Downloaded from www.Manualslib.com manuals search engine The Northstar engine is designed to minimize the need for routine
maintenance while incorporating systems to remind the driver when
service is required.
An oil life index indicator monitors ongoing operating
conditions and reminds the driver when an oil change is needed.
A low
coolant warning message keeps track of the level of this vital fluid. Direct
acting hydraulic tappets provide maintenance free zero lash operation of
the
32 valves from idle to the 6500 rpm redline. The camshafts are driven
by a
two stage roller chain assembly which is designed to provide quiet
maintenance free operation. Platinum tipped spark plugs increase the
replacement interval to
100,OO miles.
The four valves per cylinder design provides more efficient engine
breathing, resulting in higher power than comparable
two valve engines.
The induction system uses smooth thermoplastic tubes
to channel air into
the cylinders. These smooth tubes simulate the elaborate port polishing
methods used on racing engines. The shape and length
of the tubes
boosts horsepower by using sonic pressure waves created by the motion of
the inlet valves to increase the amount
of air entering each cylinder. Once
the intake charge has entered the cylinder, the centrally located spark
plug ensures fast and efficient burning of the fuel/air mixture.
This engine is designed to be very durable. The aluminum block has
cast-in-place iron cylinder liners for greater wear resistance. High
strength connecting rods support the
free floating piston pins in bronze
bushings for superior high speed performance.
The fillets of the nodular
iron crankshaft undergo a high pressure compression rolling operation to
improve their resistance to fatigue.
Quiet operation is enhanced by the use
of special materials and designs.
The front cover of the engine is stamped from laminated steel which
damps out noise. Special cam cover gasket seals isolate va1v.e train
operation. The fuel injectors are placed inside the induction system
housing to eliminate the clicking noise which
is common to other fuel
injected engines.
The Northstar engine is designed to provide years
of efficient, reliable,
satisfying operation.
319
Downloaded from www.Manualslib.com manuals search engine rack. The rack piston converts hydraulic pressure to a linear force which
moves the rack left or right. The force is then transmitted through the
inner and outer tie rods to the steering knuckles, which turn the wheels.
If hydraulic assist is not available, manual control is maintained. However
under these conditions more steering effort is required.
4.6 LITER NORTHSTAR ENGINE
Displacement ............................... .4.6L (279 cu.in.)
No. of Cylinders .............................. 8 - 90 Degree V
Power (ACC. to
SAE 51349) ............... 270 (bhp) @ 5600 rpm
Torque (ACC. to
SAE 51349) ............ 300 (lbs. ft.) @ 4000 rpm
SLS
...................................... 204 (kW) @ 5600 rpm
...................................... 407(N*m) @ 4000 rpm
STS
Power (ACC. to SAE 51349) .1. ............ 295 (bhp) @ 6000 rpm
Torque (ACC. to
SAE 51349) ............ 290 (lbs. ft.) @ 4400 rpm
...................................... 220 (kW) @ 6000 rpm
...................................... 393 (Nom) @ 4400 rpm
Bore
........................................ 93mm (3.66 in.)
Stroke
...................................... .84mm (3.31in.)
Compression Ratio
................................... 10.3:l
Cylinder Heads
............................... Cast Aluminum
Cylinder Block
...... Die Cast
Aluminum with Iron Cylinder Bores
Intake Manifold
............ Die Cast Magnesium / Thermoplastic
........................................ Air Induction Tubes
Valve System
................... Direct Acting Hydraulic Tappets
Intake Valve
................................. 33mm (1.29 in.)
Exhaust Valve
................................ 29mm (1.14 in.)
Firing Order
.................................. 1-2-7-3-4-5-6-8
Pistons
...................................... Cast Aluminum
Left Bank
.......................................... 2-4-6-8
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