These are exceptional cases, including large bore engines
intended for E2 applications, in which, due to their oscillating masses
and construction, engines cannot be run at low load at nominal speed
without the risk of damaging essential components. In such cases,
the engine manufacturer shall make application to the Administration
that the test cycle as given in table 1 above may be modified for
the 25% power mode with regard to the engine speed. The adjusted engine
speed at 25% power, however, shall be as close as possible to the
rated engine speed, as recommended by the engine manufacturer and
approved by the Administration. The applicable weighting factors for
the test cycle shall remain unchanged.