Subaru SVX 1992 Manual page 202

ENGINE
[W5C4] 2-3
(3) If the cylinder inner diameter exceeds the limit
after boring and honing, replace the crankcase .
Immediately after reboring, the cylinder diameter may
differ from its real diameter due to temperature rise.
Thus, pay attention to this when measuring the cylin-
der diameter.
Limit of cylinder enlarging (boring) :
0.3 mm (0.012 in)
3. PISTON AND PISTON PIN
1) Check pistons and piston pins for damage, cracks,
and wear and the piston ring grooves for wear and
damage . Replace if defective .
2) Measure the piston-to-cylinder clearance at each
cylinder as instructed in CYLINDER AND PISTON . If any
of the clearances is not to specification, replace the
piston or bore the cylinder to use an oversize piston .
3) Make sure that piston pin can be inserted into the
piston pin hole with a thumb at 20°C (68°F) . Replace if
defective.
RorNmark
Top ring
-R or N mark
Second ring
Upper rail
Oil ring
Spacer
~3- -Lower rail
B2-115]
Fig . 120
2) Squarely place piston ring and oil ring in cylinder
using piston, and measure the piston ring gap with a
thickness gauge.
Unit : mm (in)
Standard Limit
0.20-0.30
Top ring (0,0079- 0.5 (0.020)
0 .0118)
Piston
0.37-0.52
Second ring
(0 .0146-
1 .0 (0.039)
ring gap
0.0205)
0.20-0.60
Oil ring rail (0 .0079- 1 .5 (0.059)
0 .0236)
Standard clearance between piston pin and hole in
piston :
0.004 - 0.008 mm (0 .0002 - 0 .0003 in)
Standard clearance between piston pin and hole in
connecting rod :
0 - 0.018 mm (0 - 0.0007 in)
4. PISTON RING
1) If piston ring is broken, damaged, or worn, or if its
tension is insufficient, or when the piston is replaced,
replace piston ring with a new one of the same size as
the piston .
"R" is marked on the end of the top and second rings .
When installing the rings to the piston, face this mark
upward .
C2-408
Fig. 119
The oil ring is a combined ring consisting of two rails
and a spacer in between . When installing, be careful
not to make misassembly .
Cylinder block top surface
_
/
30 mm
hi kess
0
(1 .18 in)
~
\ ~lgauge
i
I I
: .~~
o 0
\\ r C2-390
Fig . 121
63