What type of cooling system uses air from the atmosphere to cool the engine?

   Air Cooling

 In a convection heating system, what rises to the top?

   Hot water

 What device is used to circulate water in a cooling system?

    Centrifugal Pump

 What does specific gravity compare?

    Weight of a substance to distilled water

 What does oil's ability to hold particles in suspension refer to?

    Viscosity

 What is friction?

    Rubbing of surfaces

 What is viscosity?

    Resistance to flow

 What does lubricant do between metal parts?

    Acts as a cushion

 What does viscosity grade indicate?

    Thickness of oil

 What does the viscosity index number indicate?

     Temperature effect on viscosity

 What instrument measures viscosity?

     Viscosimeter

 What is a benefit of multi-grade oils?

     Flexibility in temperature

 What type of friction must lubricants withstand extreme loads?

     Kinetic Friction

 What does SAE stand for?

     Society of Automotive Engineers

 What is the primary purpose of lubricant?

     To reduce friction

 What is the primary purpose of lubricants in aviation?

    To reduce friction

 Which characteristic of aviation lubricants helps them perform well at high altitudes?

    Thermal stability

 What property of lubricants helps them protect against corrosion in aircraft engines?

    Additives

 Why is it important for aviation lubricants to have a low freezing point?

    To maintain performance in cold temperatures

 What characteristic ensures that aviation lubricants can flow easily during start-up?

    Low viscosity

 What is the primary requirement for aviation reciprocating engine lubricants?

    They must reduce friction

 Why must lubricants for reciprocating engines have good thermal stability?

    To prevent breakdown at high temperatures

 What property helps reciprocating engine lubricants resist oxidation?

    Additives

 Which characteristic is important for lubricants to maintain proper flow during cold starts?

    Low viscosity

 Why is it essential for reciprocating engine lubricants to have good anti-wear properties?

    To protect engine components from wear