TM-9-2815-205-24 Technical Manual for M113 Engine 6V53 6V53T Download
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ENGINE SYSTEMS - Continued internal engine parts, particularly the exhaust valves. The turbocharger forces additional pressurized air into the cylinders (called supercharging) to allow burning of more fuel for additional power. Crankcase Ventilation System For model 5063-5299, the crankcase ventilation system consists of a breather tube assembly, a filtering element in a collector, and crankcase vapor passages. For models 5063-5392, 5063-5393, and 5063-539L, the crankcase ventilation system consists of filtering elements in the rocker arm covers and crankcase vapor passages. Seepage of a small amount of air past the piston rings maintains a slight pressure in the engine crankcase. This air sweeps up through the engine to draw off oil vapors through the breather elements. Electrical System The electrical system consists of a starter, air box heater or glow plug cold start system, and related wiring. The starter is equipped with a shift lever and solenoid plunger, totally enclosed to protect it against dirt, and a sprag overrunning clutch. Pressing the starting switch energizes the starter solenoid, which engages the starter pinion with the teeth of the flywheel ring gear. The starter drives the pinion and rotates the engine. When the engine begins to operate, the sprag clutch permits the pinion to overrun on its shaft until the starting switch is released, which prevents overspeeding of the starter. The air box heater heats the air entering the cylinders to assist in ignition of fuel at low ambient temperatures. A fuel and air mixture is sprayed into the air box and a spark ignites a flame. The flame heats the incoming engine air which is fed directly into the cylinders. The glow plug cold start system is an alternative means to assist in engine starting at low ambient temperatures. It consists of glow plugs, which are installed in the cylinder heads, and a controller that regulates the starting cycle and preglow/afterglow duration. Gear Train The gear train consists of a crankshaft gear, idler gear, fuel pump drive gear, and two camshaft gears. Models 5063-5393 and 5063-539L, also haves a hydraulic pump drive gear. The gear train is located between the rear end plate and flywheel housing. All gear train gears are helical. The crankshaft gear is pressed and keyed to the crankshaft. The idler gear rotates on a stationary hub. The camshaft gears are pressed and keyed to their respective camshafts and secured by their retaining nut and locking plate. The camshaft gears mesh with each other and run at the same speed as the crankshaft gear. The stamped timing marks on the face of the gears show proper timing. The overflow oil from the camshaft pockets, camshaft end bearings, and idler gear bearings lubricates the gear train. Oil from the cylinder block oil gallery lubricates the fuel pump drive gear, hydraulic pump drive gear, and idler gear bearings. Governor The limiting-speed, mechanical governor is mounted between the blower and flywheel housing. The governor holds the injector racks in the advanced fuel position for starting when the speed control lever is in the idle position. Immediately after starting, the governor moves the injector racks to control idle and maximum engine speed during operation. OPERATIONAL DESCRIPTION General This particular engine series has a two stroke cycle (sometimes called a two cycle). A two stroke engine completes one cycle (intake, compression, power, and exhaust) every time the piston goes up and down - up TM 9-2815-205-24 0003 0003-2