Class 12 Automotive Chapter 2 Serviceability, Replacement or Repair of Engine Components

Class 12 Automotive Chapter 2 Serviceability, Replacement or Repair of Engine Components Solutions English Medium As Per AHSEC New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters Class 12 Automotive Chapter 2 Serviceability, Replacement or Repair of Engine Components Question Answer and select need one. Class 12 Automotive Chapter 2 Serviceability, Replacement or Repair of Engine Components Notes Download PDF. AHSEC Class 12 Elective Automotive Question Answer English Medium.

Class 12 Automotive Chapter 2 Serviceability, Replacement or Repair of Engine Components

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. AHSEC Class 12 Elective Automotive Textual Solutions are part of All Subject Solutions. Here we have given AHSEC Class 12 Automotive Textbook Solutions English Medium for All Chapters, You can practice these here.

Serviceability, Replacement or Repair of Engine Components

Chapter: 2

SESSION 1: RECONDITIONING OF VALVE MECHANISM

Check Your Progress

A. Fill in the blanks:

1. The valve mechanism controls the submission of inlet gases and emission of exhaust gases in relation to the rotation of the ________________. 

Ans: Cam shaft.

2. Valve ______________ is necessary to diagnose leakages of combustion gases and improve engine performance. 

Ans: Timing.

3. During the valve lapping operation, abrasive/emery paste is applied on the valve face, and the lapping stick is turned in both clockwise and anticlockwise directions to ensure proper sealing between the valve and ________________. 

Ans: Valve seat.

4. The Overhead Cam (OHC) mechanism consumes less engine power for valve operation and is located at the _________________. 

Ans: Cylinder head.

B. Multiple Choice Questions:

1. Which of the following components controls the timing and quantity of gas or vapor flow into an engine? 

(a) Piston rings. 

(b) Rocker arm.

(c) Valve. 

(d) Camshaft. 

Ans: (d) Camshaft.

2. What is the primary reason for conducting a compression test of an engine’s valve mechanism? 

(a) To measure fuel efficiency.

(b) To check for coolant leaks. 

(c) To assess valve leakage. 

(d) To evaluate oil pressure. 

Ans: (c) To assess valve leakage. 

3. In an Overhead Cam (OHC) mechanism, where is the camshaft fixed. 

(a) In the crankcase. 

(b) In the cylinder head. 

(c) On the rocker arm. 

(d) In the valve guide. 

Ans: (b) In the cylinder head.

4. What is the purpose of the valve lapping operation during reconditioning? 

(a) To measure valve leakage. 

(b) To replace damaged valves.

(c) To adjust valve tappet clearance. 

(d) To ensure proper sealing between the valve and valve seat.

Ans: (d) To ensure proper sealing between the valve and valve seat.

C. Answer the following questions:

1. What is poppet valve?

Ans: The valves used in internal combustion engines are usually known as poppet valves. A poppet valve is a valve typically used to control the timing and quantity of gas or vapour flow into an engine.

2. How many kinds of valve used in IC Engine? 

Ans: Valve mechanism are classified as given below:

(i) Overhead valve mechanism (OHV).

(ii) Overhead Cam mechanism (OHC).

3. What are the purposes of a valve?

Ans: It controls the submission of inlet gases and emission of exhaust gases at the right time in relation to the rotation of the cam shaft.

4. Briefly describe a function of a valve & draw its line diagrams with details. 

Ans: Valve mechanism: It controls the submission of inlet gases and emission of exhaust gases at the right time in relation with the rotation of the cam shaft.

Line diagrams: 

5. What are the seat angles & why it is required? 

Ans: (i) Measure the angle of the valve seat with the help of a bevel protractor. 

(ii) Check the margin of the valve seat; if it is less than 2 mm replace the valve seat. 

(iii) If it is more than 2 mm, then it is suggested to carry out valve seat grinding operation. 

(iv) Select grinder/ cutter of appropriate size and angle. 

(v) Fix the holder and pilot to the grinding stone/cutter. 

(vi) Now grind the valve seat with a machine or manually and cut the valve seat to get the required angle.

6. Which part control opening & closing of a valve? 

Ans: The valve advance mechanism controls the supply of fuel and increases the engine efficiency at high speeds.

7. Write the name of the tools required for valve seat grinding. 

Ans: Select grinder/cutter of appropriate size and angle. Fix the holder and pilot to the grinding stone/cutter.

SESSION 2: REPLACEMENT OF PISTON RINGS

Check Your Progress

A. Fill in the blanks:

1. The primary functions of piston rings in an internal combustion engine are to seal the ________________ so that there is no transfer of combustion gases from the chamber to the crankcase. 

Ans: Combustion chamber.

2. The top two rings in most automobile engines are known as _________________, while the lower ring is an oil ring responsible for controlling oil supply. 

Ans: Compression rings.

3. Piston rings are subjected to wear due to movement within the cylinder bore as the piston moves from _______________ to Bottom Dead Centre. 

Ans: Top Dead Centre.

4. During the inspection of piston clearance in a multi-cylinder engine, a set of tools including spanners, a micrometer, and a _______________ gauge is used to ensure correct gaps and clearances. 

Ans: Feeler.

B. Multiple Choice Question:

1. What is the main function of piston rings in an internal combustion engine? 

(a) To increase fuel efficiency.

(b) To regulate exhaust emissions.

(c) To cool down the engine components.

(d) To seal the combustion chamber and prevent gas leakage.

Ans: (d) To seal the combustion chamber and prevent gas leakage.

2. Which type of piston ring is responsible for controlling the supply of oil to the cylinder liner? 

(a) Compression ring. 

(b) Exhaust ring. 

(c) Oil ring.

(d) Power ring.

Ans: (c) Oil ring.

3. What is the primary reason for the wear of piston rings in an engine? 

(a) Movement within the cylinder bore during engine cycles. 

(b) Inadequate cooling. 

(c) Excessive lubrication. 

(d) Irregular combustion. 

Ans: (a) Movement within the cylinder bore during engine cycles.

4. What is the purpose of inspecting the end gap of a piston ring? 

(a) To measure the thickness of the ring. 

(b) To check for wear on the cylinder bore.

(c) To ensure proper alignment of the piston ring.

(d) To determine the oil consumption rate of the engine.  

Ans: (c) To ensure proper alignment of the piston ring.

SESSION 3: INSPECTION AND REPLACEMENT OF CYLINDER LINER/ BORE SLEEVE, CONNECTING ROD AND ENGINE BEARING

Check Your Progress

SESSION 4: TESTING OF COOLING SYSTEM AND REPLACEMENT OF DEFECTIVE COMPONENTS

Check Your Progress

SESSION 5: REGULAR SERVICING OF MPFI SYSTEM

Check Your Progress

SESSION 6: CRDI AND NON CRDI SYSTEM

Check Your Progress