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taken to avoid damage to any exposed parts and to avoid dirt entering
openings.
The parts which have been removed should be returned to
position as soon as the restriction has been passed.
In case
it
is
necessary
to hoist
the engine either
front
end
upwards or reverse gear end upwards, the attachment of slings must be
done very carefully to avoid the possibility of damage to the parts on
which the weight may bear.
It is best if special rigging work be done
by someone experienced and competent in the handling of heavy machi-
nery.
ENGINE BOLTS
It
is
recommended
that
bronze
or
stainless
hanger
bolts
of
appropr iate size be used through the engine flexible mounts.
Lag
screws are less preferred because their hold on the wood is weakened
every time they are moved, whereas the lag bolt stays in position and
the nut on top is used to tighten the engine down or is removed to
permit the engine to be lifted.
The bolt itself stays in position at
all times, as a stud, and the bond between the bolt and the wood is
not weakened by its removal.
FOUNDATION FOR ENGINE
A good engine bed contributes much toward the satisfactory opera-
tion of the engine.
The engine bed
must be of rigid construction and
neither deflect nor twist when sub-
jected to the engine weight or the
position the boat may have to take
under
the
effects of
rough
seas.
The bed must keep the engine within
one or two thousandths of an inch
of this position at all times.
It
has to withstand the forward push
of the propeller which is applied
to
the
propeller
shaft,
to
the
thrust washer bearing in the engine
and finally to the engine bolts and
eng ine "bed.
In fiberglas
hulls,
we recom-
mend that similar wooden str ingers
as
in wooden hulls be formed
and
fitted,
then glassed
to
the hull
securely.
This allows hanger bolts
to
be
installed
firmly
in
wood,
thus reducing noise and transmitted
vibration.
Preformed fiberglas engine beds
when used should be of sufficient
A
B
thickness to properly support the engine and should be well glassed to
the hull when installed.
The temptation to install the engine on a pair of fiberglas "angle
irons· should be resisted.
Such construction will allow engine vibra-
tions to pass through to the hull.
Flexible mounts require a firm
foundation against which to react if they are to do their job.
When
possible, follow bed design
"An
and avoid bed design
"Sn.
4
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