10.7
Section 10
Internal Components
10
Figure 10-6. Measuring Piston Ring End Gap.
4. After installing the new compression (top and
middle) rings on the piston, check the "piston-to-
ring" side clearance. See Figure 10-7 Compare
findings against the maximum recommended
side clearances listed below. If side clearance are
greater than specified, a new piston
must
be used.
Compression Ring-To-Grove Side Clearance
CH11, 12.5, 13, and 14
Top ................. 0.040/0.150 mm (0.0016/0.0041 in.)
Middle .......... 0.040/0.072 mm (0.0016/0.0028 in.)
CH15, 16
Top ................. 0.0600/0.1050 mm (0.00236/0.00413 in)
Middle .......... 0.0400/0.0850 mm (0.00157/0.00335 in.)
Figure 10-7. Measuring Piston Ring Side
Clearance.
Install Piston Rings
To install piston rings, proceed as follows:
NOTE:
Rings must be installed correctly. Ring
installation instructions are usually included
with new rings sets. Follow instructions
carefully. Use a piston ring expander to install
rings. Install the bottom (oil control) ring first
and the top compression ring last. Refer to
Figure 10-8.
Figure 10-8. Piston Ring Installation.
1. Oil Control Ring (Bottom Groove): Install the
expander and then the rails. Make sure the ends
of expander are not overlapped.
2. Compression Ring (Center Groove): Install the
center ring using a piston ring installation tool.
Make sure the “pip” mark is up and the PINK
dykem stripe is to the left of end gap.
3. Compression Ring (Top Groove): Install the top
ring using a piston ring installation tool. Make
sure the “pip” mark is up and the BLUE dykem
stripe is to the left of end gap.
Connecting Rods
Offset Stepped-Cap Connecting Rods are used in all
these engines.
Inspection and Service
Check bearing area (big end) for excessive wear, score
marks, running and side clearances (refer to Section 1,
Specifications, Tolerances, and Special Torque Values).
Replace rod and cap if scored or excessively worn.
Service replacement connecting rods are available in
STD crankpin size and
0.25 mm (0.010 in.)
undersize.
Always refer to the appropriate parts information to
ensure that correct replacements are used.
Piston Ring
Piston
Top Compression Ring
Center Compression
Rails
Expander
Oil Control Ring
End Gap
Dykem
‘‘Pip’’ Mark