Page 11
———
022-10 Engine
Crankpin diameter:
:
Standard mm (in) 51.981-52.000 (2.0465-2.047 2)
First undersize mm (in) 51.731-51.750 (2.0367-2.0374)
Second undersize mmr (in) 51.481-51,500 (2.0268-2.0278)} —
Third undersize mm (in) 51.237-51.250(2.0172-2.0177)
Fourth undersize mim {in} 50.987-51.000 (2.0074-2.0079)
Main journal diameter:
Standard mm (in) 57.981-58.000 (2.2827-2.2835)
First undersize mm (in) 57,731-57.750 (2.2729-2.2736)
Second undersize 1 mm (in) 57.481-57.500 (2,2630-2.2638) =
Third undersize mm (in) 57 .237-57.250 (2.2534-2.2539)
Fourth undersize mm (in) 56.987-57.000 (2.2436-2.2441)
Valve gear
Valve clearance, mm, in engine having stood for
30 min after running at normal temperature
N.B,: B204 engines only.
rd B201 engines Turbo Other engines
R Onchecking: inlet 0.15-0.30 0.15-0.30
exhaust 0.40-0.50 0,.35-0,50
On adjusting: inlet 0.20-0.25 0.20-0.25
exhaust 0.45-0.50 0,40-0.45
eee BS
Saab 900
Page 12
ee ee
Engine 022-11
N.B. i
The exhaust valves have a stellite coating and
should therefore not be machined. Grinding
= using valve grinding paste is the only recommen-
—— ded method, The exhaust valves in engines with
fuel injection are sodium filled and the sodium
must therefore be removed before the valves are
7 scrapped.
Valve guides
— B201 B202
—=— Length mm (in) 46.65 (1.837) 49,0(1.9291)
= Outer diameter mm (in) 13.040-13.051 12.039-12 050
2a (0.5134-0,5138) (9.4740-0,.4744)
an Bore for valve Guides mm (in) 13.000-13.018 12.000-12.018
incylinderhead (0,5118-0.5125) (0.4724-0.4731)
i Maximum clearance mm (in) 0.5 (0.2) measured on valve head
between valve stem raised 3 (0.2) above seat
and valve guide
Fa Valve springs =
) B201 B202
i Length when fitted mm (in) 39.5 (1.56) 37.0 (1.4567) =
Free length mm (in) i 45.7 (1.88) 45+ 1.5(1.78+ 0.05) |
Length when under
load of 740-800N
(162 - 174 |bf) mm (in) 29.5 (1.16) Length
when under
load of 595-645N
(131-141 |bf) mm (in) 28.4 (1.12)
Saab 900
Page 13
022-12 Engine
Cam followers
-/" B201 B202 L
Diameter mm (in) 37.87-38.98 32.959-32.975
: (1,4909-1,4953) (1.2976-1.2982)
Height mm (in) 33 (1.2992) 26 (1.0236)
Bore for cam followers
in cylinderhead
(camshaft bearing mm (in) 38.000-38.016 33.000- 33.016
assembly) (1.4961-1,.4967) (1.2992-1.2998)
Shims for valve adjustment ..
Diameter mm (in) | 15.5 (0.6102)
Thickness mm (in) 1.77-2.89 (0.0697-0.1138)
23 shims available within the range,
at intervals of 0.05 mm (0.002 in)
Camshaft
B201 B202
No. of bearings 5 5
Bearing diameter mm {in) 28.94 28.922-28.935
(1.1394) (1.1387-1.1392)
End float mm (in) 0.08-0.25 0.08-0.35
(0,.0031-0,0098) (0.0031-0.0138)
Cam lift at 0 valve clearance
Intet Valves Exhaust Valves
B201 carburettor 1981- mm (in) 10.8 (0.425) 11.0 (0.433)
B201i 1981- mm (in) 10.8 (0.425) 11.0 (0.433)
B201 Turbo : -1982 mm (in) 9.1 (0.358) 10.5 (0.413)
B201 Turbo APC 1981- mm (in) 10.8 (0.425) 11.0 (0.433)
B202 Turbo -1985 mm (in) 8.65/6.65 8.65
B202 Turbo with
cat. converter -1986 (0.341/0.262) (0.341)
B202i 1986-
B202 Turbo 1986-
B202 Turbo with
cat. converter 1987- mm (in) 8.65 (0.341) 8.65 (0.341)
Saab 900
Page 14
Engine 022-13
Valve timing
ia ip (at design clearance: 0.35 mm, inlet; 0.55 mm,
2\ exhaust)
Inlet Valves Exhaust Valves
> Open Ciose Open Close
3) Engine Model Year BIDC ABDC BBDC ATDC
B201 Carburettor 1981- 10° 54° 46° 18°
82011 1981- 10° 54° 46° ie
B202i 1986- 16° 44° 61° 13°
=, 8201 Turbo-1982 12 40° 62° es
a B201 Turbo APC 1981- ; 10° 54° 46° 18°
B202 Turbo -1985 10° 56° 56° 16°
_— B202 Turbo 1986- 16° 56° 61° 3:
—
Saab 900
Page 15
022-14 Engine
Tightening torques
Torque, Nm Torque, Ibf ft Dimension
Main bearings 110 81 M12
Big-end bearings 55 41 M10
Camshaft bearing caps, B201 15 11 M8
B202 15 14 M8 -
Valve cover B201 5 37 M6
B202 15 44 M8
Crankshaft pulley 190 141 M16
Rear engine plate (flywheel end) 20 14.8 M8
Flywheel 59 44 M 40
Oil pump F 8 5.9 M6
Spark plugs 28 20.7 M14x1.25
Chaintensioner, B201 12 8.9 M6
Chain guide, . B201 412 8.9 M6
Chain tensioner, B202 63 46.6 M10
Camshaft sprocket, 8204 20 14.8 M8
Camshaft sprocket, B202 63 46.6 M190
Engine to gearbox 25 18.5 2
Inlet manifold 18 13.5 Ms
Thermostat housing 18 13.5 M8
Ms Throttle housing 18 13.5 M8
Exhaust manifold, Turbo 25 19 M8
allather models 20 14.8 M8
Timing cover
Distributor, B201 5 Poa f M&S
B202 20 14.8 M8 7
Oil filter 10 7.4 3/4"-16 UNF
Oil pressure switch 10 7.4 1/4”-1.8 NPTF
EGR valve 15 14 M14x1.5
Engine block heater plug 55 40.7 3/8” BSP
Drain plug, coolant 30 22.2 Mi4x15 |
Knock detector, M82 earlier 8 5.9 L -
M83 onwards 20 14.8 =
All other bolts should be tightened as follows:
Dimension Tightening torque
Nm lbf ft
MS 5 3.6
M6 10 7.2
Ms 20 14.4
M10 40 23.8
Saab 900
Page 16
URI tc
Technical Description 200-1
Technical Description
EYiS Iria Leas Cats Sa bate are es 200-1 Lubricatingsystem ......... 200-5
