FNM HPE Series Installation Manual page 29

the transom, as in the following figures. Depending on the
configuration of the engine compartment, the point of emission
of the engine exhaust gas (elbow) may be located:
1. Case A, discharge at more than 15 cm from the waterline
– Figure 27 below. In this case it is advisable to install a
silencer suitably sized to prevent the return of waste water
into the engine and draw the exhaust line with a
gooseneck shape:
exhaust
silencer
Figure 27 - Engine exhaust in configuration A
2. Case B, discharge subjected or less than 15 cm above
the waterline – Figure 28 sotto. In this case it is necessary
to remove the sea water supply sleeve between the
manifold and the exhaust elbow on the engine and install
an anti-siphon at the minimum height of 40cm from the
waterline, so as to avoid the risk of return of water to the
exhaust when the engine is stopped. The two circuits
(water and gas) to be joined again in a lower point of the
discharge line before the silencer. Use a gooseneck
exhaust geometry with the highest point at a minimum
height of 45cm from the waterline. Check with the
manufacturer of the silencer the correct installation
position.
exhaust
silencer
gas + water
Figure 28 - Engine exhaust in configuration B
The filler on the transom must always be above (min 5 cm) the
waterline.
The silencer must always be below the engine exhaust elbow .
In the installation of flexible sleeves, always guarantee that the
bending angles are not narrow and that the inner tube is not
directed directly against the sleeve, as in Figure 29.
waterline (worst case)
engine
gas + water
anti-siphon
waterline (worst case)
engine
gas water
The inner tube of the discharge elbow contains the
exhaust gas at high temperatures that could damage
the sleeve, leading to a loss of water in the engine
compartment.
FNM® Series HPE – Installation Manual – 25