Diesel engine exhaust noise can be reduced in an exhaust muffler by （）

A . clear B . hazy light brown C . hazy light blue D . hazy light grey

A . low combustion temperature B . a leaking fuel nozzle check valve C . late fuel injection D . plugged oil-scraper ring hole

A . decreased piston to cylinder head clearance B . increased exhaust system back pressure C . early fuel injection timing D . low scavenge air temperature

A . too light of a load B . injection timing is too early C . overloading of the engine D . too low of a compression ratio

A . a cracked liner B . burning lube oil C . an overloaded engine D . insufficient combustion air

A . low sulfur content in the fuel B . a loose injector inlet connection C . late fuel injection D . high injection pressure

A . late ignition B . water in the fuel C . high compression temperature D . starting valve stuck ope

A . prevent engine back pressure at heavy loads B . increase total engine efficiency at low loads C . prevent boiler corrosion at low engine loads D . improve engine fuel consumption at any load

A . excessive cylinder lubrication B . a lugging engine C . a leaking cylinder liner D . overloading of one cylinder

A . (1) only B . (2) only C . both (1) and (2) D . neither (1) nor (2)

A . reduce heat radiation to the engine room B . aid in preventing turbocharger overheating C . condense and drain moisture from exhaust gases D . dampen exhaust gas pulsations in the manifold

A . increasing the linear velocity of the exhaust gases B . changing directions of exhaust gas flow C . decreasing the temperature of the exhaust gases D . accelerating the exhaust gas through a reduced size orifice

A . the proper back pressure B . the cooling water temperature C . correct timing and proper seating D . accurate metering and the exhaust temperature

A . Light blue haze B . Light brown haze C . Light gray haze D . Perfectly clear

A . chemical analysis B . back pressure readings C . pyrometer readings D . infrared analysi

A . proper fuel injection B . water in the fuel C . incomplete combustion D . burning of lube oil

A . increased engine back pressure B . sulfuric acid corrosion C . surface pitting of the turbocharger D . moisture impingement on the turbocharger compressor blade

A . over-speeding of the engine B . failure of the engine to shut down C . no effect of engine mounting bolts D . high exhaust temperature

A . after TDC B . before TDC C . after BDC D . before BDC

A . fuel dribbling from leaking fuel injectors B . burning fuel with a high carbon content C . burning fuel with a high vanadium content D . burning fuel with a lower sulphur content

A . cold intake air B . excessive compression pressure C . excessive cylinder lubrication D . a light load

A . pyrostats and a voltmeter B . a gas-filled bellows, a tube and a pressure gauge C . thermocouples and a voltmeter D . ammeters and thermocouple

A . pyrometer B . bourdon gauge C . pneumercator D . manometer

A . passing the exhaust through long head pipes B . diffusing exhaust vibrations through activated carbon baffles C . increasing the exhaust gas velocity D . reducing the exhaust gas velocity