And Connecting Rods; Inspecting The Camshaft; Installing The Camshaft/Gears; Piston And Connecting Rod Disassembly - Westerbeke 12C-TWO Operator's Manual

CAMSHAFT
I
PISTONS AND CONNECTING RODS
Inspecting The Camshaft
Make a thorough inspection of the injection pump and the
valve camshafts. Check the Oldham's coupling, each ball bear-
ing and the cam lobes for wear. Also check the push rods and
tappets.
Check ball bearings
for wear and noise.
Check for cam lobe
- f o r wear and damage.
Inspect Oldham's
Coupling for wear.
TAPPET
Check for cam
contact and
surface wear.
Injection Pump Camshaft Cam Lobe Height
Standard 30mm (1.18in)
Limit 0.7mm (0.027in)
Valve Camshaft Lobe Height
Standard 27.37mm (1.078in)
Limit 1.0rtlm (O.D39in)
r7t\
t..m:ASURING
CAM HEIGHT
Installing The Camshafts/Gears
Coat the cam lobes and bearings with oil then install them in
the reverse order of removal.
Position the timing marks on the gears aligning them with the
marks on the idler gear. After installation is complete check
and adjust the fuel injection timing and valve clearances.
Remove the rings from each pistorr with the piston ring pliers.
Using the piston setting tool, pull out the piston pin from each
piston.
Protecting your eyes with safety glasses, disengage and with-
draw the snap rings. Although mechanics generally press out
(and sometimes hammer out) piston pins, these practices are
discouraged. Instead, time should be taken to heat the pistons,
either with a heat gun or by using a hot plate. Pins will almost
fall out of heated pistons.
While the piston is still warm, check for bore integrity. Insert
the pin from each side. If the pin binds at the center, the bore
might be tapered; if the bore is misaligned, the pin will click or
bind as it enters the far boss.
NOTE:
The number stamped on the rod shank and cap should
correspond to the cylinder number. Sometimes these numbers
are scrambled or missing, and the mechanic must supply them.
Stamp the correct numbers on the pads provided and, to pre-
vent confusion, deface the originals.
CONNECTING
ROD
Inspect for
end play
or twist.
Inspect piston for
wear, seizure, and
streaks. Check the
clearance between
piston and cylinder.
Standarrl:
0.0027 • 0.0033/n
(0.07· 0.84mm)
PISTON PIN
§
~:;~~n~;!ct
for damage
and wear.
PRESSING OUT
PISTON PIN
End play
Standard:
0.0039- 0.0138/n
(0.1 - 0.35mm)
Inspect lor
~
PISTON
wear and
damage. Inspect ring
grooves for
IDLER GEAR/
(NOTE TIMING GEAR MARKS 1 & 2)
-CRANKSHAFT GEAR
PISTON AND CONNECTING ROD DISASSEMBLY
PISTON
Remove the oil pan, gasket and the oil screen strainer.
Chalk the cylinder number on the side face of the big end of
each connecting rod to prevent confusing the connecting rods.
Remove the connecting rod cap from each piston and rod
assembly and draw the assembly upward from the cylinder.
Take care not to allow the connecting rod to scratch the crank-
shaft pin and cylinder. Keep the removed parts (connecting
rod, rod cap, piston, etc.) classified by cylinders.
16
- wear.
o
I
BEARINGS-
PISTON SETTING TOOL
Check tor contact,
seiziJre, flaking,
and fusion.
Oil Clearance
Standard:
0.00087 • 0.0020/n
{0.022- o.osimm)