Hyundai Theta engine

Theta is the name of a series before four-cylinder gasoline engine with two overhead camshafts and four valves per cylinder. The engines are in Asan (South Korea), as well as from Theta II in Montgomery ( Alabama), Shandong (China) and Hwaseong (South Korea ), built the development site of the theta series.

The theta series comes from the Global Engine Manufacturing Alliance and replaces the 1995 released beta engine series since 2005. The motors are built with displacements from 1.8 to 2.4 l and independently adjusted by the individual manufacturers in the areas of cost, noise and performance. For example, have the Chrysler editions since 2004, an adjustment of both camshafts ( D- CVVT ), Hyundai / KIA that the outlet was only in 2008 submitted with the Theta II series. Chrysler in turn uses an indirect air quantities measured MAP sensor, while the theta - series integrates a direct measurement, thermal MAF sensor. The development of the engine block was mainly in charge of Hyundai, the CVVT those of Chrysler, which appeared in this Mercedes -Benz V6 engines 2003 Implementation related as a basis. The rights to the individual technologies have each contributor Company, 2009 bought Chrysler still all shares of founded in 2002 developing society GEMA.

The engine block and cylinder head are in contrast to the previous beta, both made ​​of aluminum. The 2.0 -liter edition ( 134 kg, 124 kg Theta II ) has a "square engine" cylinder shape: Bore and stroke are 86 mm equal. The 2,4- L- variant has a bore of 88 mm and a stroke of 97 mm. This variant without direct predecessor weighs 146 kilograms ( Theta II 136 kg ), only two more than the 2.0L Beta version. Unlike the previous series, the engines have been added to a balance shaft for the mass balance. This reduces energy losses in the digit horsepower range and the resulting noise. As the series has about two liters of displacement, compensation is deemed necessary.

While in the Theta - line only the largest variation is controlled by an electronic accelerator pedal, this is standard on Theta II. The idle speed is 650 rpm.

The inlet and exhaust camshafts are connected by a timing chain, which is driven by a second of the crankshaft. Thus, the motors do not require regular replacement of the timing belt as in the predecessor.

The valves are mechanical tappets without resting platelets (hence " shimless mechanical bucket tappets " ) operated. They are lighter and cheaper than hydraulic tappets and less dependent on good oil viscosity. The wear surfaces of the plunger and cam, thus making the valve clearance is greater and it can be an audible ticking sound occur (see ) because the cam hits something jerky on the tappets - the harder volume produces the ticking sound. This may disappear by the expansion in the engine is warm, yet the valve clearance has thus become large. Its test is provided in the maintenance schedule of all 95,000 kilometers, a maintenance but only when necessary. In this the removed material would be offset by a new, slightly longer tappets. The exchange may possibly be merged with the spark plugs ( 160,000 km ).

Theta

The engine block has "siamese " cylinders, which means that the cylinders are cast together and are not completely washed by cooling water. In addition, they are reinforced by a cast-in lead frame at the bottom of the engine block. Both minimizes distortion and vibration. The better thermal conductivity of aluminum leads also to more rapid achievement of operating temperature and reduced friction by unevenly extended cylinder.

This design is good for high pressures prepared, as they occur in turbocharged and direct injection engines. It was therefore taken in 2006 with the exception of the " Siamese " cylinders for the gamma range. Both series received since 2009 supercharged versions and those with direct injection.

Each theta motor has a CVVT ( continuous variable valve timing is ) called camshaft adjustment for the intake side. This only affects the overlapping of the valve opening of inlet and outlet side ( the opening timing at the input side is variable ), but not on the valve lift and the opening duration. It is therefore comparable to the BMW single Vanos technology. It causes a higher torque at low speeds and reduces especially the emissions of nitrogen oxides by the action of exhaust gas recirculation is used leading to a large overlap - in this case the discharged exhaust gas is already sucked back into the combustion chamber. The CVVT is supplied by BorgWarner TEC and not always listed because it is standard..

The motor controller accepts the software EMS - II from Siemens VDO.

The average per capita real consumption of the series is 9.5 l/100 km.

Theta II

Mercedes put the " world engines " of 2004 not in its own products a, asked 2008 but at around a common development. However, Hyundai did not accept this offer. In the same year, the group released the revision of its " World Engine " series Theta.

Theta - II engines have a variable intake manifold (Variable Intake System). This takes account of the pulsation of the air in the intake pipe, which is formed by the opening and closing of the valves. Find the wave a rhythm adapted their way into the cylinder, creating a resonant charging effect. These open at low and high speeds suitable for this purpose, short air. At intermediate speeds a flap closes and out the air through a long tube.

