Simplified for Seminar presentations

1. Seminar Presentation On
Six Stroke Engine

2. Content
• What is a six stroke engine???
• Working principle
• Engine Modifications
i. Fuel Tank
ii. Material
iii. Cam Shaft
iv. Water Injector
• Advantages
• Limitations
.

3. What Is A Six Stroke Engine???
• The SIX-STROKE engine is a type of internal combustion
engine based on conventional four stroke engines.
• It has some additional features to make it more energy
efficient and to reduce emissions.
• A six stroke engine has two power strokes as compared to
one power stroke of the conventional four stroke engine.

4. Working Principle
• A six stroke engine describes a number of different approaches in the
internal combustion engine to capture the waste heat from the four stroke
Otto cycle and use it to power an additional power and exhaust stroke of the
piston.
• Designs either use steam or air as the working fluid for the additional power
stroke.
• As well as extracting power, the additional stroke cools the engine and
removes the need for a cooling system making the engine lighter and giving
40% increased efficiency over the Otto Cycle.
• In case of a 2 stroke or 4 stroke engine the cylinder head and cylinder walls
merely act as a parasite by absorbing useful heat energy. In case of a six
stroke engine this no longer happens because the cylinder head and cylinder
walls act as an integral part of the power generation cycle.

6. First Stroke
Piston Moves from TDC to BDC and creates
vacuum pressure in the cylinder. Due to the vacuum
pressure air fuel is sucked into the cylinder via the
inlet port.
Second Stroke
Piston Moves from BDC to TDC and compresses the
mixture.
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Third Stroke
• At the end of the compression stroke the
fuel is ignited and burnt. The pressure and
temperature in the cylinder increases
rapidly. The increased temperature
pushes the piston downward.
Forth Stroke
• The burnt product is pushed out from the
exhaust valve by scavenging

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Fifth Stroke
• At the end of the exhaust stroke the
cylinder temperature becomes around
1000-1200 C.
• At this stage atomized water expansion is
injected into the cylinder.
• The water turns into vapor increasing its
volume around 1600 times. This causes
the piston to move from TDC to BDC.
Sixth Stroke
• The Piston is again reciprocated back
from BDC to TDC.

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Engine Modifications
1. Fuel Tank
• The Fuel tank in a six stroke engine has to be divided into two parts. One part will
contain fuel and other part will contain water.
• The water used should be distilled and pure.
2. Materials Used For Engine Components
• The engine components are subjected to thermal stresses developed due
to injection of water into the superheated cylinder. The rapid
temperature changes can cause micro cracking or fracture of the engine
components due to continuous compression and expansion.
• For this purpose the engine components are manufactured using thermal
resistant alloys like:
i. Silicon Carbide ii. Zirconia iii. Alumina-Tungsten Alloys

10. 3. Cam Shaft Design
• In traditional four stroke engines the angular speed of the
camshaft is half of the crankshaft. The Cam rotates ones for
every two revolutions of the cam.
• In six stroke engine the camshaft has been designed to turn
one revolution for every three revolution of the crankshaft.
• The camshaft of 6-stroke engine contains three cams.
i. Intake Cam
ii. Exhaust Cam
iii. Water Injector Cam

11. 4. Water Injector
• The water injection is done by the help of water injector which is
operated by the cam. This thing can be done more effectively by the
use of water metering.
• Water metering pump is a positive displacement pump capable of
driving a fixed quantity of water into the cylinder at regular intervals.

12. Analysis and Testing
1. Pressure And Volume Diagram
• Work obtained by six stroke is the sum of
the both combustion work and
vaporization work. So that the break
mean effective pressure will increase.

13. 2. Fuel Flow Rate
• Amount of fuel supplied to the engine
per unit time is the fuel flow rate.
• As the diagram shows the fuel flow
rate of 6-stroke engine is 50% lesser
than the conventional 4-stroke engine.

14. 3. Thermal Efficiency
• The thermal efficiency of the engine is the power produced by
the engine to the power available from fuel.
• The thermal efficiency of the four stroke engine lies between
20-30%, where as
• The thermal efficiency of six stroke engine lies between 40-50%.

15. Advantages Of Six Stroke Engine
• Due to an additional power stroke efficiency of the engine
increased.
• Better scavenging and more extraction of work
• Reduction in fuel consumption by at least 40%.
• Reduction in pollutants like NOx, CO ,CO2,photochemical
smog etc, up to 55%.
• Increase in indicated thermal efficiency.
• Minimize necessity of heat exchanger e.g. radiator.

16. Limitations Of Six Stroke Engine
• Early engine starting problems.
• Running Problems in cold regions.
• Requirement Of neutral water.
• Engine size increases due to additional components.
• Higher manufacturing costs.

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