7) vane contour
8) camshaft bearing
9) oil passage
10) excessive wear 11) cylinder wall 12) main bearing
3、Translate the following into English 1) 高油耗 2) 气门导管 3) 进气歧管 4) 废气管
5) 计算出, 解决, 断定, 6) 有错误 7) 导致
8) 与……熟悉
9) 在大多数情况下 10) 燃烧室 11) 润滑系统
4、Translate the following sentences into Chinese
1) In most cases of low oil pressure, the pressure is satisfactory when the engine is first started up, then drops as the engine warms up.
2) In rare cases of low oil pressure, the pressure is always low no matter whether the engine is cold or hot.
3) If the engine runs at low temperature for most of the time, it is easy to form sludge that is a mayonnaise-like mixture of water, oil, dirt and other product of combustion.
4) In the case of some older engines equipped with a combination of vacuum and fuel pump, a broken diaphragm will permit oil to be drawn directly from the crankcase into the intake manifold, and from there into the combustion chambers. 5) When oil is being consumed by passing through the engine, it usually will cause heavy blue smoke to come from the exhaust pipe, particularly after the engine has idled for several minutes.
拓展素材：
Engine Service and Maintenance
This section describes the servicing of crankshafts, main bearings, and engine blocks and cylinders.
Crankshaft and main bearing service
Most modern automotive engines have precision-insert-type main bearings which can be replaced without removing the crankshaft. Many bearing difficulties can be taken care of by this method of bearing replacement. However, if the bearing problem has been caused by such conditions as a warped engine block, stopped-up oil passages, a worn journal, or a bent crankshaft, then simply replacing the bearings will not correct
36
the condition. Such conditions as these will cause uneven bearing wear, with some bearings wearing faster (and more unevenly) than others.
If the bearings seem to have worn fairly uniformly, then the chances are that only crankshaft journal checks and bearing replacement will be required. Use of the bearing-oil-leak detector will determine whether or not bearing wear has been uneven. If bearing wear is uneven, then the safest procedure is to remove the crankshaft from the engine block and check both separately for alignment and for clogged oil passages.
Semi-finished main bearings require finishing and fitting after installation, so that the crankshaft must be taken out.
Cylinder and cylinder block service and maintenance
Before any service operations are performed, the cylinder block should be cleaned and inspected. There are several methods of cleaning. One method uses steam directed by a nozzle onto the block to wash away oil, sludge and dirt. A good solvent applied with a brush will also clean the block. After the block is cleaned, inspect it for cracks, especially in the cylinder walls, top, water jackets, and main bearing webs. The piston and ring movement, the high temperatures and pressures of combustion, the washing action of gasoline entering the cylinder--all these tend to cause cylinder wall wear.
There are certain limits to which cylinders may wear tapered or out of round before they require refinishing. Special drastic replacement rings will control compression and oil in cylinders with some taper and out-of-round wear. But when wear goes beyond a certain point, even the severest rings can’t hold compression and control oil, loss of compression, high oil consumption, poor performance, and heavy carbon accumulations in the cylinder will result. In such a case, the only way to get the engine back into good operation condition is to refinish the cylinders and fit new pistons and new rings to them.
If wear, taper, or eccentricity is not too great, only honing will be required. In operation, the hone revolves in the cylinder, and the abrasive stones in the hone remove material from the cylinder wall. If wear is too great to be taken care of by honing alone, cylinder must be bored first and then honed.
Cylinders must be cleaned thoroughly after the honing or boring operation. Even slight traces of grit or dust on the cylinder wall may cause rapid ring and wall wear and early engine failure.
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Unit 2
Engine Troubleshooting for Cooling System
学习目标：
1、知识目标：
掌握冷却系统常见的两种故障的形成原因。 2、技能目标：
掌握冷却系统的专业术语、专业词汇；
理解冷却系统一些故障和造成它们的一些原因。
学习任务：
Can you answer the following questions about cooling system of engines？
1、When the engine is running and the coolant is boiling, can you add cold water
directly into the cooling system?
2、If the engine is overheating and the coolant is constantly losing, what should you
firstly do when you try to repair it?
3、When you decide that crack is the cause of overheating, is it easy to locate it?
4、What might happen if you add mineral water into the cooling system for several
years?
5、List the causes for overheating. 6、List the causes for overcooling.
