Motor Engineering – MEO CLASS 4 MMD PAPER

171. If you get a heavy scavenging air fire, which one of the following part is likely to take the most serious damage ?

1. Stuffing box.
2. Exhaust valve.
3. Piston.
4. Crosshead bearing.

ANS.: A

172.Why are we blowing the engine before start (slow turning on air) ?

1. To be sure that we do not have water collected in the cylinders.
2. To be sure that no parts are loose, or that the engine is blocked from rotation.
3. To get fresh air into cylinders ensuring a safe start of the engine.
4. To be sure that all indicator cocks are closed, and no passage into the combustion chamber.

ANS.: A

173. The cylinder oil for FO with high sulphur content is supposed to be:

1. acidic.
2. Alkaline
3. neutral.
4. does not matter.

ANS.: B

174. A 2 stroke engine is usually equipped with an auxiliary blower fan, which is supposed to be used:-

1. continuously, together with the turbochargers to ensure enough air to the engine during full speed running.
2. during continuously reduced speed under a longer sea voyage.
3. during manoeuvre and manoeuvre speed condition (arrival and departure)
4. during a scavenging fire, to help put out the fire.

ANS.: C

175.What do you consider as the most important  task after a piston job ?

1. A search inside the crankcase for tools and rags.
2. Starting the auxillary blower to ventilate the scavenging belt, and the cylinder liners, to ensure that the engine has sufficient fresh air for starting.
3. Patch up destroyed paint work on the crankcase doors.
4. Starting the engine to see that it rotates

ANS.: A

176.Why is it so important to keep the lub oil viscosity within safe limits?

1. To keep the oil protective film between moving metal surfaces . 
2. The luboil viscosity has no influence on the oil’s lubrication ability.
3. To keep the additives in good condition.
4. It is not important

ANS.: A

177. Total Base Number ( TBN ) is important as a measure of neutralizing ability against strong  Acids. What will You do if this TBN base number is reduced to a low level?-

1. Renew lub oil in the system.
2. Send  one lub oil sample to new  analysis.
3. Nothing.
4. Purify the oil system.

ANS.: A

178. What can happen with a lub. oil cooled piston if you stop the lub. oil pump immediately after You stop the engine?

1. Nothing happens.
2. The oil flashpoint will be changed.
3. Overheating of the piston, and oil coke deposits in the cooling chambers
4. You save the oil sealings in the piston.

ANS.: C

179.You have checked the oil viscosity in an auxiliary engine with the viscosity test kit. The result shows that the viscosity is high. What will you do?

1. Decrease the cooling water temperature for the oil.
2. Clean the system and change the oil
3. Increase the cooling water temperature for the oil.
4. Increase the lub oil pressure.

ANS.: B

180.You have checked the oil viscosity in an auxiliary engine with the viscosity test kit. The result shows that the viscosity is low. What will you do?

1. Clean the system and change the oil.
2. Increase the oil temperature.
3. Start to purify the oil.
4. Decrease the oil temperature.

ANS.: A

181.What could be the reason if the lub oil viscosity increase?

1. Heavy fuel oil leakage to the lub oil system.
2. The lub oil viscosity will not increase.
3. Water-leakage to the lub oil system
4. High lub oil temperature.

ANS.: C

182.What could be the reason if the lub oil viscosity decrease?

1. Heavy fuel oil leakage to the lub oil system.
2. Diesel oil leakage to the lub oil system
3. Low lub oil temperature.
4. Wrong lub oil pressure

ANS.: B

183. A water content greater than 2 % is detected in a lub oil system. What is the best action to do?

1. Continuous purifying the system with the lub oil pumps running.
2. Boil out the water by increasing the temperature.
3. Segregate the oil in a seperate tank for continuous purifying.
4. It is no danger before the water level reach 6-8%.

ANS.: C

184. What long term effect will excessively high temperature have on lubricating oil quality?

1. Cause oxidation which reduce viscosity.
2. Evaporates the oil giving high consumption.
3. The oil flashpoint will be changed.
4. Cause oxidation which increase viscosity.

ANS.: D

185.Which would be the most suitable place to obtain an oil sample for analysis?

1. From the lub. oil pump suction line.
2. From the system pipeline
3. From the oil cooler drain.
4. From the filter drain.

ANS.: B

186. If water contamination occurs in the crankcase oil of an auxiliary engine the oil viscosity will:-

1. Increase.
2. Nothing happens.
3. Stay at the same.
4. Decrease.

ANS.: A

187.What type of lubricating oils are generally used in auxiliary engines?

1. Detergent.
2. Alkaline.
3. Synthetic.
4. It is not important.

ANS.: B

188.In a Burmeister & Wain main engine, at what point is cylinder oil injected?

1. Just before “Top Dead Centre”.
2. As the piston passes “The Lubrication Points” in a downward direction
3. As the piston passes “The Lubrication Points” in an upward direction
4. Just before “Bottom Dead Centre”

ANS.: C

189. What differential pressure would you expect to find across an engine lub.oil filter?

1. 1.2 Bar
2. 3.0 Bar
3. Zero
4. 0.2 Bar

ANS.: D

190.You notice the sump level in an engine has increased and no new oil has been added. What action would you take?

1. Drain some oil from the engine.
2. Stop the engine and look for a fuel or water leak.
3. Reduced the load, and look after fuel or water leak.
4. Leave it the same.

ANS.: B

191.Oil analysis results show a high level of tin. What could be the cause of this?

1. Bearing damage.
2. Water contamination.
3. Fuel contamination
4. Too high lub.oil temperature.

ANS.: A

192. We have two kinds of turbocharging systems: constant pressure and impulse. The difference between these two can be found in:

1. The exhaust gas receiver.
2. Scavenging air coolers.
3. The blades on the exhaust gas turbine.
4. The scavenging valves of the engine.

