Session 8: Engine Timing (Tuning)
Unit 5: Regular Maintenance of an Engine
Textual Question-Answers
Check Your Progress
A. Fill in the blanks
1. Valve timing is used for………………
Ans: controlling the opening and closing of valves
2. Ignition timing helps in ……………. of an engine
Ans: smooth running
3. Injection timing is used…………Ans: to inject fuel at the correct time
4. Stroboscope helps in………… of ignition timing.
Ans: checking
B. Multiple choice questions
1. Which component is used in timing lights to dynamically set theexplosion timing of an otto cycle combustion engine?
(a) Stroboscope Lamp or Gun
(b) Piston
(c) Ring
(d) Rotary
Ans: (a) Stroboscope Lamp or Gun
2. The fuel injector injects the fuel at the right time at the endof………………….
(a) suction stroke
(b) compression stroke
(c) expansion stroke
(d) exhaust
Ans: (b) compression stroke
3. Full foam of MPFI system……………….
(a) Multi Point Fuel Injection
(b) Multi Fuel Point Injection
(c) Multi Point Fuel Induction
(d) None of the above
Ans: (a) Multi Point Fuel Injection
4. What is the full form of CVTI?
(a) Charged Motion Variable Time Ignition
(b) Changed Motion Variable Time Ignition
(c) Combustion Motion Variable Time Ignition
(d) All of the above
Ans: (d) All of the above
C. Answer the following questions
1. What is meaning of timing?
Ans: Timing means the correct and precise moment at which an engineoperation such as valve opening, ignition of spark, or fuel injection takes placeduring the engine cycle.
2. Give the differences between ignition and injection timing.
Ans: Ignition timing refers to the timing of spark production in a petrol engine to ignite the air–fuel mixture, whereas injection timing refers to thetiming at which fuel is injected into the combustion chamber, mainly in diesel and fuel-injected engines.
3. Name tool used in checking engine timing.
Ans: Stroboscope or timing light is used to check engine timing.
