Deck 30: Cylinder Head and Valve Guide Service

Question 1

Cylinder heads with four valves flow more air than those with two valves because they ________.

A)Increase the velocity of the air
B)Use a higher lift camshaft
C)Have a greater open area
D)Both A and C

Answer 1

Both A and C

Question 2

Two technicians are discussing a Hemi engine. Technician A says that a Hemi is an engine with aHemi-spherical shaped combustion chamber. Technician B says that all Hemi engines are cam-in-block designs. Which technician is correct?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Answer 2

Technician A only

Question 3

Technician A says that an Audi five-valve engine uses three intake valves and two exhaust valves.Technician B says that it uses three exhaust valves and two intake valves. Which technician is correct?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Answer 3

Technician A only

Question 4

The gasket surface of a cylinder head, as measured with a precision straightedge, should have a maximum variation of ________.

A)0.001 inch in any 6-inch length or 0.004 inch overall
B)0.004 inch in any 10-inch length or 0.008 inch overall
C)0.002 inch in any 6-inch length or 0.004 inch overall
D)0.020 inch in any 10-inch length or 0.020 inch overall

Question 5

A warped aluminum cylinder head can be restored to useful service by ________.

A)Machining the gasket surface to one-half of the warped amount and then heating the head in an oven and allowing it to cool slowly
B)Heating it to 500°F for 5 hours and cooling it rapidly before final machining
C)Grinding the gasket surface and then align honing the camshaft bore
D)Heating in an oven at 500°F with shims under each end, allowing it to cool, and then machining it

Question 6

Some vehicle manufacturers recommend repairing integral guides with ________.

A)Replacement valve guides
B)Knurling
C)Valve guide inserts
D)OS stem valves

Question 7

Typical intake valve stem-to-guide clearance is ________.

A)0.001 to 0.004 inch (0.025 to 0.076 mm)
B)0.015 to 0.020 inch (0.4 to 0.5 mm)
C)0.030 to 0.045 inch (0.8 to 0.10 mm)
D)0.005 to 0.010 inch (0.13 to 0.25 mm)

Question 8

What other engine component may have to be machined if the cylinder heads are machined on a V-type engine?

A)Intake manifold
B)Distributor mount (if the vehicle is so equipped)
C)Exhaust manifold
D)Block deck

Question 9

Which type of valve guide is most used in a cast-iron head?

A)Integral
B)Powdered metal (PM)
C)Bronze
D)Thin-wall sleeve type

Question 10

Which of these statements is TRUE about surface finish?

A)Cast-iron surfaces should be smoother than aluminum surfaces
B)A cylinder head should be much smoother than a crankshaft journal
C)The rougher the surface, the higher the microinch finish measurement
D)The smoother the surface,the higher the microinch finish measurement

Question 11

Technician A says that the most commonly used combustion chamber types include hemispherical, and wedge. Technician B says that coolant and lubricating openings and passages are located throughout most cylinder heads. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 12

Technician A says that cylinder head resurfacing machines include grinders and milling machines.Technician B says that cylinder head reconditioning should start with resurfacing of valves. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 13

Technician A says that the only valve guide repair option for integral valve guides is to use oversize-stem valves. Technician B says that valve guides should be checked for wear using a ball gauge or a dial indicator. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 14

For lowest hydrocarbon emissions, which of these engine design features is used?

A)Increased (as much as possible) quench area
B)Low combustion chamber surface area-to-volume ratio
C)High combustion chamber surface area-to-volume ratio
D)Non-centrally mounted spark plug

Question 15

To help ensure proper engine cooling, most cylinder head designs use ________.

A)Long exhaust ports and short intake ports
B)Large exhaust crossover passages
C)Short exhaust ports and long intake ports
D)Coolant passages restricted by head gaskets

Question 16

Which of these operations should be performed first?

A)Grinding the valves
B)Resurfacing the head
C)Installing replacement guides
D)Grinding the seats

Question 17

The use of a knurling tool is being described. After the knurling tool displaces the metal inside the guide, a ________ is run through the guide to produce a restored, serviceable valve guide.

A)Reamer
B)Drill bit
C)Ball gauge
D)File

Question 18

Technician A says that the intake valve runs hotter than the exhaust valve because the intake valve has the greater surface area. Technician B says that the exhaust valves usually do not burn due to the scavenging effect of the exhaust stream. Who is right?

A)Technician A only
B)Technician B only
C)Both technicians A and B
D)Neither technician A nor B

Question 19

Pressed-in valve ________ are used in aluminum heads

A)Guides
B)Seat inserts
C)Springs
D)Both A and B

Question 20

Valve ________ occurs when both valves are open at the same time at the end of the exhaust stroke and at the beginning of the intake stroke.

A)Overlap
B)Rotation
C)Collision
D)Inversion

Question 21

Valve guides are measured using a micrometer and a hole gauge.

Question 22

Resurfacing of the cylinder head has no effect on the compression ratio.