Engine mountings B201 ....... 200-7
Engine body
General
The water cooled engine is a four-in-line with
either single (B201) or twin (B202) overhead
camshafts. The crankcase ventilation is totally
enclosed. The cylinder block is inclined at an
angle of 45 to the right and the cylinder head is
) of the cross-fiow type, i.e. with the inlet ports on
one side and the exhaust ports on the other. The
engine is mounted with the clutch towards the
front of the car and with the timing chain and the
no. 1 cylinder towards the rear. The engine is
available in carburettor, fuel injection and
turbocharged versions and in 8-valve and 16-
valve variants.
Saab 900
Page 17
200-2 Technical Description
Cylinder block
The cylinder block is made of special cast iron,
cast in one piece. The cylinder bores, sur-
rounded by cooling jackets, are drilled straight
out of the block. The block also contains oilways
for the lubricating system.
Crankshaft and bearings
The crankshaft is a forging. The journals have
been ground, hardened and have undergone
‘Tenifer’ treatment to provide a hard, non-metal-
lic surface, which affords good protection
against bearing seizure. The crankshaft is sup-
ported by five main bearings, with end-float ad-
justment made at the centre bearing. Oilways
are drilled in the shaft for lubrication. All main
bearing shells are replaceable.
The crankshaft drives the oil pump which is inter-
posed between the timing cover and the
crankshaft pulley.
The waterpump and alternator are driven from
the crankshaft by a V-belt.
The steering servo pump and AC compressor are
also driven by V-belts from the crankshaft pul-
leys.
Saab 900
Pi
Th
vit
or
fle
pr
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Page 18
Technical Description 200-3
Pistons
The pistons are made of light alloy and are pro-
vided with grooves for two compression rings and
one oil scraper ring. The top compression ring is
flat with a chromium finish. The second com-
pression ring has oil-control properties and is
slightly wider than the top ring. The actual oi!
scraper is a three-piece ring.
Cylinder head
The cylinder head is a precision, light-alloy cast-
ing and the stee! valve seats are press-fitted in
the head. The head is bolted to the block.
The valves are made of steel and have
chromium-plated stems. The heads on the inlet
valves are induction hardened and those on the
exhaust valves stellited.
Connecting rods
The connecting rods are forged and incorporate
bushes for the gudgeon pins. Gudgeon-pin
bushes and big-end bearing shells are replace-
able.
The gudgeon pins are of the fully-floating type,
being free to turn in both piston and connecting
rod. Axial movement of the pins is limited by
circlips inside the piston boss.
Cylinder head on 16-valve B202 engine
Saab 900
Page 19
200-4 Technical Description
The combustion chambers are hemispherical
and, on the B202 engine, each cylinder has four
valves, with the spark plug being located cent-
rally.
Camshafts and cam followers (B202)
The engine has twin overhead camshafts, each
of which is mounted in five bearings. The cams
have a wide base circle, which provides a large
amount of lift but little stress. The camshafts are
driven by a chain with an effective automatic
chain tensioner. The camshafts are direct acting
on the valves via hydraulic bucket-type cam fol-
lowers. The distributor is driven direct from one
of the camshafts.
The hydraulic cam followers adjust automatically
to differences in valve clearance caused by vari-
ations in temperature. The main advantage of
the hydraulic cam followers is that they operate
silently and are extremely reliable.
Saab 900
Page 20
Technical Description 200-5
cally
vari-
& of
rate
SAAT
x
KS ¢
Oi! flow through the cam follower
Each cam follower has two storage chambers
and one high-pressure chamber. Aspring-loaded
ball valve seals the orifice between the high-
pressure chamber and the adjacent storage
chamber. A return spring in the high-pressure
1 Storage chamber
2 Leakage orifice
3 Check valve
4 High-pressure chamber
5 Spring
chamber acts on the sliding piston, tomaintaina
constant clearance between the cam follower
and the base circle of the cam. Atthe same time,
the high-pressure chamber expands and makes
up the oil volume, to compensate for leakage
losses occurring at actuating pressure in the
orifice between the piston and the cylinder.
Lubricating system (B202)
The lubricating system for the engine has forced-
flow circulation. The oil pressure is generated by
a gear-type pump consisting of a pinion and an
eccentric ring gear. The pump is driven by the
crankshaft and is interposed between the timing
cover and the crankshaft pulley. A relief valve in
the timing cover limits the oil pressure and di-
verts surplus oil to the inlet side of the pump.