Page 80 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

LESSON 19 - 24: Importance of measuring cylinder block

components for actual wear to decide
serviceability

Objectives

At the end of this lesson you shall be able to
• explain Importance of measuring cylinder block components
• decide Serviceablility of cylinder block components.

Importance of measuring cylinder block components: Measuring the wear of cylinder block components
is important to determine their serviceability as it ensures that the engine operates efficiently. Excessive wear
can cause poor performance, oil consumption, and even engine failure due to excessive oil consumption. By
accurately assessing wear, mechanics can decide whether components need to be replaced or whether they
can still perform adequately within specified tolerances. This helps maintain engine longevity and overall vehicle
reliability.
Here is some important point for measuring a cylinder block Components

For Cylinder bore diameter: Measuring the diameter of the cylinder bore ensures that it remains within
manufacturer specifications. Excessive wear can increase oil consumption and reduce compression.
For Cylinder taper and out-of-roundness: Checking taper (gradual increase in diameter from top to bottom)
and out-of-roundness (variation in diameter around the cylinder) helps ensure uniform piston movement and
proper sealing.

For Check Cylinder wall thickness: Assessing the thickness of the cylinder walls is important to detect thinning
due to wear or corrosion. Thin walls compromise structural integrity and can lead to catastrophic failure.
For checking Surface finish: Inspecting the surface finish of the cylinder walls helps ensure proper lubrication
and piston ring sealing. Rough surfaces can cause excessive friction and accelerated wear.
For Check Deck Height: Measuring the distance between the cylinder deck and the crankshaft centerline helps
maintain proper piston-to-valve clearance and compression ratio.

Bearing Surfaces: Checking bearing surfaces for scoring or grooving helps determine the condition of main and
rod bearings, ensuring proper lubrication and reducing the risk of bearing failure.
For checking Alignment: Checking for any misalignment or distortion of the cylinder block ensures proper
mating with other engine components such as the cylinder head and crankshaft.

67
CITS : Automotive - Mechanic Diesel - Lesson 15 - 18