ANS.: A

193. We have a problem with surging in the turbocharger. Which of the following could be the cause?

1. Worn out bearings on the turbocharger.
2. The lubrication oil pump is malfunctioning.
3. Dirty rotor blades.
4. Dirty scavenging air cooler on the air side

ANS.: D

194. The revolutions on the turbocharger have increased during the night with unmanned engine. Could this be caused by:

1. The viscosity of the fuel is to high .
2. We have favourable winds and current.
3. The current and wind are holding the vessel back
4. Poor combustion due to malfunction of fuel valves

ANS.: C

195. The turbocharger (constant pressure) is making “whoofing” noises. What might be the cause?

1. Heavy seas from behind.
2. A faulty turbocharger bearing.
3. One or more leaking exhaust-valve(s).
4. Strong current against

ANS.:A

196. After how many hours would you consider changing the turbocharger bearings, even though all appears to be normal?

1. 12.000 hours.
2. 4.000 hours.
3. 25.000 hours.
4. 30.000 hours.

ANS.: A

197.The timing of the engine is delayed. The exhaust temperatures are high. How would you expect this to affect the turbocharger?

1. Decreased turbocharger revolutions.
2. Surging of the turbocharger.
3. Increased turbocharger revolutions
4. Higher air and gas temperature after turbocharger.

ANS.: C

198.We have a problem with vibration in the turbocharger. What might be the cause?

1. Dirty air inlet filter.
2. The turbine rotor is not balanced
3. The lubricating oil needs to be changed.
4. Worn out turbocharger bearings.

ANS.: B

199. With full load on the main engine, the RPM for the turbocharger is too low. What may cause this?

1. The diffuser ring is damaged.
2. Exhaust temperatures on the main engine are too high.
3. Dirty nozzle ring.
4. The lubricating oil pump is malfunctioning.

ANS.: C

200. With full load on the main engine, the turbocharger tachometer reads: Too low RPM. Why?

1. Damaged connection between pick-up and tachometer unit
2. Pick up is not connected to turbocharger.
3. Turbocharger need to be cleaned/overhauled.
4. Pick up for tachometer is wrongly adjusted.

ANS.: D

201.The lubricating oil on the exhaust side of the turbine blower gets very dirty after only a few hours in service. What can the reason be?

1. Exhaust gas leaking into the oil chamber
2. Wrong type of oil used.
3. Lubricating oil is mixed with salt water
4. Worn out bearing turbine side

ANS.: A

202. After water-washing the turbocharger exhaust side, the blower starts to vibrate. What has happened?-

1. Water drain for washing system is clogged.
2. Foundation bolts for the blower unit are loose
3. The rotor blades are damaged or the blades are not properly cleaned
4. Inlet filter partly clogged.

ANS.: C

203. The blower’s air delivery is not sufficient. What is the cause?

1. Air temperature in engine room too high.
2. Dirty scavenge duct.
3. Clogged air inlet filter.
4. Cooling water temperature too high

ANS.: C

204.Why is it important to slow down the main engine RPM while water-washing the turbocharger?

1. To protect the bearings .
2. To protect the exhaust gas economizer.
3. To protect the blower side .
4. Not to damage the rotor blades.

ANS.: D

205. Some engine manufacturers recommend that washing of the compressor side is not carried out. Is this due to:

1. Greasy sludge from the compressor sticking between the fins in the air coolers, necessitating extra cleaning of these.
2. Large volumes of water being carried over into the cylinders of the engine.
3. The nozzle ring becoming corroded
4. The thermal shock exhibited by the vanes.

ANS.: A

206.What is the meaning of the term “valve clearance”?

1. The clearance between the rocker arm and valve pushrod.
2. The clearance between valve spindle disc and seat.
3. The clearance between the rocker arm and camshaft pushrod.
4. The clearance between the rocker arm and valve pushrod in either warm or cold state.

ANS.: A

207.The meaning of lapping a valve and valve seat is:.

1. Adjust the overlapping of the inlet and exhaust valves.
2. Grind the valve against the valve seat to obtain a uniform sealing surface.
3. Machining the valve in a lathe machine.
4. Repair by welding.

ANS.: B

208. Some 4-stroke engines are fitted with a rotocap on the cylinder head valves. For what reason?

1. Rotate the inlet valve during operation.
2. Distribute the exhaust gas or the air inlet better to improve combustion.
3. Improve the scaling surface function, increase the service time of the exhaust valve in the engine
4. To prevent the valve spindle from sticking.

ANS.: C

209.When overhauling the cylinder covers on a modern 4-stroke engine, is it important not to interchange inlet and exhaust valves?

1. Not so important.
2. Important due to different material and working conditions.
3. Can be changed  if same size.
4. Important due to different type size valve guide.

ANS.: B

210.What is the purpose of the cylinder head safety valve?

1. To relieve excessive high pressure in the cylinder to protect the engine from being damaged.
2. To adjust the cylinder pressure to a safe working pressure.
3. A valve for safety stop (emergency) of the engine.
4. For indication of engine being overloaded.

ANS.: A

211. Most of the engine makers recommend to change the cylinder head gaskets each time a piston overhaul is carried out. Why?

1. To obtain a proper sealing and correct distance between piston and cover in TDC position.
2. To increase the consumption of parts so they can make more money.
3. To avoid heat transfer to the cylinder head.
4. To be granted a proper sealing with a new gasket.

ANS.: A

212. Some 4-stroke engines are equipped with cooled fuel valves. Why is it so important to keep the coolant’s temperature correct?

1. For cooling only.
2. For preheating only
3. To avoid overheating the fuel nozzle
4. For cooling and to maintain correct viscosity on the fuel when injected

ANS.: C