Illustrations Illustrations have been designed to clearly and simply communicate the specifi c topic. Several illustrations have been updated for this edition to show the latest equipment. End-of-Chapter Content End-of-chapter material provides an opportunity for review and application of concepts. A concise Summary provides an additional review tool and reinforces key learning objectives. This helps you focus on important concepts presented in the text. Review Questions allow you to demonstrate knowledge, identifi cation, and comprehension of chapter material. ASE-Type Questions help you prepare for the types of questions encountered on the ASE certifi cation tests. 64 Diesel Engine Technology Copyright Inc. points to prevent the oil inside the block escaping. The crankshaft has a number of key parts and including journals, oil galleries, and timing gears. The piston acts as a movable seal that forms the bottom of the combustion chamber. Grooves cut into the side surface of the piston are fitted with piston rings that seal in the com- pression and combustion pressure, and also control the lubri- cating oil film on the wall of the cylinder liner, Figure 4-6. The top piston ring is a compression ring, which forms a seal with the cylinder wall. The middle or intermediate piston rings control about 10% of the compression and combustion pressures, but their main job is to reduce oil consumption inside the cylinder. The bottom piston ring is an oil control ring, which distributes the lubricating oil over the wall of the cylinder and prevents the oil from entering the combustion chamber. Crankshaft The crankshaft converts the reciprocal (up and down) motion of the pistons into rotary (turning) motion. This rotary motion is transferred to the and eventually to the transmission or driveline. Since the crankshaft must transmit all of the power produced by the engine, it the engine’s strongest part, Figure 4-7. The crankshaft protrudes through the cylinder block at the front and rear of the engine. Oil seals at Cylinder block Cylinder block A B Liner is only the wall of the cylinder Liner is the cylinder Piston Piston O-rings Coolant passages Figure 4-4. The two types of liners used in diesel engines. A—Dry liners are thin and do not make contact with the coolant. B—Wet liners are much thicker since they do not have the walls of the block for support. They come into direct contact with the engine coolant. Piston ring Piston ring Connecting rod Figure 4-5. The piston, connecting rod, and crankshaft work together to change the energy of combustion into usable motion. (Cummins Engine Co., Inc.) Figure 4-6. The diesel engine uses three types of piston rings. The top ring is the compression ring and is designed to con- tain combustion chamber pressures. The middle compression/ scraper ring also holds in compression and helps to scrape excess oil from the cylinder walls. The lower ring is called the oil ring or oil control ring. Its job is to keep excess oil from reaching the combustion chamber. Compression ring Oil control ring Intermediate ring Figure 4-7. Typical diesel engine crankshaft. Note the names of the various crankshaft parts. (Cummins Engine Co., Inc.) Connecting rod journals Crankshaftfthk throws Main bearing journals C ght GGoodheart-Willcox CCo., ffrom ft f ffeatures, i ge ft s ansferred fflywheel n ft r prod y , iis Fig ft gh eng uusedhavethese sIfareparts Fi . en ine ft. En ine C ti jou C Chapter 26 Engine Reassembly and Installation 543 Copyright Goodheart-Willcox Co., Inc. Summary Keep the working area, tools, equipment, and engine components clean at all times during the reassembly process. been stored prior to reassembly, reinspect the parts for rust and cleanliness, and clean if needed. Refer to the engine service manual for proper nut, bolt, and stud torque, clearances between compo- nents, and any end play or other specifications. Apply a sealer to any plug, fitting, or fastener (including studs), that intersects with a through hole and comes in contact with lubricating oil, coolant, or diesel fuel. The exact assembly sequence will vary slightly from engine to engine. Always follow manufacturer service manual procedures and recommendations. Always use new gaskets and seals. Lubricate press-fit parts using vege- table-based lubricant before assembly. Always use the installation and protective tools speci- fied by the engine manufacturer. The durability and service life of a rebuilt engine is directly affected by the quality of the run-in procedure. An engine can be run-in using one of three methods: an engine dynamometer, a chassis dynamometer, or a highway run-in. The exact procedure for run-in will vary depending on the type of method used. Because the lubricating oil film on the rotating parts and engine bearings may not be sufficient for proper lubri- cation when the engine is first started, the engine should be prelubricated using a pressure lubricator filled with the recommended oil. Review Questions—Chapter 26 Answer the following questions using the information provided in this chapter. 1. During an overhaul, _____, O-rings, and filters should always be replaced and never reused. 2. Install all piston rings in the piston grooves using a _______. 3. When installing the flywheel, a _______ and _______ should be used. 4. List the three major methods of performing engine run-in. 5. Engines should always be prelubricated using a _______ before being started for the first time after rebuilding. 6. What are the proper fuel system checks prior to begin- ning the engine run-in procedure? 7. The _______ should be lubricated with about one pint of _______ prior to initial startup after rebuilding. 8. If the oil level suddenly rises after sitting for several minutes, _______ or _______ is leaking into the crankcase. 9. List at least five conditions that require the engine dyna- mometer run-in procedure be stopped immediately. 10. On some vehicles, it may be necessary to disconnect the _______ from the transfer case. 1. Technician A says keeping the work area and compo- nents clean is vital to a successful overhaul and engine reassembly. Technician B says that slight amounts of dust entering the engine will be flushed out in the lube oil and cause no major problem. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 2. During reassembly, Technician A says you should use a clearance setting based on past experience with other engine models by the same manufacturer. Technician B says you should look the clearance up in the service manual for that specific engine. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 3. During reassembly, Technician A says you should lubricate all press-fit parts using heavy-duty engine oil. Technician B says you should use no lubrication at all on these parts. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 4. Technician A says any plug, fitting, or fastener (including studs), that intersects with a through hole and comes in contact with lubricating oil, coolant, or diesel fuel should have a sealer applied to it. Technician B says these components should have a locking compound applied to them before installing. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 5. Wear surfaces of mating parts should be coated with _______ before reassembly. (A) vegetable-based oil (B) clean engine oil (C) diesel fuel (D) nothing ASE-Type Questions