[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.884-7]
[Page 64-65]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND
ENGINES (CONTINUED)--Table of Contents
Subpart I--Emission Regulations for New Diesel Heavy-Duty Engines; Smoke
Exhaust Test Procedure
Sec. 86.884-7 Dynamometer operation cycle for smoke emission tests.
(a) The following sequence of operations shall be performed during
engine dynamometer testing of smoke emissions, starting with the
dynamometer preloading determined and the engine preconditioned
(Sec. 86.884-12(c)).
(1) Idle Mode. The engine is caused to idle for 5.0 to 5.5 minutes
at the manufacturer's recommended curb idle speed. The dynamometer
controls shall be set to provide the speed and load necessary to comply
with the heavy-duty ``curb idle'' definition per Sec. 86.084-2, in
accordance with predominant engine application.
(2) Acceleration mode. (i) The engine speed shall be increased to
200 50 rpm above the measured free idle speed measured at
the point where the throttle begins to move from part-throttle to the
full throttle position. The speed anywhere during this mode should not
exceed this checkpoint speed by more than 50 rpm. The duration of this
first acceleration shall be three seconds or less measured from the
point where the speed first begins to increase above idle to the point
where the throttle reaches full open position.
(ii) Immediately upon completion of the mode specified in paragraph
(a)(2)(i) of this section, the throttle shall be moved rapidly to, and
held in, the fully open position. The inertia of the engine and the
dynamometer, or alternately a preselected dynamometer load, shall be
used to control the acceleration of the engine so that the speed
increases to 85 percent of the rated speed in 5 1.5 seconds.
This acceleration shall be linear within 100 rpm as specified in
Sec. 86.884-13(c).
[[Page 65]]
(iii) After the engine reaches the speed required in paragraph
(a)(2)(ii) of this section the throttle shall be moved rapidly to, and
held in, the fully closed position. Immediately after the throttle is
closed, the preselected load required to perform the acceleration in
paragraph (a)(2)(iv) of this section shall be applied. For electric
motoring dynamometer operation in speed mode, the deceleration shall be
performed in 21.5 seconds.
(iv) When the engine decelerates to the intermediate speed (within
50 rpm), the throttle shall be moved rapidly to, and held in, the fully
open position. The preselected dynamometer load which was applied during
the preceding transition period shall be used to control the
acceleration of the engine so that the speed increases to at least 95
percent of the rated speed in 10 2 seconds.
(v) For electric dynamometer operation in speed mode, motoring
assist may be used to offset excessive dynamometer inertia load when
necessary. No negative flywheel torque shall occur during any of the
three acceleration modes in paragraph (a)(2) of this section except for
a maximum of 10ft-lbs. for the first 0.5 second of the mode.
(3) Lugging mode. (i) Immediately upon the completion of the
preceding acceleration mode, the dynamometer controls shall be adjusted
to permit the engine to develop maximum horsepower at rated speed. This
transition period shall be 50 to 60 seconds in duration. During the last
10 seconds of this period, the average engine speed shall be maintained
within 50 rpm of the rated speed, and the average observed power
(corrected, if necessary, to rating conditions) shall be no less than 95
percent of the maximum horsepower developed during the preconditioning
prior to the smoke cycle.
(ii) With the throttle remaining in the fully open position, the
dynamometer controls shall be adjusted gradually so that the engine
speed is reduced to the intermediate speed. This lugging operation shall
be performed smoothly over a period of 355 seconds. The rate of
slowing of the engine shall be linear, within 100 rpm, as specified in
Sec. 86.884-13(c).
(4) Engine unloading. Within five seconds of completing the
preceding lugging mode, the dynamometer and engine controls shall be
returned to the idle position described in paragraph (a)(1) of this
section. The engine must be at free idle condition within one minute
after completion of the lugging mode.
(b) The procedures described in paragraphs (a)(1) through (a)(4) of
this section shall be repeated until three consecutive valid cycles have
been completed. If three valid cycles have not been completed after a
total of six consecutive cycles have been run, the engine shall be
preconditioned by operation at maximum horsepower at rated speed for 10
minutes before the test sequence is repeated.
[48 FR 52203, Nov. 16, 1983, as amended at 49 FR 48141, Dec. 10, 1984;
52 FR 47870, Dec. 16, 1987; 62 FR 47122, Sept. 5, 1997]