Lesson Notes By Weeks and Term - Senior Secondary 2

TERM – 1^ST TERM

WEEK THREE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:

Subject: AUTO MECHANICAL

Topic: AUTOMOBILE: A PETROL ENGINE III

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Identify the advantages of Two-Stroke Cycle engine

II.) Identify the advantages of Four-stroke cycle engine

III.) Differentiate between two stroke and four stroke cycle engine

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

PRESENTATION	TEACHER’S ACTIVITY	STUDENT’S ACTIVITY
STEP 1 INTRODUCTION	The teacher explains the advantages of two stroke and four stroke cycle engine	Students listens attentively to the teacher
STEP 2 EXPLANATION	Teacher discusses the differences between two stroke and four stroke cycle engine	Students exhibit attentiveness and active engagement
STEP 3 NOTE TAKING	The teacher writes a summarized note on the board	The students copy the note in their books

 

NOTE

AUTOMOBILE: A PETROL ENGINE III

Advantages of Two-Stroke Cycle engine

1. Two-stroke engines have fewer moving parts, making them simpler and often lighter.
2. Due to their simpler design, two-stroke engines can deliver more power per unit of weight compared to four-stroke engines.

3.Two-stroke engines complete a power cycle in every revolution, providing potentially higher power output compared to four-stroke engines of similar size.

4. Fewer parts mean fewer components that can break or wear out, resulting in potentially lower maintenance requirements.

Advantages of Four-Stroke Cycle engine

1. Four-stroke engines typically burn fuel more efficiently due to the separate intake, compression, power, and exhaust strokes, leading to better fuel economy.
2. Four-stroke engines tend to produce fewer emissions because they have a dedicated exhaust stroke, allowing better control over combustion and exhaust processes.
3. Four-stroke engines have a more balanced power delivery, resulting in smoother operation compared to the sometimes choppy power delivery of two-stroke engines.
4. With less wear and tear per cycle, four-stroke engines generally have a longer lifespan than two-stroke engines, especially in applications where durability is crucial, such as automotive and industrial uses.

Differences between two stroke and four stroke cycle engine

Two stroke cycle	Four stroke cycle
Completes intake, compression, power, and exhaust in two strokes	Completes intake, compression, power, and exhaust in four strokes
Oil is mixed with fuel for lubrication	Oil is stored separately and circulated for lubrication
Higher power-to-weight ratio, but less fuel efficiency	Lower power-to-weight ratio, but more fuel efficient
Tends to produce more emissions due to incomplete combustion	Produces fewer emissions due to more controlled combustion

 

EVALUATION: 1. Mention 4 advantages of two stroke cycle engine

2. Mention 4 advantages of four stroke cycle engine
3. Differentiate between two stroke and four stroke cycle engine

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively