automotive final 2nd semester

All the following statements about diesels are true EXCEPT:

• diesel engines have more lugging power then gas engines

• diesel engines are heavier then gasoline engines

• diesel engines use spark plugs to get the engine started

• diesel engines are more durable then a gas engine

compression ratio in a diesel engine is:

• 7:1-9:1

• 8:1-10:1

• 17:1-25:1

• 24:1-35:1

The ideal (stoichiometric) air/fuel ratio for gasoline engine is:

• 12:1

• 14:1

• 17:1

• 14.7:1

to complete a four-stroke cycle in one cylinder, the crankshaft must rotate _____ degrees.

• 180

• 360

• 540

• 720

which V-type engine valve train design may use four camshafts?

• OHC

• DOHC

• OHV

• DOHv

Tech A says that the compression ratio is the amount of air/fuel mixture that is being compressed. Tech B says the bigger the gas particles, the more rapid they will burn. Who is correct?

• A only

• B only

• Both A and B

• Neither

Excessive friction in an engine can cause _____

• heat

• wear

• sludge

• both heat and wear.

the valve ports are used to _____

• A. keep oil out of the cylinder

• B. let exhaust gases out of the cylinder

• C. let oxygen and gasoline into the cylinder

• Both B & C

The average engine contains one camshaft lobe for each _____

• cylinder

• piston

• valve

• connecting rod

When the piston is moving up in the cylinder and all the valves are closed ____

• a vacuum is produced

• the exhaust gases are being pushed out of the cylinder

• air/fuel mixture is being compressed

• rotary motion is being produced