Download IS 14234 (1996): Lubricants for Two-stroke Spark Ignition Air

IS 14234 : 1996
Piston-rings-cylinder assembly, spark plug and new
or reconditioned muffler.
C-4 TEST FUEL
C-4.1 The test fuel used during running-in and the
test duration would be a leaded gasoline conforming to the physico-chemical characteristics of
IS 2796 as given in Table 6. The level of lead content, saturetes, olefins and aromatics shall be as
given in Table 6. If required, TEL may be added to
the test fuel to raise its lead content to specified
level of 0.4 to 0.63 g/l. Fuel shall not contain nonlead metallic antiknock compounds or oxygenated
blending compounds such as alcohols or ethers. It
shall contain lead as lead alkyls (conventional
motor mix) and shall have a minimum motor octane number of 83 and maximum sensitivity (RONMON) of 12.
The cylinder will usually require replacement after
100 to 150 running hours. After about 1000 to
1500 running hours the entire engine will normally
require replacement.
C-8 SPARK PLUG
MICO W-175-z 1 or equivalent. Reset gap to 0.5
mm.
C-9 IGNITION CONTROL
Spark advance : 25” btdc.
Contact breaker points gap : 0.3 to 0.5 mm.
C-4.2 Fuel from the same source shall be used in
series of tests in which the performance of test oil
is compared with reference oil for calibration.
C-10 CLEANING OPERATION
C-4.3 About 1.50 1 fuel is required for a test and
additional 40 1 for the running-in.
Before each test sequence, the engine must be
cleaned. Cylinder head and piston crown is decarbonized and washed in a suitable degreasing bath.
Wash cylinder and piston in white spirit and when
dry smear the bore with the high quality reference
oil or test oil.
C-5 REFERENCE OILS
C-5.1 CEC high reference oil RL-05 and low
reference oil RL-81 are used for calibration purposes. The properties of these oils are summarized
in Table 7. Equivalent indigenous high and low
referenceoils duly approved may also be used. CEC
RL-05 reference oil or equivalent indigenous oil is
used for running-in and as an assembly lubricant.
C-I1 MODIPICATION OF CYLINDER HEAD
The cylinder head must be fitted with a shielded
thermocouple.The thermocoupleshould
preferably be of the iron-constanton type J, but any thermocouple capable of performing satisfactorily
under the test conditions may be used. The general
dimensions of a typical thermocouple are shown in
Fig. 1 and machining required for through hole in
cylinder head are shown in Fig. 2. The through hole
in which the thermocouple must fit closely, should
be about 10 mm diameter but the thread diameter
must be less than 14 mm. The thermocouple is
mounted in the head so that its tip is flush with the
internal surface of the head without penetrating the
shield. Ensure proper contact of the hot junction
with the inner surface of the tip of the thermocouple assembly.
C-5.2 About 7.5 1 of reference oil is required to
run a calibration test, and 2.0 1for running-in.
C-6 CANDIDATE OIL
About 7.5 1 are required for a 50 h test. At least
twice this amount should be provided to take care
of the eventuality rerun of the test.
C-7 PREPARATION OF APPARATUS
A systematic inspection and calibration of all
equipments and instruments shall be made as per
manufacturers recommendations and ensure their
proper functioning. Any defective or worn out parts
must be replaced. For initial build of theengine, use
a new cylinder, piston, rings, cylinder head. and
cyltndcr base gaskets. The cylinder head is fitted
with a thermocouple as specified in C-11.
C-12 SPARK PLUG GASKET
TEMPERATURE
Replace the standard washer of the spark plug with
a copperwasher fitted with a thermocouple to it for
the measurement of its average temperature. The
design of the washer and thermocouple is shown in
Fig. 3. For this test sequence the spark plug gasket
temperature (SPGT) is controlled at 190”&5”C by
controlling the cooling air flow.
Rebuild the test engine as per proceduregiven
in C-21. lf the engine has been used twice for this
sequence, the following parts must be replaced with
new parts.
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