Internal Combustion Engine 2009 Objective Paper

38) In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the

a)metal particles loosened by wear

b)air when no air cleaners are used

c)condensation of water wapors

d)breakdown of the lubricating oil itself


39) On small diesel engines, a noticeable decrease in the time interval between the replacement of the lube filter cartridge indicates

a)piston ring blow-by

b)dirty air filter

c)excessive oil pressure

d)excessive oil temperature


40) When the lower edge of the spiral begins to uncover the release port in a jerk pump, the

a)pumping continues until the plunger travels its full stroke

b)effective pumping stroke of the plunger ends

c)pressure drops slowly until the full stroke is attained

d)plunger rotates to the zero delivery position until the next stroke


41) Some diesel engines are fitted with a thermometer in the cooling water outlet from each cylinder. If the cooling water temperature from all cylinders begins to rise above normal, you should suspect

a)increased blow-by in all cylinders

b)incomplete combustion in all cylinders

c)overloading in all cylinders

d)insufficient fuel delivery to all cylinders


42) Proper operation of the main engine reduction gear set requires the operator to monitor

a)the sump oil level

b)oil flow sight glasses

c)bearing temperatures

d)all of the above


43) The duration of fuel injection developed by an individual port-and-helix fuel injection pump, is determined by the

a)total pump stroke

b)pump plunger diameter

c)plunger helix angle

d)effective pump stroke


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