Diesel fuel is relatively safe to handle due to its low volatility, but the fumes will self-ignite and continue to burn steadily if the fuel is heated to the （）.

A . ignition quality of the fuel B . calorific value of the fuel C . flash point of the fuel D . rate of fuel consumptio

A . supercharging B . scavenging C . turbulence D . swept volume charging

A . octane number B . cetane number C . viscosity in Saybolt seconds D . air fuel ratio

A . cetane number B . volatility point C . viscosity index D . octane number

A . quantity of fuel injected is decreased B . quantity of fuel injected will always be increased C . start of injection is advanced D . duration of injection will always be greater

A . the exhaust will be clear B . fuel consumption will be low C . all the fuel will be burned at top dead center D . fuel consumption will be high

A . the piston is just coming upward from the bottom dead center B . the piston has moved about one-fifth of the way up C . the piston has moved most of the way up and almost reached the TDC D . the piston has just past the TDC

A . heat conduction into the injected fuel oil B . heat conduction into the water jacket wall C . water circulation through passages in the holder D . fuel oil circulation through passages in the holder

A . electronic ignition system B . compression of air by the piston C . friction in the fuel injector D . fuel oil bearing system

A . The cetane number is obtained by comparing the fuel with cetane a colorless liquid hydrocarbon B . The higher the cetane number, the shorter the ignition lag C . The highest cetane number of fuel is 100 D . All of the above

A . a spark plug B . injectors C . the heat of compression D . increasing jacket water temperature

A . a cooling system B . a lubrication oil system C . an electric system D . an injection system

A . intake valves B . carburetor C . exhaust ports D . injector nozzle

A . crankcase B . cylinder C . scavenge box D . pisto

A . turbocharger B . injection nozzle tip C . carburetor D . fuel oil pum

A . a combination of constant volume and constant pressure B . a combination of constant temperature and constant pressure C . entirely constant pressure D . entirely constant volume

A . ignition quality of the fuel B . high heating value of the fuel C . amount of carbon residue after combustion D . internal flow resistance in the injector

A . feel the high pressure fuel line B . check the cylinder exhausts for white smoke frequently C . check the cylinder exhaust temperature D . isolate each cylinder and inspect the injector

A . spark plugs B . glow plugs C . heat of compression D . a magneto

A . the firing pressure in the cylinder B . a metering helix inside the pump C . varying the physical length of the plunger stroke D . varying the clearance between the injector cam and the injector rocker arm

A . assist in a quick cutoff of fuel injection B . allow oil backflow from the injector to the helix C . reduce fuel oil pressure between injection strokes D . meter the quantity of fuel delivered

A . high exhaust temperature B . low exhaust temperature C . fuel knock in each cylinder D . mechanical knock in each cylinder

A . The cetane number affects the amount of injection lag B . The cetane number is an indication of the fuels viscosity C . Ignition lag is reduced with fuels having a high cetane number D . The cetane number is of little significance in the combustion proce

A . permission B . emission C . omission D . Missio