Engine Practical Workshop: Engine Disassembly - Assignment Example

Part A) Engine Practical Workshop Engine Disassembly Engine disassembly Procedure The adjuster clamps were slackened. The alternator was levered away from engine. The adjuster clamp bolts were slackened and the alternator pushed towards engine to release belt tension. The belts were removed. The removal procedure was reversed while refitting. The hose clips were released the top radiator hose pipe was removed. Then the hose clips were released and the bottom radiator hose pipe was removed. The bolts and setscrews were removed securing fan cowl to radiator. Setscrews were removed securing radiator to radiator frame assembly. The radiator was raised from radiator frame assembly. The setscrews securing the radiator the stabilizer to the radiator frame were removed. The earth cable was removed from the batteries. The alternator air cooling cover was removed. The wiring from the alternator was disconnected. The V-belt tension was slackened, the radiator bracket was removed and the V-belts removed by pulling them over the fan blades the V-belts were checked. The alternator was removed. Reinstallation was the opposite of the removal procedure. The V-belts were tensioned. The wiring was reconnected and the alternator air cooling cover was refitted. The earth cables were reconnected to the batteries. The air inlet pipe was removed from the compressor. The lubricating oil supply pipe was removed. The air supply pipe was disconnected from the governor and the two brackets removed from the cylinder block. The steering pump was removed. The bolts by which the compressor was attached to the timing case were removed. The compressor with the governor supply pipe from the engine were removed the governor supply was checked for carbon deposits. The bolts and set screws securing top half of fan cowl were removed. The cowl was removed. The damper was carefully removed from crankshaft pulley. The back tab of lockwasher was knocked and then the bolt securing pulley to crankshaft was removed. The sealing lip of new seal was smeared with grease and care was taken not to damage the seal, the seal was inserted into timing casing. The engine oil was drained into suitable containers. The bolts and setscrews securing the starter motor front mounting bracket to the sump were removed. The turbo charger oil was drained at the sump. The dipstick was withdrawn and the dipstick tube disconnected from the sump. The front timing cover was removed. The engine was turned until timing mark on camshaft gear aligned with timing mark on back plate. The fuel pump drive coupling was suitably marked in relation to timing pointer. The back tab of tab washer was knocked then the bolt removed securing camshaft drive gear to camshaft. The camshaft gear was withdrawn. The clutch was removed. The back tabs of lock plates were knocked then the setscrews securing flywheel to crankshaft adapter was removed. Using suitable jacking bolts the flywheel was withdrawn from crankshaft adapter. The crankshaft rear oil seal housing was removed. The heat shield was removed from frame-side below exhaust manifold. The clamp securing exhaust down pipe to flywheel housing was released to exhaust manifold. Turbocharger was removed; the exhaust down pipe was removed. The setscrews securing thrust cap to crankcase were removed the cap was removed noting joint and the bush examined for wear or damage. Rocket shaft assembly was removed. The push rods were removed. Noting the connections the electrical leads were disconnected from alternator. The alternator mounting bolts were slackened and drive belt tension released; the drive belts and alternator were removed A tool was screwed into the end of the crankshaft then the engine was turned until timing mark on the camshaft gear aligned with timing mark on back plate. Suitably the relationship between idler gear and camshaft gear was marked. The back tab of tab washer was knocked; the bolt securing camshaft drive gear to camshaft was removed. The camshaft gear was withdrawn. The cylinder was removed. The big-end bearings were removed. The carbon deposits from top of cylinder liners were cleaned. The connecting rods and pistons were pushed up out of cylinder block. The turbo charger was removed. The attaching nuts and the spacer bushes were removed and the exhaust manifold removed. The temperature transmitter’s cables were removed from change speed lever support bracket. The screws and nuts securing change speed lever support bracket to exhaust and induction manifolds were removed. The clamp exhaust elbow to exhaust was removed. The exhaust manifold elbow was removed. The nuts securing exhaust manifold to cylinder head was removed, the manifold were removed and gaskets discarded. The removal procedure was reversed when refitting noting clean joint faces and use of new joints. Engine Assembly The removal procedure was reversed while refitting noting to tighten the rear center mountings bolts to torque figures. To tighten the engine front mounting rebound bolts to the dimension, to refill the engine coolant system with coolant and lubricating systems. The fuel was bled. The steering wheel was