The fuel is
sucked up from the tank by the fuel lift pump.
When the piston is in the lower position, the
fuel injector injects a very small amount of fuel
into the cylinder under a pressure of >200
bar. When the piston moves upwards, the fuel-air
mixture in the cylinder is ignited by the
increasing compression. Excess fuel supplied by
the fuel pump will return to the tank via a
return fuel line. There will be a constant
circulation of fuel when the engine is running.
After maintenance (f.i. changing the filter
element) air in the fuel lines can be removed by
manual operation of the fuelpump before engine
During circulation, the fuel is
passing the filter all the time. The filter
element is collecting the moisture and fine
particles from the fuel.
Any waterdrops sucked up
from the tank will agglomerate in the glass
reservoir. Due to a higher weight, water will be
will be visible in the lower part of the
transparent bowl and can be drained via the drain
plug in the baseplate.
I installed the
fuel tank under deck on a bulkhead between the
engine compartment and the storage compartment.
This 25 liter tank is very suitable for small
sailingboats. Because of the very efficient fuel
consumption of the 10HP diesel engine, it will
take a long time to empty the tank completely.
The fuel level is visible through the hard
plastic tank surface. The fuel is refreshed a few
times during the season, so no very old fuel is
remaining in the tank when the boat is stored
during the winter season. The tank itselve is
made of very stable material and will not couse
any debris going into the fuel.
via the ventilation opening will replace fuel
used. Water vapours within the air are
condensating in the tank. Because of its higher
weight, water will sink eventually to the bottom
of the tank. During day and night temperature
changes, the the air pressure within the tank
will go up and down, which causes outside air
being breathed in and out all the time. This
effect is greater when the tank will be emptier.
A full tank is preferable in many ways : less
risk of water in your fuel or an empty tank just
when you need your engine !
picture : Vetus
Saildrive.info The Netherlands