Yang Quan sat in his seat and listened to all the speeches, then put down his pen and tilted his head to look at Yuan Qingli next to him, and shook his head to signal that he could summarize.

Since it was just a quality briefing meeting, he didn't want to waste everyone's time too much.

Yuan Qingli packed up his notebook, got up and said, "Regarding today's meeting, you have worked hard. The results of the first production test of the Liberty Man are not encouraging. From a design point of view, the ejector rod machine has performed very well in Brazil and other countries, and I believe that no one doubts the design of this engine, but why is the result so unsatisfactory after our test this time?

I would like to summarize the speeches made by you, and there are basically two points. The first is the processing problem, because of equipment or personnel and other reasons, the size of the product produced is not in place, so there are some overheating of the machine parts, the power of the problem.

The second is the material problem, yes, the Freelance that we have piled up in the lab at any cost does not have a problem with performance, but now there are all kinds of problems with the preparation of the selected materials for mass production. Mass production is a fact that must be faced with cost consideration. I heard a lot of complaints in the office about how difficult it was to find materials, and I knew that it was difficult, if it wasn't hard to believe that Jinling was full of engine factories.

Letting go of the horizon, we look outside. There are a lot of parts factories and enterprises in Shancheng, and they are all excellent. Our research team can visit with the purchasing department to inspect their products and communicate directly face-to-face.

In addition, the sooner the Liberty is mass-produced, the more bonuses there will be. Let's keep up the good work!"

Yuan Qingli stared at Yang Quan and finished the last sentence, and as soon as the words fell, a round of applause immediately rang out in the conference room. Everyone turned their gazes to Yang Quan along with Yuan Qingli, waiting for him to say something.

Yang Quan raised his hands and stood up like a surrender, and pressed down into the void with a smile, and everyone immediately paused for a while, "Director Yuan's words are my words, the thickness of the red envelope guarantees that you are satisfied, and you have to speed up to ensure that I am satisfied." ”

As soon as the words were finished, before the applause resumed stronger, the slightly younger and bold even whistled, and everyone secretly resolved to speed up and work overtime tonight.

This is the second time that Yang Quan has expressed his expectations for mass production, and everyone remembers the thickness of the last red envelope, as well as the expressions of his family after returning home with the red envelope. The sound of the envelope slapping on the dining table in the hall, the infatuation in the wife's eyes when she opened the envelope and saw the bills made the man feel great satisfaction, and his inner pride rushed through his body.

After participating in the quality meeting, I hurried to the next new product meeting with Yuan Qingli.

After the direction of upgrading the engine cylinder expansion of the Liberty 125CC to 150CC was decided at the last plenary meeting, some members of the research institute turned to the mass production work of the Liberty Man, and some were assigned to the research work of the 150CC engine. Because the two products have the same origin, many parts can be used, so Yuan Qingli, who is in charge of the 125CC work, also had to rush to participate.

Chang Zheng's deputy designer has now been promoted to deputy director, alongside another deputy director, and Yuan Qingli manages the institute together.

Chang Zheng said while drawing on the blackboard: "The Liberty Variant design, the current expansion of the cylinder increases the changes of pistons, piston rings, piston pins and cylinders. However, if the matching crankshaft connecting rod assembly, crankcase, main bearing and other supporting parts and moving parts are not changed, the engine will have no reserve power and torque, so that the engine will always be at high temperature, high speed and high load.

The solution to high temperature is very simple, we can change air cooling to water cooling or oil cooling. However, under the "three highs", it will only consume the kinetic energy of the engine, which will cause serious loss of machine parts, and the final result will be that the engine life will be greatly shortened. ”

How to expand the cylinder and how to upgrade to 150CC is not a simple matter.

Yang Quan recalled that in his previous life, there were indeed many manufacturers who studied and expanded the cylinder at will without technical support, and the product was sold, but the sales reputation was not too good, and the life expectancy was the most basic fact. In fact, expanding the cylinder is not a difficult thing, many netizens who know a little about motorcycle engines have tried to upgrade on their own, and have achieved success.

Honda, as a representative of Japanese manufacturers, has also done this. HONDA'S CB125, FOR EXAMPLE, WAS ONLY 125CC IN RB AT THE EARLIEST, BUT IT WAS UPGRADED TO 145CC IN SOUTHEAST ASIA (THAT'S HOW THE GL145 CAME FROM).

Take the GL145 as an example, although it is a cylinder expander, the heat load of the engine is not too high, and the power is also very good, the displacement power of 145 can reach 10KW, and there is nothing bad about such a cylinder expander.

On the other hand, some domestic engines rashly expand the cylinder or even increase the stroke to obtain a large displacement under the premise of insufficient technical strength, the consequence may be high heat load, large fuel consumption, and the engine is easy to power attenuation after long-term use, and the life is shortened.

Chang Zheng mentioned that the temperature is high, and it is also an idea to cool down by changing the cooling method. If there is a high temperature, it is not correct to simply do so and there must be a problem in the design. If the temperature is only slightly higher, it is true that you can use water cooling or oil cooling.

Air cooling is cooled by the air brought by the vehicle, and the air-cooled cylinder barrel will be designed with a large heat sink, and the cylinder head will be designed with a fan hot sheet and air duct (air cooling is mostly a single-cylinder engine or V2 machine with low speed and high torque).

The advantage of air cooling is that the cooling system has zero failures (free cooling) and the air-cooled engine has a low cost and takes up less space. Its disadvantage is that the heat dissipation is slow, and it is limited by the engine form, such as the in-line 4-cylinder, he rarely uses air-cooling, and the middle 2-cylinder can not effectively dissipate heat, so the air-cooled is only suitable for 2-cylinder engines.

Water cooling is a cooling method with a better heat dissipation effect, and the principle of water cooling is to cool down the cylinder liner and cylinder head by wrapping the cylinder liner and cylinder head with flowing water.

The advantage is that it can effectively control the temperature of high-power and high-speed engines, and the throttle valve will be closed until the oil temperature rises when the temperature of the water-cooled car is low to achieve the best lubrication effect. Its disadvantages are also obvious: high cost, complex structure, high failure rate, because there is an external water tank that occupies a large space.

Water cooling is a necessary cooling system for multi-cylinder high-power and high-speed engines (as well as water-oil dual cooling). A small-displacement 125CC Liberty or a 150CC single-cylinder car is not suitable for changing to water cooling, because that is useless, and the general 125 simply can't generate so much heat.

Oil cooling is standard on mid-range street bikes, and stability and fan heating are all in the market. If it is the next design with a larger displacement of 250CC, you can consider oil cooling.

Air cooling is the standard configuration of daily scooters, zero failure of the cooling system, low engine cost, as long as the maintenance is done properly, there will be no high temperature problem, but the water cooling car has more high temperatures.

In short, the single-cylinder low-speed car 150CC is completely sufficient with air cooling as long as it is not a design problem.