准备材料：
New Words
overheating [???????????] n. 过热 overcooling [??????????] n. 过冷 indicate [?????????] v. 显示
gauge [????] n. 量表 v.测量 violent [?????????] adj. 剧烈地 coolant [????????] n. 冷却液 noticeable [??????????] adj. 明显的 emphasize [?????????] v. 强调 crack [????] n. 裂缝
consequent [???????????] adj. 随之发生的 radiator [??????????] n. 散热器 hose [????] n. 软管 corrosion [????????n] n. 锈 locate [???????t] v. 定位 visible [???????] adj. 看得见的 complicated [?????????????] adj. 复杂的 suspect [????????] v. 怀疑
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opening [???????] n. 口子, 穴 immerse [??????] v. 沉浸
reveal [???????] v.显示,揭示,暴露 locknut [???????] n. 锁紧螺母 loosen [??????] v. 松开
distributor [????????????] n. 分电器
circulate [???????????] v. 循环 thermostat [??????????] n. 节温器 release [???????] v. 释放 i.e. [?????] adv. 也就是 suitable [?????????] adj. 合适的
Phrases and Expressions
instrument panel. 仪表板 cast iron 铸铁 visual inspection 目测
drive belt. 驱动皮带 cooling fan 冷却风扇 water jacket. 水套 naked eye 裸眼
cylinder head 缸头 cylinder block 缸体 mineral water 矿泉水 hard scale 坚硬的水垢
improper spark timing, 不正确的点火时间 energy transformation 能量转换 temperature switches 温控开关
inevitable consequence 不可避免的后果 valve port 气门口
阅读素材：
The cooling system troubles we are quite familiar with are overheating and overcooling. In this unit, we are going to find out the reasons behind these troubles. Engine overheating
There are many conditions of the automobile that result in overheating, and the degree of overheating is indicated by the temperature gauge on the instrument panel. Some conditions will cause only a slight change in the recorded temperature, other causes will result in a rapid rise in temperature and violent boiling of the coolant. What we should realize is that even a slight increase in recorded temperature will be more noticeable in engine performance. Before discussing the many causes of
39
overheating, it is important to emphasize that when the engine is hot and the coolant is boiling, water could only be added after the engine is stopped. [1] When the system is hot and the water level is low, cold water will go directly to the cylinder and the rapid chilling could cause the cast iron to crack.
When troubleshooting the cause for overheating and consequent loss of coolant, the first step is to make careful visual inspection to see if there is any evidence of external leakage. [2] All surfaces of the radiator and its hose connections should be carefully inspected. Leaks generally cause corrosion, which is easily seen. The visual inspection also must include the cooling fan and its drive belt.
It is not too unusual for cracks to form in the engine water jacket. When cracks occur, the condition is usually indicated by extreme overheating. The crack is often difficult to locate, because it is not always visible to the naked eye. The condition is also complicated by the fact that the crack usually will close when the engine is cold, and open only when the engine is at operating temperature. [3]
When cracks are suspected as the cause of excessive water loss or extreme overheating, the procedure is to remove the cylinder head and close the openings of the water jacket with suitable plugs or with special equipment. Air is then applied to the water jacket, and the head is immersed in water. Air bubbles will quickly reveal the location of the crack. Using hot water will warm the head and lead to open the crack. [4] This method of locating cracks is particularly helpful when the crack is located in a valve port and can’t be reached with other methods. [5] The same method is used to locate cracks located in the cylinder block, and also for retesting after repairs have been made. [6]
After many years of driving, especially you often add mineral water into the cooling system, rust and hard scale will accumulate to such an extent that the engine will often overheat, especially in summer.
Another cause for overheating is the improper spark timing, either early or lag, which not only raises the engine temperature, but also damages the engine, reduces the energy transformation and increases fuel consumption. [7] So loosen the locknut in the distributor, adjust the spark timing as soon as possible.
