[Code of Federal Regulations]
[Title 40, Volume 31]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1051.615]
[Page 656-657]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 1051_CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES
AND VEHICLES--Table of Contents
Subpart G_Compliance Provisions
Sec. 1051.615 What are the special provisions for certifying small recreational engines?
(a) You may certify ATVs with engines that have total displacement
of less than 100 cc to the following exhaust emission standards instead
of certifying them to the exhaust emission standards of subpart B of
this part:
(1) 25.0 g/kW-hr HC+NOX, with an FEL cap of 40.0 g/kW-hr
HC+NOX.
(2) 500 g/kW-hr CO.
(b) You may certify off-highway motorcycles with engines that have
total displacement of 70 cc or less to the following exhaust emission
standards instead of certifying them to the exhaust emission standards
of subpart B of this part:
(1) 16.1 g/kW-hr HC+NOX, with an FEL cap of 32.2 g/kW-hr
HC+NOX.
(2) 519 g/kW-hr CO.
(c) You may use the averaging, banking, and trading provisions of
subpart H of this part to show compliance with this HC+NOX
standards (an engine family meets emission standards even if its family
emission limit is higher than the standard, as long as you show that the
whole averaging set of applicable engine families meet the applicable
emission standards using emission credits, and the vehicles within the
family meet the family emission limit). You may not use averaging to
meet the CO standards of this section.
(d) Measure steady-state emissions by testing the engine on an
engine dynamometer using the equipment and procedures of 40 CFR part
1065 with either discrete-mode or ramped-modal cycles. You must use the
type of testing you select in your application for certification for all
testing you perform for that engine family. If we test your engines to
confirm that they meet emission standards, we will do testing the same
way. We may also perform other testing as allowed by the Clean Air Act.
Measure steady-state emissions as follows:
(1) For discrete-mode testing, sample emissions separately for each
mode, then calculate an average emission level for the whole cycle using
the weighting factors specified for each mode. In each mode, operate the
engine for at least 5 minutes, then sample
[[Page 657]]
emissions for at least 1 minute. Calculate cycle statistics for the
sequence of modes and compare with the specified values in 40 CFR
1065.514 to confirm that the test is valid.
(2) For ramped-modal testing, start sampling at the beginning of the
first mode and continue sampling until the end of the last mode.
Calculate emissions and cycle statistics the same as for transient
testing.
(3) Measure emissions by testing the engine on a dynamometer with
one or more of the following sets of duty cycles to determine whether it
meets applicable emission standards:
(i) The following duty cycle applies for discrete-mode testing:
Table 1 of Sec. 1051.615--6-Mode Duty Cycle for Recreational Engines
----------------------------------------------------------------------------------------------------------------
Minimum time
Mode No. Engine speed Torque in mode Weighting
(percent) \1\ (percent) \2\ (minutes) factors
----------------------------------------------------------------------------------------------------------------
1.............................................. 85 100 5.0 0.09
2.............................................. 85 75 5.0 0.20
3.............................................. 85 50 5.0 0.29
4.............................................. 85 25 5.0 0.30
5.............................................. 85 10 5.0 0.07
6.............................................. (\3\) 0 5.0 0.05
----------------------------------------------------------------------------------------------------------------
\1\ Percent speed is percent of maximum test speed.
\2\ Percent torque is percent of maximum test torque at maximum test speed.
\3\Idle.
(ii) The following duty cycle applies for ramped-modal testing:
Table 2 of Sec. 1051.615--Ramped-Modal Cycle for Testing Recreational Engines
----------------------------------------------------------------------------------------------------------------
RMC mode Time Speed (percent) \1,2\ Torque (percent) \2,3\
----------------------------------------------------------------------------------------------------------------
1a Steady-state..................... 41 Warm Idle.............. 0
1b Transition....................... 20 Linear Transition...... Linear Transition.
2a Steady-state..................... 135 85..................... 100
2b Transition....................... 20 85..................... Linear Transition.
3a Steady-state..................... 112 85..................... 10
3b Transition....................... 20 85..................... Linear Transition.
4a Steady-state..................... 337 85..................... 75
4b Transition....................... 20 85..................... Linear Transition.
5a Steady-state..................... 518 85..................... 25
5b Transition....................... 20 85..................... Linear Transition.
6a Steady-state..................... 494 85..................... 50
6b Transition....................... 20 Linear Transition...... Linear Transition.
7 Steady-state...................... 43 Warm Idle.............. 0
----------------------------------------------------------------------------------------------------------------
\1\ Percent speed is percent of maximum test speed.
\2\ Advance from one mode to the next within a 20-second transition phase. During the transition phase, command
a linear progression from the torque setting of the current mode to the torque setting of the next mode.
\3\ Percent torque is percent of maximum test torque at the commanded test speed.
(4) During idle mode, hold the speed within your specifications,
keep the throttle fully closed, and keep engine torque under 5 percent
of the peak torque value at maximum test speed.
(5) For the full-load operating mode, operate the engine at wide-
open throttle.
(6) See 40 CFR part 1065 for detailed specifications of tolerances
and calculations.
(e) All other requirements and prohibitions of this part apply to
these engines and vehicles.
[67 FR 68347, Nov. 8, 2002, as amended at 70 FR 40503, July 13, 2005]