ANNEX I Requirements for the EU type-approval of a type of engine or engine family for an agricultural and forestry vehicle type as a separate technical unit regarding the pollutants emitted

9. Engine family

9.1. Parameters defining the engine family

The engine family may be defined by basic design parameters 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 in order to ensure that only engines with similar exhaust pollutant emission characteristics are included within an engine family.

For engines to be considered to belong to the same engine family, the following list of basic parameters must be common.

9.1.1.

Combustion cycle: 2 stroke/4 stroke

9.1.2.

Cooling medium: air/water/oil

9.1.3.

Individual cylinder displacement

• within 85 % and 100 % of the largest displacement within the engine family

9.1.4.

Method of air aspiration: naturally aspirated/pressure charged

9.1.5.

Fuel type: Diesel/Petrol

9.1.6.

Combustion chamber type/design

9.1.7.

Valve and porting — configuration, size and number

9.1.8.

Fuel system

For diesel:

• pump-line-injector

• in-line pump

• distributor pump

• single element

• unit injector

For petrol:

• carburettor

• port fuel injection

• direct injection

9.1.9.

Miscellaneous features

• Exhaust gas recirculation

• Water injection/emulsion

• Air injection

• Charge cooling system

• Ignition type (compression, spark)

9.1.10.

Exhaust after-treatment

• Oxidation catalyst

• Reduction catalyst

• Three way catalyst

• Thermal reactor

• Particulate trap

9.2. Choice of parent engine

9.2.1.

The parent engine of the engine family shall be selected using the primary criterion of the highest fuel delivery per stroke at the declared maximum torque speed in accordance to the essential characteristics of the engine family set out in Appendix 2 of Annex II of Directive 97/68/EC. If two or more engines share this primary criterion, the parent engine shall be selected using the secondary criterion of highest fuel delivery per stroke at rated speed. Under certain circumstances, the approval authority may conclude that the worst case emission rate of the family can best be characterized by testing a second engine. Thus, the approval authority may select an additional engine for tests based on features which indicate that it may have the highest emission levels of the engines within that engine family.

9.2.2.

If engines within the same engine family incorporate other variable features which could be considered to affect emitted pollutants, these features must also be identified and taken into account in the selection of the parent engine.