In 18th century gasoline and
steam engines have low efficiency.
Low efficiency in these engines
inspired Rudolf to make engine
with high efficiency.
In 1878, Rudolf diesel invented
the compression-ignition engine.
By 1893 Diesel had obtained a
patent for his engine what we
know called the diesel engine.
Types of Diesel Engine
• Two Stroke
• Four Stroke
Working (Two Stroke)
When the piston is at BDC, it uncovers the
air intake valves. Air fills in the cylinder.
Piston compresses the air. Diesel fuel is
sprayed into the cylinder, it ignites. This is the
The pressure created by the combustion of
the fuel drives the piston downward. This is
the power stroke.
As the piston nears the bottom of its
stroke, all of the exhaust valves open. Exhaust
gases rush out of the cylinder.
Intake stroke: Intake valves open
letting in air moving the piston down.
Compression stroke: Piston moves
back & compresses air.
Combustion stroke: As the piston
reaches the top, fuel is injected at the
right time, ignited, forces the piston
Exhaust stroke: Piston moves back to
the top, pushing out the exhaust created
from the combustion out of the exhaust
Two Stroke V/S Four Stroke
• Two stroke engines has to make
one revolution to produce a
power stroke. This gives two
stroke engine more power.
• More polluting.
• Fuel efficiency is less.
• Four stroke engines has to make
two revolutions to produce
• Less polluting.
• Fuel efficiency is more.
Diesel Engine V/S Gasoline Engine
• The air is compressed first, and
then the fuel is injected.
• Fuel is mixed with air,
compressed by pistons and
ignited by sparks from spark
• Has spark plug for ignition.
• Has no spark plug combustion is
due to the heat of compressed
• High compression ratio.
• Produce more noise pollution.
• Gives maximum 35-40%
• Low compression ratio.
• Produces less noise pollution.
• Gives mximum25% efficiency.