The exhaust was a CVVT control and is thus similar to the BMW Double Vanos. The now D (ual ) - CVVT named system contributes to improved performance.

The contact surfaces of the tappets have been coated with a diamond-like carbon coating to reduce friction.

The average per capita real consumption of the series is 9.8 l/100 km for SUVs and 9.2 l for sedans.

Theta II Turbo

2009, a turbocharged version of the 2.0 L was for the Hyundai Genesis Coupe - Theta II developed. The turbocharger used is a Mitsubishi TD0. Depending on the octane fueled performance is increased to 210 ( 91 ) or 223 hp ( 95 octane ). These levels correspond to the levels of quality American " Regular" ( AKI 87) and "Premium" ( AKI 93).

As in the later Theta II turbo GDI exhaust manifold with temperatures up to 950 ° C for 200 ° C. Higher temperatures interpreted as the theta variants without a turbocharger. This eliminates the need for a fuel- enhancing, but also cooling enrichment of the mixture. The cylinder heads are compact designed and introduced two new features to enhance performance, the later use in the GDI variant found: The piston pin is not fixed but flexible (full-floating ) stored, which reduces its friction on the cylinder. And at the cylinder bottom a fine oil mist is sprayed, the cooling effect allowing higher speeds and pressures. Motor vehicle and are available in Europe since November 2010.

Theta II GDI

After four years of development in Hwaseong (South Korea) and 100 million euros in development costs appeared with the Theta II GDI 2.4 L in November 2009, the first Hyundai / Kia fuel injection. In the late 1990s there was with the Omega V8 already one developed by Mitsubishi GDI engine in the Hyundai Equus, which required for its system typically high compression super gasoline. This was then, however, rare in South Korea. The resulting performance degradation allowed the customers complain. Hyundai responded in 2002 with the switch to manifold injection, while Mitsubishi even the use of the motor asia due to the crisis after 15 months again had to stop. Despite these initial difficulties Hyundai made ​​it in collaboration with Mitsubishi until 2008 for its top model.

In the intake manifold injection for gasoline engines, the injection valve is in the suction pipe upstream of the inlet valve. In the direct injection is injected directly into the cylinder. The Einspitzventil is exposed to the high pressures and temperatures in the cylinder. Hyundai used like most competitors GDI for homogeneous, stoichiometric mixture formation and waives an inhomogeneous stratified ( stratified fuel charge). Stratified charge engines have some disadvantages, such as a higher particulate emissions.

Is initiated with a pilot injection and ignition to move the piston in motion. While downward movement of the thrust -imparting, actual fuel injection and ignition follows. Through this more precise, as it is directly taking place in the cylinder fueling the Kompresssionsrate could be increased to 1 in the cylinder of 10.5 to 11.3. It leads to an approximately five percent fuel savings (see ) and also results in a higher exhaust temperature. Of these, the faster heated catalyst which can thus reduce the emissions during the cold start phase by one-third benefited. The higher injection pressure of 150 bar (without GDI about 5 bar ) also causes a more homogeneous fuel atomization and thus a cleaner combustion. He is accompanied by a typical system tick noise (see video at 4:00 ).

Several friction-reducing modifications have been made also to enable the higher compression abrasive. While the contact surfaces of the valve lifter was covered with a diamond-like carbon layer since the theta II series, it is supported in the GDI of a chromium nitride coating of the piston rings. As in the Theta II turbocharged piston pin is also not fixed, but flexible (full-floating ) stored, which reduces friction and increases the pressure resistance by 30%. Directly on the piston crown a fine oil mist is sprayed, the cooling effect allowing higher pressures.

The manifold (Variable Intake System ) has been extended by one notch to three.

The adjustable camshafts are driven by a newly developed, quieter and more durable steel chain. Furthermore, the engine block, crankshaft and catalyst are easier, and the latter by the use of five instead of eight counterweights. Overall, the engine now weighs five kilograms less than the non- variant GDI. He will consume 10% less. This is not directly verifiable because it still does not replace normal Theta II.

Theta II Turbo GDI

A combination of turbo and GDI was introduced at the New York Auto Show 2010. Similar to Volkswagen in 2005, the introduction is first with a 2.0 L model, and thus in performance-oriented segment.

