Hio

1. 2 STROKE & 4 STROKE
ENGINES
PRESENTED BY: SYED SAAD AHMED ZAIDI
ID: 1827-2021

2. 4 STROKE ENGINE
The four-stroke engine is the most common types of internal combustion
engines and is used in various automobiles (that specifically use gasoline as
fuel) like cars, trucks, and some motorbikes (many motorbikes use a two
stroke engine). A four stroke engine delivers one power stroke for every two
cycles of the piston (or four piston strokes)

3.  Intake stroke: The piston moves downward to the bottom, this increases the
volume to allow a fuel-air mixture to enter the chamber.
 Compression stroke: The intake valve is closed, and the piston moves up the
chamber to the top. This compresses the fuel-air mixture. At the end of this stroke,
a spark plug provides the compressed fuel with the activation energy required to
begin combustion.
 Power Stroke: As the fuel reaches the end of it’s combustion, the heat released
from combusting hydrocarbons increases the pressure which causes the gas to
push down on the piston and create the power output.
 Exhaust stroke: As the piston reaches the bottom, the exhaust valve opens. The
remaining exhaust gas is pushed out by the piston as it moves back upwards

4. 2 STROKE ENGINE
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that
completes a power cycle with two strokes (up and down movements) of the piston
during one power cycle, this power cycle being completed in one revolution of the
crankshaftIn a two-stroke engine, the end of the combustion stroke and the
beginning of the compression stroke happen simultaneously, with the intake and
exhaust (or scavenging) functions occurring at the same time.Two-stroke engines
often have a high power-to-weight ratio, power being available in a narrow range of
rotational speeds called the power band. Two-stroke engines have fewer moving
parts than four-stroke engines.

5. Overall, a two-stroke engine contains two processes:
Compression stroke: The inlet port opens, the air-fuel mixture enters the chamber
the piston moves upwards compressing this mixture. A spark plug ignites the
compressed fuel and begins the power stroke.
Power stroke: The heated gas exerts high pressure on the piston, the piston moves
downward (expansion), waste heat is exhausted.