FORD Cobra 4.6L (4V) - Manual (Page 2)

303-01C-2 303-01C-2 Engine — Cobra 4.6L (4V)
DESCRIPTION AND OPERATION (Continued)
• From the main journals, the oil is routed through • Oil pump displacement has been selected to
cross-drilled passages in the crankshaft to provide adequate volume to ensure correct oil
lubricate the connecting rod bearings. Controlled pressure both at hot idle and maximum speed.
leakage through the crankshaft main bearings and
• The relief valve calibration protects the system
connecting rod bearings is slung radially outward
from excessive pressure during high viscosity
to cool and lubricate the cylinder walls as well as
conditions.
the entire connecting rod, piston and piston rings
• The relief valve is designed to provide adequate
assembly.
connecting rod bearing lubrication under
• The left cylinder head is fed from a drilling into
high-temperature and high-speed conditions.
the supply passage feeding the main gallery at the
front of the cylinder block. The right cylinder
Cooling System
head is fed from a drilling into the rear of the
The engine cooling system includes the following:
main gallery. Main gallery pressure is reduced as
• radiator it enters the cylinder head galleries through fixed
serviceable orifices located at the upper part of
• water pump
the feed passages. It is this reduced pressure in
• the electric cooling fan motor and fan blade,
the cylinder head galleries which feeds the
activated by the variable control module
camshaft journals, the hydraulic lash adjusters
• the degas bottle, which aids in maintaining the
and the primary and secondary timing chain
correct volume of engine coolant
tensioners.
• water thermostat
• The camshaft lobe and roller followers are
lubricated by splash created through valve train
• upper radiator hose
operation.
• lower radiator hose
Oil Pump • heater water hoses
The lubrication system of the 4.6L (4V) engine is
Drive Belt System
designed to provide optimum oil flow to critical
The 4.6L (4V) DOHC engine is equipped with a
components of the engine through its entire
serpentine drive belt. To ensure maximum life, a
operating range. The heart of the system is a
replacement drive belt should be of the same type
positive displacement internal gear oil pump using
as originally installed.
top seal rotors. Generically this design is known as
a gerotor pump, which operates as follows.
• The accessories mounted on the front of the
engine are belt-driven by the crankshaft.
• The oil pump is mounted on the front face of the
cylinder block.
• The serpentine drive belt is routed over each
accessory pulley, driven by the crankshaft pulley
• The inner rotor is piloted on the crankshaft post
bolted to the crankshaft.
and is driven through flats on the crankshaft.
For service procedures, including tensioning, refer to
• System pressure is limited by an integral,
Section 303-05.
internally-vented relief valve which directs the
bypassed oil back to the inlet side of the oil
pump.
2003 Mustang, 8/2002