Hyundai KIA dew
| Hyundai KIA | |
|---|---|
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| dew | |
| Manufacturer: | Hyundai Kia Automotive Group |
| Production period: | 2008-present |
| Design: | 90 ° V |
| Engines: | 4.6 L (4627 cm³), 5.0 L (5038 cm³) |
| Cylinder firing order: | 1-2-7-8-4-5-6-3 |
| Previous model: | none |
| Successor: | none |
| Similar models: | none |
The Tau series is an eight-cylinder petrol engine with a four-fold 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 range with a bore of 92 mm and a stroke of 87 mm. The 5.0 L variant has been expanded to 96 mm. Weights have not yet been published. The idle speed is 550 revolutions per minute, with the 4.6 L engine it increases to 700 in park and idle position of the automatic. The Tau series is the only one not offered in Europe, all others were installed at least in part for Europe.
All engines in the Tau range are controlled by an electronic accelerator pedal .
The power transmission from the crankshaft to the cylinder head takes place by means of a maintenance-free timing chain , the ancillary units are driven by a toothed belt. An inspection is planned for this every 30,000 km, an exchange only if necessary.
The valves are operated via roller rocker arms that act like a rocker. The cam rests on its apex. During its rotation it pushes one side and thus the valve downwards, while the hydraulic valve valve, which is stretched by means of a built-in spring, is always flush on the other . This form of valve clearance compensation is maintenance-free, even an inspection is not included in the maintenance schedule. Wear would be communicated by a ticking sound. This also occurs during winter cold starts for about a minute until the oil in the hydraulic valve valve reaches the viscosity required to compensate for the play. In the versions with 344 and 375 HP, an ignition fault can also be the cause of the noise ( cf. ).
dew
The first eight-cylinder engine exclusively developed by Korea was presented in 2008 with the 4.6 L Tau. In the same year, a 5.0 L version for the long version of the Hyundai Equus luxury sedan followed . In 2010, both received a performance upgrade, the details of which are described below. The five-year development of the series cost $ 260 million and ended just before the economic crisis began . In view of the simultaneous trend towards smaller displacements and the manufacturer's goal of achieving the lowest average fuel consumption in the US market by 2025, the range's potential for larger displacements was dispensed with. Above five liters of displacement, the increase in performance was no longer linear with additional consumption. In the year of the Tau premiere, General Motors and Ford announced their departure from V8 series. In 2009 and 2010 the Tau V8 was included in the “ Ward's 10 Best Engines ” list. Ward's AutoWorld is a trade journal for the auto trade that has been published since 1924.
At the end of the 1990s there was already a gray cast iron V8 engine developed by Mitsubishi, the Omega V8, in the Hyundai Equus . It had direct petrol injection (GDI), which, however, required premium petrol due to the high compression that is typical of the system. This was rare in South Korea at the time. The resulting drop in performance made customers complain. Hyundai responded in 2002 by switching to manifold injection, while Mitsubishi itself had to stop using the engine after 15 months due to the Asian crisis. Regardless of these initial difficulties, Hyundai produced it in cooperation with Mitsubishi for its top model Equus until 2008.
Tau engines have a dual CVVT named camshaft adjustment for the intake and exhaust side. This has an impact not on the timing of valve opening of both sides of the valve lift and the opening period . It is therefore comparable to the BMW double VANOS technology . In addition to better torque in the lower speed range, it primarily reduces nitrogen oxide levels by using the exhaust gas recirculating effect of a large overlap - exhaust gas that has already been emitted is sucked back into the combustion chamber.
The valves are opened with reduced friction using roller rocker arms with hydraulic valve clearance compensation. This keeps the valve clearance permanently at zero and thus avoids ticking noises. In contrast to mechanical bucket tappets, however, more attention must be paid to the oil quality and level. If the hydraulic valve tappet is partially filled with air, for example because the oil level is too low, it does not fulfill its backlash-compensating effect and ticking noises occur. The combination of hydraulic valve lifters with roller finger followers is the lowest friction and most costly form of valve actuation to manufacture. It was taken over into the Kappa series , which was also published in 2008, and is the only one for which Hyundai / KIA no longer provides for inspections and thus underlines their freedom from maintenance.
The series has a variable intake system. This takes into account the pulsation of the air in the intake manifold, which occurs when the valves are opened and closed. If these negative and positive pressure impulses find their way into the engine compartment that is adapted to their rhythm, a slight resonance charging effect occurs, similar to a turbocharger . To achieve this, a suitable, short air path opens at low and high speeds. At medium speeds, the longer air duct is used by means of a flap, which results in consistently high torque.
