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Kia’s new 1.0-liter turbocharged three-cylinder ‘Kappa’ engine


Kia’s all-new 1.0-liter T-GDI (turbo gasoline direct injection) ‘Kappa’ engine will make its world production debut at the 85th Salon International de l’Automobile in Geneva on 3 March 2015. Previewed by Kia in a special powertrain technology exhibition at Geneva in 2013, the new downsized engine is now fitted in a production model for the first time – the new Kia cee’d GT Line.

Kia’s new 1.0-liter turbocharged three-cylinder ‘Kappa’ engine

World production debut – the new Kia cee’d GT Line

The first car to benefit from Kia’s new 1.0-liter T-GDI engine will be the new cee’d GT Line range. In this application, the new Kappa engine will develop 118 hp and 172 Nm torque, and has been engineered to deliver lower CO2 emissions than the 1.6-liter GDI engine found in other cee’d models, pending homologation closer to the GT Line’s launch later in the year.

After the cee’d GT Line, which goes on sale across Europe in Q4 2015, the new 1.0-litre T-GDI engine will be made available on a range of other Kia models in future.

Sustainable engine downsizing strategy

The new power unit is the first of Kia’s upcoming range of downsized engines to make its debut in Europe, and has been developed in-house by Kia’s powertrain development team at its Namyang, Korea R&D center.

Engineers’ key aims throughout development were to provide immediate engine response, highly-efficient combustion and access to maximum torque from low engine speeds.

Throughout the T-GDI’s development, Kia’s R&D teams have aimed for a 10 to 15 per cent improvement in fuel efficiency compared to the brand’s current 1.6-liter GDI engine.

High pressure fuel injection and improved air flow

The new downsized engine features a newly-developed laser-drilled injector, with six individual holes. Instead of consistently injecting the fuel-air mixture onto certain points within the combustion chamber, the laser-drilled holes, laid out in a pyramid shape, provide a more even spread of fuel and air throughout the cylinder. Backed by a high pressure pump, the new laser-drilled injectors are able to provide fuel injection pressure of up to 200 bars.

The adoption of a straight air intake port – instead of the gently curved port in Kia’s existing 1.6-litre GDI engine – improves air flow to the combustion chamber for improved fuel efficiency. The straight air intake port ends in a sharper air intake throat, reducing air resistance at all stages of air intake to the engine, improving cylinder tumble flow for faster, more efficient combustion and reducing engine knocking.

Single-scroll turbocharger with electric scavenging motor

The T-GDI’s single-scroll turbocharger is paired with an electric waste-gate motor, which improves the turbocharger’s performance. As well as scavenging clean air for the engine to re-use for combustion, it is able to open the waste-gate at the same time to improve waste air flow.

In the Kia cee’d GT Line, the engine’s maximum 172 Nm torque is available across a wide 1,500-4,100 rpm range, with maximum power arriving at 6,000 rpm.

Lower exhaust gas temperatures and split cooling

The engine is also fitted with an integrated exhaust manifold, which lowers the exhaust gas temperature slightly. The engine’s temperature is regulated with the adoption of a new dual-thermostat split cooling system. This allows the engine block and cylinder heads to be cooled independent of one another, the main thermostat controlling the flow of engine coolant to cylinder heads above 88°C to reduce knocking, and an engine block thermostat shutting off coolant flow above 105°C to reduce mechanical friction and aid efficiency.

Source: Kia
Romain’s opinion:
It is pleasant to see that gasoline engines are integrating more and more technologies. The focus during the last 20 years was put on diesel (at least in Europe) but since 5 years, the technology development focus is switching to gasoline. I’m convinced that in ten years, the gasoline engines will compete with equivalent diesel engines in terms of fuel economy. Do you think that the diesel/gasoline mix will reach a tipping point in a near future?

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