1pc is acceptable.

    engine model and engine number

   The engine model is the design number, is the engine after the series number, it is a large classification of the type of engine and other engines of the difference, including the parameters, more convenient for the engine manufacturer to identify and find the relevant issues。
   The engine number is used to identify the engine factory time, production unit, batch or order number, there are problems, to facilitate the reverse factory to find and solve the production process problems。