Volvo D11 series, Руководство по установке

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Engine foundation
Aligning the boat
The installation work is made easier if the hull is
aligned horizontally before starting. Block up the hull
so that the calculated water lines, both longitudinal
and transverse, are parallel with the horizontal plane.
A spirit level is a good help.
Check when manufacturing the bed that the upper
bed plane, the mating plane, is parallel and correctly
positioned in relation to the centre line of the propel-
ler shaft. A guide sleeve with the same diameter as
the propeller shaft can be used in the stern tube to
help with the alignment of the bed.
General
The engine bed should be dimensioned so that it is
rigid in all directions to distribute the load as much
as possible into the hull. The greatest possible area
of the engine bed, and with cross members, must be
fastened to the hull to give the best noise and vibra-
tion insulation.
Plane requirements, rigid mounting
It is very important that the engine bed is dimension-
ally stable when the engine has a rigid mounting.
The maximum height deviation (movement) between
the engine’s attachment plane must be within 3 mm
(0.2"). In other words it is important that the bed
is so torsionally and bending rigid that the plane
requirements are not exceeded as a result of move-
ments in the hull in rough sea, or when the boat is
put on shore or into the sea.
Design
The bed should have a design basis that enables it to
absorb by an adequate margin the engine torque, the
compressive force of the propeller, and the dynamic
forces (mass forces) that occur during movement in
rough sea.
When designing the bed it is important that there is
sufficient space under the engine for the movement
of the engine, and that there is also access to the in-
spection covers (certain engine versions).
If possible the bed should be designed so that the
reverse gear and flexible coupling can be dismantled
and lifted out separately.
The engine bed can be built separately and then
carefully measured and bonded into the hull, or be
built up directly in the hull.
When designing the bed the dimensional drawings
for the engine and the boat should if possible be used
to check the space round the engine and the height
and position of the bed in relation to the propeller
shaft. The height depends on whether a flexible en-
gine suspension is to be used or whether the engine
is to have a rigid suspension, and the inclination of
the bed should correspond with the inclination of the
propeller shaft. The height should include a shim of
0 mm (0.4") avoiding the bed being too high.
It is important to drain any water around the engine
bed to the location of the bilge pump.
The figure to the left shows an example of a well-de-
signed engine bed.