IS 7451 : Part 2 : 2006 /ISO 1204 : 1990 Reciprocating Internal Combustion Engines Part 2 Designation of the Direction of Rotation and of Cylinders and Valves in Cylinder Heads, and Definition of Right-Hand and Left-Hand In-Line Engines and Locations on

National Foreword

This Indian Standard (First Revision) which is identical with ISO 1204 : 1990 ?Reciprocating internal combustionengines - Designation of the direction of rotation and of cylinders and valves in cylinder heads, and definitionof right-hand and left-hand in-line engines and locations on an engine? issued by the International Organizationfor Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of theAutomotive Primemovers Transmission, Steering Systems and Internal Combustion Engines SectionalCommittee and approval of the Transport Engineering Division Council.

The Sectional Committee decided to align the Indian Standard with the corresponding International Standardwherever feasible and wherever the domestic considerations were not so intense so as to have standardsdifferent from the ISO Standards. This decision was taken with a view to upgrade the quality of the productsin-line with the International Standards.

The second edition of the above ISO Standard cancels and replaces the first edition (ISO 1204 : 1972) aswell as ISO 1205 : 1972, ISO 2276 : 1972 and ISO 3249 : 1975. These standards have been combined intoone standard and new clause covering the designation oi valves in cylinder heads of reciprocating InternalCombustion engines has been added.

In view of above IS 7451 (Part 3) : 1974, IS 7451 (Part 4) : 1974 and IS 7451 (Part 5) : 1975 are amalgamatedinto IS 7451 (Part 2).

This standard was first published in 1974. The first revision was undertaken due to revision of the basestandard as indicated above. The following technical changes have been incorporated:

a) Position of the observer is explained in detail.

b) New clause on designation of valves (7) and designation of valves in cylinder heads (4.2) have beenincluded.

The text of the ISO Standard has been approved as suitable for publication as an Indian Standard withoutdeviations. Certain conventions are, however, not identical to those used in Indian Standards. Attention isparticularly drawn to the following:

a) Wherever the words ?International Standard? appear referring to this standard, they should be readas ?Indian Standard?.

b) Comma(,) has been used as a decimal marker while in Indian Standards, the current practice is touse a point (.) as the decimal marker.