milnersXcoupe
New Member
- Messages
- 95
- Location
- new paltz, new york . USA
2007 Lexus LS460
- 4,608 cc 4.6 liters V 8 front engine with 94 mm bore, 83 mm stroke, 11.8 compression ratio, double overhead cam, variable valve timing/camshaft and four valves per cylinder 1UR-FSE
83mm stroke = 3.267716535
- Premium unleaded fuel 91
- Fuel economy EPA highway (mpg): 27 and EPA city (mpg): 19
- Multi-point injection fuel system
- The engine uses direct, in-cylinder fuel injection along with traditional port fuel injection for a claimed 36 percent reduction in fuel consumption.
- 22.2 gallon main premium unleaded fuel tank
- Power: 283 kW , 380 HP SAE @ 6,400 rpm; 367 ft lb , 498 Nm @ 4,100 rpm
HybridCars.com - quote -:
To reduce the overall weight of the engine, the cylinder block is die-cast from a lightweight, high-strength aluminium alloy. The block structure and rib reinforcement design have been finalized through the incorporation of cylinder combustion pressure data to minimize both vibration and noise. The engine head cover is also constructed in a lightweight magnesium alloy.
The new V8 features a D-4s (direct injection 4-stroke superior version) stoichiometric direct injection system, the world’s only automotive injection system to adopt two injectors per cylinder—one injector installed in the combustion chamber and a second
The D-4s system's port injectors employ 2 holes to inject fuel at a maximum pressure of 4 bar, while the in-cylinder injectors feature twin, 0.52 x 0. 3 mm rectangular slits producing a double fan injection pattern to effect the most homogeneous possible air/fuel mix.
Under cold start conditions, D-4s employs port injection during intake and direct injection during compression, producing a lean air/fuel mixture of 15-16:1. By concentrating the richer mixture around the spark plug it is possible to raise the combustion temperature, contributing to a quicker warm up of the Lexus thin-wall catalysts.
At idle, the engine runs on direct injection alone, due to its higher efficiency. In addition, and unique to the LS 600h and GS 450h, the electronic management maintains engine revolutions at an ideal speed to improve warm-up.
When the engine is running under a low- to medium-load at lower speeds, both direct and port injection systems are used during the intake stroke. This creates an homogeneous, 4.5: stoichiometric air/fuel ratio to stabilize combustion, improve fuel efficiency and reduce emissions.
When the engine is running under heavy loads, the direct injection system alone is employed. This achieves an intake cooling effect by injecting fuel directly into the combustion chamber, which improves the efficiency of each charge. It also allows for a higher engine compression ratio of 11.8:1, reducing pre-ignition tendencies and improving engine output and performance. Once again, a 12-15:1 stoichiometric air/fuel ratio is effected during the intake stroke.
D-4s substantially reduces combustion fluctuations in comparison to any conventional, direct or port injection system. D-4s realizes optimum engine efficiency throughout the power band and improving torque by 7.5\% across the rev range, while minimizing fuel consumption and emissions.
The engine is also equipped with Lexus' Dual VVT-i. This optimized, low-pressure loss, variable intake and exhaust valve timing system incorporates VVT-iE, the world's first electric motor-driven intake camshaft, which operates across the full engine revolution and temperature spectrum.
Hydraulic VVT cannot operate below 1,000 rpm or during engine warmup. However, the Electric Motor Driven VVT system will operate across the full engine revolution and temperature spectrum, with a cam response speed of 50 degrees per second towards the lag phase and 50 degrees per second towards the advance phase.
Due to cam phase shifts when the engine stops, it is difficult to halt the cam at the optimum position for engine re-start using the electric motor alone. For that Lexus engineers have developed a mechanism employing frictional resistance and speed reduction gearing to hold the cam phase in the ideal position for engine start-up.
The new V8 further features a semi-dual exhaust manifold that reduces interference in the flow of exhaust gases, further improving output and combustion efficiency.
- 4,608 cc 4.6 liters V 8 front engine with 94 mm bore, 83 mm stroke, 11.8 compression ratio, double overhead cam, variable valve timing/camshaft and four valves per cylinder 1UR-FSE
83mm stroke = 3.267716535
- Premium unleaded fuel 91
- Fuel economy EPA highway (mpg): 27 and EPA city (mpg): 19
- Multi-point injection fuel system
- The engine uses direct, in-cylinder fuel injection along with traditional port fuel injection for a claimed 36 percent reduction in fuel consumption.
- 22.2 gallon main premium unleaded fuel tank
- Power: 283 kW , 380 HP SAE @ 6,400 rpm; 367 ft lb , 498 Nm @ 4,100 rpm
HybridCars.com - quote -:
To reduce the overall weight of the engine, the cylinder block is die-cast from a lightweight, high-strength aluminium alloy. The block structure and rib reinforcement design have been finalized through the incorporation of cylinder combustion pressure data to minimize both vibration and noise. The engine head cover is also constructed in a lightweight magnesium alloy.
The new V8 features a D-4s (direct injection 4-stroke superior version) stoichiometric direct injection system, the world’s only automotive injection system to adopt two injectors per cylinder—one injector installed in the combustion chamber and a second
The D-4s system's port injectors employ 2 holes to inject fuel at a maximum pressure of 4 bar, while the in-cylinder injectors feature twin, 0.52 x 0. 3 mm rectangular slits producing a double fan injection pattern to effect the most homogeneous possible air/fuel mix.
Under cold start conditions, D-4s employs port injection during intake and direct injection during compression, producing a lean air/fuel mixture of 15-16:1. By concentrating the richer mixture around the spark plug it is possible to raise the combustion temperature, contributing to a quicker warm up of the Lexus thin-wall catalysts.
At idle, the engine runs on direct injection alone, due to its higher efficiency. In addition, and unique to the LS 600h and GS 450h, the electronic management maintains engine revolutions at an ideal speed to improve warm-up.
When the engine is running under a low- to medium-load at lower speeds, both direct and port injection systems are used during the intake stroke. This creates an homogeneous, 4.5: stoichiometric air/fuel ratio to stabilize combustion, improve fuel efficiency and reduce emissions.
When the engine is running under heavy loads, the direct injection system alone is employed. This achieves an intake cooling effect by injecting fuel directly into the combustion chamber, which improves the efficiency of each charge. It also allows for a higher engine compression ratio of 11.8:1, reducing pre-ignition tendencies and improving engine output and performance. Once again, a 12-15:1 stoichiometric air/fuel ratio is effected during the intake stroke.
D-4s substantially reduces combustion fluctuations in comparison to any conventional, direct or port injection system. D-4s realizes optimum engine efficiency throughout the power band and improving torque by 7.5\% across the rev range, while minimizing fuel consumption and emissions.
The engine is also equipped with Lexus' Dual VVT-i. This optimized, low-pressure loss, variable intake and exhaust valve timing system incorporates VVT-iE, the world's first electric motor-driven intake camshaft, which operates across the full engine revolution and temperature spectrum.
Hydraulic VVT cannot operate below 1,000 rpm or during engine warmup. However, the Electric Motor Driven VVT system will operate across the full engine revolution and temperature spectrum, with a cam response speed of 50 degrees per second towards the lag phase and 50 degrees per second towards the advance phase.
Due to cam phase shifts when the engine stops, it is difficult to halt the cam at the optimum position for engine re-start using the electric motor alone. For that Lexus engineers have developed a mechanism employing frictional resistance and speed reduction gearing to hold the cam phase in the ideal position for engine start-up.
The new V8 further features a semi-dual exhaust manifold that reduces interference in the flow of exhaust gases, further improving output and combustion efficiency.
