Detailed description of Six Stroke Engine with its advantages and disadvantages. It shows the various modifications required to develop a six stroke engine and its feasibility too.

1. SIX STROKE
ENGINE
BY : PRASHANT CHANDRA PUJARI
B.Tech 1st Year
Mechanical Engineering
Delhi Technological University

2. Internal Combustion Engine
An internal combustion engine is a heat engine where the combustion of a
fuel occurs with an oxidizer in a combustion chamber that is an integral
part of the working fluid flow circuit.

3. Types of Engine
1. Two Stroke
2. Four Stroke
I.C. Engine
1. Spark Ignition Engine
2. Compression Ignition Engine

4. Four Stroke Engine

5. Need Of Six Stroke Engine
• Two-thirds of the energy from combustion in a vehicle is lost as waste
heat, of which 40% is in the form of hot exhaust gas.
• The latest developments and technologies on waste heat recovery of
exhaust gas from internal combustion engines (ICE) are :
― Thermoelectric generators (TEG)
― Organic Rankine cycle (ORC)
― Six-stroke cycle IC engine
― New developments on turbocharger technology.

6. Objective
 Reduction in fuel consumption.
 Dramatic reduction in pollution.
 Better scavenging and more extraction of work per cycle.
• The engine captures the waste heat from the four stroke Otto cycle or
Diesel cycle and uses it to get an additional power and exhaust stroke of
the piston in the same cylinder.
• 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 normal Otto or Diesel Cycle.

7. Six Stroke Engine
Stroke-1 :
The inlet valve is kept open. Due to cranking, Piston moves downward
which results in the formation of a pressure difference due to which
pure air enters the cylinder.
Stroke-2 :
The inlet valve closes and the heating chamber valve opens. The
piston moves upward due to cranking forcing air into heating chamber.
The air at this stage is converted to high pressure.
Stroke-3 :
The combustion chamber valve opens and gases of combustion enter
the cylinder.
Stroke-4 :
The exhaust valve opens. The piston moves upwards and the exhaust
gases are removed via this valve.

8. Two Additional Strokes Are:
Stroke-5 :
The chamber valve opens and the pure air /water in atomized form
at high pressure and high temperature enters the cylinder which
does work on the piston and hence it moves downward resulting in
the 2nd power stroke.
Stroke-6 :
Finally the combustion chamber valve opens. The piston moves
upwards forces the pure air into the combustion chamber.

9. Six Stroke Engine

10. Schematic Diagram

11. Currently six stroke engines designs
 The Crower's six stroke engine, invented by Bruce Crower of the
U.S.A
 The Bajulaz engine by the Bajulaz S A Company, of Switzerland
 The Velozeta‟s Six-stroke engine built by the College of Engineering,
at Trivandrum in India.
 Comparison between 4-stroke and 6-stroke engine on the basis of
Brake Thermal Efficiency :
Speed (RPM) BTP % 4 Stroke Engine BTP % 6 Stroke Engine
900 28.92 32.78
1200 29.14 35.38
1500 29.93 39.02
1800 30.23 40.00
2000 31.28 41.65

12. Engine Modifications
1. FUEL TANK
• The fuel tank in a six stroke engine is divided into two parts. One
part will contain fuel and other part will contain water.
2. CAMSHAFT DESIGN
• In six stroke engine the camshaft has been designed to turn one
revolution for every three revolution of the crankshaft.
• The camshaft of the six stroke engine contains three cams :
1. Intake cam
2. Exhaust cam
3. Water/Air injector cam.

13. 3. MATERIAL USED FOR ENGINE COMPONENTS
• Due to injection of water there is rapid change in temperature which
can cause micro cracking in engine components due to continuous
compression and expansion in long period.
• Engine components are manufacturedusing thermal resistant alloys
like:
1. Silicon carbide
2. Alumina – Tungsten alloys
3. Zirconia.
4. WATER INJECTOR
• The water injection is done by the help of water injector which is
operated by the cam. The water injection is in the atomized form.

14. Advantages Of Six Stroke Engine
 Reduction in fuel consumption.
 Reduction in pollutants like NOx , CO , 𝐶𝑂2 upto 55% .
 Lower engine temperature so easy to maintain the
optimum engine temperature level for better
performance.
 Better scavenging and more extraction of work.
 Increase in thermal efficiency.
 Higher overall efficiency.

15. Limitation Of Six Stroke Engine
 Running problems in cold regions.
 Engine size increases due to additional components.
 Higher manufacturing costs.

16. Thank You