cameroon gce A level 2024 engine systems 2
cameroon gce A level 2024 engine systems 2
ECTION A
(Answer THREE questions from this section)
QUESTION1:DIESEL FUEL INJECTION
a) State the main difference in terms of operating principle between
engine.
b) Enumerate five factors that influence the mixture
c) Give four advantages of an electronic
a four–stroke diesel engine and the
| (2 marks) Petrol |
pattern in |
| 5 marks) control diesel injection aover diesel aengine mechanical cylinder (1 markx5= |
|
| 4 marks) diesel injection system . |
d) The Figure1is1 a type of fuel injection system in common use |
| Identify the type of injection | Figure 1 |
| thethe system names . and functionssystem of the following shownin Figure components 1. labelled1,2,3,4,5 and 6 | (1 mark) |
| iii. State one possible fault each f< below. (0.25 mark xl2=3 marks) e consequence on the injection system as on table |
| Identify the type of cooling system shown in the figure 2. | (1 mark) |
| In a table form, state the names and give the function of the following parts 4, 5, 6, 7 and 9 of the | |
| system above. | (0.5 mark x 5 + 0.5 mark x5= 5 marks) |
With the help of simple sketches, explain the operation of a bellows–type thermostat when the engine is
HOT and when COLD. (3 marks + 2 marks + 2 marks = 7 marks)
Explain the three modes through which heat is removed from this system.
| (2 marks x3= 6 marks) (0.5 mark x2= 1 mark) |
Give TWO materials used in the fabrication of radiators. |
QUESTION 3:THE CYLINDER HEAD AND GASKET
a. List FIVE objective factors that the designer must have in mind during the design of the
cylinder head.
b. Give FIVE functions of the cylinder head.
c. Name FOUR factors that are considered when choosing the cylinder head material
d. Which component is mounted on the cylinder head to restrict the flow of coolant thereby regulating the engine
working temperature?
e. Give FOUR reasons for torque loading a cylinder head stud or screw.
f. Give THREE effects on engine parts and operation, if there is insufficient compression between the joints and
| gasket feces g. On ANNEX 1 figure 1A and IB, indicate the correct tightening and loosening sequences of the cylinder head shown in figure 3 |
(1.5 marks) |
| (3 marks) |
What will be the main consequence if the correct tightening sequence of the cylinder head is
not respected?
i. What is the effect of excessive tightening of the cylinder head?
j. Give THREE requirements of a good cylinder head gasket.
QUESTION 4: EMISSION CONTROL
a. Define the following
i. Closed loop
ii. Open loop
iii. Lambda window
iv. Thermal after burning
b. List THREE systems put in place to control emission in an automobile.
c. List the areas in an engine where emission should be controlled
d. What is the function of the charcoal canister?
e. Figure 4 shows one type of emission control system
