South Korean automobile giant Hyundai has been developing the world’s first Continuously variably Valve Duration (CVVD) and the brand has revealed the technology at Hyundai Motorstudio in Goyang. The technology is likely to feature on Hyundai and Kia cars in the future and the brand’s Smartstream G1.6 T-GDi is likely to be the first engine to feature this technology.
The new Valve-train technology is unlike any other in the industry and conventionally in a four-stroke engine with variable valve technology the Continuously Variable Valve Timing (CVVT) or the Continuously Variable Valve Lift (CVVL) technology can only control the valve opening and the depth of the valve, the closing is secondary to the opening and is not controlled. Continuously Variable Valve Duration (CVVD) technology can control the duration, how long a valve is kept open, depending on the engine demand.
For Example, when demand of power is high on the engine, during acceleration and high-speed driving the intake valve is closed at the beginning of the compression stroke which allows maximum compression that can provide the best torque output in that range and the engine performance is improved by a claimed 4%. When the engine is under less load and at a constant speed the CVVD system opens the intake valve from the middle to end of the compression stroke which reduces compression load and thus the resistance developed on the engine is reduced, improving fuel efficiency to around 5%.
The CVVD technology will be equipped on the new V-4 turbocharged petrol, Smartstream G1.6 T-GDi engine which can produce 180 HP of power and 265 Nm of torque. The engine will also boast the brand’s Low-Pressure Exhaust Gas Recirculation (LP EGR), which recirculates some of the exhaust gasses back in the combustion chamber which reduces the temperatures and thus helps in the NOx emission reduction, the brand claims emission reduction of upto 12% with the new CVVD valve train. The LP EGR system recirculates the exhaust gasses to the front of the turbocharger to increase efficiency under high engine load.
The new Smartstream G1.6 T-GDi motor employs a new 350bar high-pressure direct injection system which is much more powerful than the older T-GDi engine with the 250bar system and the new Integrated Thermal Management System quickly heats or cools the engine to optimal temperatures.
The new Smartstream G1.6 TGDi engine with CVVD technology is expected to be employed on the upcoming Hyundai Sonata Turbo.