Notes
| regardless of | |
| both... and... | , , ... ... e.g. Both above and below the piston |
| because of | - - |
| instead of | - |
| to consist of | |
| to include smth (into) | - |
| to draw into (drew, drawn) | () |
| to push out of | |
| to reach smth | , - |
| as long as | , () |
| as soon as | |
| twice as many (much) | |
| twice less | |
| shortly after | () |
| just before | |
| to start | |
| to continue | |
| to stop, complete | |
| to communicate with | |
| although | |
| moreover | |
| nevertheless | |
| however | |
| thus | |
| under the favorable conditions | |
| to be available |
REMEMBER THE FOLLOWING ABBREVIATIONS
| BDC (bottom dead center) | |
| TDC (top dead center) | |
| cpp (controllable pitch propeller) | () |
| cst (centistoke) | |
| (Centigrade) | |
| F (Fahrenheit) | |
| HFO (Heavy Fuel Oil) | |
| ECR (economic continuous rating) | |
| MCR (maximum continuous rating) |
Irregularities in Operation, Causes and Remedies
| Symptom: | Cause: | Remedy: | ||||||||
| 1. Starting difficulties. | ||||||||||
| Insufficient or no compression. | a) Inlet and exhaust valves leaking. | Grind or replace valves, mill the seats. | ||||||||
| '' | b) Inlet and exhaust valves sticking. | Oil the valve spindles with gas oil, or remove valves for cleaning. | ||||||||
| '' | c) Insufficient rocker arm clearance. | Adjust valves. | ||||||||
| '' | d) Piston rings sticking in grooves, or worn. | Loosen rings and replace them if necessary. | ||||||||
| '' | e) Valve springs broken or slack. | Replace springs. | ||||||||
| '' | f) Cylinder liner worn. | Replace. | ||||||||
| '' | g) Cylinder liner scratched. | Replace. | ||||||||
| Fuel valve out of order. | Nozzle needle valve sticking or leaking. | Release it, grind or replace if required. | ||||||||
| Fuel pumps give no or insufficient pressure. | a) Pressure valve sticking or leaking | Clean it, replace if required. | ||||||||
| '' | b) Pressure valve holder loose. | Tighten. | ||||||||
| '' | c) Piston and lining worn. | Replace. | ||||||||
| Insufficient or no fuel supply. | a) Air in fuel system. | Ventilate | ||||||||
| '' | b) Fuel lift pump defective. | Repair pump and ventilate fuel system. | ||||||||
| 2. Engine starts, but stops shortly afterwards. | ||||||||||
| Engine starts, but stops after a while | a) Fuel tank empty | Fill tank and remove air from fuel system. | ||||||||
| '' | b) Air in fuel system | Airate. | ||||||||
| '' | c) Fuel filter choked | Clean the filter. | ||||||||
| 3. Engine does not reach maximum capacity | ||||||||||
| Insufficient or no compression. | See under "Starting difficulties". | |||||||||
| Fuel valves out of order. | '' | |||||||||
| Excessive waste of oil from fuel pumps. | Fuel pump plungers worn. | Replace plungers and sleeves. | ||||||||
| Engine takes load only momentarily. | Fuel supply blocked, fuel pump out of order. | Check the whole fuel system thoroughly. | ||||||||
| Engine does not reach full speed. | Governor drive broken. | Adjust or replace governor spring. | ||||||||
| Engine loses too much speed under load. | Incorrect adjustment of governor, or something in the system works sluggishly. | Adjust governor. Check governor system, and correct the defect. | ||||||||
| Smell of heat. | Insufficient cooling water. | Stop engine, fill in cooling water when the engine has cooled off. | ||||||||
| 4. Engine speed too high. | ||||||||||
| Languid movements of governor arm. | Governor arm has become oblique by blows or the like. | Stop engine quickly by interrupting the fuel supply and check the governor system. | ||||||||
| Incorrect adjustment of governor. | Adjust governor. | |||||||||
| 5. Engine knocks. | ||||||||||
| Ignition too advanced. | Incorrect adjustment of fuel oil pumps. | Adjust correctly. | ||||||||
| Mechanical faults. | Connecting rod bolls loose. | Check connecting rod bolts thoroughly. If cracked or defect, replace them. Tighten nuts. | ||||||||
| Mechanical faults. | a) Hot or worn bearings. | Replace bearing lining, check lube oil system, correct fault if any before restarting. | ||||||||
| '' | b) Flywheel loose. | Tighten nut and lock it. | ||||||||
| '' | c) Worn pistons and linings. | Replace them. | ||||||||
| 6. Engine smokes. | ||||||||||
| Black smoke from engine. | a) Air filter choked. | Clean filter. | ||||||||
