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WorksheetsEngine Construction L2
Total questions: 50
Worksheet time: 50mins
How many degrees of crankshaft rotation occur in one complete four-stroke cycle?
180°
360°
540°
720°
The four strokes in the correct order are:
Compression, Power, Exhaust, Induction
Induction, Compression, Power, Exhaust
Power, Induction, Exhaust, Compression
Exhaust, Power, Induction, Compression
The basic function of an engine is to convert:
Electrical energy to heat
Chemical energy to mechanical energy
Heat energy to chemical energy
Mechanical energy to electrical energy
The compression ratio of a petrol (spark-ignition) engine is typically:
4 : 1
10 : 1
16 : 1
22 : 1
A diesel (compression-ignition) engine usually has a compression ratio of about:
8 : 1
10 : 1
12 : 1
18 : 1
“Top Dead Centre” (TDC) means the piston is:
At its uppermost point in the cylinder
At its lowest point
Halfway down the bore
At maximum speed
“BDC” stands for:
Basic Drive Cycle
Bottom Dead Centre
Base Data Compression
Brake Drive Control
The stroke of an engine is:
The bore diameter
The distance the piston travels from TDC to BDC
The pressure in the cylinder
The firing order sequence
Torque is a measure of:
Turning force
Linear distance
Engine temperature
Oil pressure
The SI unit of torque is:
Kilogram-metre
Newton metre
Joule
Watt
Power is defined as:
Force × distance
Work done ÷ time
Pressure × volume
Torque × radius
One brake horsepower (BHP) equals approximately:
0.45 kW
0.745 kW
1 kW
1.45 kW
The component that converts reciprocating motion to rotary motion is the:
Crankshaft
Camshaft
Flywheel
Gudgeon pin
The camshaft in a four-stroke engine rotates at:
Twice crankshaft speed
Half crankshaft speed
The same speed
One-third speed
The ratio between crankshaft and camshaft speed is:
1 : 1
2 : 1
3 : 1
4 : 1
The valve spring’s main purpose is to:
Assist the piston
Close the valve after opening
Open the valve
Cool the valve
Valve clearance is needed to:
Allow for expansion and ensure the valve seats properly
Increase valve lift
Reduce compression
Change timing
A blue exhaust smoke usually indicates:
Oil burning
Rich mixture
Coolant leak
Low fuel pressure
A noisy valve train may be caused by:
Tight clearances
Excessive clearance
High oil pressure
Blocked air filter
The most common type of valve used in a four-stroke engine is the:
Rotary valve
Reed valve
Poppet valve
Slide valve
The firing order of a typical four-cylinder in-line engine is:
1234
1342
4321
1423
A crankshaft web is:
The bearing surface
The section between a main journal and a crankpin
A flywheel mount
The oil seal
The flywheel assists the engine by:
Maintaining momentum between power strokes
Reducing oil pressure
Increasing compression
Cooling the crankshaft
The main function of piston rings is to:
Seal combustion gases and control oil
Support the piston pin
Balance the crankshaft
Measure compression
The piston crown must withstand:
Coolant flow
High heat and pressure
Valve spring tension
Oil pump pressure
26. A gudgeon pin connects the:
Piston to the connecting rod
Camshaft to the crankshaft
Valve to the rocker arm
Flywheel to the clutch
Gudgeon pins are often hollow to:
Reduce weight
Increase strength
Hold oil
Ease installation
“Piston slap” is caused by:
Excessive clearance allowing piston tilt
Low compression
Rich mixture
Valve bounce
Thrust washers control:
Crankshaft end float
Valve clearance
Camshaft timing
Piston travel
Bearing “nip” refers to:
The slight interference fit preventing bearing rotation
Bearing clearance
Oil film thickness
Crush depth
Cylinder liners are used to:
Provide a wear-resistant surface
Increase compression
Reduce torque
Lower engine temperature
A wet cylinder liner differs from a dry liner because:
It is in direct contact with the coolant
It is press-fitted without seals
It has no flange
It is made of steel
The main advantage of using multiple cylinders is:
The connecting rod transmits:
Piston force to the crankshaft
Oil pressure to the head
Air to the combustion chamber
Fuel to the injector
Excessive wear on crankshaft journals may cause:
Low oil pressure
High compression
Rich mixture
Slow idling
The purpose of balance weights on a crankshaft is to:
Reduce vibration
Increase compression
Control oil pressure
Aid starting
A vibration damper is fitted to the crankshaft to:
Reduce torsional vibration
Increase speed
Assist oil flow
Retard timing
Engine mounts are designed to:
Reduce noise and vibration transmitted to the body
Support the battery
Cool the engine
Increase engine speed
A supercharger is:
Mechanically driven by the engine
Driven by exhaust gas
Driven by electric motor
Used only in diesel engines
A turbocharger is powered by:
Exhaust gases
The alternator
The camshaft
A fan belt
The function of an intercooler is to:
Cool compressed air from the turbocharger
Heat intake air
Cool engine oil
Increase exhaust temperature
Excessive oil consumption accompanied by blue smoke usually indicates:
Worn piston rings or valve guides
Blocked fuel filter
Rich fuel mixture
Faulty spark plugs
The correct tightening sequence of cylinder head bolts is important to:
Prevent distortion of the head
Increase torque
Reduce oil consumption
Align timing marks
The cylinder head provides:
Combustion chamber and valve mounting
Lubrication for the crankshaft
Oil filtration
Fuel storage
The most common modern combustion-chamber design in petrol engines is the:
Hemispherical
Bowl in piston
Pentroof
Wedge
The main reason the inlet valve is larger than the exhaust valve is to:
Increase air/fuel flow into the cylinder
Allow more exhaust out
Reduce compression
Cool the combustion chamber
In a hybrid vehicle, the electric motor is powered by:
High-voltage batteries recharged through regenerative braking
Low-voltage 12 V battery
Alternator output
Solar panels only
“Series hybrid” means:
The engine powers a generator which charges the batteries
Both engine and motor drive the wheels
Two engines run in series
Battery only operation
“Parallel hybrid” means:
Either the engine or the motor can drive the vehicle
Only the motor drives the vehicle
Only the engine drives the vehicle
Engine and motor run independently of each other
A typical safety precaution when working on hybrid vehicles is to:
Follow manufacturer’s high-voltage isolation procedure
Disconnect the 12 V battery only
Work with metal jewellery on
Spray water on cables to cool them
