Hyundai Tau engine
In series Tau is an eight-cylinder petrol engine with four-time overhead camshaft ( QOHC ) and four valves per cylinder. The engines are built in Ulsan ( South Korea).
The engine block and cylinder head are made of aluminum. The 4.6 -liter edition opens the series with a bore of 92 mm and a stroke of 87 mm. The 5.0 L version was expanded to 96 mm. Weights have not yet been published. The idle speed is 550 rpm, the 4.6 L engine it rises in park and idle position of the automatic to 700, the series Tau is the only one not offered in Europe, all others at least were built in part of Europe.
All motors of tau series are controlled via an electronic accelerator.
The power is transmitted from the crankshaft to the cylinder head by means of maintenance-free timing chain, the ancillaries are driven by a toothed belt. For this is an inspection of all 30,000 km provided an exchange only when necessary.
The valves are actuated via roller cam followers, which act like a seesaw. At the apex of the cam is located on. During his turn he expresses a page and allow the valve down while there is always aligned on the other by means of built-in spring, stretching lash adjusters. This form of the lash adjuster is maintenance-free, self- inspection is not provided in the maintenance schedule. An Erosion would notify by a ticking sound. This occurs even in wintry cold start for about a minute until the oil in the hydraulic tappets reached the necessary viscosity to compensate for the game. In versions with 344 and 375 PS can also be a cause of ignition failure noise (cf. ).
Dew
The first eight-cylinder engine exclusively Korean development in 2008 was presented with the 4.6L Tau. In the same year followed by a 5.0 L version of the long version of the luxury sedan Hyundai Equus. 2010, both received a performance boost, the details of which are described below. The five-year development of the series cost 260 million U.S. dollars and ended shortly before the economic crisis. Given the simultaneous trend towards smaller displacements as well as the manufacturers aim to achieve the lowest average consumption in the U.S. market until 2025, was dispensed with the potential of the series to larger displacements. About five liters of displacement, the output increase would differ largely from linear to more consumption. General Motors and Ford announced in the dew premiere of her departure from V8 series. 2009 and 2010, the Tau V8 was included in the list " Ward's 10 Best Engines ". Ward 's Auto World is appearing since 1924 trade publication for the auto trade.
In the late 1990s there was with the Omega V8 already one developed by Mitsubishi V8 cast iron engine in the Hyundai Equus. He had gasoline direct injection ( GDI), but required premium gasoline because of their typically high compression system. This was then 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 flagship Equus.
Tau engines feature dual CVVT named camshaft adjustment for the intake and exhaust sides. This has an influence on the timing of the valve opening from both sides, but not on the valve and thus the opening period. It is therefore comparable to the BMW Double Vanos technology. In addition to better torque in the lower speed range, it reduces mainly nitric oxide levels by the exhaust back leading effect is used a large overlap - this ejected gas is already sucked back into the combustion chamber.
The opening of the valves is done friktionsreduziert via roller cam followers with hydraulic valve clearance compensation. This keeps the valve clearance permanently to zero, thus avoiding tick noise. For this, however, more attention on oil quality and was in contrast to mechanical tappets. Is the lash partially filled about by low oil level with air, he does not fulfill his game balancing effect and it comes to tick noise. The combination of hydraulic tappets with roller cam is the friction poorest and most costly in the form of preparation of the valve actuator. It was taken in the also appeared in 2008 Kappa series and is the only one for Hyundai / KIA does not provide more inspections and underlines their maintenance.
The series features a variable intake system (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 these under and over pressure pulses a rhythm adapted their way into the engine compartment, there is a light resonance charging effect, similar to a turbocharger. To achieve it opens at low and high speeds suitable for this purpose, short air. At medium speeds, the longer air guide is used by means of a flap, resulting in consistently high torque.
The 90 ° V- orientation of the two four-cylinder banks has the advantage of the full compensation of inertial forces first and second order, since moves on the opposite bank always opposite a cylinder for just ignited. The result is a very smooth engine operation and the saving thus an unnecessary balance shaft.
