Specifications

(4) Second piston ring gap should be positioned on
the opposite side of the combustion chamber recess.
(5) Oil control ring gap to be located 30 degrees to
the left of combustion chamber recess.
(6) When assembling pistons check that compo-
nents are installed in the same position as before dis-
assembly, determined by the numbers stamped on
the crown of individual pistons. Engine cylinders are
numbered starting from gear train end of the engine.
Face chamber recess side of piston towards
camshaft . Therefore, the numbers stamped on con
rod big end should also face in the same direction. To
insert piston into cylinder use a ring compressor as
shown in (Fig. 102).
PISTON PIN INSTALLATION
(1) Secure connecting rod in soft jawed vice.
(2) Lubricate piston pin and piston with clean oil.
(3) Position piston on connecting rod.
CAUTION: Ensure combustion recess in piston
crown and the bearing cap numbers on the con-
necting rod are on the same side.
(4) Install piston pin.
(5) Install clips in piston to retain piston pin.
(6) Remove connecting rod from vice.
INSTALLATION
(1) Before installing pistons, and connecting rod
assemblies into the bore, be sure that compression
ring gaps are staggered so that neither is in line with
oil ring rail gap (Fig. 101).
• The top piston ring gap must be positioned at 30
degrees to the right of the combustion chamber
recess (looking at the piston crown from above).
• The second piston ring gap should be positioned
on the opposite side of the combustion chamber
recess.
• The piston oil control ring gap is to be located 30
degrees too the left of the combustion chamber
recess.
(2) Before installing the ring compressor, make
sure the oil ring expander ends are butted and the
rail gaps located as shown in (Fig. 101).
(3) Immerse the piston head and rings in clean
engine oil, slide the ring compressor, over the piston
and tighten with the special wrench (Fig. 102).
Ensure position of rings does not change dur-
ing this operation .
(4) Face chamber recess side of piston towards
camshaft.
(5) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Insert
Fig. 98 Piston Ring to Groove Clearance
Fig. 99 Piston Rings—Removing and Installing
Fig. 100 Piston Ring Identification
9 - 48 ENGINE WJ
REMOVAL AND INSTALLATION (Continued)