TM  10-4320-226-14 capacity and is filled with oil. The oil pump is a gear type element driven by a gear in the engine’s front cover. When the engine is operating, a gear drives the oil pump and oil is pumped from the oil sump to the oil cooler. The oil cooler is a coil cooled by the cooling fan. The cooling fan causes oil to cool to a lower temperature. Oil is then pumped into the oil filter which is a throw-away element. Contaminants are removed from the oil and the oil is pumped to the engine metering plugs . Metering plugs are oil jets within the engine block that spray oil on to internal parts of the engine. Oil is also pumped to the injection pump lube Supply l The fuel injection pump lube supply is a line on the side of the oil filter housing and directs oil to the injection pump. Excess oil in the injection pump spills into the timing cover. In  addition,    the low oil pressure switch and sending unit are located at the oil filter housing discharge. The  oil  pressure switch is set to automatically open when the oil pressure drops below 4 psi (27.579  kPa). 1.14.2.5.3  Cooling   Fan. The cooling fan is attached to the engine and is driven by a V-belt connected to the drive pulley. The cooling fan causes forced air flow across the top of the engine cylinder heads and oil cooling coil. Forced  air  flow cools the cylinder heads and oil. This  cooling  process  prevents  overheating  of  the engine. 1.14.2.5.4   Cylinder  Head  and  Valves. The 350 GPM Pumping Assembly uses three cylinder heads. Each cylinder head functions the same and can be removed separately. The cylinder head contains an intake valve and exhaust valve. The intake and exhaust valves open and close intake and exhaust ports. The intake port is connected to the intake manifold and the exhaust port is connected to the exhaust manifold. 1.14.2.5.5   Crankshaft   Block. The  crankshaft  block  provides  mounting  for  various  engine components. It has an intake manifold that provides a connection to air assembly. Air is taken from the air assembly through the intake manifold into the combustion chamber of the cylinder head. A breather pipe is connected to release gases from the  combustion  chamber  to  prevent  excess  pressure  buildup. 1.14.2.5.6  Camshaft  and  Timing  Gears. The camshaft and timing gears control valve opening  and  closing  times. The speed at which valves open and close is also determined by the camshaft and timing gears. The time at which valves open and close (valve timing) and duration of valve opening are stated in degrees of crankshaft rotation. Timing is determined by the timing  gears. Timing gears are driven by the engine’s camshaft. The  engine’s camshaft drives the engine components that close the intake and exhaust valves. In addition, timing gears control the fuel infection and oil lubrication. Timing  of the engine is critical to prevent damage. 1.14.2.5.7  Pistons  and  Connecting  Rods. The pistons are connected to connecting rods that are attached to the crankshaft. The pistons provide the force to drive the engine’s  flywheel. As the crankshaft is turned, connecting rods force the pistons upward  and  downward. Since the pistons are in sealed cylinders, the pistons compress air that is brought into the intake openings as described in paragraph  1.14.2.5.1. The up and down movement of pistons forces connecting rods to turn the crankshaft and flywheel. Refer to paragraph 1.14.2.5.1 for a more detailed operation of the four stroke piston operation. 1.14.2.5.8  Crankshaft   and   Flywheel. The crankshaft and flywheel provide transfer of heat energy from the pistons into mechanical energy. When the pistons are forced downward by the ignition of fuel,    the crankshaft turns, causing the flywheel to turn. In  addition,    the crankshaft forces the other pistons connected to the crankshaft  upward. Each time a piston is forced downward,    another  piston  is  forced to TDC. The piston at TDC causes another combustion to occur and is forced downward. The 350 GPM Pumping Assembly uses three pistons that are timed together by timing gears connected to the engines camshaft. ‘The crankshaft is also connected to a timing gear of the engine’s camshaft. Each time the crankshaft turns, it forces the camshaft to turn. The pump assembly is connected to the flywheel. Since the flywheel must turn with the crankshaft, the pump assembly driven at the speed of the engine. 1-16 is