TM10-3930-660-34 b.   Fuel System.  Engine fuel system is described in para.  4-2. c.    Cooling System.  Engine cooling system is described in para.  5-2. d.   Lubrication System.  Engine lubricating oil is forced through various internal passages by an internally mounted, gear type pump (1).  Oil is cleaned by a disposable filter cartridge (2) and is cooled by engine coolant flow through a cooler (3) mounted to the side of the engine.  A pressure operated bypass valve (4) is incorporated to provide continued oil flow around filter in the event filter becomes clogged.  A differential pressure of 20 psi will open filter bypass valve.  A pressure regulating valve (5), located in the front of the engine, is designed to open at a pressure of 60 psi to protect pump and other system components against excessive pressures. e.    Air  Intake  System.    Air  intake  system  includes  an  air  cleaner,  turbocharger  (6),  intake  manifold  (7)  and  connecting piping.  Purpose of air intake system is to provide a supply of clean, pressurized air for fuel combustion in the engine cylinders.    Turbocharger  rotation  draws  air  through  the  air  cleaner,  where  most  airborne  contaminants  are  removed, and forces this air, under pressure into the intake manifold.  From the intake manifold, air is distributed to the cylinders through timing action of the intake valves. f.  Exhaust System.  Exhaust system includes exhaust manifold (8), turbocharger turbine (9), exhaust piping and muffler. Exhaust gases are directed against the turbine blades, causing turbine to rotate at high speed.  Exhaust gases leaving turbocharger pass through the muffler, which reduces level of exhaust noises. 3-2