Deck 9: Cylinder Heads

Question 1

What would most likely be a limit for valve stem taper?

A) 0.001" (0.250mm)
B) 0.005" (0.254mm)
C) 0.0005" (3.175mm)
D) 0.010" (3.810mm)

Answer 1

A

Question 2

The margin of the valve must be within specifications in order to properly dissipate heat.

Answer 2

True

Question 3

Technician A says that warped cylinder heads can sometimes be straightened. Technician B says that cracked cylinder heads can sometimes be repaired by welding. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Answer 3

C

Question 4

What is the condition called where the valve head pulls away from the stem just above the fillet?

A) stem warpage
B) stem necking
C) burned valve
D) spun stem

Question 5

It is sometimes necessary to strike the valve spring retainers with a soft faced hammer to remove the valve keepers.

Question 6

Technician A says that worn valve guides can cause valves to burn. Technician B says that stem necking is caused by worn valve guides. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 7

Spark ignition occurs just after top dead center during the compression stroke.

Question 8

Umbrella valve stem seals move up and down with the valve.

Question 9

Technician A says that worn valve stem seals will affect oil consumption. Technician B says that valve stem seals are normally reused during an overhaul. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 10

Interference engines can suffer valve damage if the timing belt were to break.

Question 11

Integral valve seats are removed by heat for replacement.

Question 12

Technician A says that engine components made from different materials thermal expand at different rates. Technician B says that the gasket must be able to withstand scrubbing or even shearing during uneven expansion and contraction while maintaining its seal. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 13

Leaking valve stem seals will cause low cylinder compression.

Question 14

A cylinder head is being disassembled. One of the valves is mushroomed at the tip preventing the valve from being removed. Technician A says a hammer and a thin punch should be used to drive the valve out. Technician B says a hydraulic press may be used to remove the valve. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 15

Excessive valve clearance can cause valves to burn.

Question 16

Valve inspection is being discussed. Technician A says that intake valve margin must not measure less than 1/32". Technician B says that a valve with bent stems must be discarded. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 17

A typical valve stem to guide clearance would be 0.01".

Question 18

All of the following would immediately rule out the reuse of a valve EXCEPT ____.

A) bent stem
B) burned face
C) excessive carbon deposits
D) non-visible margin

Question 19

Large carbon deposits on the neck of the valve will cause abnormally high compression.

Question 20

Technician A says that valve stem height is measured from the valve spring seat to the valve stem tip. Technician B says that incorrect valve stem height causes excessive oil consumption through the valve guides. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 21

Technician A says any type of valve guide can be used with any type of valve. Technician B says some guides are incompatible with stainless steel valves. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 22

List four basic measuring tools that can be used when checking the valve guides.

Question 23

Warpage is being measured on the mating surface cylinder head around the edges and across the center. Technician A says that 0.003" (0.076mm) warpage is generally acceptable. Technician B says that if the warpage is excessive, the engine was most likely overheated. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 24

Valve face and valve seat reconditioning is being discussed. Technician A says that when an interference angle is used, both the valve and the seat are machined at exactly the same degree cut. Technician B says that as the valve seat is cut, the valve stem height increases. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 25

When using a carbide cutter, how many angles are cut at the same time on the valve seat?

Question 26

Technician A says that micrometers used in conjunction with a small hole gauge can be used to obtain a valve guide to valve stem measurement. Technician B says that dial indicators are sometimes used to measure valve guide to valve stem clearance. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 27

Technician A says most valve guide inserts use an interference fit to the cylinder head. Technician B says many newer engines use thread valve guide inserts. Who is correct?

A) Technician A
B) Technician B
C) Both A and B
D) Neither A nor B

Question 28

After grinding the valve seat, the valve stem height is too tall. What could be done to correct this on some engines?

Question 29

Where does the valve transfer its heat to properly cool itself?

Question 30

Technician A says that worn valve guides can cause excess oil consumption. Technician B says that valve guides can be measured with a dial bore gauge. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 31

Valve stem height is the measurement of the valve:

A) Installed and closed
B) Installed and open
C) From valve tip to valve spring
D) None of the above

Question 32

Valve face to seat contact can be checked using:

A) A dial indicator
B) Prussion blue
C) A throating stone
D) Feeler gauges

Question 33

What tool or tools are used to check for warpage on the mating surface of the cylinder head?

A) dial indicator and V-blocks
B) straight edge and feeler gauge
C) depth micrometer and feeler gauge
D) straight edge and dial indicator

Question 34

Which of the following statements about valve interference angle are incorrect?

A) Interference angles are specified by all manufacturers
B) Angles are usually 1/2 to 1 degree
C) Interference improves valve sealing
D) The valve face and seat are cut at different angles

Question 35

How are integral valve seats repaired when there is not enough metal left to cut properly?

Question 36

What is usually considered a minimum thickness for the valve margin?

Question 37

How much metal should be cut from the valve face while reconditioning?

Question 38

When reconditioning the valve guides, what is the last step involved to obtain the correct diameter inside the guide?

Question 39

What tool is used to measure valve seat concentricity?

Question 40

Technician A says that the valve guides must be repaired before machining the valve seats. Technician B says that valve seats may be removed and replaced on some cylinder heads. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 41

How is valve stem height measured and what does it affect?

Question 42

Explain what excessive machining on a head surface causes.

Question 43

What is throating and why is it done?

Question 44

Describe three different types of valve stem seals.

Question 45

A 15-degree angle is being cut on a valve seat. What is this type of cut called and what happens to the seat?

Question 46

Explain the difference between free-wheeling and interference engines.

Question 47

Explain how valve guide knurling restores proper valve guide clearance.