TITLE 40 - PROTECTION OF ENVIRONMENT

CHAPTER I - ENVIRONMENTAL PROTECTION AGENCY

SUBCHAPTER U - AIR POLLUTION CONTROLS

PART 1039 - CONTROL OF EMISSIONS FROM NEW AND IN - USE NONROAD COMPRESSION - IGNITION ENGINES

subpart c - CERTIFYING ENGINE FAMILIES

1039.230 - How do I select engine families?

  (a) Divide your product line into families of engines that are expected to have similar emission characteristics throughout the useful life.

Your engine family is limited to a single model year.

  (b) Group engines in the same engine family if they are the same in all the following aspects: (1) The combustion cycle and fuel.

  (2) The cooling system (water-cooled vs. air-cooled).

  (3) Method of air aspiration.

  (4) Method of exhaust aftertreatment (for example, catalytic converter or particulate trap).

  (5) Combustion chamber design.

  (6) Bore and stroke.

  (7) Number of cylinders (for engines with aftertreatment devices only).

  (8) Cylinder arrangement (for engines with aftertreatment devices only).

  (9) Method of control for engine operation other than governing (i.e., mechanical or electronic).

  (10) Power category.

  (11) Numerical level of the emission standards that apply to the engine.

  (c) You may subdivide a group of engines that is identical under paragraph (b) of this section into different engine families if you show the expected emission characteristics are different during the useful life.

  (d) You may group engines that are not identical with respect to the things listed in paragraph (b) of this section in the same engine family if you show that their emission characteristics during the useful life will be similar.

  (e) If you combine engines from different power categories into a single engine family under paragraph (d) of this section, you must certify the engine family to the more stringent set of standards from the two power categories in that model year.