MC 78-01
Technical Report
Particulate Measurement - Motorcycle Test Results
by
Eugene Danielson
February 1978
NOTICE
Technical reports do not necessarily represent the final EPA
decision on issues. They are intended to present a technical analysis
of an issue and recommendations resulting from the assumptions and
constraints of that analysis. Agency policy constraints or data received
subsequent to the date of release of this report may alter the recommend-
ations reached. Readers are cautioned to seek the latest analysis from
EPA before using the information contained herein.
Standards Development and Support Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Office of Air and Waste Management
U.S. Environmental Protection Agency
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Summary
Particulate testing has been successfully completed on two different
two-stroke powered motorcycles. The results indicate that; the amount of
particulate material produced by motorcycles is no greater than that
from light-duty diesel automobiles. This conclusion is based on the
fact that of the two motorcycles tested, the higher emitter (Kawasaki
KE-100) produced approximately the same amount of particulate material
over the FTP driving cycle as a Mercedes 300D diesel produces. The
amount of particulate produced by the lower emitter (Yamaha DT 100) was
about one-fourth that of the higher emitter.
Discussion
Experimental tests have been conducted to help determine whether or
not motorcycles produce substantial amounts of particulate material.
Two motorcycles, a Kawasaki KE-100 (100 cc) and a Yamaha DT-100 (100 cc) ,
were used for these tests. Both were powered by two-stroke engines.
Two-stroke powered motorcycles were selected because it was felt that
these would produce the highest amount of particulate material and
therefore give an indication of the upper bound on the amount of parti-
culate material produced by motorcycles. Presented on the attached
table is a summary of the results of this testing. These data indicate
that over the FTP cycle, the amount of particulate produced by the
Kawasaki KE-100 (higher emitter) is approximately the same as that
produced by a Mercedes 300D diesel (i.e., about 0.31 gm/km). The Yamaha
DT-100 motorcycle produced about one-fourth the amount of particulate
produced by the Kawasaki motorcycle over the same driving cycle. These
data form the basis for the statement in the Summary which concluded
that the amount of particulate material produced by motorcycles is no
greater than that from typical light-duty diesel automobiles.
It should be noted that the repeatability of the measured particulate
produced by the Yamaha is fairly poor. This is considered to be due to
the fact that this motorcycle was a manual start vehicle and that some
difficulty was encountered in starting it (i.e., 8-10 strokes were
required for starting). Also, the amount of particulate being collected
was comparatively small and hence higher percentage weight differences
are calculated for a given weight difference.
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Test Procedure
In order to test motorcycles for particulates, an eight inch dilution
tunnel was assembled and checked out along with the 20.88 inch roll
diameter dynamometer previously used for motorcycles. (Previous parti-
culate testing conducted at EPA (Ann Arbor) has used an 18 inch dilution
tunnel.) After successful completion of the assembly and checkout,
testing began.
Particulates were collected by isokinetically removing a sample of the
diluted exhaust from the tunnel. The sample was then passed through a
glass fiber filter which removed all of the particulate material (see
attached figure). The weight of the particulate collected is considered
to be the net weight difference between the clean filter and the loaded
filter. It should be noted that the filter was both pre-conditioned
(before test) and post-conditioned (after test) with respect to the
water content of the filter. That is, steps were taken to insure that
only particulate material, and not water was counted in the net weight
of the material.
One other important fact must be mentioned in conjunction with the
sample system, and that is the fact that the CVS unit used for this
testing was a critical flow venturi type, while the sample probe was a
straight through type (i.e., not critical flow). However, the claim
that the sample was taken isokinetically is valid because the temper-
ature of the diluted exhaust in the tunnel varied less than 10°F (between
75°F and 85°F) during any test. This temperature difference translates
into a one percent error in sample flow rate. This claim is further
substantiated by the fact that the measured sample flow and the measured
CVS flow indicated that in most cases the sample flow was within five
percent of the desired isokinetic flow. (Setting the sample pump to
the precise flow rate is considered to be the largest source of error.)
A final comment with respect to the Test Procedure must be made concerning
the driving cycle and hot start/cold start filter distinction.
Throughout this program, testing was conducted following FTP type procedures,
including driving cycle, except for one major modification. This
modification was to actually drive out the last 870 seconds of the hot
portion of the test (i.e., conduct a 4 bag test). With this modified
driving cycle two particulate filter samples were taken in sequence.
The first sample was taken during the cold start part of the test (bags
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1 and 2) and the second sample was taken during the hot start part of
the test (bags 3 and 4). By collecting particulates in this way no
assumptions had to be made concerning the amount of particulate produced
during the last 870 seconds of the cycle (bag 4). Hence, direct calcu-
lation of the FTP weighted mass of particulates could be made. This
concept is diagrammed below.
Cold Start \
Filter No. 1 '
L Bag 1 _v
^ 505 sec/
Bag 2_
870 sec
/10 rain.*
soak '
Change
Filters
/
Hot Start s.
x Filter No. 2 '
/Bag 3 v
r505 sec/
/ Bag 4 \
^ 870 sec f
Weight Factor = 0.57
Weight Factor = 0.43
Weighted mass = 0.43 x Net Weight of filter #1 + 0.57 x Net Weight of filter #2
Results
Presented on the attached sheet is a summary of both the gaseous and
particulate emissions. The highest particulate level measured from the
Kawasaki was 0.353 gm/km, and from the Yamaha 0.095 gm/km. As discussed
previously these data form the basis for concluding that the amount of
the particlate emissions produced by motorcycles is no greater than from
typical light-duty diesel automobiles. For comparison, a Mercedes 300D
diesel produces about 0.31 gm/km over the FTP driving cycle, and parti-
culates from other light-duty diesel automobiles have been measured as
high as 0.6 gm/km.
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Motorcycle Particulate Collection Set-Up
To Dry Gas Meter
Room
Air
Exhaust from
Motorcycle
Dilute
ExhausfT
Particulate
Sample Filter
Isokinetic Probe
8 Inch Dilution
— Tunnel
Note: Not to scale.
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Summary of Motorcycle Particulate Test Results
Japan Test
EPA #1 Test
EPA #2 Test
Japan Test
EPA #1 Test
EPA #2 Test
HC (gm/km)
3.7
5.5
5.6
HC (gm/km)
3.8
3.6
4.0
KAWASAKI KE-100
Particulate (gm/km)
CO (gm/km) Weighted Cold Start
15
20 0.320 0.314
9.8% 15%
21 0.353 0.365
% =A~
Ave.
YAMAHA DT-100
Particulate (gm/km)
CO (gm/km) Weighted Cold Start
10
10 0.068 0.088
33.1% 20.4%
11 0.095 0.108
% =A~
Ave.
Hot Start
0.325
0.344
Hot Start
0.053
4
0.086
5.7%
47.5%
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