Document ID: chunk:federal_register_of_legislation:F2021C01210:reg:6:p9
Version: federal_register_of_legislation:F2021C01210
Segment Type: reg
Provision Reference: reg 6 (pt 9/24)
Character Range: 24395–27221

method described in annex 4 to this Regulation, shall not exceed the limits prescribed in annex 7 to this Regulation.
        6.3.4 At the request of the manufacturer additional tests described in annexes 4 and 5 shall be performed to obtain free acceleration values for derivatives of the approved engine permitted by paragraphs 7.2. and 7.3. of this Regulation.
        6.3.4.1 If the engine manufacturer desires to have the visible pollutants measured over a smaller range of torque and/or speed than is allowed by paragraph 7.3. of this Regulation, then the approval of the engine type will be for the limited range of torque and speed.
        6.3.4.2 If at a later stage it is desired to extend the approval of the engine to cover the whole of the torque/speed range allowed by paragraph 7.3. of this Regulation then a further engine would have to be submitted for test so that the visible pollutants can be established for that part of the load/speed range which has previously been omitted.
        6.3.5 If in order to meet some parts of the torque and speed ranges it is necessary to have additional specifications then these shall be declared in the format of annex 1 and attached to the documentation submitted.
        6.3.6 The value of the free acceleration absorption coefficient allocated to the engine will be appropriately chosen in accordance with its rated speed and torque from the matrix of values established by the method in annex 5 to this Regulation.
        6.3.7 In the case of engines with an exhaust-driven supercharger the absorption coefficient measured under free acceleration shall not exceed the limit prescribed in annex 7 for the nominal flow value corresponding to the maximum absorption coefficient measured during the tests at steady speeds, plus 0.5 m-l.
        6.4 Equivalent measuring instruments shall be allowed. If an instrument other than those described in annex 8 to this Regulation is used, its equivalence for the engine considered shall be required to be proved.

7. MODIFICATION OF THE ENGINE TYPE AND EXTENSION OF APPROVAL
        7.1 Every modification of an engine within an engine type with regard to the characteristics in annex 1, shall be notified to the administrative department which approved the engine type. Details of these modifications shall be declared in the format of annex 1. Within the constraints imposed by paragraphs 7.2 and 7.3, the department may then either:
        7.1.1 Consider that the modifications made are unlikely to have an appreciable adverse effect, and that in any case the engine still complies with the requirements,  or
        7.1.2 Require a further test report from the technical service responsible for conducting the test.
        7.2 For the purposes of this Regulation with regard to the emission of visible pollutants the