This document describes the working principles and design of a six-stroke engine that uses water injection to improve efficiency. The six-stroke engine adds two additional strokes to the conventional four-stroke cycle to capture heat from the combustion process. In the secondary power stroke, water is injected into the superheated cylinder where it vaporizes, expanding and producing additional power. Thermodynamic analysis shows the six-stroke engine has higher thermal efficiency and lower fuel consumption compared to a four-stroke. However, modifications are needed to the engine components, camshaft, and valves to accommodate the additional strokes. While more efficient, the six-stroke engine also faces drawbacks such as difficulty starting when cold and requiring a source of neutral water.

1. BRUSH CROWER TYPE(WATER INJECTION)
Prateek Kumar Das
Trident Academy of Technology, Bhubaneswar

2. CONTENTS
 INTRODUCTION
 WORKING PRINCIPLE
 THERMODYNAMIC ANALYSIS
AND COMPARISION WITH 4-STROKE
 MODIFICATION REQUIRED
 ADVANTAGES
 DRAWBACKS
 CONCLUSION

3. INTRODUCTION

4. The concept of six stroke engine was developed in mid 20th
century when pollution due to the conventional IC engine
increased.
The six stroke engine “Using water” was developed
By Brush Crower in 2006 and he patented his product at the end of
2007.
Six stroke engine is a type of internal combustion engine
based on conventional four stroke engine, but it`s additional two
strokes make it more efficient and reduce the emission. The engine
captures heat, which is lost from conventional four stroke cycle and
additional strokes use it to produce power by introducing water
inside the super heated cylinder.

5. WORKING PRINCIPLES

6. The working principles of six stroke engine is based on the concept of
four stroke engine but with some modification, another two strokes are added.
SUCTION STROKE
The piston moves from top dead center to the
Bottom dead center and creates vacuum pressure .
So the Air and fuel mixture is sucked in to the
Cylinder.

7. COMPRESSION STROKE
The piston moves from
Bottom dead center to top dead
center and compresses the
Mixture. The mixture is compressed
To high temperature and pressure.
POWER STROKE:
At the end of compression
stroke the fuel is ignited and
burnt. The pressure inside the
cylinder increases rapidly and
it pusses the piston down and
the power is transmitted from
piston to wheel.

8. EXHAUST STROKE:
The Burnt product is
pushed through the exhaust
valve by the upward movement
of the piston.
SECONDARY POWER STROKE:
At the end of the exhaust
stroke the cylinder temperature
becomes around 900-10000 C. At
this stage water is injected by an
Injector in the form of fine droplets.
The water turns in to vapour
increasing volume around 1600
times when it comes in contact
with the superheated cylinder.

9. The water turns into vapour
increasing volume around
1600 times when it comes in
contact with the superheated
cylinder.
SECONDARY EXHAUST STROKE:
In this stroke the water vapour
is exhausted by the upward
motion of the piston.

10. THERMODYNAMIC ANALYSIS
AND
COMPARISION WITH
4-STROKE ENGINE

11. 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.
Pressure and volume diagram

12. Valve timing diagram of 6-stroke engine
IVO: Inlet Valve open
EVO: Exhaust Valve Open
IVC: Inlet Valve Close
EVC: Exhaust Valve Close
WC : Water Injection

13. Thermodynamic analysis of power strokes:
Fuel power stroke:
Water injection 2
0
power stroke

14. In order to determine the engine parameters, in 2011 HONDA
motors conducted the first simulation of the six stroke engine by using a
modified Honda GC190 engine.
SIMULATION RESULTS
POWER AND TORQUE V/S ENGINE SPEED

15. Cycle analysis and Comparison
FUEL FLOW RATE:
The amount of fuel flow to the engine per unit time is known as fuel flow rate.
As the diagram shows the fuel flow rate of 6-stroke engine is 50% lesser than
the conventional 4-stroke engine.

16. 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%.

17. BRAKE SPECIFIC FUEL CONSUMPTION
It is the ratio of fuel consumption per second to the brake power.
As from the diagram the brake specific fuel consumption of 6-stroke
engine is much lower than the conventional six stroke engine.

18. Factors affecting the engine performance
 Water injecting pump
 Used fuel and lubrication
 Valve timing of the engine
 Temperature of the cylinder wall

19. MODIFICATIONS REQUIRED

20. FUELTANK:
 The fuel tank should divided into two parts, as one part will contain fuel and the
other part will contain water.
 The water used should be neutral and distilled.
ENGINE COMPONENTS MATERIAL
The engine components like piston, cylinder , cam, crank, valves etc. are
subjected to severe thermal stress. The thermal stress developed due to the injection
of water into the very hot cylinder. The rapid temperature changes may cause micro
crack and fractures in the engine components as the periodical compression and
expansion takes place.
So the engine components should be designed with high thermal resistive
metal alloys to withstand the stress and prevent failure of engine.
The materials that can be used are…
Silicon Nitride(Si3N4)
Silicon Carbide(SiC)
Zirconia(ZrO2)
Alumina-Tungsten alloy etc.

