Mitsubishi Innovative Valve timing Electronic Control system
- MIVEC (Mitsubishi Innovative Valve timing Electronic Control system) is the general name for all engines equipped with the variable valve timing mechanism developed by Mitsubishi Motors.
Mitsubishi Motors has been focusing for a long time on technologies to control valve timing and amount of lift with the aim of achieving high power output, low fuel consumption, and low exhaust emissions. The MIVEC engine was first used in 1992 in the Mirage, and since then Mitsubishi Motors has been adding a number of enhancements to produce an even better performance. In the Outlander launched in 2005, the Delica D:5 and the Galant Fortis launched in 2007, Mitsubishi Motors adopted a mechanism that continuously and optimally controls the intake and exhaust valve timing.
Now, the all-new MIVEC engine controls both intake valve timing and amount of valve lift at the same time, all the time.
The all-new MIVEC engine with a simple SOHC structure is used for the Japanese-market GALANT FORTIS and GALANT FORTIS SPORTBACK from 2011, OUTLANDER from 2012.
ALL-NEW MIVEC SOHC 16 VALVE (4J1 model)
The all-new MIVEC engine's environmental performance is improved compared to the previous MIVEC engine. It reduces pumping losses by adjusting the intake air volume by variating intake valve lift stroke as well as throttle valves, improving fuel efficiency. Moreover, the all-new MIVEC engine improves fuel consumption due to other factors, including improvement of combustion stability through optimization of the combustion chamber structure and reduction of friction through optimization of the piston structure.
Furthermore, although the all-new MIVEC engine adopts a simple SOHC structure, engine performance is equal to the previous MIVEC engine. In addition the AS&G (Automatic Stop And Go) idling-stop system achieves a smooth stop-and-start with minimal vibration along with reduced fuel consumption at restart due to the reduction of air intake volume by the all-new MIVEC system,
Features of the All-new MIVEC System - 1
Minimizing pumping loss contributes to very high fuel efficiency!
With a conventional gasoline engine, the intake air volume is controlled by a throttle valve, increasing the air intake resistance when a piston descends. The all-new MIVEC engine restrains this air intake resistance by controlling the intake valve lift as well as the valve opening/closing timing simultaneously and continuously.
Thus the all-new MIVEC engine improves fuel consumption by reducing pumping loss during intake.
Features of the All-new MIVEC system - 2
The all-new MIVEC engine's SOHC achieves continuous variable valve timing and lift!
The all-new continuously-variable valve system make valve lift stroke, the length of valve-opening time and valve opening timing continuously and simultaneously variable through a control shaft (see figure below).
With this mechanical interlock structure, cooperative control of hydraulic variable valve timing phase system becomes unnecessary. Accordingly the new MIVEC system can be adopted to the simple SOHC structure.
Consequently the new MIVEC realizes light weight and compact new engine.
The all-new variable-valve structure simply adds an oscillating cam, a support shaft, and a center rocker arm to the conventional SOHC's rotating cam, rocker arm and rocker shaft. The range of motion of the oscillating cam is made continuously variable by moving the fulcrum position of the center rocker arm through rotation of the control shaft (intake rocker shaft) by an electric motor.
MIVEC DOHC 16-valve Engine (4B1)
The 4B1 MIVEC engine series used in the Outlander as well as the Japanese-market Delica D:5 and Galant Fortis models uses the continuously variable intake and exhaust valve timing MIVEC system that continuously and optimally controls the intake and exhaust valve timing according to engine running conditions. This system delivers high performance and fuel efficiency.
Continuously controlling the intake cam and exhaust cams independently, this system provides a combination of maximum power output, high fuel efficiency, and a high level of environmental performance by making possible more precise valve control according to RPM and engine load than intake-only systems.
MIVEC DOHC-12valve Engine (3A9, 3B2)
The MIVEC engine used in "Mirage" model uses the continuously variable intake valve timing MIVEC system that continuously and optimally controls the intake valve timing according to engine running conditions.
This system delivers high performance and low fuel consumption.