Optimising ICE Efficiencies with CVVD Technology

Optimising ICE Efficiencies with CVVD Technology

Optimising ICE Efficiencies with CVVD Technology

The new Continuously Variable Valve Duration (CVVD) technology by Kia Motors indicates there is still much left with internal combustion engines and can't be written off for a cleaner tomorrow

Electric vehicles have been the talk of the town. As pollution problems continue to haunt the urban cities across the world, the automotive industry is desperately looking at options that can lead faster to a greener tomorrow. Industry experts believe electric vehicles can bring in a much-needed breath of fresh air, however, the existence of internal combustion engines can't be ruled out overnight and continue to optimise capacities of the traditional mobility expert.

Kia Motors recently-introduced Continuously Variable Valve Duration (CVVD) technology on its latest offering G1.6 T-GDi engine, the new four-cylinder in-line gasoline turbo unit that puts out 180 Ps power and 265 Nm torque. The new Smartstream engine features the CVVD technology that has been developed Kia Motor's Parent company Hyundai Motor Group. The company aims to optimise engine performance by four percent and increase fuel efficiency by five percent, while reducing emissions by a massive 12 % even for mass production engines. The engine also features Low-Pressure Exhaust Gas Recirculation (LP EGR) for enhanced fuel efficiency. 

Internal combustion engines have been largely governed by variable valve control technology (VVT) in which the engine power is generated via fuel intake-compression-expansion-exhaustion cycle. In this, VVT regulates the timing of both opening and closing operations (Continuously Variable Valve Timing – CVVT) and control the air volume intake by managing the depth of valve opening (Continuously Variable Valve Lift – CVVL). However, the variable valve control technologies could not act as per varied driving situations since the valve's closing timing was subordinate to opening timing only and not designed to work with valve duration regulation. 

The CVVD technology works on improved timing for valve opening and closing as per the driving conditions to enhance ICE's performance. According to Kia Motors, CVVD undertakes intake valve operation starting from middle to the end of compression stroke even when the vehicle requires low engine output during constant speeds, which leads to reduced resistance caused by compression thereby leading to fuel efficiency. Even when the vehicle is undertaking high speeds, the intake valve is shut at the start of the compression stroke leading to maximised amount of air being used for combustion, thus leading to enhanced torque for quicker acceleration. 

A part of hot gases exhaled by the engine are returned back to the combustion chamber by the Low-Pressure Exhaust Gas Recirculation system, which leads to reduction in nitrogen oxide emissions. The system redirects a part of hot gases to the front of turbocharger compressor rather than intake system that enhances efficiency during high loads. 

The new Smartstream system also has been deployed with Integrated Thermal Management System that controls engine temperature at optimal levels along with a strong direct spray system that achieves 350 bar or pressure. The system has also been engineered with low-friction moving parts that combines with technologies to reduce engine friction by a whopping 34 %. 

Hyundai claims to deploy the new Smartstream G1.6 T-GDi engine on one of its upcoming Kia models that the company will launch in H2 2019. Although electric vehicle sales are gradually picking up across the world, the CVVD technology introduction move certainly indicates that there is still much left in the optimisation of internal combustion engines and can't be written off while we march ahead for a cleaner tomorrow. 


Anirudh Raheja
Author: Anirudh Raheja
A technology lover by passion, and an automobile journalist by profession. Anirudh has been networking extensively with key industry stakeholders to understand the diversity of automotive industry and keeps himself abreast with the industry developments. He is always keen to learn new things and skills that keep him 'Committed, Resourceful and Motivated'. He tweets @itsme_anirudh