Valve Train

Question 1

On carbureted engines, a _____ supercharger system pressurizes the air cleaner above the carburetor or fuel injection system.

Answer 1

blow-through

Question 2

Two technicians are discussing freewheeling engines. Technician A says that a freewheeling engine is one in which the valves will not contact the pistons if the timing chain or belt breaks. Technician B says that a freewheeling engine is one that does not slow the vehicle down when decelerating. Who is correct?

Answer 2

Technician A only

Question 3

Technician A says on a flat tappet engine, the lifters do not need to be replaced when the camshaft is replaced. Technician B says when replacing a roller camshaft, the lifters must be replaced. Who is correct?

Answer 3

Neither technician

Question 4

Technician A says there is no need to lubricate the valve stems upon reassembly. Technician B says intake and exhaust seals are the same materials and shapes. Who is correct?

Answer 4

Neither technician

Question 5

All of the below are factors in camshaft performance EXCEPT _____.

Answer 5

valve size

Question 6

Technician A says a mushroomed valve can be driven out with a punch and a hammer. Technician B says the mushroomed tip must be dressed with a file before the valve can be removed. Who is right?

Answer 6

Technician B

Question 7

An engine has excessive valve guide wear. Technician A says to ream the guide and install a new valve with an oversized stem. Technician B says to knurl the valve stem and reinstall it in the guide. Who is right?

Answer 7

Technician A

Question 8

Cam-in-block engines use pushrods to transmit motion from the lifters to the rocker arms.

Answer 8

True

Question 9

A properly working supercharger will increase the density of the air in the cylinder.

Answer 9

True

Question 10

Technician A says that a gear on the camshaft drives the distributor. Technician B says the exhaust and intake valves each operate on a separate lobe on the camshaft. Who is correct?

Answer 10

Both technicians

Question 11

Technician A says a fixed geometry turbocharger requires pressure relief because it operates over a wide rpm band. Technician B says a wastegate is commonly used to control the speed of the turbine in automobile engines. Who is correct?

Answer 11

Technician B

Question 12

Another term for mechanical lifter is tappet.

Answer 12

True’

Question 13

Technician A says excessive valve lift causes piston-to-valve interference. Technician B says high valve overlap can lead to clearance problems between the valves and pistons. Who is correct?

Answer 13

Technician B

Question 14

Two technicians are discussing valves. Technician A says that most exhaust valves are smaller then intake valves. Technician B says most intake valves are larger then exhaust valves. Who is correct?

Answer 14

Both Technicians

Question 15

Technician A says valve overlap occurs at the bottom of the intake stroke. Technician B says valve overlap occurs at the top of the intake stroke. Who is correct?

Answer 15

Technician B

Question 16

Technician A says that basket-type coil springs are installed with the tighter part of the coil against the head. Technician B says grinding a valve seat will not affect the installed height of the valve spring. Who is correct?

Answer 16

Technician A

Question 17

Technician A says aluminum heads usually have an aluminum shim beneath the valve spring. Technician B says as the valves are removed from the head, they should be kept in order. Who is correct?

Answer 17

Technician B

Question 18

What value is determined by multiplying the lobe lift by the rocker arm ratio?

Answer 18

gross valve lift

Question 19

Turbochargers are driven by _____.

Answer 19

exhaust flow

Question 20

Removal of 0.020” from OHC surfaces will result in 1° of advance in valve timing.

Answer 20

False’.

Question 21

The camshaft is the determining factor in how efficiently the engine pumps air.

Answer 21

True’.

Question 22

All of the following are timing components EXCEPT _____.

Answer 22

lifter

Question 23

Valve springs are being discussed. Technician A says you should discard a 2” spring that is 1/16” out of square. Technician B says out-of-square springs can cause uneven valve guide wear. Who is correct?

Answer 23

Technician B

Question 24

Technician A says aluminum heads can be checked for cracks with a process known as magnafluxing. Technician B says a red dye penetrant is used to check for cracks on cast iron heads. Which technician is correct?

Answer 24

Neither technician

Question 25

All of these are dynamic superchargers EXCEPT _____.

Answer 25

positive displacement

Question 26

An engine with a turbocharger is a normally aspirated engine.

Answer 26

False’

Question 27

Two factors of cam lobe profile are called lift and length.

Answer 27

False

Question 28

Technician A says springs should be tested for squareness, tension, and height. Technician B says to stack VSI shims under a valve spring until the spring pressure is correct. Who is correct?

Answer 28

Technician A

Question 29

The camshaft is the determining factor in how efficiently the engine pumps air while operating at various speeds.

Answer 29

True

Question 30

The turbine wheel and shaft assembled with the compressor wheel comprise the ____.

Answer 30

rotor