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专业名称：汽车检测与维修技术 年 级：二○一三级 课程名称：汽车英语 主讲教师：
二0一四年六月五日
1. 教师致辞 2. 上课须知 3. 学员个人档案 4. 课程内容目录 5. 课程内容
教师致辞
《汽车英语》是高职高专院校汽车专业的核心课程之一，是一门建立在英语基础知识上，适应市场需要，培养学生灵活运用汽车专业知识和英语语言能力，解决与国际市场接轨过程中遇到的实际问题的实用性课程。该课程的建设对加强我国汽车制造业、汽车服务业的建设与发展，促进学生就业以及就业后在企业后续拓展空间等方面都是非常有意义的。
与其他课程相比，本学期开设的《汽车英语》具有以下特点： 1.课程教学为专业服务 汽车英语教学内容除基础英语的教学内容外，注重与汽车专业知识相结合，完全以学生就业实际为导向，模拟学生可能在工作中遇到与英语有关的问题，如阅读英语操作说明书，用英语向外商介绍汽车的基本构造等，加以分析总结，设计出最能和就业接合的教学程式，在注重加强学生对英语基础知识的理解的基础上，强化学生对汽车专业英语材料的阅读理解能力以及针对汽车市场的职业外语交际能力，熟练掌握专业文献中常用的固定词汇与英语翻译技巧。
2.教学手段灵活多样 该课程采用教学与实践相结合的教学方法，充分利用多媒体、图片、实物演示等各种教学手段，采用课堂演示、交流与学生讨论、练习相结合的形式，注重培养学生独立阅读和翻译英语文章的能力，以及与之相适应的动手操作能力和实践运用能力，同时教师讲授紧密结合课堂练习，借以巩因教学内容，加深学生印象。
3.充分利用实习实践基地 为加强学生的实践与应用，该课程在设置上要求充分利用校内外实训基地，鼓励学生参加实践，在实践中加深理解，强化运用英语的能力，使学生的实际动手能力得到保证。
上课须知
1．学生上课不能迟到，不得无故旷课，有事请提前给老师请假。 2．上课做到课前预习，课后复习。 3．学生做到主动学习。
4．在动手中学习，做中学，学中做，学做一体。 5．知识是学出来的，能力是练出来的，注重手脑并用。 6．做到尊敬师长、互学互助。
7．在活页教材内容页中均设置了说明栏，每位学生可根据自已的实际学习情况，将学习难点、重点及学习心得、体会写在说明栏中。期末结束后便形成一本具有个人风格的教材，我们将组织评选，评出优秀个性化教材。
Chapter 2 Automobile Troubleshooting Technologies
Unit 1
Engine Troubleshooting for Lubrication System
学习目标：
1、知识目标：
掌握润滑系统常见的三种故障的形成原因。 2、技能目标：
掌握正确的名词，动词，形容词和副词表达润滑系统的一些故障和造成它们的一些原因。
学习任务：
Can you answer the following questions about lubrication system of engines？ 1、 List the causes for low oil pressure of engines. 2、 List the causes for high oil pressure of engines. 3、 How does the sludge form?
4、 List the causes for high oil consumption of engines. 5、 How to quickly locate engine external oil leakage?
准备材料：
New Words
Trouble shooting [?????????????] n. 发现并修理故障 trouble [??????] n. 故障
cause [????] n. 原因 v. 引起 satisfactory [??????????????] adj. 满意的 proof [pru:f] n. 证据
excessive [????????] adj. 过度的 clearance [?????????] n. 间隙 thicken [??????] v. 变厚，变稠 maintain [????????] v. 保持 sufficient [?????????] adj. 足够的 malfunction [???????????] n. 故障 excess [??????????????] n. 过度 replacement [????????????] n. 代替 occur [?????] v. 发生 sludge [?????] n. 软泥
mayonnaise [??????????] n 蛋黄酱 combustion [???????????] n. 燃烧 emulsify [??????????] v. 使乳化
deposit [????????] n. 沉淀物 v. 沉淀 varnish [???????] n. 清漆
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substance [?????????] n. 物质 extent [????????] n. 程度 leakage [????????] n. 泄露 crankcase [??????????] n. 曲轴箱 diaphragm [?????????] n. 振动膜 procedure [??????????] n. 步骤 clog [????] v. 堵塞 idle [?????] v. 怠速 condense [????????] v. 浓缩
accumulate [?????????????] v. 积聚
Phrases and Expressions
lubrication system 润滑系统 be familiar with 与……熟悉 high oil consumption 高油耗
figure out 计算出, 解决, 断定, in most cases 在大多数情况下 connecting rod bearing 连杆轴承 main bearing 主轴承 camshaft bearing 凸轮轴轴承 thin out 变稀
worn bearing 磨损的轴承 in rare cases 在少数情况下 well lubricated 良好润滑的 excessive wear 过度磨损 gear teeth 齿轮牙 vane contour 叶轮轮廓 oil passage 油道 piston ring 活塞环
cylinder wall 汽缸壁 at fault 有错误 intake manifold 进气歧管 combustion chamber 燃烧室 valve guide 气门导管 exhaust pipe 废气管 result in 导致
阅读素材：
The lubrication system troubles we are quite familiar with are low oil pressure, high oil pressure and high oil consumption. In this unit, we are going to figure out the causes behind these troubles. Low oil pressure
32
In most cases of low oil pressure, the pressure is satisfactory when the engine is first started up, then drops as the engine warms up. This condition is almost a positive proof that excessive clearance exists at some point, or points, such as connecting rod bearings, main bearings, camshaft bearing, etc. [1] When cold, the oil has thickened and does not flow readily through the clearance. When the oil heats up and thins out, it flows through the worn bearing so fast that the pump can’t maintain sufficient pressure. [2]
