Lesson Notes By Weeks and Term v4 - SHS 2
INTRODUCTION TO ENGINE TECHNOLOGY
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
INTRODUCTION TO ENGINE TECHNOLOGY
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Applied Technology
Class: SHS 2
Term: 1st Term
Week: 4
Grade code: 2.1.1.LI.4
Strand code: 1
Sub-strand code: 1
Content standard code: 2.1.1.CS.1
Indicator code: 2.1.1.LI.4
Theme: AUTOMOTIVE TECHNOLOGY
Subtheme: INTRODUCTION TO ENGINE TECHNOLOGY
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
Class: SHS 2 / Grade 11 Period: [Period number, e.g., 1 & 2] Performance Indicator: Learners can identify the parts of the lubrication system, explain their functions, and list the major engine components that are lubricated.
(A) The Purpose of the Lubrication System (15 mins)
The primary job of the lubrication system is to distribute clean engine oil to all moving parts of the engine. This achieves several critical goals. Let's remember them with the acronym S.C.C.F.W: S - Sealing: The oil forms a thin film that fills the tiny gaps between the piston rings and the cylinder wall. This creates a good seal, preventing combustion gases from leaking past the piston (blow-by) and ensuring the engine has good compression and power. C - Cooling: As oil circulates, it absorbs a large amount of heat from hot components like the bottom of the pistons and the crankshaft bearings. It then carries this heat back down to the oil sump, where it can cool down. The oil acts like a liquid cooling agent for the bottom half of the engine. C - Cleaning: Tiny particles of metal from wear, as well as soot and dirt from combustion, can build up inside an engine. The circulating oil picks up these contaminants and carries them to the oil filter, which traps them. This is why engine oil gets dark and dirty over time and must be changed. F - Friction Reduction: This is the most obvious function. Oil creates a microscopic layer between moving parts, so they glide on the oil film instead of grinding against each other. This drastically reduces friction. Less friction means less heat, less wear, and more power delivered to the wheels. W - Wear and Corrosion Prevention: By reducing friction, the oil directly prevents the metal parts from wearing out. Additionally, modern engine oils contain special additives that form a protective layer on metal surfaces, preventing rust and corrosion from moisture and acids that are by-products of combustion.
(B) Parts of a Typical (Wet Sump) Lubrication System (20 mins)
Most cars and small trucks in Ghana use a "wet sump" system. This means the main oil supply is stored in a pan at the bottom of the engine. Let's examine the key parts. Oil Sump (or Oil Pan): What it is: A metal pan bolted to the bottom of the engine block. Function: It acts as a reservoir to store the engine oil when the engine is off. It also helps to cool the oil as air passes over its surface while the car is moving. Oil Pickup Tube and Strainer: What it is: A tube that extends from the oil pump down into the sump. The end of the tube has a mesh screen (the strainer). Function: It is the 'straw' that sucks oil up from the sump. The strainer is a coarse filter that prevents large pieces of debris from entering and damaging the oil pump. Oil Pump: What it is: The heart of the system, usually driven by the crankshaft or camshaft. It can be a gear type or rotor type pump. Function: It is a mechanical pump that pressurizes the oil and forces it to circulate throughout the engine. Without the pump, the oil would just sit in the sump. Pressure Relief Valve: What it is: A small, spring-loaded valve, often located inside the oil pump. Function: It's a safety device. It prevents excessive oil pressure, especially when the engine is cold and the oil is thick. If pressure gets too high, the valve opens and dumps some oil back into the sump. Oil Filter: What it is: A canister containing a paper-like filter material. All the pressurized oil from the pump must pass through this filter. Function: Its job is to trap the small, harmful particles (metal, soot, dirt) that the oil has picked up. This ensures that only clean oil is sent to lubricate the delicate engine parts. This is a replaceable part and is changed during a service. Oil Galleries (or Passages): What they are: A network of small tunnels and holes drilled throughout the engine block and cylinder head. Function: They are the 'arteries' and 'veins' of the system, acting as pathways to deliver the pressurized, clean oil from the filter to all the necessary components. Dipstick: What it is: A long, thin metal rod that goes into the engine. Function: Used to manually check the level of oil in the sump. It has markings for "MIN" (Minimum) and "MAX" (Maximum). Oil Pressure Warning Light/Gauge: What it is: A sensor in an oil gallery connected to a warning light or gauge on the car's dashboard. Function: It alerts the driver if the oil pressure is dangerously low. If this light comes on, the driver must stop the engine immediately to prevent severe damage.