| '' | b) Fuel valve out of order. | See under "Starting difficulties". | ||||||||
| '' | c) Insufficient compression. | |||||||||
| '' | d) Engine overloaded. | Reduce load. Never overload. | ||||||||
| '' | e) Thermostat valve leaking. | Replace valve. | ||||||||
| Black smoke from engine. | Lube oil forces its way past leaky piston and oil rings into combustion chamber. | Replace oil and piston rings. | ||||||||
| 7. Excessive fuel oil consumption. | ||||||||||
| Engine runs hot. | Engine overloaded. | Reduce load(never overload). | ||||||||
| Insufficient compression. | See under "Starting difficulties". | |||||||||
| Leaky fuel system. | a) Fuel pipes leaking. | Repair or replace. | ||||||||
| '' | b) Fuel pump plungers and linings worn. | Replace defective parts. | ||||||||
| Increasing oil level. | Fuel lift pump diaphragm defective. | Replace diaphragm. | ||||||||
| Engine smokes. | a) Fuel valves out of order. | Clean and adjust valves. | ||||||||
| '' | b) Thermostat valve leaks. | Replace valve. | ||||||||
| 8. Excessive lubricating oil consumption. | ||||||||||
| Lube oil enters combustion chamber. | Oil piston rings worm. | Replace rings. | ||||||||
| '' | Pistons and cylinder linings worm. | Replace defective parts. | ||||||||
| Lube oil leaks out of crank shaft end bearings. | Oil seal rings and bearings worn. | Replace seal rings and repair bearings. | ||||||||
| 9. Engine runs hot. | ||||||||||
| Smell of heat. | a) No cooling water. | Stop engine, fill up with cooling water when engine cooled off. | ||||||||
| '' | b) Engine overloaded. | Unload engine. | ||||||||
| Cooling water temperature too high. | Lack of cooling water owing to defective cooling water pump or escape of water from leakage. | Remedy the fault. | ||||||||
| Cooling water too high. | a) Defective thermostat. | Replace thermostat. | ||||||||
| '' | b) Fan belt too loose. | Tighten belt. | ||||||||
| '' | c) Radiator choked. | Clean radiator. | ||||||||
| '' | d) Pressure vacuum valve out of order. | Repair valve. | ||||||||
| Lube oil pressure insufficient. | a) Lube oil filter choked. | Clean filter. | ||||||||
| '' | b) Lube oil pump defective. | Repair pump. | ||||||||
| '' | c) Lube oil pressure line leaks. | Repair or replace line. | ||||||||
| '' | d) Defective lube oil overflow valve. | Repair valve. | ||||||||
| 10. Engine jars. | ||||||||||
| Engine misfires. | a) Air in fuel system. | Ventilate. See under "Starting difficulties" and "Engine does not reach maximum capacity". | ||||||||
| '' | b) Fuel valves out of order. | |||||||||
Exercise 1. Answer the following questions:
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1) What is a diesel engine?
2) How is the diesel engine power expressed?
3) What are the characteristics of slow-speed diesel engine? (name the cylinder bore, rpm, power output).
4) What kind of engine is called a directly-coupled engine, slow or medium-speed?
5) In what kind of ships are medium-speed engines applied? What are their particulars?
6) What are the advantages of slow-speed engines and benefits of medium-speed ones?
7) Where is high-speed diesel engine installed and what are its characteristics?
8) What fuel does each of these types of diesel engines burn?
9) How else can diesel engines be classified?
10)Where is combustion chamber in the double-acting engine situated?
11) Why are double-acting engines obsolete now?
12) What cycles do diesel engines have? Describe them.
13) During what period does the complete cycle of operation take place in the two-stroke engine?
14) What are the advantages of the four-stroke engines over the two-stroke ones?
Exercise 2. Give synonyms to the following words.
To spray, to drive, to pass, to open, to leave, to fall, to occur, to develop, to obtain, to increase, to start, to reach, to include, to finish, to work.
Exercise 3. Give antonyms to the following words.
Low, upward stroke, inlet valve, scavenging port, to reduce, to expand, to drop, to absorb, to stop, above, popular, before, light.
Exercise 4. Explain in English what is meant by:
Combustion chamber, suction stroke, compression stroke, combustion and expansion stroke, exhaust stroke, upward stroke, downward stroke, scavenging port, exhaust valve, fuel injection valve, uniflow scavenging, air charge, burned gases.