The characteristic feature of this engine is its twin-scroll turbocharger, which almost completely separates the exhaust of each cylinder from each other. Homogenize turbulence attributable to exhaust gas flow, the so more energy to drive the turbine. The same design has about the 1.6 - liter turbo engine of the BMW Mini and Citroen DS3.

As always draws a cylinder air while another exhaust discharges, where the air currents can slow each other. This happens even if the ejecting cylinder an inlet valve is opened ( valve overlap ) so as to suck out through the accelerated exhaust gas more fresh air. At this time, but already begins with the ejection of the other cylinder, the exhaust gas pushes on a common exhaust gas channel in the former and the discharge slows. In addition, reduced exhaust pressure from the turbine needed, however. This can usually be counteracted only by the shortest possible valve overlap. However, the associated lack of suction of the exhaust gas reduces the incoming fresh air volume and as a result the performance due to less combustible oxygen. The separation of the exhaust paths in two air ducts on the other hand allows a longer valve overlap with sogsteigernder effect. At the same time, the exhaust pressure is maintained.

After testing about 30 turbochargers, Hyundai opted for a modification of the Mitsubishi TD04 - 19T, the turbine blade number was reduced from 12 to 11 in order to achieve a faster response. The exhaust manifold it previously contained housing the twin-scroll turbine and as a component of austenitic steel and cast supplied by BorgWarner. It is designed for exhaust gas temperatures up to 950 ° C. Together with the reinforced valve ( seat ) s in the engine block, and brought in by the cooling effects of the direct injection GDI and sprayed oil mist can be dispensed with a consumption- enhancing, but also cooling enrichment of the mixture. The pressure relief valve ( wastegate ) is controlled electronically, which enables precise control over mechanical pressure build-up as to avoid the " turbo lag ". To reduce emissions, it is open during the cold start phase. Thus, the exhaust back pressure, and the catalyst is heated decreases faster. The same pressure reduction is lowering consumption used in the part-load phases without turbo assistance. For an additional pressure reducing effect, the catalyst placement far behind the turbocharger. This favors the power delivery with niederoktanigem regular gasoline, which used to auto-ignition tendency at high pressure ( cf. knock resistance ).

The apparently very low compression ratio of 9.5 to 1 is common in turbo Motorn. The 137 hp per liter of displacement are almost twice much as the values ​​of the first theta generation in 2004, the potential of the then designed basic design with highly pressure -resistant cylinders are used. In the North American market have the motor to launch more power than any V6 offerings and offering the consumption of all four-cylinder of the middle class.

Theta II HEV

The first in-house hybrid drive for compact vehicles followed in January 2011, a Theta - II -based for greater Hybrid Electric Vehicles. Use it takes place in two flow-optimized mid-size sedan. Conceptually, it retains the principle of the first system, leading it from mild to full hybrid, which means that the vehicle can also be driven purely electrically. According to the manufacturer, this applies to almost 100 km / h requires a considerable skill in daily life but for the necessary, gently accelerating. The fastest possible acceleration takes 9.2 seconds to 100 km / h

To reach the vehicle price of 25.795 U.S. dollars, the electric (40 hp) gasoline engine ( 169 hp ) back to work in parallel, which is the hybrid of minimal complexity and thus also minimizes the weight. Here, both motors can drive the wheels - if necessary, at the same time, so parallel. A serial system, however, directs the petrol engine power in the battery. From here you will then receive only the electric motor, the sole responsibility of the drive to the wheels - the petrol engine is so arranged " in series " with the electric motor in series or. The disadvantage is that when saving and retrieving the battery power conversion surplus energy is lost. The Toyota Hybrid Synergy Drive therefore combines both arrangements. Thus, the gasoline engine, in addition to driving the wheels at the same time charging the battery. The operating states to work out where it acts to increase efficiency but requires considerably more development time and complexity in the control of each produced vehicle. When forced Sporty driving in town, however, the Toyota system used by three liters less per 100 km than the Theta II HEV with 12 liters. The consumption in normal city driving is in the practical North American EPA rating for both between six and seven liters. Here, the Sonata Hybrid uses four liters of pure gasoline version.

