1 Passage 1 （原题库第 1 篇）Valve drive mechanismThe valve drive mechanism commands the inlet and exhaust valves at the required timing. 第 3 题 The valve drive mechanism consists of an inlet and exhaust cam follower (8) each suspended in a plunger of the tappet assembly (7), two tubular push rods (4) with ball joints, two nodular cast iron rocker arms (2) suspended in a rocker arm bearing bracket, two yokes (5) and a yoke guide pins. See Fig. 4-1. The tappet rollers follow the cam profiles and transfer the movements through push rods to the rocker arms. 第 4 题 The rocker arms operate the inlet and exhaust valves through yokes (5). Lubrication for the rocker arms comes from the engines secondary oil supply manifold through drillings in the cylinder head and rocker arm bracket. 第 2 题 The tappet assembly receives lubricating oil via channels in the engine block from the main supply manifold. For the roller and shaft, the oil is supplied through the guiding plunger. 第 4 题 To compensate for heat expansion a clearance must exist between the rocker arm and yoke.第 1 题 All adjustments have to be done on a cold engine only. 1. According to the Passage, the best time to adjust the valve clearance is _. A. before the engine is started B. when the engine is running C. after the engine has just been stopped D. when something has gone wrong with the engine 注：根据文章来看，调节阀间隙的最好时间是在发动机启动之前。2. The roller and the tappet assembly are lubricated by means of_. A. the main lube system B. the secondary oil system C. the special pumping system D. the turbine oil system 注：滚轮和挺杆组件借助于主润滑系统润滑。3. According to the Passage, the valve drive mechanism does not include_. A. tappet rollers B. push rods C. nodular cast iron D. yokes and guide pins 注：根据文章来看，阀驱动机构不包括球墨铸铁。 （包括挺杆滚轮、顶杆、吊梁和导销）4. To close valves tightly, which clearance should be inspected according to the maintenance schedule? A. The one between the cam and the tappet roller. B. The one between the push rods and the ban joints. C. The one between the rocker arms and the yoke D. The one between two tubular push rods. 注：依据保养清单，要紧密的关闭阀件，应检查摇臂和吊梁之间的间隙。2 Passage 2 （原题库第 3 篇）Charge air cooler The engine is equipped with a charge air cooler. The insert type charge air cooler is mounted in a welded casing (air trunk). The trunk is bolted to the engine block.第 1 题 Standard is a two-stage cooler mounted. The first stage, through which the charge air flows, is cooled with water from the HT cooling system and cooks the charge air till approx. 90 100 oC. The second stage is supplied with water coming from the LT water system and cooks the charge air further till the required temperature of approx. 50oC. 第 2 题 (B) By controlling the water flow through the LT cooler the charge air temperature can be kept constant at the required temperature. The circulating coolant water should always be under positive pressure and should be as clean as possible. The operating air temperature should be maintained by controlling the coolant inlet temperature. Whilst the engine is running the air and coolant temperatures and pressures at inlet and outlet should be checked and logged periodically. 第 3 题 Variations from normal indicate faults developing such as fouling of the film plates or obstruction of the water tubes. 第 4 题 Check daily, during operation of the engine, the working of the telltale hole at the free end of the charge air receiver. The function of this hole is to inform the operator the presence of water in the charge air receiver. Under normal condition only compressed air should escape from this hole. 1. According to the Passage, the expression HT probably means_. A. HIGH TANK B. HIGH TEMPERATURE C. HEAT TRANSMISSION D. HEAT TRANSFER 注：根据文章来看 , HT 的意思是： high temperature，高温。2. In order to maintain the change air temperature we should control_. A. the coolant inlet temperature coming from the first stage cooler B. the coolant flow coming from the second stage cooler C. the coolant outlet temperature coming from the second stage cooler D. the coolant flow coming from the flint stage cooler 注：为维持增压空气的温度，我们应控制来自第二级冷却器的冷却剂流量。3. The charge air temperature departing from normal may indicate that_. A. condensate can be formed B. only compressed air should escape from the telltale C. the film plates are becoming dirty or the water tubes are blocked by scaleD. cooling water may have been carried into the cylinders 注：增压空气温度偏离正常表明镀膜变脏或水管被水垢堵塞。4. The function of the telltale hole is to_. A. detect whether compressed air has escaped from the hole B. control the coolant inlet temperature C. determine whether the coolant water is under positive pressure D. inform the operator the presence of water in the charge air receiver 注：警报孔或监视孔的作用是 通知作业员扫气箱中有水。 telltale hole 监视孔，指示孔，警报孔；charge air receiver. 扫气箱Passage 3 （原题库第 6 篇）第 1 题 At the first start, listen carefully for possible jarring sounds. If anything is suspected, stop the engine immediately, otherwise stop the engine after 5 minutes