|Hyundai’s Kappa engine. Click to enlarge.|
Hyundai has unveiled its newly-developed Kappa gasoline engine in two variants: a 1.2-liter version for India, and two 1.25-liter versions for Europe and the rest of the world. The first car to have the Kappa engine installed will be the i10, produced at Hyundai Motor Co.’s Indian subsidiary in Chennai. Hyundai will also apply the engine in its i20 A- and B-segment cars, with a Kappa-engined i20 to be revealed at the Paris auto show this fall.
Hyundai’s i10 minicar with a 1.25-liter Kappa engine carries a fuel economy rating of 5.0L/100km (47 mpg US) in the European combined test cycle, with CO2 emissions of 119 g/km. The Euro-4 compliant, inline four-cylinder engines produce 57-59 kW (76-79 hp) of power and torque of 112-118 Nm (82-87 lb-ft).
|Cutaway of the i10 with Kappa. Click to enlarge.|
Kappa adopts a number of weight- and friction-reducing technologies to achieve its fuel economy. The engine block is made from high pressure die-cast aluminum which results in considerable weight savings. At 82.4 kg (182 lbs) (1.2L engine with manual gearbox), Kappa is the lightest in its class among leading European and Japanese-made engines (using the same measuring criteria across the competitive set), according to Hyundai.
Kappa’s main block features a ladder frame construction for structural stiffness while its cylinders are fitted with cast-iron liners for improved abrasion durability. Additional weight was shaved off by integrating the engine support bracket with the timing chain cover.
|The offset crankshaft helps reduce side forces. Click to enlarge.|
According to Hyundai, the most significant engineering innovation applied in the Kappa is the offset crankshaft, an engineering concept first adopted in the Gamma engine introduced last year.
Unlike a conventional engine where the centerline of the cylinder bore is in perfect vertical alignment with the rotating axis of the crankshaft, the Kappa’s centerline is offset by a small distance. By creating this offset distance, engineers have succeeded in minimizing the side force created by the pistons. The net effect is an improvement in fuel consumption and a reduction in noise, vibration and harshness.
Engineers also devised an innovative piston concept to reduce piston mass. The shape of the piston skirt was optimized to reduce its size while the compression height of the piston was also reduced, resulting in weight savings. The optimized piston skirt is also treated with Molybdenum Disulfide (MoS2), a special anti-friction coating.
Physical Vapor Deposition (PVD) is used to apply an ultra-thin layer of chromium nitride (CrN) to the piston’s oil ring. CrN ensures high wear resistance and a low friction coefficient. CrN-coated piston rings using PVD is a technology borrowed from the Tau V8 engine that Hyundai introduced earlier this year.
Friction between the oil ring and cylinder wall has been further minimized by reducing the oil ring tension. The smaller mass and special surface treatment of the piston skirt and oil rings yielded additional savings in fuel consumption.
Kappa is the first Hyundai engine to be fitted with an accessory drive belt which does not require a mechanical auto-tensioning adjustment device, reducing the hardware and further lowering weight and cost. Because it is designed to maintain an ideal tension setting, the belt runs quieter and with proper preventative maintenance and care, the belt will last 100,000 miles.
Kappa uses a new, longer reach spark plug which enabled engineers to enlarge the size of the water jacket to promote more efficient engine cooling around the critically important spark plug and exhaust port area. Cooler operation also prevents engine knocking.
The long reach spark plug (M12 thread) also enabled engineers to enlarge the valve diameter for increased airflow and combustion efficiency.
Kappa’s valvetrain features a roller swing arm to lower friction in the valvetrain. Hydraulic lash adjusters ensure zero clearance between the valve stem and roller swing arm, eliminating valve tapping noise.
A new valve spring features an innovative beehive shape and smaller retainer. Its reduced weight and spring load help lower friction and improve fuel economy. Kappa’s valvetrain is driven by a silent-type steel timing chain that replaces a roller-type timing chain.
A lightweight, heat-resistant engineering plastic was specified for the intake manifold. This reduces cost and weight and yields an overall performance improvement.
Kappa is the eleventh in Hyundai’s series of gasoline engines. Annual output from the Chennai plant is forecast to reach 250,000 units per year. With the newly-constructed No. 2 Kappa engine plant, HMI will have a total engine manufacturing capacity of 570,000 units per year, including the existing 320,000 units-per-year No. 1 Epsilon and Alpha engine plant. The Kappa engine plant began production today (15 July).
Hyundai Motor India (HMI) launched the i10 in October 2007 and has sold 184,465 units as of the end of June, one of HMI’s best sellers.