Petrol and electric motor of the Theta II HEV are connected to a six- speed automatic transmission. This save approximately 600 dollars and resembles the acoustic to a conventional automatic vehicle to - in contrast to the continuous speed of a CVT transmission of the Hybrid Synergy Drive from Toyota. Only the Honda Accord hybrid had earlier this combination, new is the Hyundai / KIA system that does not require the automatic fuel- enhancing torque converter. In its place, a coupling is attached. With it, the gasoline engine can be uncoupled from the electric motor as in a manual transmission. This saves the electric motor driving a planetary gear a coupled permanently (Toyota) or the torque converter. This is to act effektivierend when driving at a constant speed and leads with 5.9 l/100 km actually a highway consumption below the other Sonata engines ( 6.7 liter ) and the middle-class hybrids Toyota Camry Hybrid ( 6.9 l ) and Ford Fusion Hybrid (6.5 l). The divergence for pure Theta petrol version is equipped with 0.7 l over long distances but small.

To reduce costs, they decided on a normal Theta II engine and thus against a direct injection. But has been modified, the opening duration of the intake valve, the engine is now operating in the hybrid typical Atkinson cycle. In this case, in the compression stroke the intake valve is closed late, so that the piston pushes a third of the intake air back into the intake system. The mixture remaining amount in the cylinder is now less energy and thus reduces the power to the level of a small motor, in this case of a 2L -theta II The advantage is now in the following ignition cycle. The larger 2.4 - liter engine offers a longer piston stroke ( here 11 mm ) so that the amount of fuel can put their energy into thrust more than in kurzhubigeren 2-liter engine. Therefore, the Atkinson cycle is more efficient, lower power is like an electric motor more than made up. The seemingly high compression ratio of 13:1 arises only from their basis of calculation, the ratio of total cylinder space and residual space after compression. The smaller amount of mixture fits into a much smaller residual space, but it is no longer compressed than in the normal Theta II

The gasoline engine as the Toyota system is started by a second, smaller electric motor (here " hybrid starter-generator " ), who works as a starter. Hybrid Typically this is about eight times as strong as the starter of a non-hybrid engine and therefore acoustically imperceptible. The coupling of the motor is slightly noticeable only at low speeds.

How the Chevrolet Volt also use Hyundai / KIA as early as 2009 a lithium- polymer battery for energy storage of the electric motor. It is supplied by LG Chemical. An advantage is its opposite lithium - ion batteries higher energy density at lower production costs, higher mechanical robustness and charging cycles. The manufacturer puts it on a shelf life of 10 years or 240,000 kilometers, which corresponds to the Hyundai - drive warranty in the USA. For him, the first owner even get a Lifetime Warranty, which is at the sale but was replaced by the 10-year standard and so affect only the smallest amounts of vehicle. Its capacity is 1.4 kWh at a voltage of 270 V. This is on par with the Prius, Camry and Ford Fusion batteries, but these are still manufactured in nickel -metal hydride technology. Also, by compact lithium -ion battery with 44 kg vehicle weight of 1550 kg, the lightest of all middle-class hybrids, and is 170 kg above that of the Toyota Prius and Auris HSD hybrid compact. In South Korea, the Theta II engine is replaced by a 150-hp 2.0 -liter Nu.

Data

Use

Listed are the world's built Theta engines for each model, not in every country all listed configurations are offered.

Hyundai ix35

• G4KJ: Autumn 2010 outside Europe

Hyundai Genesis Coupe

• Genesis Coupe BK G4KF: 2009-2012
• G4KH: from summer 2012

Hyundai Grandeur

• Grandeur TG G4KE: 2008-2010

• G4KJ: 2011 to present

Hyundai Sonata

• Sonata NF G4KA, G4KC: 2004-2008
• G4KD, G4KE: 2008-2010

• G4KD, G4KE: 2009 to present
• G4KJ, G4KH: 2010 to present outside Europe
• G4KK: 2011 until today in the U.S. and Canada

Hyundai Santa Fe

• Santa Fe CM G4KE: 2010 to present

Hyundai H-1

• H-1 TQ G4KG: 2008 to present (China)

KIA Carens

• Carens UN G4KA, G4KC: 2006 to 2009 in the U.S. and Canada
• G4KG: 2009 set up today in Canada, the USA 2010

KIA Forte

• Forte TD G4KD, G4KE: 2008 -present

KIA Magentis

• Magentis MG G4KA, G4KB, G4KC: 2005-2008
• G4KD, G4KE: 2008-2010

• G4KD: 2010 to present outside Europe
• G4KJ, G4KH: 2010 to present outside Europe
• G4KK: from the beginning of 2011 in the U.S. and Canada

KIA Sorento

• Sorento XM G4KE: 2009 to present

KIA Sportage

• Sportage SL G4KD, G4KE: 2010 to present
• G4KJ: 2011 to present outside Europe