Engine Works & Wears•   Engine Wear•   Combustion Process•   Internal Components•   External Components•   Cooling System•...
Function of Fuel System• Meters the amount  of fuel to achieve  desired power• Regulates engine  speed and timing  sequenc...
Fuel System Operation
Types of Fuel Systems• Pump & Line                                          • Unit Injection       Current Scroll Fuel Sy...
Fuel Delivery - History         •        Pre-Combustion (PC)         •        Direct Injection (DI)                       ...
Sleeve Metering Fuel SystemBarrel                        Fill PortPlungerSleeveSpill Port              Filling            ...
Scroll Metering Fuel System• Pump & line governor• Few moving parts• Simple mechanical governor• Easy starting & service• ...
MUI System             •    A unit injector is                 positioned above each                 cylinder             ...
EUI System             • A unit injector is               positioned above each               cylinder             • An El...
EUI - Injector Fill                      • Without pressure from                        the rocker arm, a                 ...
EUI - Injection                  • On a signal from the                    ECM, the solenoid                    closes the...
EUI - Injection                  • Fuel continues to inject                  until the ECM signals the                  so...
HEUI System              • A unit injector is positioned                above each cylinder              • An Electronic C...
Cat Fuel System – Single Fuel                                Fuel Manifold                                   Pump         ...
Fuel System Wear & Failure Causes• Short unit injector life due to excessive abrasive particles in  the fuel    Abrasive ...
Fuel System Wear & Failure Causes• Injector sticking or seizure due to fuel overheating    Fuel in the injector “cooks” a...
Fuel System Wear & Failure Causes• Poor quality oil    Fuel may be low in viscosity or lubricity. Fuel which is old     o...
Effect of Work Environment•   Dust•   Temperature/Climate•   Hours of continuous operation•   Terrain
System Improvement• Reduce system damage caused by fuel    Water Separator    Primary Fuel Filter    Bypass Flow• Minim...
Stripping Out Water• Water Separator    Second line of defense       • All free water       • 87% emulsified water    In...
Removing Larger Debris• Primary Fuel Filter    10+ micron particle retention      • prevents premature secondary        f...
Remove Fine Abrasives• Secondary Fuel Filter    2 micron and larger      • 98% efficient    Reduces wear on fuel injecto...
Double Filter/Double Life• Series filtration    Second filter “safety net”       • Second filtering pass       • Filter f...
Engine Works & Wears•   Engine Wear•   Combustion Process•   Internal Components•   External Components•   Cooling System•...
Air Intake & Exhaust System Functions                                             Boost air at 300                Inlet ai...
Air System
Air System Components• Precleaner• Air Filters• Filter Service  Indicator• Turbochargers• Aftercooler• Intake & Exhaust  M...
Air System Operation•   Flow    1. Precleaner    2. Air Filters    3. Turbocharger    4. Intake Manifold &       Cylinder ...
Air System Wear & Failure Causes• Single most common problem – dust ingestion     Causes accelerated abrasive wear of pis...
Engine systems   diesel engine analyst - part 2
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Engine systems diesel engine analyst - part 2

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Engine systems diesel engine analyst - part 2

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Engine systems diesel engine analyst - part 2

