Subaru XT 1988 Service Manual page 159

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ENGINE 2-3
HEAD GASKET
1) The cylinder head gaskets are provided with wire rings at
the bore sections in order to increase pressure- and heat-
resistant properties as well as an effective seal.
2) The oil passage is provided with an O-ring to improve
sealing.
CAMSHAFT CASE
11
The camshaft case holds the camshaft, and is an
aluminium die-\:asting.
2) The oil rei ief valve for the hydraulic lash adjuster is built
into the cam case.
The oil filler duct is mounted on the right-hand camshaft case,
and the distributor on the left-hand camshaft case.
3) The camshaft case has a groove all around the cylinder
head mating surface, and fluid packing is filled into this groove
for sealing.
ROCKER COVER
1) The rocker cover is a light-weight and compact aluminium
die-casting.
2) This rocker cover adopts a float-supporting system with a
rubber ring type gasket and an oil seal washer to reduce the
noise level.
3
CRANKSHAFT
The crankshaft is made from special wrought iron which
provides sturdiness. All corners of the journals are processed
with "deep roll" treatment.
The horizontally opposed engine configuration provides
greater strength against bending and torsional stresses wh ile
reducing the total length of the crankshaft.
PISTON AND PISTON RING
1) The piston is cast from aluminum alloy which features a
small thermal expansion rate. Its top land is provided with
valve rei ief and its skirt section has an elliptical, tapered design
to provide heat- and wear-resistance.
The shaped piston and short piston pin effectively reduce the
weight of the piston ASSY.
2) Three piston rings are used for each piston - two com-
pression rings and one oil ring.
These piston rings have small wall thickness to reduce weight
and oi I consumption.
OIL PAN
The oil pan incorporates a double-layer baffle plate to stabilize
the oil surface, and also improves rigidity along with reducing
noise.