Subaru Impreza 2003, Service Manual

Page: 214 / 3610

ME(H4SO)-2
MECHANICAL
GENERAL DESCRIPTION
1. General Description
A: SPECIFICATIONS
NOTE:
STD: Standard
I.D.: Inner Diameter O.D.: Outer Diameter US: Undersize OS: Oversize
Engine
Model 1.6 L 2.0 L 2.5 L
Type
Horizontally opposed, liquid cooled, 4-cylinder, 4-stroke gasoline
engine
Valve arrangement Belt driven, single over-head camshaft, 4-valve/cylinder
Bore
×
Stroke mm (in)
87.9
×
65.8
(3.46
×
2.591)
92
×
75 (3.62
×
2.95)
99.5
×
79.0
(3.917
×
3.110)
Displacement
cm
3
(cu in)
1,597 (97.45) 1,994 (121.67) 2,457 (150)
Compression ratio 10.0
Compression pressure
(at 350 rpm)
kPa (kg/cm
2
, psi)
1,020 — 1,275 (10.4 — 13.0, 148 — 185)
Number of piston rings Pressure ring: 2, Oil ring: 1
Intake valve timing
Opening 10
°
BTDC 4
°
BTDC 1
°
BTDC
Closing 46
°
ABDC 48
°
ABDC 51
°
ABDC
Exhaust valve timing
Opening 42
°
BBDC 48
°
BBDC 50
°
BBDC
Closing 10
°
ATDC 4
°
ATDC 6
°
ATDC
Valve clearance
Intake mm (in) 0.20
±
0.02 (0.0079
±
0.0008)
Exhaust mm (in) 0.25
±
0.02 (0.0098
±
0.0008)
Idling speed
[At neutral position on MT, or
“P” or “N” position on AT]
rpm
With OBD: 650
±
100 (No load)
850
±
100 (A/C ON)
Without OBD: 700
±
100 (No load)
850
±
100 (A/C ON)
650
±
100 (No load)
850
±
100 (A/C ON)
Firing order 1
→
3
→
2
→
4
Ignition timing BTDC/rpm
With OBD:
5
°±
10
°
/650
Without OBD:
5
°±
10
°
/700
With OBD:
10
°±
10
°
/650
Without OBD:
10
°±
10
°
/700
10
°±
10
°
/650
Belt
tensioner
adjuster
Protrusion of adjuster rod 5.2 — 6.2 mm (0.205 — 0.244 in)
Belt
tensioner
Spacer O.D. 17.955 — 17.975 mm (0.7069 — 0.7077 in)
Tensioner bush I.D. 18.00 — 18.08 mm (0.7087 — 0.7118 in)
Clearance between spacer and bush
STD 0.025 — 0.125 mm (0.0010 — 0.0049 in)
Limit 0.175 mm (0.0069 in)
Side clearance of spacer
STD 0.20 — 0.55 mm (0.0079 — 0.0217 in)
Limit 0.81 mm (0.0319 in)
Valve
rocker arm
Clearance between shaft and arm
STD 0.020 — 0.054 mm (0.0008 — 0.0021 in)
Limit 0.10 mm (0.0039 in)