  1. 1. Engine Works & Wears• Engine Wear• Combustion Process• Internal Components• External Components• Cooling System• Lubrication System• Fuel System• Air System• Electronics Single Fuel System
  2. 2. Function of Fuel System• Meters the amount of fuel to achieve desired power• Regulates engine speed and timing sequence• Helps control emissions
  3. 3. Fuel System Operation
  4. 4. Types of Fuel Systems• Pump & Line • Unit Injection  Current Scroll Fuel System  MUI  New Scroll Fuel System  EUI  Sleeve Metering Fuel System (SMFS)  HEUI  Program Electronic Engine Controls (PEEC)  Common Rail (Single Fuel) 1973 1981 1983 1988E 1994 CSFS MUI NSFS UI HEUIPre 1970 1970 1975 1980 1985 1990 1995 2000 2005Timeline 1974 1987 2004 SMFS PEEC Rail
  5. 5. Fuel Delivery - History • Pre-Combustion (PC) • Direct Injection (DI) Fuel Line Fuel Line Fuel InjectorElectrical Wire Fuel Injector Mechanically Glow Plug Nozzle Controlled Fuel Injector Unit Injector Housing Assembly Pre-Combustion Piston Piston Heat Plug Pre-Combustion Direct Injection Direct Injection Pencil Style Unit Injector
  6. 6. Sleeve Metering Fuel SystemBarrel Fill PortPlungerSleeveSpill Port Filling Begin Continue End Injection Injection Injection
  7. 7. Scroll Metering Fuel System• Pump & line governor• Few moving parts• Simple mechanical governor• Easy starting & service• More tolerant of dirt• Economical
  8. 8. MUI System • A unit injector is positioned above each cylinder • A mechanically actuated governor controls fuel rate (scroll metered) with flyweights and springs • Timing is fixed
  9. 9. EUI System • A unit injector is positioned above each cylinder • An Electronic Control Module (ECM) controls fuel rate and timing • Injectors are mechanically actuated by a camshaft
  10. 10. EUI - Injector Fill • Without pressure from the rocker arm, a spring keeps the plunger retracted • Fuel flows into the injector through the fill / spill port, past the solenoid valve and into the barrel
  11. 11. EUI - Injection • On a signal from the ECM, the solenoid closes the fuel valve • Pressure elevates at the tip to the 5,500 psi needed to unseat the valve • Injection begins
  12. 12. EUI - Injection • Fuel continues to inject until the ECM signals the solenoid to open the valve • Injection timing and duration is controlled by the ECM
  13. 13. HEUI System • A unit injector is positioned above each cylinder • An Electronic Control Module (ECM) controls fuel rate, timing, and injection pressure • The injector is hydraulically actuated
  14. 14. Cat Fuel System – Single Fuel Fuel Manifold Pump C6.6 Injector
  15. 15. Fuel System Wear & Failure Causes• Short unit injector life due to excessive abrasive particles in the fuel  Abrasive particles damage sealing surfaces causing leakage of high pressure fuel and low engine power  Abrasive particles are inherent in most fuels  Most particles can be removed by using High Efficiency filters• Injector seizure due to excess water in the fuel  Always small amounts of water in fuel, which is harmless  Excess water in fuel reduces the lubricating film strength of fuel and causes seizure of the injector plunger and barrel  Maximum amount of allowable water in fuel is 0.1%
  16. 16. Fuel System Wear & Failure Causes• Injector sticking or seizure due to fuel overheating  Fuel in the injector “cooks” and produces varnish which causes components to stick or seize  Viscosity of hot fuel is inadequate and the fuel film thickness will not provide adequate protection against scuffing or seizure of the plunger and barrel  Fuel overheating can be caused by operating in extreme ambient temperatures. An auxiliary fuel cooler installed in the fuel supply line to the cylinder heads may be required to limit fuel temperatures  Running fuel tank too low, or running out of fuel causes the fuel to cycle through the engine too frequently and becomes very hot. This can be avoided by keeping the fuel tank levels at ¼ full or above
  17. 17. Fuel System Wear & Failure Causes• Poor quality oil  Fuel may be low in viscosity or lubricity. Fuel which is old or oxidized often contains excessive gums or resins which promotes injector sticking or seizure.
  18. 18. Effect of Work Environment• Dust• Temperature/Climate• Hours of continuous operation• Terrain
  19. 19. System Improvement• Reduce system damage caused by fuel  Water Separator  Primary Fuel Filter  Bypass Flow• Minimize tip failure caused by aeration  Maintain fuel supply pressure
  20. 20. Stripping Out Water• Water Separator  Second line of defense • All free water • 87% emulsified water  Injector damage
  21. 21. Removing Larger Debris• Primary Fuel Filter  10+ micron particle retention • prevents premature secondary fuel filter plugging • protects fuel transfer pump
  22. 22. Remove Fine Abrasives• Secondary Fuel Filter  2 micron and larger • 98% efficient  Reduces wear on fuel injectors and pumps • Essential for higher pressure systems • Extends life of older systems as well
  23. 23. Double Filter/Double Life• Series filtration  Second filter “safety net” • Second filtering pass • Filter failure - Double injector wear life
  24. 24. Engine Works & Wears• Engine Wear• Combustion Process• Internal Components• External Components• Cooling System• Lubrication System• Fuel System• Air System• Electronics
  25. 25. Air Intake & Exhaust System Functions Boost air at 300 Inlet air from air º- 400º cleaners Inlet air from air cleaners Exhaust out Air manifold From exhaust ports at cylinder heads• Provide adequate quantities of clean • Compresses the filtered intake air intake air into the cylinders in order to • Removes exhaust gases from the product more power cylinders and reduces exhaust noise
  26. 26. Air System
  27. 27. Air System Components• Precleaner• Air Filters• Filter Service Indicator• Turbochargers• Aftercooler• Intake & Exhaust Manifolds• Muffler
  28. 28. Air System Operation• Flow 1. Precleaner 2. Air Filters 3. Turbocharger 4. Intake Manifold & Cylinder Head(s) 5. Combustion Chamber 6. Exhaust Manifold• Wear  Turbocharger • Bearings • Seals
  29. 29. Air System Wear & Failure Causes• Single most common problem – dust ingestion  Causes accelerated abrasive wear of piston rings & liners  Most often caused by inlet leaks around flexible joints in air inlet piping  May also be caused by defective/damaged air filters, or poor maintenance practices• Plugged air filters• Turbo failures• Coolant to air leaks in the aftercooler• Hydraulic lock

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