In rare cases of low oil pressure, the pressure is always low no matter whether the engine is cold or hot. [3] If the engine oil is not short, this is mainly because of the pump’s malfunction. Since the pump is well lubricated at all times, it does not suffer from excessive wear. [4] They do, sometimes, develop an excess of clearance and require replacement of parts. [5] The gear teeth or vane contours may wear, and the gear ends and housings may wear. When excessive wear does occur, the oil pressure will drop. High oil pressure
If the engine runs at low temperature for most of the time, it is easy to form sludge that is a mayonnaise-like mixture of water, oil, dirt and other product of combustion. [6] If the engine can’t get hot enough to drive the water and vapor out of the crankcase, the water condenses on the cold wall of the crankcase. This water emulsifies with oil, carbon, dirt, etc. to from sludge. If the engine runs at high temperatures for most of the time, the heat will cause the oil to break down, and some of the elements to separate out and deposit as a varnish-like substance on the metal parts. If the sludge and varnish-like substance accumulates to such an extent that the oil passage becomes clogged, the oil will flow slower and slower, and oil pressure will get higher and higher. [7]
High oil consumption
Quite often high oil consumption is blamed on the piston rings. While worn piston rings and cylinder walls do cause increased oil consumption, there are a great number of other things that could be at fault, either singly or in combination. [8] In most cases, the oil is leaking out of one or more of the pressure lubricated bearings, and is being
33
splashed or thrown up into the cylinders under the pistons in such large quantities that no piston ring can control the excess. High oil consumption can result from external leakage of the oil or be the result of oil passing through the engine. In the case of some older engines equipped with a combination of vacuum and fuel pump, a broken diaphragm will permit oil to be drawn directly from the crankcase into the intake manifold, and from there into the combustion chambers. Worn valve guides are also a frequent cause of high oil consumption. In the case of external leakage, the exterior of the engine will be covered with oil, particularly in the immediate area of the source of the leakage. So the usual procedure of locating the source is to first carefully clean the exterior of the engine, then take the vehicle for a short drive. Stop the vehicle over a clean area and examine the exterior for evidence of oil leakage. Also, if oil has dripped on the ground, it will aid in locating the source. When oil is being consumed by passing through the engine, it usually will cause heavy blue smoke to come from the exhaust pipe, particularly after the engine has idled for several minutes. [9] After the idling period, the engine should be raced briefly and smoke should appear. Conclusion
Excessive clearances at bearings and pump’s malfunction can cause low oil pressure; sludge and varnish clogged in the oil passage can raise the oil pressure; worn piston rings and cylinder walls, external leakage and worn valve guides can consume more oil. Especially worn piston rings, cylinder walls, and valve guides can directly result in blue smoke in the exhaust pipe.
难点分析：
Notes to Text
1、This condition is almost a positive proof that excessive clearance exists at some point, or points, such as connecting rod bearings, main bearings, camshaft bearing, etc. 这种情况几乎就是一个明确的证明， 在某个点或某些点存在过大的间隙， 例如连杆轴承，主轴承，凸轮轴轴承等。
2、When the oil heats up and thins out, it flows through the worn bearing so fast that the pump can’t maintain sufficient pressure. 当机油热起来变得稀薄，它在磨损的轴承里流动地太快，从而导致机油泵不能够保持足够的压力。
3 、In rare cases of low oil pressure, the pressure is always low no matter whether the
34
engine is cold or hot.
在低油压的个别情况下，不管发动机是冷还是热，压力一直是低的。
4、Since the pump is well lubricated at all times, it does not suffer from excessive wear.
因为油泵总是被很好地润滑，它不遭受过度的磨损。
5、They do, sometimes, develop an excess of clearance and require replacement of parts.