For this, however, the crankshaft must have a cross -plane design. In this, the diagonally opposite the connecting rod move simultaneously. But this has the undesirable side effect of the non- alternating between left and right bank firing. This irregularity is then found in the air turbulence in the intake again, the must therefore be given special attention in its design. Hyundai / KIA therefore mentions the " dozens " in hand molded prototypes during the development of the intake manifold. Thus, the otherwise uneven cylinder filling could be balanced, recognizable remains the cross -plane shape at the acoustically distinctive exhaust noise. The lighter, cheaper, alternately brilliant flat -plane design would in turn generate stronger vibration caused by free inertial forces of the second order. Here is the direct opposite connecting rods move in opposite directions, but this in an inner and outer pair simultaneously, rather than in four individual shades ( see last paragraph, see picture on the right, and animation).
The flask was reduced with a MoS ² friction coating, as it affects the chromium nitride coating on the piston rings. The T5 - pressure die-casting of the cylinder block produces a more uniform expansion, which minimizes friction.
In mid-2010 there was a performance enhancing revision. Here, the valves were enlarged, which allows for faster inflow of air - especially at higher speeds, a performance-enhancing effect. In addition, the air flow in variable intake system was optimized.
Consumption is classified in the practical North American EPA rating with 13.8 to 15.7 l in the city and 9.4 to 12 l/100 km on highway driving, ascending by limousine to four-wheel drive SUV.
Problems
A short Umparken when cold and freezing temperatures, the oil pump builds not always be a sufficient pressure to open the valve of the timing chain tensioner. Then, the chain may slip and adjusts the ignition of the engine. This can lead to gasoline residues in the cylinder. The next time you start this very cause uneven running at partial black smoke from the exhaust. Hyundai updated in November 2010, the control software of the engine, in some engines, the behavior repeated, however. In this case the controller error codes P0300 ( general ignition fault ) or P0301 to P0308 ( ignition failure in cylinder 1 to 8 ) are stored. Driver recommend a " warm-up " for 30 seconds before and after the Umparken in freezing temperatures, to the increased idle speed drops. Affected are 4.6 L engines prior to model year 2011 ( Hyundai Genesis with 375 hp and KIA Borrego with 344 hp, Hyundai Equus were exported only from the 2011 model year ). After individual assessment, the manufacturer replaced the timing chain tensioner, where damage has occurred the whole engine. All repairs are covered by the five - to ten-year drive warranty in the markets it serves.
Tau GDI
In early 2011 the 5.0 L engine was equipped with a direct injection GDI named. At the same time all vehicles with Tau engine a Hyundai - own 8- speed automatic transmission instead of the 6 -stage variant of ZF Sachs Their increased efficiency is rather low, as the Genesis with a pint were reduced highway fuel consumption according to EPA standards shows. Their advantage lies in technical independence, faster acceleration and nominal disruption to the competition. For 2014, Hyundai is planning a 10 -stage variant. The new GDI engine was added in 2011 " 10 Best Engines Ward's " list like its predecessor in 2009 and '10 in the. Ward 's Auto World is appearing since 1924 trade publication for the auto trade. One reason for the decision was the highest horsepower per liter of displacement not charged V8. The development over 40 months cost 10.5 million euros
In the conventional injection for gasoline engines, the fuel injector is located in the intake manifold before the inlet valve. With increasing speeds, however, the opening time of the valve is getting shorter, and thus the time window for the introduction of the fuel. In the direct injection is therefore injected directly into the cylinder. Hyundai used like most competitors GDI for homogeneous, stoichiometric mixture formation and waives an inhomogeneous stratified ( stratified fuel charge). The latter is associated with systemic disadvantages, such as significantly increased particulate matter levels.
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, cooling as it is directly taking place in the cylinder fueling the Kompresssionsrate in the cylinder could be increased from 10.4 to 11.5. This leads to a fuel saving of around five per cent (see ) and also results in a higher exhaust temperature. Of these, the faster heated catalyst 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.
The consumption is rated at 14.7 in the city and 9.4 l/100 km on highway driving in the practical North American EPA rating. It is thus hardly above the 4.6 L model without GDI.
Data
Use
Listed are the world's built Tau engines for each model, not in every country all listed configurations are offered.
- Equus VI G8BA: 2008-2011
- G8BE: 2011 -present
- Genesis BH G8BA: 2008 -present
- G8BE: 2011 -present
- Borrego HM G8BA: 2008-2011 ( V8 option only in Canada and USA, vehicle was not accepted by the U.S. market and the distribution set there in 2009 )