Perkins 35943, Руководство пользователя, Страница: 37 / 50

35943 Chapter 5
Page 31
Engine fluids
Fuel specification
To get the correct power and performance from your engine, use good quality fuel. The recommended fuel
specification for Perkins engines is indicated below:
Cetane number: 45 minimum
Viscosity: 2.5/4.5 centistokes at 40°C
Density: 0,835/0,855 kg/litre
Sulphur: 0.2% of mass, maximum
Distillation: 85% at 350°C
Cetane number indicates ignition performance. A fuel with a low cetane number can cause cold start
problems and affect combustion.
Viscosity is the resistance to flow and engine performance can be affected if it is outside the limits.
Density : A lower density reduces engine power, a higher density increases engine power and exhaust
smoke.
Sulphur
: A high amount of sulphur (not normally found in Europe, North America or Australasia) can cause
engine wear. Where only high sulphur fuels are available, it is necessary to use a highly alkaline lubricating
oil in the engine or to renew the lubricating oil more frequently, see the table below.
Fuel sulphur
content (%)
Oil change
interval
<0.5 Normal
0.5 to 1.0 75% of normal
>1.0 50% of normal
Distillation: This is an indication of the mixture of different hydrocarbons in the fuel. A high ratio of light-
weight hydrocarbons can affect the combustion characteristics.
Low temperature fuels
Special winter fuels may be available for engine operation at temperatures below 0°C. These fuels have a
lower viscosity and also limit the wax formation in the fuel at low temperatures. If wax formation occurs, this
could stop the fuel flow through the filter.
If you need advice on adjustments to an engine setting or to the lubricating oil change periods which may
be necessary because of the standard of the available fuel, consult your nearest Perkins distributor or
Wimborne Marine Power Centre, see page 5.
Aviation kerosene fuels
These fuels are not approved for use in this engine.