Engine Reliability

MOT/FIMOT-E

Who should attend?

  • This course provides an understanding of the physical phenomena causing engine parts damage, the phenomena being thermal, mechanical, thermo-mechanical or tribologic ones. The theoretical aspect is punctuated with examples of damaged parts - pictures or real parts.
Audience :
  • Engineers and technical staff involved in design or testing, who need to know damaging and failure processes of engine components.
  • People of Quality department or aftersales technical analysis may also be interested.

Level : Advanced

Course Content

  • Engine parts damage modes

      • Mechanical engineer tools, statistical aspects of reliability.
      • Thermal damage: coking, mechanical characteristic losses, intercrystalline corrosion, burnout, creeping, melting, lubricant viscosity drop.
      • Mechanical damage: plastic distortion, unshrinking, fracture or fatigue failure, vibration impact.
      • Thermo-mechanical damage: stresses caused by constrained metal expansion.
      • Tribologic ones: lubrication parameters, stribeck curve, pitting, micro-reptation, loosening, fretting/micro-welding, abrasive wear, adhesive wear, erosive wear, cavitation, scuffing, seizing, stick-slip.
  • Mobile parts damage

      • Conrods: failure modes, almost static stresses, dynamic stresses, buckling, screws resistance.
      • Crankshaft: quasi-static (gas pressures and inertia) and dynamic (flexion and torsion) stresses, strengthening treatments, roller-burnishing, dimensioning calculations, fatigue tests.
      • Bushing damage modes: fatigue, wear, cavitation wear, abrasive wear, scale and pollution wear, micro-welding, seizing.
      • Piston: distortions, ring sticking, skirt crush, seizing, stresses in the pin bosses.
  • Fixed parts damage

      • Ignition pressure and manufacturing related mechanical stresses (assemblies, shrink fitting, tightening).
      • Thermal stresses and thermo-mechanical constraints.
      • Cylinder head: cracking, materials, fire face behavior and solutions for its resistance, other critical points.
      • Exhaust manifold: mechanical and thermal stresses, materials, failures found, solutions.
      • Cylinder head gasket: stresses, failures, influence of the cylinder head and crankcase cylinders distortions, solutions.
  • Cooling

      • Heat transfers by conduction, convection, radiation, phase change. Thermal balance.
      • Thermics and engine cooling: levels of temperatures reached, critical points, cooling fluid circulation in the block and the cylinder head.
      • External cooling circuit: permanent branch, thermally regulated branch, pump, exchangers, thermostat, ventilating, cooling fluid, dimensioning.
      • Thermal measure means: thermo-couples, thermistors, flux meter, infrared pyrometry.
  • Lubrication

      • Lubricant cleanliness and consequences on wear.
      • Engine oil rheological behavior and change of properties in service:
      • Oxidation thickening, soot, black sludge and consequences on cold starting.
      • Viscosity decrease by polymer shearing or by dilution and consequences on warm engine.
      • Thermal and oxidation stability: cracking, thickening, deposits.
      • Timing lubrication.

Learning Objectives

  • Upon completion of the course, participants will be able to:
  • diagnose the possible origin of a damage problem of an engine component,
  • talk with tests and laboratory specialists to direct parts analysis and the validation tests to be performed,
  • suggest solutions likely to solve the problem.

Ways & Means

  • Interactive training using a number of real components, pictures and videos.
  • Real life analysis of failures of components, search for origin of failures, description of the deteriorating process.
  • It is possible to manage this exercise on a component previously proposed by a learner, with a description of use conditions.