它们有时候的确发展到过度磨损，需要更换零件。
6、If the engine runs at low temperature for most of the time, it is easy to form sludge that is a mayonnaise-like mixture of water, oil, dirt and other product of combustion. 如果发动机在大多数情况下低温运作，很容易形成像蛋黄酱一样的软泥，它是水，油，赃物和燃烧的其他产物的混合物。
7、If the sludge and varnish-like substance accumulates to such an extent that the oil passage becomes clogged, the oil will flow slower and slower, and oil pressure will get higher and higher.
如果像清漆一样的东西和油泥积聚到如此大的程度就会导致油道堵塞，机油将会流动得越来越慢，油压就会越来越高。
8、While worn piston rings and cylinder walls do cause increased oil consumption, there are a great number of other things that could be at fault, either singly or in combination.
虽然磨损的活塞环和汽缸壁的确引起高油耗，许多别的地方也存在故障，可能是单独地也可能是共同地。
9、When oil is being consumed by passing through the engine, it usually will cause heavy blue smoke to come from the exhaust pipe, particularly after the engine has idled for several minutes.
当机油通过发动机本身被消耗掉时， 通常会引起排气管冒蓝烟，特别是当发动机怠速了几分钟后。
检查评价：
Exercises
1、Answer the following questions
1) List the causes for low oil pressure of engines. 2) List the causes for high oil pressure of engines. 3) How does the sludge form?
4) List the causes for high oil consumption of engines. 5) How to quickly locate engine external oil leakage? 2、Translate the following into Chinese
1) connecting rod bearing 2) well lubricated 3) piston ring 4) thin out
5) worn bearing
6) gear teeth
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1) Power stroke 2) exhaust valve 3) TDC
4) swept volume 5) engine capacity 6) clearance volume 7) compression stroke 8) kinetic energy 9) intake stroke
3、Translate the following into English 1) 活塞 2) 曲轴 3) 气阀 4) 缸径 5) 连杆 6) 下止点 7) 进气阀 8) 压缩行程 9) 压缩比
4、Translate the following passage into Chinese.
The time at which valves open and close (valve timing) and the duration of the valve opening in stated in degrees of crankshaft rotation. For example, the intake valve normally begins to open just before the piston has reached the top dead center. The valve remains open as the piston travels down to BDC and even past BDC. This is intake valve duration. An example of this could be stated as follows: IO at 17 BTDC, IC at 51 ABDC (or, intake opens 17 before top dead center, intake closes 51 after bottom dead center). Intake valve duration in this case is 248 of crankshaft rotation.
拓展素材：
Valve Timing
The time at which valves open and close (valve timing) and the duration of the valve opening in stated in degrees of crankshaft rotation. For example, the intake valve normally begins to open just before the piston has reached the top dead center. The valve remains open as the piston travels down to BDC and even past BDC. This is intake valve duration. An example of this could be stated as follows: IO at 17 BTDC, IC at 51 ABDC (or, intake opens 17 before top dead center, intake closes 51 after bottom dead center). Intake valve duration in this case is 248 of crankshaft rotation.
This leaves 129 duration for the compression stroke since compression ends when the piston reaches TDC. At this point the power stroke begins. The power stroke ends when the exhaust valve begins to open approximately at 51 before bottom dead center. The duration of the power stroke in this case is also 129.
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Since the exhaust valve is opening at 51 BBDC, this begins the exhaust stroke. The exhaust stroke continues as the piston passes BDC and moves upward to past TDC. With the exhaust valve closing at 17 TTDC, the duration of the exhaust stroke is 248. It is apparent from this description that the exhaust valve stays open for a short period of time during which the intake valve is also open. In other words, the end of the exhaust stroke and the beginning of the intake stroke overlap for a short period of time. This is called valve overlap. Valve timing and valve overlap vary on different engines.
Opening the intake valve before TDC and closing it after BDC increase the fill of air-fuel mixture in the cylinder. Opening the intake valve early helps overcome the static inertia of the air-fuel mixture at the beginning of the intake stroke, while leaving the intake valve open after BDC takes advantage of the kentia of the moving air-fuel mixture. This increase volumetric efficiency.
As the piston moves down on the power stroke past the 90 ATDC position, pressure in the cylinder has dropped, and the leverage to the crankshaft has decreased due to connecting rod angle and crankshaft position. This ends the effective length of the power stroke, and the exhaust valve can now be opened to begin expelling the burned gases. The exhaust valve remains open until the piston has moved up past the TDC position. This helps to remove as much of the burned gases as is possible and increase volumetric efficiency.
