Deck 52: Engine Diagnosis and Service: Cylinder Head and Valve Train

Question 1

While having a discussion, Technician A says that, if valve lash is too tight, the valve will not contact the valve seat for a long enough time to cool. Technician B says that if valve lash is too tight, it will cause the valve to burn. Who is correct?

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

Answer 1

C

Question 2

All of the following statements are true EXCEPT:

A)some springs have coils more closely spaced at one end than at the other.
B)cast rocker arms that are shaft mounted cannot be reground.
C)on a worn engine, valve guide seals can be replaced without removing the head.
D)stud-mounted rocker arms are not serviceable and are replaced when worn.

Answer 2

B

Question 3

All of the following statements are true EXCEPT:

A)magnaflux is the common trade name for a more sophisticated type of magnetic crack detection.
B)heads that are especially susceptible to cracks are often inspected by pressure testing
C)crack inspection on iron heads can be performed using a simple magnetic crack detector.
D)removal of 0.020" from OHC head surfaces results in about 10 degrees of retard in valve timing.

Answer 3

D

Question 4

Which of the following statements is LEAST-Likely true?

A)Servicing valve guides before seat refinishing will result in an off-center valve seat that must be reground or cut.
B)Exhaust seats are wider than intake seats because valve cooling is critical.
C)A valve that is off-center will leak, causing the engine to idle rough when cold.
D)Valve guides must be refinished before attempting to refinish valve seats.

Question 5

With cam-in-block engines, as pushrods, rocker arms, and other valve train parts wear, lash ____.

A)tightens
B)decreases
C)increases
D)stabilizes

Question 6

If the camshaft does not turn easily and the machine shop only resurfaces the bottom side of the head, a broken camshaft can result.

Question 7

When the seat and valve are reground, the stem moves further into the cylinder head. This results in increased valve stem tip height and ____________________ installed height.

Question 8

Cracks in iron heads are commonly repaired with tapered, threaded plugs. This process is known in the industry as ____________________ a crack.

Question 9

When water has been entering the combustion chamber from a leaking head gasket or a crack in the head, there will be carbon on the surfaces of the combustion chamber and piston.

Question 10

The part that will MOST-Likely warp, especially when a head gasket has failed because an engine has overheated, is the:

A)gasket
B)cylinder head
C)crankshaft
D)plenum

Question 11

When a cylinder head is removed to have the valves and seats refinished, this is called a(n) ____________________.

Question 12

The small ____________________ compressor is especially handy for compressing springs when the heads are on the engine.

Question 13

Carbon can be removed from valve necks with a wire wheel.

Question 14

Even the smallest hint of rust on a valve spring will require its replacement.

Question 15

If the head is installed on the engine and you want to rotate the camshaft to a different position during belt installation, you should move the pistons partway down in their bores (about ____ degrees) in order for the valves to clear the pistons.

A)25
B)45
C)90
D)180

Question 16

Which of the following statements is LEAST-Likely true?

A)The cam and lifters on pushrod engines become wear-mated after the first few weeks the engine is run.
B)Used lifters will rapidly wear out a new cam.
C)If a cam is to be reused, it is important that the lifters be kept in order for replacement on their respective lobes.
D)If a flat-tappet cam is replaced, replace the lifters also.

Question 17

Dress the edge of a(n) ____ tip with a file or whetstone before removing the valve from the valve guide.

Question 18

Warp readings on the top and bottom sides of an OHC head are always equal.

Question 19

During head disassembly, you should MOST-Likely measure and record:

A)valve tip
B)valve clearance
C)valve spring installed height
D)valve stem height

Question 20

While having a discussion, Technician A says that a stuck lifter plunger can sometimes be freed using an oil additive. Technician B says that it can sometimes be freed up by spraying fuel system spray cleaner down a hollow pushrod oil channel. Who is correct?

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

Question 21

How do you inspect a timing belt?

Question 22

How are valve guides repaired?

Question 23

Briefly describe the two techniques used to check valve stem-to-guide clearance.

Question 24

Under what circumstances would a hydraulic lifter fail?

Question 25

What are the steps involved in solvent testing the valve and seat?