Future KIA Motors vehicles will feature world-first Continuously
Variable Valve Duration (CVVD) engine technology. The innovation has been
developed by Hyundai Motor Group, KIA’s parent company, and was revealed
alongside the company’s new Smartstream G1.6 T-GDi engine – the first power
unit to feature the technology.
CVVD optimises both engine performance and fuel efficiency while
also being eco-friendly. The valve control technology regulates the duration of
valve opening and closing according to driving conditions, achieving a 4% boost
in performance and a 5% improvement in fuel efficiency. Furthermore, the
technology cuts emissions by 12%.
“The development of the CVVD technology is a good example how
Hyundai Motor Group is strengthening our powertrain technology,” said Albert
Biermann, President and Head of Research and Development Division at Hyundai
Motor Group. “We will continue our innovation efforts to bring forth paradigm
shifts and ensure sustainability of our business model.”
Innovation: Continuously Variable
Valve Duration
Until now, an internal combustion engine’s performance and
efficiency have been governed by variable valve control technology that adjusts
the timing of valve opening and closing and depth of the valve’s opening.
Eengine power is produced through the fuel
intake-compression-expansion-exhaustion cycle.
Typical variable valve control technologies manage the timing of
the valve’s opening and closing (as in Continuously Variable Valve Timing –
CVVT) or control the volume of air admitted by adjusting the depth of the
opening (Continuously Variable Valve Lift – CVVL). Previous variable valve
control technologies could not regulate valve duration, as the valve’s closing
timing was subordinate to opening timing and could not respond to diverse
driving situations. CVVD takes the technology in a new direction by adjusting
the length of time that a valve stays open.
When the vehicle maintains a constant speed and requires low
engine output, CVVD opens the intake valve from the middle to end of the
compression stroke. This helps to improve fuel efficiency by reducing the
resistance caused by compression. On the other hand, when engine output is
high, such as when the car is driving at a high speed, the intake valve is
closed at the beginning of the compression stroke to maximise the amount of air
used for the explosion, enhancing torque to improve acceleration.
Smartstream G1.6 T-GDi Engine
Unveiled alongside the new CVVD technology is KIA’s new
Smartstream G1.6 T-GDi engine, a four-cylinder in-line gasoline turbo unit
producing 180 ps and 265 Nm torque. The new powertrain is the first to utilise
the new CVVD technology and also features Low-Pressure Exhaust Gas
Recirculation (LP EGR) to further optimise fuel efficiency.
The exhaust gas recirculation system returns some of the hot
gases produced by the engine to the combustion chamber, producing a cooling
effect and reducing the emission of nitrogen oxides. The G1.6 T-GDi also
features a low-pressure system that redirects the burnt emission gas to the
front of the turbocharger compressor, rather than the intake system, to
increase efficiency under high load conditions.
Additionally, the new unit has an Integrated Thermal Management System that quickly heats or cools the engine to an optimal temperature, and a strong direct spray system that achieves 350 bar or pressure, surpassing the 250 bar of KIA’s existing T-GDi engine. In addition, engine friction is reduced by 34% with the application of low-friction moving parts.
The new Smartstream G1.6 T-GDi engine will be applied to a variety of future KIA vehicles. See video on the new engine technology at the following link: https://youtu.be/5atYksEpAm8
