Cylinder Head and Valve Train D2L

Question 1

How fast does the camshaft rotate relative to the speed of the crankshaft on a four stroke engine?

Answer 1

The camshaft rotates half as fast

Question 2

On a push rod engine, which of the following components contacts the rocker arm?

Answer 2

Push rod

Question 3

True or False;
Hydraulic lifters are self-adjusting, so valve lash does not need to be adjusted manually.

Answer 3

True

Question 4

What engine classification has push rods to actuate the rocker arms and valves?

Answer 4

Cam in Block

Question 5

What component is used to actuate two engine valves at the same time?

Answer 5

Valve Bridge
or
Crosshead

Question 6

How is the valve lift determined in an engine?

Answer 6

By the height of the nose or lobe (on the camshaft)

Question 7

True or False
Lifter location is unimportant when re-assembling the valve train.

Answer 7

False;
Keep lifters with same lobe because a wear pattern has already developed. Putting a lifter in different position can lead to accelerated wear.

Question 8

Where does the majority of the valve cooling occur?

Answer 8

The majority of cooling occurs between the valve face and the valve seat. (75%)

25% transfers from the valve stem to the valve guide

Question 9

What component is used if carbon is likely to become deposited on an engine valve?

Answer 9

Valve Rotator
Typically on exhaust valve, causes valve to rotate slightly every time the valve actuates, helps break carbon deposits and promotes even wear on valve and seat.

Question 10

True or False;
Valve guides need to be repaired or replaced before valve seats are repaired or replaced because it ensure correct alignment between the guide and seat.

Answer 10

True

Question 11

True or False;
Cylinder head bolts should be torqued in three stages at least, starting with the outer fasteners first, then finishing with the middle fasteners.

Answer 11

False;

centre working outwards

Question 12

2 reasons for valve clearance in an engine.

Answer 12

1. To allow thermal expansion of valve train
2. To compensate for wear of valve train components

Question 13

Which engine valve would normally have a greater amount of clearance?

Answer 13

Exhaust Valve
- to allow for greater (thermal) expansion of the components during engine operation.

Question 14

Which stage of engine cycle should the first cylinder be in, when checking for inlet and exhaust valve clearances?

Answer 14

Compression

Question 15

What condition would cause engine valves to overheat?

Answer 15

Insufficient valve lash