Bolt Tightening Methods - Westerbeke 8.0KW-60Hz Service Manual

ANGULAR NUT AND BOLT TIGHTENING METHOD
1. Carefully wash the nuts and bolts to remove all oil and
grease.
2. Apply a coat of molybdenum disulfide grease to the
threads and setting faces of the nuts and bolts.
3. Tighten the nuts and bolts to the specified torque (snug
torque) with a torque wrench.
CENTER LINE
LINE
-"--:).l
C D
4. Draw a line (A-B) across the center of each bolt.
5. Draw another line (C-D) on the face of each of the parts
to be clamped. This line should be an extension of the
line (A-B).
COINCIDING LINE
G
6. Draw another line (F-G) on the face of each of the parts
to be clamped. This line will
be
in the direction of the
specified angle
(Q)
across the center
(E)
of the nut or
bolt.
7. Use a socket wrench to tighten each nut or bolt to the
point where the line (A-B) is aligned with the line (F-G).
Example: Specified Angle and Tightening Rotation
A
3D·
1/12
of a tum
B
60·
1I6
of a tum
C
90· 1I4
of a tum
D
180· 1I2 of a tum
E
360· One full tum
NEW TIGHTENING METHOD USING PLASTIC REGION TIGHTENING BOLTS
Parts of the engine use plastic region tightening bolts. The
tightening procedure for these is different from that of con-
ventional bolts and is described in this manual.
NOTE:
The plastic region tightening bolts have fixed service
limits. These limits are indicated where they occur in this
manual and must be strictly observed.
Plastic region tightening bolts are used for the following
applications:
1. Cylinder Head Bolts
2. Connecting Rod Cap Bolts
The tightening procedure is as follows:
After tightening a bolt to the specified torque, tighten it by a
further 90· + 90· or by a further 90" to
100·.
The exact
tightening procedure differs depending on the bolt and is
described as it occurs in this manual.
Engines & Generators
9