bled. Valve clearance should be adjusted when the engine is stationary and either cold or hot. Rocking is the moment at which the inlet valve starts to open and the exhaust valve finishes closing. When the valve clearances are being adjusted the fuel injection pump should be moved to the stop position. The valve gear cover was removed and together with the oil filter was cleaned with clean diesel oil. The engine in the normal direction of rotation was cranked until the valves of No.6 cylinder are ‘rocking ‘. The clearance of the inlet and exhaust valve of No.1 cylinder was adjusted. The locknut was slacken. The adjusting screw was turned in or out with a screwdriver until the correct clearance is measured with a feeler gauge. The locknut was tightened and the adjusting screw was positioned to make sure it didn’t change. The engine was cranked 1/3 stroke to bring the next cylinder to the point of rocking, the valves of the matching cylinder was adjusted. The valve gear cover was located and the valve gear cover gasket was renewed. The retaining nuts were tightened to the specified tightening torque taking care not to damage the rubber O-ring seals. Part 1 (B) Engine Practical Workshop 2 Measure, Re-assembly and Running The componets were measured If the engine and transmission have been separated, perform the operations described 57 Ensure that the locating dowels are correctly positioned in the engine or transmission. Carefully offer the transmission to the engine, until the locating dowels are engaged. Ensure that the weight of the transmission is not allowed to hang on the input shaft as it is engaged with the clutch friction disc. On models with a "pull-type" clutch, with the transmission fully engaged with the engine, check that the release fork and bearing are correctly engaged. If the release fork and bearing are correctly engaged, the mark on the release fork should be aligned with the original mark made on the transmission housing Refit the transmission housing-to-engine bolts, ensuring that all the necessary brackets are correctly positioned, and tighten them to the specified torque setting. Refit the starter motor, and securely tighten its retaining bolts. Where necessary, refit the lower flywheel cover plate to the transmission, and securely tighten its retaining bolts. Reconnect the hoist and lifting tackle to the engine lifting brackets. With the aid of an assistant, lift the assembly over the engine compartment. The assembly should be tilted as necessary to clear the surrounding components, as during removal; lower the assembly into position in the engine compartment, manipulating the hoist and lifting tackle as necessary. With the engine/transmission in position, refit the right-hand engine/transmission mounting bracket, tightening its retaining nuts and bolts (as applicable) by hand only at this stage. Refit the left-hand engine/transmission mounting bracket assembly to the vehicle, and tighten its retaining bolts to the specified torque. Refit the centre nut and washer to the left-hand mounting, tightening it to the Refit the left-hand engine/transmission mounting bracket assembly to the vehicle, and tighten its retaining bolts to the specified torque. Refit the centre nut and washer to the left-hand mounting, tightening it to the specified torque setting. Tighten the righthand mounting bracket retaining nuts. Part 2 Crankshaft A crankshaft is used to convert reciprocating motion of the piston into rotary motion. Crankshafts are designed to absorb sudden and fatigue loads. The material of the part should therefore be tough and fatigue resistant. It is usually made of carbon steel or cast iron. The crankshafts are made by drop forging; this process is favorable compared to tither procedures because it work hardens the metal. Drop forging requires the machinist to place the work on an anvil which resembles the mould to be created. The ram then is released and strikes the top of the metal billet which can be equipped with a die for further refining. This part can also be produced through casting. Piston The piston is a disc which reciprocates within the engine cylinder. It is either stirred by the fluid or moves the fluid inflowing to the cylinder. The main function of the piston of an I.C engine is to receive the impulse from the expanding gas and transmit the energy to the crankshaft vi the connecting rod. The piston must also disperse a large amount of heat from the combustion chamber to the cylinder walls. Pistons are mainly manufactured using aluminum, cast iron and forged steel. Aluminum is used for high speed engines which have high rotary motion while cast iron is utilized in low speed engines. Piston is usually manufactured the casting process. As opposed to forging, a cast piton is produced by pouring molten aluminum alloy into a mould; this creates a more precise part. The forging process involves taking a lump of alloy and stamping the shape of the alloy into the desired shape using a die. Sump Flywheel Crankshaft Camshaft Exhaust manifold Piston Cylinder block Cylinder head Turning Grinding Drilling Spot facing Tapping Reaming Vertical boring Honing Milling Heat treatment Die casting Sand casting Forging Read More