Engine: Description and Operation

GENERAL DESCRIPTION
The 6G75 (3.8 L) engine is a six-cylinder engine. The cylinder numbers are assigned as 1-3-5 for the right bank and 2-4-6 for the left bank from the front of the engine (timing belt side). This engine is fired in the order of 1-2-3-4-5-6 cylinders.





GENERAL DESCRIPTION
The following changes are applied based on the previous 6G75D-SOHC engine.

MITSUBISHI INNOVATIVE VALVE TIMING AND LIFTING ELECTRONIC CONTROL SYSTEM (MIVEC)





The 6G75 engine uses MIVEC (Mitsubishi Innovative Valve timing Electronic Control system). MIVEC is a variable switching mechanism, which switches a valve timing and lift of an intake valve in accordance with the engine speed. In the range of the low engine speed, the idling stability is improved by decreasing the valve overlap. Advancing the closing timing of the intake valve decreases the back flow to the intake side and then the higher output due to the improvement in the volumetric efficiency is reached. Also, the low lift results in low friction. In the range of the high engine speed, the both of the high lift and retarding the closing timing of the intake valve use the intake air pulsation effect, resulting in the higher output, as well as increasing the overlap decreases the pumping loss.





In addition to the low-lift cam and the rocker arm which drive two intake valves separately, the T-lever which oscillates following the high-lift cam is positioned between the low lift cam and the rocker arm. In the range of the low engine speed, the low-lift cam drives the each valve because the wing of T lever does not reach the piston. In the range of the high engine speed, the oil pressure moves the piston within the rocker arm. The T-lever pushes the rocker arm forward and then the high-lift cam drives the both valves.





The oil pressure supplied from the rear side of the cylinder head at the right side is applied into the oil feeder control valve through the oil filter. The oil feeder control valve switches the oil pressure when the engine speed is higher than the specified one, and controls the oil pressure.