Valve Mechanism - Subaru XT 1988 Service Manual

2-3 ENGINE
Valve Mechanism
The valve mechanism adopts a timing belt driven over-head
camshaft (OHC) type. This OHC features reduced inertia mass
of the valve mechanism, and superior valve follow-up per-
formance from low to high engine speeds. The valve mecha-
nism is provided with the hydraulic lash adjusters for
maintenance-free and noiseless valve operation.
Camshaft RH
Camshaft sprocket
Idler
Fig.
2
CAMSHAFT
1) The camshafts are made of special cast iron, and are
completely treated with Lubrite except for the bearing
portions to improve initial fitting to the rocker arms. The
cam rubbed surface is chilled to increase wear-resistance.
2) The cam profile is specially designed for this OHC type,
and features higher output and less fuel consumption.
3) The cam base circle has an oil hole for lubricating the
rocker arm. The distributor drive gear is mounted on the
left-hand camshaft.
4
Intake valve
Camshaft LH
Camshaft sprocket
Timing belt LH
VALVE ROCKER AND VALVE LASH
ADJUSTER
L2-788
1) The rocker arms are special steel forgings having great
strength and rigidity. Each arm is fitted with a sintered metal
tip to improve wear resistance.
2) The hydraulic valve lash adjuster eliminates the need for
valve clearance adjustment.
3) The rocker arms and valve lash adjusters are common
between intake and exhaust valves.