Cooling; General; Inter-Cooling; Raw Water Supply - Whisper Power GV4 Piccolo Installation Manual

INSTALLATION
2.8

COOLING

2.8.1

General

For the cooling of an engine on a boat there are two methods
available: inter-cooling and keel cooling. Inter-cooling is based
on a raw water pump, heat exchanger and water-injected
exhaust.
Keel cooling means cooling the coolant (in case of the GV4
Piccolo this is oil) by circulating the hot coolant through a space
in the keel, or through a double walled skin of the boat,
through a box cooler welded in a steel boat, using a big tank or
any other external cooler.
Most of the time; using keel cooling, one apply a dry exhaust,
but other combinations could be supplied on request:
1) Inter-cooling with water injected a wet exhaust
2) Inter-cooling with a dry exhaust
3) Keel cooling with a dry exhaust
4) Keel cooling with a wet exhaust
2.8.2

Inter-cooling

When applying inter-cooling the Genverter should have its own
sea water inlet and should not be connected to any other
engine systems (see Figure 6). A properly installed cooling
1 Water level
2 Water/exhaust separator
3 Seacock
4 Waterlock
Figure 6: Raw water cooling system
8
5 Air vent (Siphon breaker);
6 Water strainer;
7 Seacock.
system is critical to keep engine temperatures within an
acceptable range. Ensure that the installation complies with the
following installation instructions.
2.8.3

Raw water supply

For raw water supply the following installation materials are
required: -a skin fitting - a sea cock - a water strainer - hoses
and clamps. In order to keep the suction resistance in the line
at a minimum, the sea water intake system (i.e. sea cock, thru-
hull fitting, inlet filter, etc.) must have an inner diameter of at
least 12.5 mm diameter (1/2"). The suction hose should be kept
as short as possible. Raw water plumbing should avoid bends as
much as possible.
Restriction of raw water flow, caused by kinked hoses,
undersized pipes or connections, will reduce the engine cooling
capability. This is the main cause for overheating of an engine.
When in doubt check the coolant flow rate using a stopwatch
and by holding a pail of a known volume under the wet-exhaust
outlet. The flow rate should be 8 to 12 litres /min.
May 2017 / M-GV4 Piccolo for marine applications / EN