[Code of Federal Regulations]
[Title 40, Volume 18]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR92.204]

[Page 477-478]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 92--CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES--
Table of Contents
 
                   Subpart C--Certification Provisions
 
Sec. 92.204  Designation of engine families.

    This section specifies the procedure and requirements for grouping 
of engines into engine families.
    (a) Manufacturers and remanufacturers shall divide their locomotives 
and locomotive engines into groupings of locomotives and locomotive 
engines which are expected to have similar emission characteristics 
throughout their useful life. Each group shall be defined as a separate 
engine family.
    (b) For Tier 1 and Tier 2 locomotives and locomotive engines, the 
following characteristics distinguish engine families:
    (1) The combustion cycle (e.g., diesel cycle);
    (2) The type of engine cooling employed (air-cooled or water-
cooled), and procedure(s) employed to maintain engine temperature within 
desired limits (thermostat, on-off radiator fan(s), radiator shutters, 
etc.);
    (3) The bore and stroke dimensions;
    (4) The approximate intake and exhaust event timing and duration 
(valve or port);
    (5) The location of the intake and exhaust valves (or ports);
    (6) The size of the intake and exhaust valves (or ports);
    (7) The overall injection, or as appropriate ignition, timing 
characteristics (i.e., the deviation of the timing curves from the 
optimal fuel economy timing curve must be similar in degree);
    (8) The combustion chamber configuration and the surface-to-volume 
ratio of the combustion chamber when the piston is at top dead center 
position, using nominal combustion chamber dimensions;
    (9) The location of the piston rings on the piston;
    (10) The method of air aspiration (turbocharged, supercharged, 
naturally aspirated, Roots blown);

[[Page 478]]

    (11) The turbocharger or supercharger general performance 
characteristics (e.g., approximate boost pressure, approximate response 
time, approximate size relative to engine displacement);
    (12) The type of air inlet cooler (air-to-air, air-to-liquid, 
approximate degree to which inlet air is cooled);
    (13) The intake manifold induction port size and configuration;
    (14) The type of fuel and fuel system configuration;
    (15) The configuration of the fuel injectors and approximate 
injection pressure;
    (16) The type of fuel injection system controls (i.e., mechanical or 
electronic);
    (17) The type of smoke control system;
    (18) The exhaust manifold port size and configuration; and
    (19) The type of exhaust aftertreatment system (oxidation catalyst, 
particulate trap), and characteristics of the aftertreatment system 
(catalyst loading, converter size vs engine size).
    (c) For Tier 0 locomotives and locomotive engines, the following 
characteristics distinguish engine families:
    (1) The combustion cycle (e.g., diesel cycle);
    (2) The type of engine cooling employed (air-cooled or water-
cooled), and procedure(s) employed to maintain engine temperature within 
desired limits (thermostat, on-off radiator fan(s), radiator shutters, 
etc.);
    (3) The approximate bore and stroke dimensions;
    (4) The approximate location of the intake and exhaust valves (or 
ports);
    (5) The combustion chamber general configuration and the approximate 
surface-to-volume ratio of the combustion chamber when the piston is at 
top dead center position, using nominal combustion chamber dimensions;
    (6) The method of air aspiration (turbocharged, supercharged, 
naturally aspirated, Roots blown);
    (7) The type of air inlet cooler (air-to-air, air-to-liquid, 
approximate degree to which inlet air is cooled);
    (8) The type of fuel and general fuel system configuration;
    (9) The general configuration of the fuel injectors and approximate 
injection pressure; and
    (10) The fuel injection system control type (electronic or 
mechanical).
    (d) Upon request by the manufacturer or remanufacturer, locomotives 
or locomotive engines that are eligible to be included in the same 
engine family based on the criteria in paragraph (b) or (c) of this 
section may be divided into different engine families. This request must 
be accompanied by information the manufacturer or remanufacturer 
believes supports the addition of these different engine families. For 
the purposes of determining whether an engine family is a small engine 
family in Sec. 92.603(a)(2), EPA will consider the number of locomotives 
or locomotive engines that could have been classed together under 
paragraph (b) or (c) of this section, instead of the number of 
locomotives or locomotive engines that are included in a subdivision 
allowed by this paragraph (d).
    (e) Upon request by the manufacturer or remanufacturer, the 
Administrator may allow locomotives or locomotive engines that would be 
required to be grouped into separate engine families based on the 
criteria in paragraph (b) or (c) of this section to be grouped into a 
single engine family if the manufacturer or remanufacturer demonstrates 
that similar emission characteristics will occur. This request must be 
accompanied by emission information supporting the appropriateness of 
such combined engine families.