Exercise 5. Explain the difference between
1) Single-acting and double-acting principles;
2) Trunk-piston, cross head and opposed-piston types;
3) Two-stroke and four-stroke engines;
4) Upward and downward strokes;
5) Exhaust valve and exhaust port;
6) Air inlet valve and scavenging port;
7) Heavy fuel oil and light fuel oil;
8) Slow, medium and high-speed diesel engines.
Exercise 6. Describe the engine installed abroad your vessel using the following words. Mention its raying (output power and RPM).
Slow, medium, high-speed, two or four-stroke, single or double acting, in-line or V-shape, with cross head or trunk piston, direct, coupled or connected, to the propeller b gear.
Exercise 7. Made up a dialogue of your own based on the dialogues given below.
THE CYLINDER AND PISTON ASSEMBLY I
Notes:
| cylinder head (cover) | |
| surface | |
| scraping | |
| to scrape | |
| machining | . |
| to renew | |
| safety valve | |
| rocker | |
| indicating cock | |
| rod | |
| valve disk | |
| bush | |
| valve stem | |
| pin | |
| turn | |
| to cut off | |
| rod | |
| valve disk | |
| bush | |
| valve stem | |
| pin | |
| turn | |
| to cut off | |
| fitting | , , |
| to weld | |
| to fit into position | |
| exhaust valve | |
| cylinder assembly | |
| we have to... we Should... | () |
The Cylinder Heads
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Mr. Wilson - What about the cylinder heads? Do the contract surfaces of the cylinder heads require machining or just scraping?
Ch. Eng. - They need both.
Mr. Wilson - Must all.the cylinder head be renewed or can some of them be repaired?
Ch.Eng. - Well, the. starting valves are to be overhauled with later pressure testing. But all the other' fittings (the safety valves, the indicating cocks, etc) should be renewed.
Mr. Wilson - Very well. According to the list of repairs you'd like to replace only four exhaust valves. Why not all of them?
Ch.Eng. - The other exhaust valves are O.K. But their disks and stems should be turned.
Mr. Wilson - Do you think that all exhaust valve rockers and rods should be replaced too?
Ch.Eng. - No,-I don't think so. But the rocker bronze bushes and pins should be renewed.
Mr. Wilson-Well, I see.
THE CYLINDER AND PISTON ASSEMBLY II
Notes:
| piston | |
| repair size | , |
| plasma - jet hard facing | |
| piston pin | |
| pressure test | |
| groove | |
| main bearing | |
| ring | |
| top-end bearing | |
| renewal | |
| measure | |
| bottom-end bearing | |
| adjust | |
| measurement | |
| clearance | |
| adjustment | |
| to rebabbit | |
| babbit = white metal = antifrictional metal | |
| to bore | |
| boring |
- Mr. Wilson - Well, let's pass on to the piston. Can you tell me. What should be done about them?
Ch. Eng. - according, to the list of repairs two piston assemblies are to be replaced. The rest require the following repairs, namely:
- plasma jet hard facing and cutting the grooves for the piston rings;
- renewal of the piston rings on all the piston;
- measuring the clearances in the top-end bearings. If required they should be rebabbited and then fitted into position with necessary clearances.
Mr. Wilson - I see. By.the way do you want the top end bearings to be rebabbited and adjusted to the new repair sizes of the piston pins or to the old ones?
Ch. Eng. - To the old ones. The pistons will require the pressure testing.
Mr. Wilson - What arc you plans about the piston telescopic system?
Ch. Eng. - Unfortunately it should be completely replaced.
Mr. Wilson - And what about the main bearings?
Ch. Engineer - The main bearings which have big cracks in babbit should be remetalled and then fitted into position. The other bearings should be used depending on their conditions and clearances.
Mr. Wilson - Shall we repair the bottom - end bearings according to the list of repairs?
Ch.Eng. - Oh, yes. Rebabbiting, boring, scraping, fitting and all that I'm sure you know what should be done.
Mr. Wilson - Well, we'll try to do our best.
Exercise 8. :
A: Do the contact surfaces of the cylinder heads require machining or just scraping?
B:......................
A: What are you planning to do with the starting valves?
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B:......................
A: What valves should be replaced?
B:......................
A: What are your plans about the piston telescopic system?
B:......................
A: And what about the main bearings?
B:......................
A: Shall we repair the bottom end bearing according to the list of repairs?
B:......................
A: How many cylinder liners should be replaced?
B:......................
Exercise 9. Translate the sentences.
1. , . . . , .
2. , . , . . .
3. , 2 . , . , , .
4. .
5. , . 2 . , . 3 , .
