Operator`s manual

Engine Bolls
Bronze or stainless steel hanger bolts of appropriate size are recommended for use through the engine's
flexible mounts. Less preferred are lag screws because their hold on the
wood is weakened every time they
are moved, whereas the hanger bolts stay
in position. If the nut on top of the hanger bolt is removed to allow
the engine to be lifted from its resting place, the hanger bolt itself remains in place as a stud. Consequent-
ly, the
bond between the hanger bolt and the wood is not weakened by the removal of the nut or the engine.
Foundation lor the Eng ine
A good engine bed contributes much toward the satisfactory operation of the engine. The engine's bed
must be rigidly constructed and neither deflect nor twist when it
is subjected to the engine's weight or to the
pressures that the boat may experience while operating
in rough seas. The bed must keep the engine's
alignment within one
or two thousandths of an inch of this position at all times. The bed has to withstand
the forward push
of the propeller shaft which pushes against the thrust washer bearing which finally pushes
against the engine's bolts and bed.
in fiberglass hulls, we recommend that similar wooden stringers as in wooden hulls be formed, fitted, and
then glassed securely
to the hull. This allows the hanger bolts to be installed firmly in the wood, thereby
reducing noise and transmitted vibration.
The engine support stringers must be as wide or wider than the engine mounting isolator.
Isolator overhang
and/or rounded stringer surfaces are detrimental
to the isolators' ability to retain vibration.
Preformed fiberglass engine beds, when used, should be of sufficient thickness
to properly support the en-
gine and should be well-glassed to the
hull when in-
stalled.
The temptation
to install the engine on a pair of
fiberglass angle irons must be resisted. Such con-
struction will
allow engine vibration to pass through
to the
hull. Flexible mounts require a firm foundation
against which they must act if they are to perform their
function. When possible, follow bed design A and
avoid bed design
B (refer to the illustration).
Supports between the bed stringers, and extending
from the stringers
to the hull, may be required for
proper support and
to aid in the absorption of vibra-
tions.
GOOD
A
BAD
B
Note: Avoid excessive height, use
solid stringer construction (A).
23 Westerbeke Diesel Engines