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Discussion Starter · #1 ·
FWIW:
I did some digging and the 3372-1U02I manual has the cam timing events listed in the painful little eye chart that uses non-standard timing events such as BBDC and ABDC = Before Bottom Dead Center and After Bottom Dead Center.

Converting all that to Normal lingo I got the following events:
Note: "d" denoting "degrees" DOES ANYONE know what the net lift is at the valve after the roller rocker to hydralic lash adjuster?

INTAKE:
Lift: 0.189" at lobe
Opens 20.5d BTDC closes 215d ATDC
VVT OPEN Zone = 20.5d BTDC to 9.5d ATDC
Duration = 236d

EXHAUST:
Lift: 0.189" at lobe
Opens 109d ATDC closes 17d ATDC
Duration = 234d

Intake/Exhaust
Degrees Overlap: 7.5 - 37.5 < This is VVT Zone, 30 degrees

Some light reading.. .. ..
Variable Valve Timing Mechanism
Function
• The variable valve timing mechanism continuously modifies the phases of the variable valve timing actuator and the intake camshaft using hydraulic pressure controlled by the oil control valve (OCV) so that optimal valve timing is obtained according to engine operation conditions.
• The oil control valve (OCV) operation is based on signals from the PCM according to engine operation conditions and it controls hydraulic pressure to the variable valve timing actuator.


Operation outline
• The variable valve timing actuator has two hydraulic chambers: a valve timing advance chamber and a valve timing retard chamber. They are located between the integrated housing of the camshaft sprocket and the camshaft integrated rotor. The oil pump supplies engine oil to each chamber. Hydraulic pressure applied to each chamber is controlled by the oil control valve (OCV), and the relative phases of the camshaft sprocket and the camshaft are modified to obtain optimum valve timing according to engine operation conditions.

At engine start
• When the stopper pin in the variable valve timing actuator engages with the rotor, which is at the position of maximum valve timing retard due to spring force, the camshaft sprocket and the camshaft rotate as one unit. When the oil pump pressure rises and the stopper pin is disengaged, it is possible to modify the relative angles
of the camshaft sprocket and the camshaft.

Advancing valve timing
• When the spool valve in the oil control valve (OCV) moves to the left according to the PCM signal, hydraulic pressure from the oil pump feeds into the valve timing advance passage, and finally to the valve timing advance chamber in the variable valve timing actuator. Then, the rotor integrated with the camshaft rotates in the valve timing advance direction, against the housing driven by the crankshaft, and the valve timing is advanced.

Maintaining intermediate valve timing
• The spool valve in the oil control valve (OCV) is located near the middle of the valve timing advance and retard positions. Because of this, hydraulic pressures are maintained in both valve timing advance and retard chambers of the variable valve timing actuator. At the same time, relative angles of the rotor and the housing
are fixed and maintained, resulting in fixed valve timing.


Operation and purpose according to driving condition
Idling range, light load range
• Due to a reduction in the amount of overlap, less combusted gas is returned to the intake port. This stabilizes idle speed in the idling range, improving fuel economy, and also ensures engine stability in the light load range.

Medium load range
• Overlap amount has been increased and the EGR ratio inside the cylinder is higher. This reduces engine friction loss (pumping loss), lowering the combustion temperature and reducing the amount of NOx in the exhaust gas. The amount of hydrocarbon emission has also been reduced through reignition of non-combusted gas.

Heavy load, low-middle speed range
• The intake valve is closed early, and high volumetric efficiency is obtained to improve low-middle speed torque. Heavy load, high speed range
• Timing for intake valve closure is delayed and high volumetric efficiency is obtained to improve maximum output.

When temperature is low
• The overlap amount has been minimized to prevent combusted gas from returning to the intake port and to reduce the additional fuel injection amount. This improves fuel economy and stabilizes fast idle speed.

When engine is started or stopped
• Startability has been improved because the overlap amount has been minimized to prevent combusted gas from returning to the intake port.
 

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Discussion Starter · #3 ·
FWIW the Andriod App Torque Pro does not not report the CAM advance/retard. As best I understand it; the ECM on the 6s does not output the PID so its not there for any software like the L3TC. But perhaps has been added in later years. My 06 does not report this variable.
I have read that at idle it's advance is 0.0 degrees (no advance).
 
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