jcb CT160, Руководство оператора, Страница: 147 / 166

Technical Data
Fluids, Lubricants and Capacities
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5.2. Any unvaporized oil will cause soot and smoke, and eventually contaminate the oil. Fuel with good
volatility burns more completely, minimizing fuel combustion, lowering the exhaust gas temperature
and does not generate black smoke.
6. Low residual carbon
6.1. Residual carbon is the carbonic residue that is generated during vaporization and decomposition of oil.
6.2. Although residual carbon and carbon accumulation in the engine have no direct relationship, they
should be minimized.
7. Free of water and foreign matter
7.1. The fuel pump in a diesel engine is extremely precise, even the smallest trace of foreign matter can
critically affect the fuel injection mechanism.
7.2. Dust or dirt in the air or a solid matter such as iron rust in the fuel must be eliminated. Water may
become mixed with fuel during storage or transportation. Most of it is removed as it settles in storage.
7.3. Colloidal water floating or dissolved in water (0.1 to 0.5%) can enter the combustion chamber. Diesel
fuel containing water loses its ignitability, adversely affecting combustion performance. Water must
also be eliminated since it will freeze in cold temperature and block filtration.
Cetane Number
Cetane numbers indicate the anti-diesel knocking characteristics of fuel. The cetane number is measured in a
similar way as an octane number using standard CFR testing engines.
A standard fuel is a mixture of n-cetane and alpha-methylnaphthalene. The former indicates the lowest knocking
point, its cetane number is defined as 100. The latter has the greatest knocking points, its cetane number is
defined as 0. Knocking of the standard fuel and the sample fuel is compared on testing engines by changing the
mixing ratio of the two components in the standard fuel until both engines show equal knocking characteristics.
The percentage of n-cetane at this point in a standard fuel is then taken as the cetane number of the sample
fuel. Anti-knocking characteristics of fuel oil can also be indicated by diesel indexes and cetane indexes, which
are derived from results of characteristics tests without using testing engines.
The cetane number for KUBOTA diesel engines must not be less than 45.
Fuel Ratings
Fuel ratings vary in different countries. Fuel must be chosen according to the operating temperature and
emission regulations. Fuel feed will be adversely affected if a fuel is used in a temperature below its pour point.
Japan (JIS K2204):
• Applicable range : This regulation specifies the diesel fuel to be used for diesel engines (mainly for
automobiles).
• Type : Diesel fuel is classified into five types, i.e., Special No.1, No.1, No.2, No.3, and Special No.3,
according to each pour point.
• Requirements - General matters : Diesel fuel is mainly composed of refined mineral oil having proper
quality as the fuel oil for diesel engines (mainly those for automobiles), and it shall not include water and
sediments.
• Required quality : The property of diesel fuel should be within the range specified in the table. Refer to
Table 27.