| Manual
for 1053 - 1054
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Fuel System
Fuel System
Feed pump 5 ( fig
11 ) sucks the fuel from tank 1 and into prefilter 4, where it is
given a preliminary
cleaning. From the feed pump the fuel is forced out through two fine
filters, 6 and 7, connected in series.
In the first of these the fuel is compelled to pass through a pack
of filtering plates which clean it thoroughly.
The second filter is sealed and is provided as an extra safety
measure.
From the sealed filter the fuel passes to the fuel chamber of
injection pump 8. This constant-stroke pump
has one pumping element for every engine cylinder. The plungers in
these elements force the fuel through
the pressure pipes to injectors 9. The pressure pipes are connected
to the injectors by special unions
containing a final edge filter which serves to stop any particles
which may get into the pipes when they are disconnected from the
engine. From the injector nozzles the fuel is sprayed into the
engine cylinders
through four holes. The high opening pressure ensures sufficient
atomization of the fuel to achieve sure
starting even if the engine is cold. Leak-off oil from the nozzles
is piped back to the fuel tank through line 10.
The first fine-filter has an overflow valve 11 ( fig. 11 ). This
opens when fuel pressure inside the filter reaches approx. 10 lb/sq.in.
( 0.7 kg/sq.cm. ). Fuel then flows out through the valve and is led
back to the tank through
pipe 12. This arrangement also ensures automatic venting of the
fine-filter as the fuel continuously passes
through the valve back to the tank. The centrifugal governor on the
injection pump permits engine r.p.m.
setting at and desired speed up to a given maximum.
Fig 11. General arrangement of fuel system,
three-cylinder engine.
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1. Fuel tank
2. Strainer in filter hole
3. Sludge pockets with drain cock
4. Prefilter
5. Feed pump
6. Fine-filter
7. Sealed fine-filter |
8.
Injection pump
9. Injector
10. Leak-off pipe
11. Over flow valve
12. Return lines to fuel tank
13. Speed governor
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Fig 12. fine-filter, unsealed.
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1. Pipe line to sealed filter
2. Sludge drain plug
3. Filter element
4. Pipe line from feed pump to filter
5. Air vent screw
6. Return line to fuel tank
7. Overflow valve |
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Fig 13. Fine-filter, sealed.
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1. Pipe line to injection pump
2. Air vent screw
3. Holding screw
4. Pipe line from unsealed fine-filter
5. Gasket
6. Felt ring
7. Pad filter
8. Felt ring |
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Marine diesels are fitted with two fuel systems
Three-cylinder engine, 1053 Bosch
Four-cylinder engine, 1054 CAV..
In both pump types the amount of fuel is controlled by a centrifugal
governor built integral with the injection
pump. The injection pump is also fitted with a cold-start device
which primes the engine with extra fuel at the
moment of start. On CAV pumps the cold-start device is controlled by
a readily accessible button. On Bosch
pumps it is controlled by a built-in, automatic link system.
Fig 14. Bosch injection pump for engine 1053
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1. Lever for centrifugal governor
2. Lubricator
3. Air vent screw
4. Stop lever |
5.
Prefilter
6. Hand pump
7. Oil dipstick
8. Level plug for lubricant |
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Fig 15. CAV injection pump for engine 1054
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1. Cold-start device
2. Air vent screw
3. Stop lever
4. Plug for inspection and oil filling
5. Ventilation filter |
6.
Idling screw
7. Level plug for lubricant
8. Oil dipstick
9. Prefilter
10. Oil dipstick |
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Fig 16.
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1. Pipe line from injection pump
2. Edge filter
3. Fuel passage
4. Nozzle
5. Nozzle needle
6. Pipe line for leak-off fuel |
The fuel enters
the injector through pipe 1. passes edge filter 2 and is led through
passage 3 down to nozzle 4.
When fuel pressure reaches approx.. 1,920 lb/sq.in ( 135 kg/sq.cm. )
nozzle needle 5 lifts and the fuel is sprayed
into the cylinder through four holes. Leak-off fuel is carried back
to the fuel tank through pipe 6.
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