21. CAM-SHAFT DESIGN AND VALVE TIMING
The valve control of the 6-stroke engine can be done in two ways.
 by mechanically cam controlled
 by solenoid valve controlled.
The mechanically cam controlled valve is based on the four stroke
design.
In four stroke original angular speed of camshaft is one half of the crankshaft. The
crankshaft rotates once for every two revolution of the crank shaft.

22. In six stroke engine the camshaft has been designed to turn one revolution
for every three revolution of the crankshaft.
Since camshaft is geared directly to the crankshaft, this makes it impossible to
change the number of teeth on each shaft to achieve the correct speed due to the
size constraint.
To overcome this a third shaft is to be installed with double reduction gearing
system.
(a)Gear reduction in 4-stroke . (b)Gear reduction in 6-stroke.

23. The camshaft of 6-stroke engine contains three cams.
 Intake cam
 Exhaust cam
 Water injector cam

24.  Cam follower modification
The bottom shape of regular follower has the flat pattern, which is
suitable with the normal camshaft for four stroke engine. The shape of the
follower must be roller or spherical shape. In this case a spherical shape is chosen
as it’s contact area is less .
Flat and Spherical follower

25. Solenoid valve
Solenoid valve with engine control unit is used in place of mechanically
driven cam for accurate injection and exhaust operation. The solenoids have then
been attached to the bracket system using 1/4-28 threaded rod and plates. This
allows for fairly fine adjustment of the valve to throw water. The original cores of
the valves have made from one inch diameter cold rolled steel. Each core
has been designed to act as the
stop when the valve is completely open.
The valves have been attached to the
pushrods using universal joints. The
push rod is Connected with solenoid coil
Which energized and DE energized by
Electric current to open and close the valve.

26. Water Injection:
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 pump or by the progressive cavity pump.
 Water metering Pump:
A positive displacement pump capable of driving a fixed quantity of
water into the cylinder at regular intervals, independent of the back pressure
applied.

27.  Progressive cavity pump:
It is a screw pump positive displacement variant. In this the working fluid passes
through series of discrete cavities as rotor is turned.
The pump is to be synchronized with the output shaft of the engine with a reduction
gear of 3:1 ratio.

28. ADVANTAGES:
 Uses rejected heat from engine
 Fuel economy increases to 60% of conventional engine
 Power output per stroke is more
 Exhaust gas emission is low
 High thermal Efficiency

29. Drawbacks:
 Early engine starting problem:
As the engine is not sufficiently hot at the starting the water injection stroke
cannot be taken place. So a prime mover is used to run the engine for some
cycle and after heating of the cylinder it is cut out.
 Running problem in cold region:
As the temperature in cold region is low there might be problem in case of
water injection stroke as the cylinder temperature is low.
 Requirement of neutral water:
As the steam is generated in 2
0
power stroke, if the water is not neutralized it
may react with the cylinder wall and with the piston top which results
cavitation and distortion of the metal. It causes the uneven heat transfer
between the water droplets and the cylinder wall which may decrease the
performance of the engine. And it is difficult to carry neutral water all the
times.

30. CONCLUSION
Six stroke engine has many advantages like high thermal efficiency, low fuel
consumption, high break mean effective pressure, low emission. However drawbacks like
initial starting problem, availability of water are also associated. The starting problem can be
Can be eliminated by using heater or glow plug and coupling a dc motor as prime mover to
the engine. Now a days research and experiments are going on to modify the engine further
and to make it for practical purpose.

31. REFERENCES :
 15th International Conference on Applied Mechanics and Mechanical Engineering, 29-31
May, 2012,report by M. M. Gasim, L. G. Chui and K. A. Bin Anwar
 Project report on Six stroke engine, Calvin College, ENGR 340
 Thermodynamic analysis testing and validation of six stroke engine Report,
University of Northern Ireland.
 Conklina J. C. and Szybist J. P., "A Highly Efficient Six-Stroke Internal Combustion
Engine Cycle with Water Injection for In-Cylinder Exhaust Heat Recovery", Energy,
Volume 35, Issue 4, pp. 1658-1664 (2010).
 Andrew De Jong, team 6 stroke, https://knightvision.calvin.edu (accessed14/2/2012).

32. THANK YOU