceeding 5 mg/kg and a water content
not exceeding 200 mg/kg.
Antioxidant treatment should be added by the supplier at a rate suitable for long term stability as
empirically determined with the assistance of the antioxidant supplier.
5.10 Check fuels, consisting of in-house typical spark-ignition engine fuels having RON accepted
reference values, low volatility and good long-term stability.
6 Apparatus
6.1 Test engine assembly, a CFR octane rating unit consisting of a single-cylinder engine consisting of
a standard crankcase, a cylinder/clamping sleeve assembly to provide continuously variable compression
ratio adjustable with the engine operating, thermal-siphon recirculating jacket cooling system, a multiple
fuel tank system with selector valving to deliver fuel through a single jet passage and carburettor venturi,
an intake air system with controlled temperature and humidity equipment, electrical controls, and a
suitable exhaust pipe.
The engine flywheel shall be connected by a belt to a special electric power-absorption motor that acts
as a motor driver to start the engine and as a means to absorb power at constant speed when combustion
is occurring (engine firing).
NOTE Test engine assembly is available from the single source manufacturer, GE Waukesha gas engine,
Dresser, Inc., 1000 West St. Paul Avenue, Waukesha, WI 53188, USA. This information is given for the convenience
of users of this International Standard but does not constitute an endorsement by ISO of this product.
6.2 Instrumentation, consisting of electronic detonation metering instrumentation, including a
detonation pickup and knockmeter to measure and display the intensity of combustion knock, as well as
conventional hardware, tubing, fasteners, electrical and electronic items.
NOTE Instrumentation is available from multiple sources. In some cases, selection of specific dimensions or
specification criteria are important to achieve proper conditions for the knock testing unit, and these are included
in ASTM D2699–12, Appendix X1 when applicable.
6.3 Reference and standardization fuel dispensing equipment, consisting of calibrated burettes or
volumetric ware having a capacity of 200 ml to 500 ml and a maximum volumetric tolerance of ±0,2 %.
Calibration shall be verified in accordance with ISO 4787. Burettes shall be outfitted with a delivery
valve and delivery tip to accurately control dispensed volumes. The delivery tip shall be of such size
and design that shut-off tip discharge does not exceed 0,5 ml. The rate of delivery from the dispensing
system shall not exceed 400 ml/min. The installation shall be in such a manner and be supplied with
fluids such that all components of each batch or blend are dispensed at the same temperature.
6.4 Gravimetric blending of reference fuels, use of blending systems that allow preparation of the
volumetrically-defined blends by gravimetric (mass) measurements based on the density of the individual
components is also permitted, provided the system meets the requirement for maximum 0.2 % blending
tolerance limits.
Calculate the mass equivalents of the volumetrically-defined blend components from the densities of the
individual components at 15,56°C (60°F).
ISO 5164:2014(E)
6.5 Tetraethyl lead (TEL) dispensing equipment, consisting of a calibrated burette, pipette assembly,
or other liquid-dispensing apparatus, having a capacity not exceeding 4,0 ml, and a critically controlled
tolerance for dispensing dilute TEL into 400 ml batches of iso-octane.
Calibration shall be verified in accordance with ISO 4787.
NOTE ASTM D 2699–12, Appendix X2 (Volumetric Reference Fuel Blending Apparatus and Procedures),
provides additional information for application.
6.6 Special maintenance tools, consisting of a number of speciality tools and measuring instruments
available for easy, convenient and effective maintenance of the engine and testing equipment.
NOTE Lists and descriptions of these tools and instruments are available from the manufacturers of the
engine equipment and those organizations offering engineering and service support for this International
Standard.
7 Sampling and sample preparation
7.1 Unless otherwise specified in the commodity specification, samples shall be taken as described
in ISO 3170 or ISO 3171 and/or in accordance with the requirements of national regulations for the
sampling of the product under test, or an equivalent national standard.
7.2 Cool samples to 2 °C to 10 °C(35 °F to 50 °F) in the container in which they are received and before
the container is opened.
7.3 Minimize the sample’s exposure to light before pouring it into the engine carburettor fuel bowl,
because of possible sensitivity to light that can affect fuel characteristics. Collect and store samples in an
opaque container.
8 Basic engine and instrument settings and standard operating conditions
8.1 Installation of engine equipment and instrumentation
Locate the octane test engine in an area where it will not be affected by certain gases and fumes that
may have a measurable effect on the RON test result (see Clause 1).
Installation of the engine and instrumentation requires placement of the engine on a suitable foundation
and hook-up of all utilities. Engineering and technical support for this function is required, and the
user shall be responsible for complying with all local and national codes and installation requirements.
Proper operation of the CFR engine requires assembly of a number of engine components and adjustment
of a series of engine variables to prescribed specifications. Some of these settings are established by
component specifications, others are established at the time of engine assembly or after overhaul, and
still others are engine running conditions that must be observed or determined by the operator during
the testing process. Annex A gives further information on the test variable characteristics.
8.2 Engine speed
Engine speed shall be 600 r/min ± 6 r/min when the engine is operating with combustion with a
maximum variation of 6 r/min occurring during a rating.
Engine speed when combustion is occurring shall not be more than 3 r/min greater than for motoring
without combustion.
6 © ISO 2014 – All rights reserved

ISO 5164:2014(E)
8.3 Valve timing
With the piston at the highest point of travel in the cylinder, set the flywheel pointer mark in alignment
with the 0° mark on the flywheel in accordance with the instructions of the manufacturer.
The four-stroke cycle engine uses two crankshaft revolutions for each complete combustion cycle. The
two critical valve events are those that occur near top-dead-centre (t.d.c.), i.e. intake valve opening and
exhaust valve closing. Intake valve opening shall occur 10,0° ± 2,5° after t.d.c. with closing at 34° after-
bottom-dead-centre (a.b.d.c.) on one revolution of the crankshaft and flywheel. Exhaust valve opening
shall occur 40° before-bottom-dead-centre (b.b.d.c.) on the second revolution of the crankshaft and
flywheel with closing at 15,0° ± 2,5° after t.d.c. on the next revolution of the crankshaft and flywheel.
8.4 Valve lift
Intake and exhaust cam lobe contours, while different in shape, shall have a contour rise of 6,248 mm
to 6,350 mm (0,246 in to 0,250 in) from the base circle to the top of the lobe so that the resulting valve
lift shall be 6,045 mm ± 0,050 mm (0,238 in ± 0,002 in). See ASTM D 2699-12, Annex A2 (Apparatus
Assembly and Setting Instructions), for procedures for measuring valve lift which shall apply for this
International Standard.
8.5 Intake valve shroud
The 180° shroud or protrusion directs the incoming fuel-air mixture and increases its turbulence in
the combustion chamber. This valve stem is drilled for a pin, which is restrained in a valve guide slot, to
prevent the valve from rotating and thus maintain the direction of swirl. The valve shall be assembled
in the cylinder, with the pin aligned in the valve guide, so that the shroud is toward the spark plug
side of the combustion chamber and the swirl is directed in a counter-clockwise direction if it could be
observed from the top of the cylinder.
8.6 Carburettor venturi
The venturi throat size, regardless of ambient barometric pressure, shall be 1,43 cm (9/16 in).
8.7 Direction of engine rotation
The crankshaft, when observed from the front of the engine, rotates in a clockwise direction.
8.8 Valve clearances
With the engine cold prior to being operated, set the clearance between each valve stem and valve rocker
half-ball to the following approximate measurements upon assembly, which will typicall
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