The 90 ° V-orientation of the two four-cylinder banks has the advantage of completely balancing first and second order inertial forces, as one cylinder on the opposite bank always moves in the opposite direction to the one that is firing. The result is a particularly quiet engine run and the saving of an unnecessary balancer shaft .
For this, however , the crankshaft must have a cross-plane design. In this case, the diagonally opposite connecting rods move simultaneously. However, this has the undesirable side effect of the firing order not alternating between the left and right bank. This irregularity is then found in the air turbulence in the intake tract, which must therefore be given special attention in its design. Hyundai / KIA therefore mentions the "dozen" hand-molded prototypes during the development of the intake manifold. This made it possible to compensate for the otherwise uneven cylinder filling, and the cross-plane shape remains recognizable by the acoustically distinctive exhaust noise. The lighter, cheaper, alternately igniting flat-plane construction would in turn generate stronger vibrations through free inertial forces of the second order. Here the directly opposite connecting rods move in opposite directions, but in an inner and outer pair at the same time, instead of in four individual gradations ( see last paragraph , see image on the right and animation).
The pistons are friction-reduced with a MoS² coating, and the chrome-nitride coating acts on the piston rings as it were. The T5 die-casting process of the cylinder block causes a more uniform expansion, which minimizes friction.
A performance-enhancing revision followed in mid-2010. The valves were enlarged, which enables the air to flow in more quickly - a performance-enhancing effect, especially at higher speeds. The air flow in the variable intake tract has also been optimized.
In the practical North American EPA rating, fuel consumption is classified as 13.8 to 15.7 l in the city and 9.4 to 12 l / 100 km on the highway, increasing from sedan to four-wheel-drive SUV.
Problems
If the car is parked briefly in a cold state and at freezing temperatures, the oil pump does not always build up enough pressure to open the valve of the timing chain tensioner . Then the chain slips and adversely affects the ignition behavior of the engine. This can lead to gasoline residue in the cylinder. The next time you start, these cause very irregular running with partly black smoke development on the exhaust. Hyundai updated the engine's control software in November 2010, but the behavior was repeated for some engines. The error codes P0300 (general ignition errors) or P0301 to P0308 (ignition errors in cylinders 1 to 8) are stored in the control unit. Drivers recommend a "warm-up phase" of 30 seconds before and after changing parking spaces in freezing temperatures until the increased idling speed drops. 4.6 L engines before the 2011 model year are affected ( Hyundai Genesis with 375 PS and KIA Borrego with 344 PS, Hyundai Equus were only exported from the 2011 model year). After checking each individual case, the manufacturer replaced the timing chain tensioner, and if damage occurred, the entire engine. All repairs are covered by the five to ten year drive guarantee in the markets supplied.
Tau GDI
At the beginning of 2011, the 5.0 L engine was equipped with direct injection called GDI . At the same time, all vehicles with Tau engines received Hyundai's own 8-speed automatic transmission instead of the 6-speed variant from ZF Sachs . Their increase in efficiency is rather small, as the Genesis shows with half a liter of reduced highway consumption in accordance with EPA standards. Your advantage lies in technical independence, faster acceleration and nominal catch-up to the competition. For 2014, Hyundai is therefore planning a 10-stage variant. Like its predecessor in 2009 and '10, the new GDI engine was included in the “ Ward's 10 Best Engines ” list in 2011. Ward's AutoWorld is a trade journal for the auto trade that has been published since 1924. One reason for the decision was the highest horsepower output per liter of displacement of non-turbocharged V8s. The development over 40 months cost 10.5 million euros
With conventional injection for gasoline engines, the injection valve is located in the intake manifold in front of the inlet valve. With increasing engine speeds, however, the opening time of the valve becomes shorter and shorter, and thus the time window for introducing the fuel. With direct injection , injection is therefore carried out directly into the cylinder. Hyundai used as most GDI competitors for homogeneous stoichiometric mixture formation and dispensed with an inhomogeneous stratified charge (stratified fuel charge). The latter is associated with system-related disadvantages, such as significantly increased fine dust values.
It starts with a pilot injection and ignition to set the piston in motion. During its downward movement, the actual fuel injection and ignition takes place. With this more precise, cooling fuel supply, which takes place directly in the cylinder, the compression rate in the cylinder could be increased from 10.4 to 11.5. This leads to a fuel saving of around five percent ( cf. ) and also causes a higher exhaust gas temperature. The catalyst, which heats up faster, benefits from this. The higher injection pressure of 150 bar (without GDI approx. 5 bar) also results in more homogeneous fuel atomization and thus cleaner combustion. It is accompanied by a system-typical ticking noise.
