ASSIGNMENT 1
FAKULTI TEKNOLOGI KEJURUTERAAN
MEKANIKAL DAN PEMBUATAN
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
INTERNAL COMBUSTION ENGINE
BMKA 3113
(ENJIN PEMBAKARAN DALAM)
ASSIGNMENT
CURRENT TECHNOLOGY ON VARIABLE VALVE AND TIMING SYSTEM
LECTURER’S NAME DR. AHMAD FUAD BIN ABDUL RASID
STUDENT’S NAME MATRIX NO:
S1. MUHAMMAD FIRDAUS BADRUDDIN BIN RAHMANSA B092210047
S2. NUR FARHANA HANIM BINTI MOHD SHAHRIM B092210249
S3. MUHAMMAD FARIZ IRWAN BIN MUHAMMAD FARID B092210032
S4. NU’AIM FITRI ZAIDANI BIN FADIL B092210350
S5. WAN RAFIZHULMIZAN BIN MOHD AZLAN B092210311
ASSESSEMENT RUBRICS
GIVEN MARKS
MARK
ASSESSMENT TASK/ITEMS
ALLOCATION
S1 S2 S3
1. Report Preparation. 40
2. Demonstration of Presentation materials. 30
3. Communication and Language. 30
TOTAL MARKS 100
Approved By: ………………………………………………..…..
(Instructor’s Signature & Stamp)
Date: …………………………………………………
1.0 INTRODUCTION
Mitsubishi’s Variable Valve Timing (VVT) technology, called MIVEC (Mitsubishi Innovative Valve
Timing Electronic Control), enhances engine performance, fuel efficiency, and emissions control. By
adjusting the timing of the intake and exhaust valves, MIVEC ensures an ideal balance between power
and efficiency for various driving conditions. It optimizes valve timing and lift to deliver better high-speed
performance and improved fuel economy at lower speeds. MIVEC also reduces emissions and ensures
smooth power delivery. Over time, Mitsubishi has advanced this technology with versions like Dual
MIVEC, which adjusts both intake and exhaust valves for even greater efficiency and performance.
MIVEC reflects Mitsubishi's commitment to innovation and sustainability in automotive engineering.
Mitsubishi introduced MIVEC (Mitsubishi Innovative Valve Timing Electronic Control) in 1992,
showcasing its commitment to enhancing performance and efficiency through dynamic valve timing.
• Early Developments (1990s)
MIVEC debuted in the Mirage Cyborg and Galant. It used a dual-profile camshaft to switch between
low- and high-speed modes, delivering power during aggressive driving while maintaining fuel
efficiency and smooth operation during normal use.
• Advancements in the 2000s
In the 2000s, Mitsubishi refined MIVEC to meet stricter emissions standards and demand for better
fuel economy. The technology was expanded to more vehicles, including larger engines in SUVs and
performance models like Lancer Evolution. Continuous Variable Valve Timing was introduced,
allowing seamless valve adjustments for improved efficiency and reduced emissions.
• Dual MIVEC and Beyond (2010s)
By the 2010s, Mitsubishi launched Dual MIVEC, controlling both intake and exhaust valves for better
combustion and power. This technology, paired with turbocharging and direct fuel injection, enhanced
performance while reducing fuel use and emissions. It powered models like the Outlander, Eclipse
Cross, and modern Lancers.
• Present and Future
Today, MIVEC remains essential to Mitsubishi’s engines, supporting efficiency and eco-friendly
designs. Integrated into hybrid systems, MIVEC ensures combustion engines complement
electrification. This innovation reflects Mitsubishi’s focus on reliability, performance, and adapting to
modern automotive demands.
2.0 THEORY
THEORY OF OPERATION ON HOW IT CAN IMPROVE ENGINE OPERATION
(MITSUBISHI MIVEC)
The Mitsubishi MIVEC (Mitsubishi Innovative Valve Timing Electronic Control) system is an advanced
technology engineered to enhance engine performance by dynamically modifying valve timing and lift
according to engine operating conditions. It pertains to essential performance metrics including fuel
efficiency, power output, and emissions regulation, guaranteeing optimal engine performance in diverse
driving conditions.
Valve Timing Adjustment
MIVEC's capability to modify valve timing facilitates precise regulation of the opening and closing of the
intake and exhaust valves throughout the engine cycle. At reduced RPMs, the system delays valve timing
to minimize overlap between intake and exhaust events. This reduces fuel wastage and facilitates complete
combustion, hence improving fuel efficiency and decreasing pollutants. At elevated RPMs, MIVEC
modifies the valve timing, enhancing overlap to provide increased air intake and expedited exhaust release.
This guarantees improved engine respiration, resulting in a substantial increase in power output.
