1999 JAGUAR S TYPE Powertrain Manual

4
Introduction
D.303.1201
AJ-V6 ENGINEThe AJ-V6 is a water cooled six cylinder engine
configured as two banks of cylinders in a 60û V
formation. Valve operation is via chain driven
double overhead camshafts on each cylinder
bank. The engine is naturally aspirated but with a
unique air intake system which significantly
improves power output. Lightweight materials are
used extensively but the structural design is such
as to maintain a strong rigid assembly.The main features of the power unit are:
¥ three stage variable geometry intake manifold
¥ electronic throttle with cable-less operation
¥ two position variable valve timing
¥ returnless fuel system
¥ fail safe cooling system
V6 Engine
D.303.1202D.303.1201 &1202
AJ-V6/AJ28

V6 EngineAJ-V6/AJ28
5
Engine Specifications
Configuration 60û V6
Displacement 2967 cc (181 cu. in)
Bore 89.0 mm (3.504 in)
Stroke 79.5 mm (3.130 in)
Compression ratio 10.5 :1
Cylinder head 2 overhead camshafts per bank, 4 valve per cylinder
Firing order 1-4-2-5-3-6
Maximum power DIN - 179 kW (240 BHP) at 6800 RPM
EEC - 175 kW (238 PS) at 6800 RPM
Maximum torque DIN - 300 Nm (221 lbft) at 4500 RPM
EEC - 293 Nm (216 lbft) at 4500 RPM
Oil specification see below
Oil volume 5.7 Litres (6 quarts)
Coolant specification see page 35
Coolant volume 10.4 Litres (11 quarts)
Weight 174 kg (384 lbs)
JOL.29550
50JOL.296
Oil Specification
All markets except the USA and Canada
Engine oil for all markets except the USA and
Canada must be to API specification SJ/ACEA A1
or A3.
The recommended SAE viscosity for different
ranges of ambient temperature are shown in
table 1.
USA/Canada
Engine oil for USA and Canada must be to API
specification SJ/ILSAC GF-2.
The recommended SAE viscosity for different
ranges of ambient temperature are shown in
table 2. For maximum economy and in most
climate conditions, SAE 5W/30 is to be preferred
but SAE 10W/30 or 15W/40 are acceptable in
moderate to hot climates.SAE/TEMPERATURE TABLE 2
SAE/TEMPERATURE TABLE 1

V6 Engine
6
Basic Engine
Engine Structure
Basic engine construction is similar to the V8 in
that a structural bedplate is used which bolts to
the cylinder block to provide a very strong
housing for the crankshaft, minimising vibration.
Both units are of cast aluminium alloy and are
accurately aligned together by the use of eight
hollow dowels.
The cylinder block is fitted with dry cast iron
liners.
The oil sump is an aluminium alloy casting which
combines a sump body and oil pan in a single
structural component. The sump mounts to the
bedplate via an aluminium gasket incorporating a
silicone rubber seal.
D.303.1360
D.303.1360
ENGINE STRUCTURE
D.303.1364
ENGINE DATA LOCATIONS
Engine Identification Data
An engine identification code tag is located on the
bank 2 side of the front cover assembly.
Mains bearing selection codes are located at the
rear of the cylinder block and on the rear face of
the crankshaft flange. The two codes are
compared using reference data provided in the
JTIS service information to identify the correct
bearing.
Engine identification codeMains bearing selection codes
D.303.1364
AJ-V6/AJ28

D.303.1210
V6 EngineAJ-V6/AJ28
7 CRANKSHAFT
D.303.1210
D.303.1208
CONNECTING ROD AND PISTON
D.303-1208
Crankshaft
The forged steel crankshaft runs in four
aluminium/tin main bearings with the lower
bearing shells supported in cast iron inserts in the
bedplate. Fore and aft location of the shaft is set
by the rear bearing assembly which consists of an
upper shell and thrust half washer and a lower,
flanged, thrust bearing shell. A keyway locates the
crankshaft timing sprockets, timing pulse ring and
crankshaft damper to the crankshaft.
Connecting Rods and Pistons
The connecting rods are manufactured from
sintered iron. The bearing caps are produced by
the fracture split method (as used on the V8
engines) to provide a strong, accurately mated
assembly. Bearing shells are of aluminium/tin
alloy.
The pistons are made of aluminium alloy with
valve cut-outs in the piston crown to allow for the
extra inlet timing advance of the VVT system.
Four cut outs are provided to enable a common
piston to be used in each engine bank. The piston
is fitted with two compression rings and an oil
control ring assembly.

V6 Engine
8
Cylinder Head
The aluminium alloy cylinder heads have square
squish combustion chambers with four valve
ports and a central spark plug. Each head is
aligned to the cylinder block via two split hollow
dowels and sealed with a composite stainless steel
gasket. Steel balls (10.11mm diameter) are used
to plug the external bores of the oilway drillings
and cup plugs are fitted to the water jacket
openings. Two half round aluminium cap inserts
are fitted via a sealant at the rear of the head.
Cam Cover
The cylinder heads are fitted with lightweight
polyester cam covers, (bank 2 is silver colored)
with silicone seals, to save weight and reduce
airborne noise. A central aperture allows access to
the coil on plug units and a second hole has a
grommet through which the VVT oil control valve
protrudes. The oil filler hole is in the LH cover.
D.303.1368
CYLINDER HEAD
D.303.1207
CAM COVER
D.303.1207
Cylinder Head Assembly
D.303.1368
AJ-V6/AJ28

V6 EngineAJ-V6/AJ28
9
Camshafts and Valve Gear
The basic camshaft consists of individual
machined cam lobes, thrust washer and end plug
assembled on a steel tube. The exhaust camshafts
also have a pressed on drive sprocket, forming a
single camshaft assembly. On the inlet camshaft
the drive sprocket is fixed to the VVT unit which
is removable but the rear end of the camshaft is
fitted with a pressed on multi-tooth sensor ring.
Each camshaft is supported in four bearings with
the front (thrust) bearing cap having a special
oilway for the VVT unit (see VVT section): on the
exhaust camshaft this oilway is redundant. The
bearing caps are made of aluminium.
The cams actuate the valves via direct acting
mechanical bucket tappets made of lightweight
aluminium with phosphate coated cast iron shims
D.303.1209
CAMSHAFTS AND VALVE GEAR
D.303.1209
mounted on top. The valve components are of
lightweight design with 5.5mm valve stems.
VVT Unit
Inlet Camshaft
Exhaust Camshaft

V6 Engine
10
D.303.1204
CAMSHAFT DRIVE
D.303.1204
AJ-V6/AJ28
Camshaft Drive
Two timing chains are used, one for each cylinder
bank and driven by separate sprockets keyed to
the crankshaft. The chains are of the silent-type,
with a multiple link construction and sprocket
engagement on one side only.
Each chain has a hydraulic tensioner, fed from the
engine oil supply, which acts on a pivoted
tensioner arm with side flanges. Fixed guides bear
on the drive side of the chains and are unique to
each side.
A single piece aluminium alloy front cover is
aligned to the cylinder block by two dowels andencloses the timing gear. The crankshaft front oil
seal fits into the front cover and the inner lip
bears on the crankshaft damper.
Crankshaft timing disc
VVT unit

V6 EngineAJ-V6/AJ28
11
D.303.1220
IGNITION COIL COVERIgnition Coil Cover
A plastic ignition coil cover, embossed with
ÔJAGUAR V6Õ, is fitted to engine bank 2 only. The
cover is attached via two push fit studs on the
camshaft cover.
D.303.1220