In the practical North American EPA rating, consumption is rated at 14.7 in the city and 9.4 l / 100 km on the highway. It is barely above the 4.6 L model without GDI.
Data
| series | Engine code | Displacement (cm³) | Stroke × bore (mm) | Power (PS) at (1 / min) | Torque (Nm) at (1 / min) | cylinder | compression | Charging | injection |
|---|---|---|---|---|---|---|---|---|---|
| dew | G8BA 1 | 4627 | 87.0 x 92.0 | 349/380/390 2 3 at 6500 | 435/451/451 at 3500 | 8th | 10.4 |
VIS (2 way) |
MFI |
| dew | G8BB | 5038 | 87.0 x 96.0 | 400 at 6400 | 500 at 3500 | 8th | 10.4 | VIS (2 way) |
MFI |
| Tau GDI | G8BE 4 | 5038 | 87.0 x 96.0 | 430 5 at 6400 | 510 at 3500 | 8th | 11.5 | VIS (2 way) |
GDI |
commitment
The Tau motors installed worldwide are listed for each model; not all configurations are offered in every country.
- Hyundai Equus
- Equus VI
- G8BA: 2008–2011
- G8BB: 2009–2011 (as a government vehicle in South Korea)
- G8BE: 2011-present
- Hyundai Genesis
- Genesis bra
- G8BA: 2008-present
- G8BE: 2011-present
- KIA Borrego
- Borrego HM
- G8BA: 2008–2011 (V8 option only in Canada and USA, vehicle was not accepted by the US market and sales there ceased in 2009)
Individual evidence
- ↑ Production in Asan ( Memento of the original from December 27, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 145 kB)
- ↑ Displacement variants of the series
- ↑ Model starts in 2011
- ↑ a b c KIA Borrego manual p. 396 Inspection intervals ( Memento of the original from January 14, 2011 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 12.8 MB)
- ↑ See valve closed ( Memento from July 16, 2014 in the Internet Archive ), valve open ( Memento from February 21, 2014 in the Internet Archive )
- ↑ a b comparison
- ↑ Brief ticking noise of the hydraulic valve lifters in a cold environment
- ↑ Manufacturer target of 50 MPG fleet consumption according to the CAFE standard by 2025
- ↑ 50 MPG according to CAFE standard (4.7 l / 100 km) = 37 MPG according to EPA standard (6.4 l / 100 km)
- ↑ Non-linear increase in Tau consumption from 5 L cubic capacity
- ↑ GM Northstar without successor, EcoBoost V6 replaces Ford V8
- ↑ Mitsubishi 8A80 GDI engine in the Mitsubishi Proudia / Dignity and Hyundai Equus ( Memento of the original from April 27, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Explanation of the Hyundai CVVT technology including images
- ↑ Types of valve clearance compensation with their advantages ( Memento of the original from July 26, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Gas exchange # four-stroke reciprocating engine
- ↑ animation (video)
- ↑ Hyundai Equus R&D Story p. 8
- ↑ "V8 babbling"
- ↑ animation
- ↑ Coatings of the pistons in Tau V8
- ↑ Revision of the Tau V8 2010
- ↑ Hyundai Genesis EPA rating 17/25 mpg
- ↑ KIA Borrego EPA rating 15/20 mpg ( Memento of the original from November 21, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Description of causes 2009
- ↑ Description of causes 2011
- ↑ Report on ineffective, new control software ( memento of the original from November 29, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Error codes and report on the same, here effective control software
- ↑ Model year 2011: Not affected
- ↑ Model year 2009: Software update for a misfire (November 1st, 2010)
- ↑ Recommended warm-up phase
- ↑ Free replacement of the motor with the same behavior afterwards
- ↑ Free replacement of the chain tensioner without reporting any new problems
- ↑ Hyundai 5-year limited warranty in Canada
- ↑ Hyundai 5 year warranty in Russia
- ↑ Hyundai's 10-year drive warranty in the USA
- ↑ KIA 10-year drive guarantee in the USA ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 571 kB)
- ↑ KIA 5-year limited warranty in Canada
- ↑ a b Press release on the Tau GDI debut
- ↑ Development of a 10-step automatic system at Hyundai ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Costs and duration of the Tau GDI development
- ↑ Video on Tau GDI
- ↑ Hyundai GDI uses a homogeneous mixing ratio
- ↑ Fine dust values in gasoline engines increased due to direct injection
- ↑ See video from 4:00
- ↑ Hyundai Genesis EPA rating 17/26 mpg
