Under the wave of electrification, I don't know if you remember the "golden displacement" dispute that once belonged to the engine. This debate, from natural inhalation to the era of turbocharging, seems promising to usher in the final answer as the internal combustion engine car draws to a close. After all, we have analyzed too many 1.5T and 2.0T engines, and it is no accident that these two displacement engines will be more options for consumers to face when buying fuel vehicles in the future.
For car companies, they are also very happy to see this simple "architecture". In fact, at the beginning, the combination of 1.5T + 2.0T can be simpler. 2.0T = 4 0.5L, then 3 0.5L can be equal to 1.5T, the technical path, and even the bore, stroke and distance can be reproduced. So some of the three-cylinder 1.5T engines we are familiar with have appeared in this way.
However, in front of the market, car companies still think too simply. Technology put aside, three cylinders is considered "original sin". So the 1.5T, which was originally positioned lower, has become the most powerful product of each company. Today we are going to talk about the new four-cylinder 1.5T engine from Geely Automobile, code-named BHE15-EFZ. This power is expected to be installed in models such as Geely ICON, and it is likely to replace the 1.5T power of geely and Lynk & Co models in the future.
The engine is turned backwards, and the high performance is there?
Statistically speaking, Geely's new 1.5T engine has a maximum horsepower of 181Ps and a maximum torque of 290N·m. This is not only a significant upgrade of Geely's current power system, but also no less than in the face of the same displacement power such as honda earth dream 1.5T, as well as Changan, Great Wall, GAC Trumpchi and so on. Previously, from the product point of view, we have talked about Chinese brands in the car products, and strive to go out of the circle through the sports label, which relies on the new engine that focuses more on power performance. The same is true for Geely.
Structurally, the biggest feature of this new 1.5T engine is that it adopts an inverted layout. We may usually listen to the distinction between horizontal and vertical engines, and the reverse positioning is relatively strange. In fact, the reverse structure is only for the transverse engine, because the longitudinal intake and exhaust structures are on both sides, and there is no so-called "positive and negative". The "reverse" structure, that is, the position of the intake and exhaust is reversed, that is, the intake manifold is in the direction of the front of the car, and the exhaust manifold is on the inside of the engine compartment (forward and backward out).
The intake air front, first of all, the use of air cooling effect, reduce the air density at the intake end, increase the oxygen content per unit area. The focus is also on the exhaust end, the rear exhaust opens the distance from the engine, reducing the system load from the heat dissipation angle, and from the structural point of view, the exhaust system no longer needs to bypass the engine underneath, but directly backwards, the exhaust efficiency is higher. Moreover, the reverse structure can further reduce the center of gravity of the engine, which is an attempt to fundamentally approach the control advantages of the vertical engine model for the model with the horizontal engine. Those who like to use this structure are mostly ford, Mazda, and other brands that focus on horizontal platforms and pay attention to driving pleasure and performance output.
"Non-mainstream" must have "problems", and the problem is how to solve them
Although the model equipped with this new 1.5T engine has not yet been officially launched, from the data, it is indeed possible to feel Geely's pursuit of performance this time. However, the reverse engine has so many benefits, but it is still quite niche, and it certainly has its inherent shortcomings. First of all, for the engine, in the case of reverse placement, the exhaust channel is too smooth, resulting in insufficient back pressure in the exhaust pipe when running under low working conditions, and the exhaust end is easy to "open the door" before the work stroke reaches the lower stop point, resulting in a loss of work efficiency. The exhaust efficiency is not ideal, which in turn affects the intake efficiency. Especially in the case of manifold injection, fuel that does not enter the cylinder is prone to carbon deposits. But at least at low speeds, reverse-mounted engine models tend to have a "sense of powerlessness."
In addition, the reverse-mounted engine has two structural "small flaws" outside the technical path. The first is that the cockpit noise is easy to be large, after all, the exhaust end is closer to the cockpit, and the noise is also reasonable. Another point is that the air conditioning cooling effect is easily affected, and the exhaust structure causes the air conditioning pipeline to be easily "heated". It's an advantage in the winter, but it's hard to say in the summer. Therefore, many reverse-mounted engine models, in the case of unopened air conditioning, the air outlet may also have a small amount of waste heat dissipation. However, these two points can be solved by piling up sound insulation materials and strengthening the air conditioning system, which are points outside the technical path of the engine.
Back to the engine itself, Geely has also made many optimizations for the shortcomings of the reverse type, the first of which is the high-pressure direct injection technology of 350Bar. Direct injection is the best solution for bypassing manifold injection and the effect of valve switches on the concentration of the fuel mixture. The 350Bar high pressure is also currently the level of the first echelon and is one of the most effective ways to meet the current stringent emission regulations. At the same time, in order to further optimize the intake air flow, the injector adopts a central layout, which can achieve a more complete mix of oil and gas and improve fuel efficiency.
On the other hand, as a turbocharged engine, the pressure of the exhaust gas turbine is also one of the ways to overcome the problem of weak power output of the reverse engine in the low working environment. Geely equipped the 1.5T engine with a small inertia electronically controlled supercharger to achieve the agility of power output in low-rpm environments. Secondly, the engine is also equipped with an electronically controlled turbo pressure relief valve, which is obviously Geely's high power output. It's just that the reverse layout of the turbine is more complex in design. First, the turbocharger will also be located on the inside of the engine compartment, further increasing the pressure on the cooling system. Secondly, the clean air entering from the air filter needs to be circled from the inside of the engine compartment, and after entering the pressurized and intercooled, it enters the engine from the front end. If it is a naturally aspirated engine, it can be connected directly and does not require a detour.
Write at the end:
Because Geely Group's product line is too rich, perhaps many people forget that its products are very fond of making a fuss about performance, such as the quite successful Lynk & Co 03 series and so on. As more and more Chinese brands begin to roll up the power on the 1.5T power, Geely has also sacrificed the "killer" of the reverse layout. To know that the reverse horizontal engine is very easy to "vigorously out of the miracle" of the existence, such as the Mercedes-Benz M139 engine, just after the M133 based on the reverse layout, on the basis of the 2.0T squeezed out 421 horsepower. However, for the "civilian" Geely's new 1.5T engine, how to optimize the performance release under full working conditions, as well as cooling, sound insulation, and space layout, etc., is also worthy of our further attention.