Automotive

Hyundai announces "world's first" Continuously Variable Valve Duration engines

Hyundai announces "world's fir...
Hyundai/Kia have announced what they term the "world's first continuously variable valve duration" system
Hyundai/Kia have announced what they term the "world's first continuously variable valve duration" system
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The system appears to operate by moving the camshafts off center to effect a change
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The system appears to operate by moving the camshafts off center to effect a change
The technology appears to affect both valve opening and closing times, with the high point of the valve lift cycle staying put in the combustion cycle
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The technology appears to affect both valve opening and closing times, with the high point of the valve lift cycle staying put in the combustion cycle
An illustration of the CVVD system's anatomy
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An illustration of the CVVD system's anatomy
Hyundai/Kia have announced what they term the "world's first continuously variable valve duration" system
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Hyundai/Kia have announced what they term the "world's first continuously variable valve duration" system

Set to debut in a new 1.6-liter 4-cylinder Smartstream turbo engine, Hyundai's new valve tech is able to continuously change the duration of valve openings to suit driving conditions, which Hyundai says results in a 4 percent performance boost, 5 percent better fuel economy and 12 percent lower emissions.

Hyundai calls it the "world's first continuously variable valve duration (CVVD) technology," and says it differs from garden-variety variable valve timing systems because their valve closing timing is dependent on their opening timing. Instead, this system adjusts the length of time the valve is open, staying open longer at lower RPM and lower engine loads to improve efficiency by reducing compression resistance.

At higher RPMs and engine loads, the valves close quicker, at the beginning of the compression stroke, to maximize the amount of air in the cylinder when the spark ignites it and deliver extra torque and performance as a result.

The system appears only to operate on the intake valves, and calling it the "world's first" should raise the ire of companies like Camcon Automotive and Koeniggsegg's FreeValve, which use digitally-controlled valve actuation systems to precisely control not only the opening and closing times of each valve, but how much lift it's got as well – thus giving you full control over the valve duration and a bunch of other things besides.

The technology appears to affect both valve opening and closing times, with the high point of the valve lift cycle staying put in the combustion cycle
The technology appears to affect both valve opening and closing times, with the high point of the valve lift cycle staying put in the combustion cycle

Instead of this level of full control, the Hyundai Motor Group's solution appears to move the camshaft slightly off center to control the length of time the valve's open for, and this appears to affect both opening and closing timing, with the maximally open point staying at the same spot in the combustion cycle.

Hyundai and Kia will begin rolling the tech out on new cars soon, and has unveiled the first engine to feature CVVD tech, the Smartstream G1.6 T-GDi engine. It's a four-cylinder 1.6-liter turbo making 180 hp and 265 Nm (195 lb-ft) of torque. In addition to the valve tech, it'll also run low-pressure exhaust gas recirculation to help cool the combustion chambers and reduce nitrogen oxide emissions, and a thermal management system designed to quickly heat or cool the engine into its optimal temperature range.

We'll first see the Smartstream engine in the upcoming Hyundai Sonata Turbo, due to appear later in 2019. Check out a video of the valve tech below, which isn't massively informative, but is certainly very stylish, even if it does seem to imply that the engine lives in one of the wheel hubs.

Source: Hyundai Group

13 comments
Phil
its great that engineers rethink very old technology to improve it so that we can use a little less of our polluting fossil fuels. We need different choices not the same old stuff. Engineers need to be directed to use their ideas on different energy sources and motive engines, such as electric motors and batteries or hydrogen fuel cells etc. Auomotive industry in general, and the petrochem industry, need to make a radical right turn.
jerryd
An E motor is 98% efficient, doesn't waste energy when not needed and has a 2x as fat, flat from 0 to 12k rpm torque curve. Vs the pitiful polluting gasoline one! Which to chose?
Captain Danger
Jerryd Show me the specs an electric motor that has full torque from 0-12000 RPM. They may be out there but I doubt they are the size of anything remotely capable of powering a car - even a tiny Hydunai. I'll stick with my V8's Thank you very much
fen
@Jerryd, and how long would it take me to pull a boat on a trailer from Paris to Barcelona with that e motor? Its a very modest trip, 1000km, 9 and half hours in this hyundai.
Mr T
Captain Danger, your wonderful V8 is slower than most of the EVs on the market (EVs have more torque, like it or not), makes 3-4 times more pollution, even if the EVs run from mostly coal fired power, needs infinitely more engine maintenance (electric motors need none), and costs you thousands a year more to run. Think about it...
apprenticeearthwiz
Shades of the record breaking Mallard steam engine. Technological advancement right before the technology becomes redundant.
yawood
apprenticeearthwiz, ICE technology has a long way to go before it becomes redundant. It can't be made redundant until something better comes along. Hydrogen is promising but it looks like it could be another 50 years or so before batteries are good enough for electric cars (with battery storage) to become useful. My wife and I just drove 1200km home in 13 hours (including rest stops) from Port Macquarie to Melbourne in Australia and did it on one tank of diesel in our BMW. There are simply no electric cars that can do that.
SimonClarke
Some interesting comments and some woefully uneducated ones. Why spent so much time, money and effort on producing something that has no life expectancy, I like the Mallard reference. Forget Internal Combustion and forget Hydrogen, for cars and other small vehicles, Electric propulsion is here, and it is growing faster than anything like it in the past, get with it or get left behind.
amazed W1
Simon Clarke, how much lithium is there left in the world for all the batteries we would need for a completely electric future, in everything from houses to cars to I-phones? Until we find a material/technique for a transportable form of electricity storage as good, all round, as lithium, it would not be wise to scrap research into more efficient less polluting IC engines.
ljaques
Right you are, Loz. The question I have is how they got both right wheel hubs to become engines. Pretty neat tech, no matter.