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Unit 4
Internal Combustion Engine Construction
学习目标：
1、知识目标：
熟悉发动机的结构、及其各部分功能。 2、技能目标：
掌握发动机构造相关的专业术语和词汇； 能进行相关内容的阅读和翻译。
学习任务：
Can you answer the following questions about internal combustion engine construction？
1、 List the main parts of the engine overall mechanics? 2、 What are the main function of the engine block？ 3、 What does the connecting rod be made from？ 4、 What is the function of the crankshaft？ 5、 What controls the length of the stroke?
准备材料：
New Words.
lubrication [??????????????] n.润滑 fasten [??????] v.使固定 camshaft [?????????] n.凸轮轴 alloy [?????] n.合金 nickel [?????] n.镍 chromium [?????????] n.铬 casting [????????] n.铸件 aluminum [???????????] n.铝 wear [???] n.耐磨性 hemi [????I] n.半球形 wedge [????] n.楔型，楔入 rocker [?????] n.摇臂
Circular [?????????] adj.圆形的 groove [?????] n.沟, 槽 Forge [?????] v.铸造，锻造 Crankpin [?????????] n.曲轴销 Bush [???] n.轴瓦，套筒 Bronze [?????] n.青铜 Lead [????] n.铅 Tin [???] n.锡
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Split [?????] n.切口，中断 Rotary [????????] n.旋转的 Journal [???????] n.轴颈 Throw [????] n.摆幅
coordinate [???????????] v.协调
respectively [???????????i] adj.分别的，各自的
Phrases and Expressions
engine block 发动机缸体 cylinder head 气缸盖 water jacket 水套 oil gallery 油道 overhead-cam(OHC) 顶置凸轮 push-rod 推杆 gray iron 灰铸铁 be lined with 镶有 cylinder sleeve 气缸套 Steel band 钢圈
fit into 放入，放进 piston ring 活塞环 ring groove 活塞环槽 piston pin 活塞销
pin boss 活塞销凸台 crankshaft journal 曲轴轴颈 steel-backed 钢背的 in conjunction with 连同
reciprocating motion 往复运动 carbon steel 碳钢 align with 匹配
timing gear 正时齿轮 vice verse 反之亦然 valve train 气门机构
阅读素材：
The engine has hundreds of other parts. The major parts of engine are engine block, engine heads, pistons, connecting rods, crankshaft and valves. The other parts are joined to make systems. These systems are the fuel system, intake system, ignition system, cooling system, lubrication system and exhaust system. Each of these systems has a definite function.
The engine block is the basic frame of the engine. All other engine parts either fit inside it or fasten to it. It holds the cylinders, water jackets, and oil galleries. The
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engine block also holds the crankshaft, which fastens to the bottom of the block. The camshaft also fits inside the block, except on overhead-cam engines (OHC). In most cars, this block is made of gray iron, or an alloy of gray iron and other metals, such as nickel or chromium. Engine blocks are castings. Some engine blocks, especially those in smaller cars, are made of cast aluminum. This metal is much lighter than iron. However, iron wears better than aluminum. Therefore, the cylinders in most aluminum engines are lined with iron or steel sleeves. These sleeves are called cylinder sleeves. Some engine blocks are made entirely of aluminum.
The cylinder head fastens to the top of the block, just as a roof fits over a house. The underside forms the combustion chamber with the top of the piston. The most common cylinder head types are the hemi, wedge, and semi-hemi. All three of these terms refer to the shape of the engine's combustion chamber. The cylinder head carries the valves, valve springs and the rockers on the rocker shaft, this part of the valve gear being worked by the push-rods. Sometimes the camshaft is fitted directly into the cylinder head and operates on the valves without rockers. This is called an overhead camshaft arrangement. Like the cylinder block, the head is made from either cast iron or aluminum alloy.
The piston is an important part of a four-stroke cycle engine. Most pistons are made from cast aluminum. The piston, through the connecting rod, transfers to the crankshaft the force created by the burning fuel mixture. This force turns the crankshaft .Thin, circular, steel bands fit into grooves around the piston to seal the bottom of the combustion chamber. These bands are called piston rings.[1] The grooves into which they fit are called ring grooves. A piston pin fits into a round hole in the piston. The piston pin joins the piston to the connecting rod. The thick part of the piston that holds the piston pin is the pin boss. [2] The piston itself, its rings and the piston pin are together called the piston assembly.
