Publicidad
Idiomas disponibles
Idiomas disponibles
High Pressure (On Engine)
The high fuel pressure necessary for direct injection is supplied by the high pressure fuel pump. The high pressure fuel pump
is mounted on the rear of the engine under the intake manifold and is driven by a three-lobe cam on the camshaft. This high
pressure fuel pump also regulates the fuel pressure using an actuator in the form of an internal solenoid-controlled valve that
is controlled by the ECM.
Crankcase Ventilation System Description (LT4)
A positive crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors.
Filtered air from the air induction system duct is supplied to the crankcase, mixed with blow-by vapors, and passes through
a crankcase ventilation metering device before entering the supercharger. The primary component in the positive crankcase
ventilation (PCV) system is the PCV flow metering device (valve or orifice) . Vacuum changes within the supercharger result in
flow variations of the blow-by vapors. If abnormal operating conditions occur, the design of the PCV system permits excessive
amounts of blow-by vapors to back flow through the crankcase vent tube and into the engine induction system to be consumed
during normal combustion. This engine ventilation system design minimizes oil consumption and significantly reduces the
potential for oil ingestion during vehicle limit handling maneuvers. The LT4 engine utilizes an integral positive crankcase
ventilation (PCV) system which is located in the Valve Lifter Oil Manifold Assembly beneath the Supercharger Assembly. The
Valve Lifter Oil Manifold Assembly contains composite oil separating baffles and PCV plumbing. Filtered fresh air is routed
from upstream of the throttle plate to the engine oil tank where it mixes with crankcase gasses and is passed to both engine
rocker arm covers. The rocker arm covers' design shields rocker arm oil spray, thereby reducing the potential for oil being
drawn back into the tank during backflow of the ventilation system. Blow-by vapors are routed from the valve lifter oil manifold
assembly through a fixed orifice (7.5 mm) within a steel PCV tube, then into the underside of the supercharger near the front of
the valve lifter oil manifold assembly.
The following parts maybe purchased to assist in PCV connection, see figure 4. The system must supply filtered air to the PCV
system. Connection must be between the Mass Air Flow meter and the throttle body.
Tube-PCV (1) 12681424
Tube-PCV (2) 12687310
Tube-PCV (3) 12687313
Fig. 4
Tube-PCV (1)
Variable Camshaft Timing
This engine has the ability to vary the camshaft position versus the piston position. If you chose to use the Chevrolet
Performance engine controller kit, then it will vary camshaft timing to improve emission and fuel economy, while still producing
great power. At idle, for example, the cam is at the full advanced position, allowing exceptionally smooth idling. Under other
conditions, the phaser adjusts to deliver optimal valve timing for performance, drivability and fuel economy. At high rpm it may
retard timing to maximize airflow through the engine and increase horsepower. At low rpm it can advance timing to increase
torque. Under light loads, it can retard timing at all engine speeds to improve fuel economy. A vane-type phaser is installed
on the front of the camshaft to change its angular orientation relative to the sprocket, thereby adjusting the timing of valve
operation on the fly. It is a dual-equal cam phasing system that adjusts camshaft timing at the same rate for both intake and
exhaust valves. The system allows linear delivery of torque, with near-peak levels over a broad rpm range, and high specific
output (horsepower per liter of displacement) without sacrificing overall engine response, or drivability. It also provides another
effective tool for controlling exhaust emissions.
LT4 Wet Sump Engine
TITLE
ALL INFORMATION WITHIN ABOVE BORDER TO BE PRINTED EXACTLY AS SHOWN ON 8 1/2 x 11
WHITE 16 POUND BOND PAPER. PRINT ON BOTH SIDES, EXCLUDING TEMPLATES.
TO BE UNITIZED IN ACCORDANCE WITH GM SPECIFICATIONS.
Tube-PCV (2)
Tube-PCV (3)
IR 02JA18
DATE
17AU15
02JA18
19332622
PART NO.
REVISION
Initial Release - Rocko Parker
Revision - Rocko Parker
4
35
SHEET
OF
AUTH
ECA P5E00313
N/A
Publicidad