Variable Valve Lift Mechanism
A fundamental characteristic of MIVEC is its capacity to modify valve lift. The system employs a
hydraulic actuator to alternate between two cam profiles: low-lift for efficiency and high-lift for
performance. Under low-load situations, the low-lift cam profile limits valve opening, decreasing air
intake and conserving fuel. In high-load or high-speed scenarios, the high-lift cam profile optimizes air
intake, facilitating improved combustion and enhanced power output. This dual-lift capability ensures an
optimal equilibrium between fuel efficiency and performance.
Electronic Control Unit (ECU)
The ECU functions as the central control unit for the MIVEC system. It perpetually assesses multiple
characteristics, including engine speed, throttle position, and load, to ascertain the ideal valve timing and
lift configurations. The ECU thereafter transmits signals to hydraulic actuators and oil control valves to
effectuate these modifications in real-time. This accuracy guarantees that the engine functions efficiently
and effectively in all driving circumstances.
Improvement in Engine Operation
By dynamically optimizing valve timing and lift, MIVEC provides several operational benefits:
1. Enhanced Fuel Economy: At low speeds, the system’s focus on minimizing valve overlaps and
using low-lift cam profiles ensures minimal fuel consumption.
2. Increased Power Output: At higher speeds, advanced timing and high-lift profiles allow the
engine to generate significantly more power by improving airflow and combustion efficiency.
3. Reduced Emissions: Improved combustion efficiency across all RPM ranges reduces the
production of unburned hydrocarbons and other pollutants.
4. Smoother Driving Experience: The system’s ability to seamlessly switch between different
modes ensures a smooth transition from efficient cruising to powerful acceleration, enhancing
overall derivability.
3.0 SYSTEM/ TECHNOLOGY
Basic Operation
• In the MIVEC, the intake camshaft sprocket and the camshaft are designed to slide, and the
system regulates the volume of oil that is supplied to the oil chambers (for timing advance and
retard), which are provided in the camshaft.
• The phase angle between the sprocket and the camshaft is controlled by controlling the duty
cycle of the current that is applied to the oil control valve, which is provided in the cylinder head.
Timing advance
• The oil pressure from the cylinder block enters the advance chamber in the V.V.T. sprocket, and
the vane rotor moves towards timing advance, thus causing the intake camshaft (which is
coupled to the vane rotor) to advance.
Timing retard
• The spool valve in the oil control valve moves towards timing retard in accordance with the
timing advance control signal from the engine-ECU.
4.0 ADVANTAGES/ DISADVANTAGES OF THE SYSTEM
MIVEC SYSTEM
ADVANTAGES DISADVANTAGES
Improved Fuel Efficiency Complexity
Enhanced Power Output Cost
Reduced Emissions Potential for Malfunctions
Versatility Dependency on ECU
Smoother Performance
5.0 YOUR OPINION ON THE TECHNOLOGY FOR THE NEAR FUTURE? ANY
IMPROVEMENT SHOULD BE DONE ON THE SELECTED TECHNOLOGY?
Improvement.
As we know, cylinder heads equipped with VVT systems like MIVEC contain numerous components,
making the head relatively heavy.
• Use lightweight of material .Example : alluminum alloy, or composites compound
• Optimized component design example. We smaller the component , maybe we can hollow the
camshaft, if we have the advance material to do it.
4G92 MIVEC HEAD
• As we can observe, the water passages in this cylinder head are limited, and improvements could
be made in the future by modifying the current water passage layout.
• We can improve thermal reaction in the system.
• In the motorsport industry, numerous improvements are made to standard cylinder heads to
achieve optimal fuel efficiency. One such improvement is the use of multi-angle valve seats.
• Advanced head work requires precision and accuracy to ensure optimal performance and
efficiency.
6.0 REFRENCE
Wikipedia contributors. (n.d.). MIVEC. In Wikipedia. Retrieved January 16, 2025, from
https://en.wikipedia.org/wiki/MIVEC
Mitsubishi Motors Corporation. (n.d.). History of Mitsubishi Motors. Retrieved January 16, 2025, from
https://www.mitsubishimotors.com/en/company/history/company/
Motor Authority. (2011, November 28). MIVEC tech, stop-start for better MPG in new Mitsubishis.
Retrieved January 16, 2025, from https://www.motorauthority.com/news/1067607_mivec-tech-stop-
start-for-better-mpg-in-new-mitsubishis
Glean's Garage. (2019, December). Mitsubishi MIVEC: How it works. Retrieved January 16, 2025,
from https://www.gleansgarage.com/2019/12/mitsubishi-mivec-how-it-works/
MIVEC (Mitsubishi Innovative Valve Timing Electronic Control system) <135 engine> (n.d.).
http://mmc-
manuals.ru/manuals/colt/online/Service_Manual/2009/13/html/M213202350020100ENG.HTM