The connecting rod is made of forged high-strength steel. It transmits motion from the
piston to the crankpin on the crankshaft. The connecting rod little end is connected to the piston pin. A bush made from a soft metal, such as bronze, is used for this joint. The lower end of the connecting rod fits the crankshaft journal. This is called the big
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end. For this big-end bearing, steel-backed lead or tin shell bearing are used. These are the same as those used for the main bearings. The split of the big end is sometimes at an angle, so that it is small enough to be withdrawn through the cylinder bore. The connecting rod is made from forged alloy steel. [3]
The crankshaft, in conjunction with the connecting rod, coverts the reciprocating motion of the piston to the rotary motion needed to drive the vehicle. It is usually made from carbon steel which is alloyed with a small proportion of nickel. The main bearing journals fit into the cylinder block and the big end journals align with the connecting rods. At the rear end of the crankshaft is attached the flywheel, and at the front end are the driving wheels for the timing gears, fan, cooling water and alternator.[4] The throw of the crankshaft, the distance between the main journal and the big end centers, controls the length of the stroke. The stroke is double the throw, and the stroke-length is the distance that the piston travels from TDC to BDC and vice versa. [5]
The valve system is made up of those parts needed to open and close the valves at just the right time. To coordinate the four-stroke cycle, a group parts called the valve train opens and closes the valves (moves them down and up, respectively). These valve movements must take place at exactly the right moments. The opening of each valve is controlled by a camshaft.
难点分析：
Notes to Text
1、The piston, through the connecting rod, transfers to the crankshaft the force created by the burning fuel mixture. This force turns the crankshaft. Thin, circular, steel bands fit into grooves around the piston to seal the bottom of the combustion chamber. These bands are called piston rings. The grooves into which they fit are called ring grooves.
活塞通过连杆与曲轴相连，并将燃烧混合气产生的力传给曲轴。这种力使曲轴转动。把薄钢圈放进活塞周围的凹槽以密封燃烧室的底部。这些圈叫做活塞环。安装活塞环的凹槽称为活塞环槽。
2、A piston pin fits into a round hole in the piston. The piston pin joins the piston to the connecting rod. The thick part of the piston that holds the piston pin is the pin boss.
活塞销装在活塞的环形的孔里。活塞销把活塞和连杆连接起来。用来支撑活塞销
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的活塞厚的部分称为活塞销凸台。 3、A bush made from a soft metal, such as bronze, is used for this joint. The lower end of the connecting rod fits the crankshaft journal. This is called the big end. For this big-end bearing, steel-backed lead or tin shell bearings are used. These are the same as those used for the main bearings. The split of the big end is sometimes at an angle, so that it is small enough to be withdrawn through the cylinder bore. The connecting rod is made from forged alloy steel.
衬套由软金属制成，例如青铜，被用于这种连接。在连杆低端安装曲柄轴颈。这被称为连杆大头。对连杆大头轴承来说，使用的是钢背铅轴承或轴瓦式锡轴承。这些轴承与那些被用作主要轴承的轴承相同。大头的裂口有时有一个角度，以便足够小通过气缸。连杆由锻造的合金钢制成。
4、The crankshaft, in conjunction with the connecting rod, converts the reciprocating motion of the piston to the rotary motion needed to drive the vehicle. It is usually made from carbon steel which is alloyed with a small proportion of nickel. The main bearing journals fit into the cylinder block and the big end journals align with the connecting rods. At the rear end of the crankshaft is attached the flywheel, and at the front end are the driving wheels for the timing gears, fan, cooling water and alternator. 曲轴和连杆一起，把活塞的往复运动转化为驱动车辆需要的旋转运动。通常由含少量镍的碳钢制成。主要轴承轴颈安装在气缸体和匹配连杆大头末端的轴颈上。曲轴的后端连接着飞轮，前端是连接着定时齿轮、风扇、冷却水和交流发电机的驱动轮。
5、The throw of the crankshaft, i.e. the distance between the main journal and the big end centers, controls the length of the stroke. The stroke is double the throw, and the stroke length is the distance that the piston travels from TDC to BDC and vice versa. 曲轴的摆幅，即在主要轴颈和连杆大头末端中心之间的距离，控制着冲程的行程。一个冲程等于两个摆幅的行程，即活塞从上止点运动到下止点的距离，反之亦然。
检查评价：
Exercises
1、Answer the following questions
1) List the main parts of the engine overall mechanics? 2) What are the main function of the engine block？ 3) What does the connecting rod be made from？ 4) What is the function of the crankshaft？ 5) What controls the length of the stroke? 2、Translate the following into Chinese 1) casting 2) rocker 3) crankpin 4) water jacket 5) oil gallery 6) gray iron
7) cylinder sleeve
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8) pin boss 9) carbon steel
3、Translate the following into English 1) 气缸盖 2) 顶置凸轮 3) 活塞环 4) 正时齿轮 5) 配气系统 6) 轴颈
4、Translate the following passage into Chinese.
