170.For an ordinary four-stroke diesel engine the exhaust valves close _____.
A． after TDC √ B． before TDC C． after BDC D． before BDC
171.For an ordinary four-stroke engine the exhaust valves open _____.
A． after TDC B． before TDC C． after BDC D． before BDC √
172.For an ordinary four-stroke engine the inlet valves open _____.
A． after TDC B． before TDC √ C． after BDC D． before BDC
173.For an ordinary modem marine four-stroke engine the inlet valves close _____.
A． after TDC B． before TDC C． after BDC √ D． before BDC
174.For one or two types of engine, the piston and rod can be withdrawn downwards from the
cylinder into the crankcase and then out through the _____. A． cylinder casing B． cylinder bore C． crankcase door √
D． aperture in the cylinder block
175.For one or two types of engine, the piston and rod can be withdrawn downwards from the
cylinder into the crankcase and then out through _____. A． the cylinder cover B． the bottom of bed-plate C． the sump
D． the crankcase door √
176.Four strokes consist of suction, compression, _____ and exhaust stroke.
A． combustion √ B． condensation C． charging D． evaporation
177.Fresh water is used for the cooling of cylinder jackets and _____ of the marine diesel
engine.
A． cylinder covers √ B． lubricating space C． crosshead D． exhaust manifold
178.Fuel has been injected but ignition failsThe possible cause may be _____.
A． leaky exhaust valve
B． increased scavenging air temperature C． engine cylinders not scavenged sufficiently D． water in the fuel oil √
179.Fuel injected into a diesel engines cylinder is ignited by _____.
A． the heat compressed fuel/air mixture in the cylinder √ B． the fuel igniter C． the fuel injector D． the fuel pump
180.Fuel injection uses the jet pump system and a Woodward type hydraulic _____ is used to
control engine speed. A． controller B． governor √ C． instrument D． apparatus
181.Fuel injection valves should be taken out, cleaned, and lifting checked every _____.
A． two to four months B． four to six months √ C． six to eight months D． year
182.Fuel is delivered into the combustion space by _____.
A． a cooling system B． a lubricating system C． an electric system D． an injection system √
183.Fuel is not supplied to the corresponding cylinder due to a failure of _____.
A． the motor
B． the fresh water generator C． the governor D． the fuel pump √
184.Fuel is not supplied to the corresponding cylinders due to _____.
A． a failure of the motor B． a failure of lubricator
C． a failure of cylinder D． a failure of fuel pump √
185.Fuel oil is pumped by means of _____ from the bunker tanks.
A． a transfer pump √ B． a bilge pump C． a service pump D． a vacuum pump
186.Fuel oil is thought to be one of the main factors _____ the operation and maintenance
of an engine.
A． have nothing to do with B． having nothing to do with C． have much to do with D． having much to do with √ 187.Fuel pump index is _____.
A． the viscosity index B． the fuel oil contents C． the starting speed
D． the reading at the rack √
188.Fuels of high quality with their earlier ignitions will cause higher _____ pressure in
cylinders of a diesel engine. A． compression B． maximum √ C． rated D． oil
189.Generally the function of lubrication is to form of a film of lubricant between any two
surfaces that have relative _____, so that surfaces dont get touch with each other. A． gravity B． motion √ C． ratio D． density
190.Generally the gudgeon pin is fully floating in both connecting rod small end and _____.
A． the crosshead B． the crankshaft C． large end
D． the piston bosses √
191.Generally, the gudgeon pin is fully floating in both connecting rod small end and _____.
A． the piston rings B． the piston rods
C． the piston bosses √ D． the piston heads
192.He said that he had turned the main engine one complete revolution with the _____.
A． turning gear √ B． steering gear C． spur gear D． chain gear
193.Head tank should be used to remove _____ from cooling water.
A． scale B． sludge C． chemicals D． air √
194.Heat energy is a source of power, but _____ will cause damage to the engine.
A． excessive heat √ B． insufficient heat C． effective cooling D． high output
195.Here some oil in the oily water separator, as a result of its lower _____, will separate
and rise into the oil collection space. A． temperature B． viscosity C． density √ D． velocity
196.High-speed rotating in a centrifugal purifier can produce a force _____ larger than the
force of gravity.
A． many thousand times √ B． between times C． one time D． at times
197.If _____ are taken at regular intervals, any unequal distribution of load will be easily
found out.
A． differential of crank-webs B． indicator diagrams √ C． lube oil reading out
D． misalignment of crank-throws
198.f a kind of liquid is used to cool the diesel engine, it is invariably called _____.
A． lubricant B． coolant √
C． combustion product D． second refrigerant
199.If diesel oil in this tank is used, the _____ of the oil must not exceed 120 degree F.
A． viscosity B． flash point C． acid value D． temperature √
200.If the atomizer holes are enlarged beyond the makers recommended size, the atomizer must
be _____. A． repaired B． replaced √ C． replenished D． repeated
201.If the engine _____ for a long period, there will be a danger of frost.
A． must to stand inoperative B． has to stand inoperative √ C． must be stood idle D． will stand idle
202.If the engine does not start on air, it may be due to _____.
A． low compression of the fuel pumps B． incorrect timing of fuel pumps C． the starting air valves stuck √ D． air-locks in fuel oil pipeline
203.If the engine does start on air, but combustion does not immediately begin, the cause
may be _____.
A． failure of the fuel pumps B． starting air pressure too low C． stop valve in air line closed D． the turning gear still engaged √
204.If the engine does start on air, but combustion does not immediately begin, the cause
may not be _____. A． low compression
B． failure of the fuel pump to discharge fuel C． incorrect timing of fuel pump D． turning gear being still on √
205.If the flame from combustion in the cylinder of a four-stroke engine past the piston
into the space below, the accumulation of flammable mixture would be ignited, thus resulting in _____.
A． the crankcase explosion √