Valvetrain test

Question 1

All of the following are timing components EXCEPT _____.

Answer 1

lifter

Question 2

An engine has excessive valve guide wear Technician A says to ream the guide and install a new valve with an oversize stem.

Technician B says to knurl the valve stem and reinstall it into the guide. Who is correct?

Answer 2

Technician A

Question 3

Cylinder heads are being discussed. Technician A says porting is when the size of a passageway is altered. Technician B says polishing smoothes the surface of the port. Who is right?

Answer 3

Both technicians

Question 4

Cylinder heads should be checked in five planes for warpage, distortion, bend and twist. What tool or tools should be used to check these issues?

Answer 4

Straight edge and a feeler gauge

Question 5

If your engine has a rocker arm ratio of 1.5:1 and the camshaft lobe pushes up on the rocker arm .400” at the pushrod side, how far would the valve be pushed off of its seat?

Answer 5

.600

Question 6

Modern day engines can have _____ valves per cylinder.

two
three
four

Answer 6

all of the above

Question 7

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 7

Technician B

Question 8

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

Answer 8

Technician B

Question 9

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 9

Technician B

Question 10

Technician A says cross-flow heads improve engine breathing. Technician B says cross-flow heads inhibit engine breathing. Who is correct?

Answer 10

Technician A

Question 11

Technician A says if an OHC camshaft does not turn easily, the head may need straightening.

Technician B says that if warpage is out of specification on the cam side of an OHC head, the head can be straightened. Who is correct?

Answer 11

Both A and B

Question 12

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 12

Neither technician

Question 13

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

Answer 13

Technician A

Question 14

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 14

Technician A

Question 15

Technician A says that before a valve guide can be repaired, the valve seat should always be ground. Technician B says the exhaust and intake valves each operate on a separate lobe on the camshaft. Who is correct?

Answer 15

Technician B

Question 16

Technician A says to grind less than .020 from the tip of the valve stem to avoid grinding through he hardened area.

Technician B says the tip of the valve should be ground approximately twice the amount removed from the seat. Who is correct?

Answer 16

Both A and B

Question 17

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 17

Technician B

Question 18

The benefit of using roller rockers is:

Answer 18

Reduced wear and friction

Question 19

To measure valve spring installed height you measure:

Answer 19

From the spring seat to the bottom of the spring retainer.

Question 20

Turbochargers are driven by _____.

Answer 20

exhaust flow

Question 21

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 21

Technician B

Question 22

What are the names of the angles used when grinding valve seats?

Answer 22

Top, seat and Throat

Question 23

An engine with a turbocharger is a normally aspirated engine.

Answer 23

‘False’.

Question 24

Another term for mechanical lifter is tappet.

Answer 24

True’.

Question 25

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

Answer 25

‘True’

Question 26

Intake valves are smaller than exhaust valves.

Answer 26

False’

Question 27

Springs that have been overheated will stretch and be longer.

Answer 27

False’.

Question 28

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

Answer 28

‘True’.

Question 29

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

Answer 29

False’.

Question 30

Valves will contract as they warm up during use.

Answer 30

False