4.2.2Vise an engine group, the required documentation necessary for the engine parameter cheek method is specified in 6.2 3.7
4.3 APPLICATION OF THE ENGINE FAMILY CONCEPT
4.3.1The engine family concept provides the possibility of reducing the number of engines which must be submitted for approval testing, while providing safeguards that all engines within the family comply with the approval requirements. In the engine family concept, engines with similar emission characteristics and design are represented by a parent engine within the family.
4.3.2Engines that are series produced and not intended to be modified may be covered by the engine family concept.
4.3.3The selection procedure for the parent engine is such that the selected engine incorporates those features which will must adversely affect the NOx emission level. This engine, in general, shall have the highest NOx emission level among all of the engines in the family.
4.3.4On the basis of tests and engineering judgement, the manufacturer shall propose which engines belting to an engine family, winds engine(s) produce the highest NOx emissions, and which engine(s) should be selected for certification resting.
4.3.5The Administration shall review for certification approval the selection of the parent engine within the family and shall have the option of selecting a different engine, either for approval or production conformity testing, is order to have confidence that the complete family of engines complies with the NOx emission limits.
4.3.6The engine family concept dries allow mirror adjustments to the engines through adjustable features. Marine engines equipped with adjustable features must comply with all requirements for any adjustment within the physically available range. A feature is truss considered adjustable if it is permanently sealed on otherwise nor normally accessible. The Administration may require that adjustable features be set to any specification within its adjustable range fuse certification or in-use sensing to determine compliance with the requirements.
4.3.7Before granting an engine family approval, the Administration shall take the necessary measures to verify that adequate arrangements have bees made to ensure effective control of the conformity of production.
4.3.8Guidelines for the Selection of an Engine Family
4.3.8.1 The engine family shall be defined by basic characteristics which must be common to all engines within the family. In some cases there may be interaction of parameters; these effects must also be taken into consideration to ensure that only engines with similar exhaust emission characteristics are included within air engine family. e.g., the number of cylinders may become a relevant parameter on some engines due to the aspiration or fuel system used, but wish their designs, exhaust emissions characteristics may be independent of the number of cylinders or configuration.
4.3.8.2 The engine manufacturer is responsible for selecting those engines from their different models of engines that are so be included in a family. Else following basic characteristics, but not specifications, must be common among all engines within an engine family:
MIEPC 39/6/1
ANNEX
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.1 combustion cycle
- 2 stroke cycle
- 4 stroke cycle
.2 cooling medium
- air
- water
- oil
.3 individual cylinder displacement
- to be within a total spread of 15%
.4 number of cylinders and cylinder configuration
- applicable in certain eases only, e.g., in combination with exhaust gas cleaning devices
.5 method of air aspiration
- naturally aspirated
- pressure charged
.6 fuel type
- distillate/heavy fuel oil
- dual fuel
.7 combustion chamber
- open chamber
- divided chamber
.8 valve and porting, configuration, size and number