There are a couple of routes to take depending on your budget and goals. The main four options are:
1. Intake – either a Cold Air Intake or a high flow filter. 2. Exhaust System 3. Engine Management
4.Supercharger Pulley Reduction
A cold air intake or high flow filter gives your engine the ability to ―ingest‖ more air and then the ECU can modify the air/fuel ratio for a more powerful ―charge‖. Some vendors claim their intakes to be worth 18+ hp…that may be a little high…but we have seen 0-60 times improve by 3 seconds.
拓展素材：
Tuning element
What comes first, second, third, and so on?
So you want to more power, better handling, stronger braking, and a ―cooler‖ car but you don’t have a ton of cash right now.
Can you only go step 1 or 2 right now, but want to make sure you do not spend money in the future fixing a mistake you make right now because of your limited budget?
Well, have we some good news for you! Make the right choices/decisions/purchases now and you won’t be thinking down the road ―what if‖! It even works in life.
Here, we will lay out a couple of alternative paths and help to set you on the right one for you budget and performance goals.
From exhaustive research, the top four performance items to start with are: 1. Engine (Make more power) 2. Suspension 3. Wheels/Tires 4. Brakes
Most enthusiast will go in the order listed above (the order is a natural progression. For example, you may need larger wheels/tires if you decide to go with one of the ―Big Brake Kits‖. But everyone has their preferences and may choose a different order).
Let's break them down...
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Engine
There are a couple of routes to take depending on your budget and goals. The main four options are:
1. Intake – either a Cold Air Intake or a high flow filter. 2. Exhaust System 3. Engine Management
4.Supercharger Pulley Reduction
A cold air intake or high flow filter gives your engine the ability to ―ingest‖ more air and then the ECU can modify the air/fuel ratio for a more powerful ―charge‖. Some vendors claim their intakes to be worth 18+ hp…that may be a little high…but we have seen 0-60 times improve by 3 seconds. Exhausts – Cat Back & Header
You hear a lot of people complain that an exhaust system for the MINI can be a little pricey for the actual horsepower you gain. However, it is perhaps the best second step. While a Cat-Back is a good start, a new header with a high flow cat completes the exhaust system.
Think about it. If you plan on making your engine work harder (increased power), don’t make rob some of that power through ―pumping losses‖ (making the engine work to expel exhaust gases). Reducing exhaust back pressure allows for increased ―throughput‖. In a nutshell, a high flow exhaust system is the solid foundation you need for future power upgrades. Supercharger Pulley
There isn’t a part out there that gives you more bang for the buck! For around $160 (+ labor…which can run up to $300+) your Cooper S can pump out an extra 25 hp! A 15% reduction in the supercharger pulley size increases boost from 11 psi to around 15 psi.
A word to the warranty conscious…though a supercharger pulley is the fastest way to get better 0-60 times…it is also the fastest way to void your factory warranty. That is part of the reason why we recommend doing the cold air intake and exhaust systems first.
Engine Management
You can install some engine management before or after the supercharger pulley install. The engine management will make the biggest difference AFTER the pulley install.
200+ Ponies!
With the intake, exhaust, header and engine management you can reasonably expect 180-190 hp to the wheels (which translates to 200+ hp at the flywheel). At $2,000 that is considerably less that the $5,000 for the John Cooper Works. In essence, you are paying for warranty with the Works package. Don’t get me wrong, it is a very good, well put together package…with the added benefit that you get to keep your warranty. Wheels/Tires
Not only do a wheels/tires upgrade separate your car from \significant improvement in handling. Suspension
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The best bang for the buck in suspension modifications is changing out the rear sway bar...simple to do yourself...and ooooohhh what a difference! The next best suspension upgrade for the money is a set of lowering springs Brakes
Steel lines, rotors, and pads are the cheapest thing to change out...but for truly breath taking power...consider a \
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