RDG603A17 – Issue 1 – Shire 30_40_50 WB/RB Manual
Page 20 of 51
Figure 6: Correct Installation of the Lift Silencer
1. The swan neck must reach at least 450mm (18”) above the waterline, when
installed on hull centreline.
2. The top of the silencer should be at least 300mm (12”) below the water injection
point.
3. The silencer must be installed as near as possible to the centreline of the hull,
particularly where severe angles of heel are expected. The swan neck must be
450mm above heeled water line.
4. Remember that 15% of the volume of the exhaust hose may be water. The size
of the silencer selected must be such that water draining into it will fit it by no
more than one third.
5. A siphon break must be used.
The silencer may only be used in a Water Injected marine exhaust system. The overall
design of the system, and choice of components, will have a result on the back pressure in
the exhaust which is vital to the performance and life of the engine.
Barrus recommend
that Halyard (M&I) Limited are used for the Lift Silencer, Siphon Break and other
components. Contact Halyard (M&I) Limited for further information.
The silencer must be drained before the boat is craned or transported and during the
winter.
There must be at least 450mm distance between the water injection point and the position
of the silencer to allow adequate cooling of the exhaust gases. Maximum temperature
during continuous operation of the silencer is limited to 85 degrees centigrade. Normally in
a well-designed system, the temperature of the silencer should be between 50-70 degrees
centigrade. Such operation will result in longer exhaust life.
Connections to the silencer should be made using suitable exhaust hose, which is type
