Six Stroke Engine

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Six Stroke Engine

The six-stroke engine is a type of internal combustion engine based on the four-stroke engine, but with additional complexity to make it more efficient and reduce emissions. The six stroke engine has 2 power strokes, one fuel, one steam or air. The currently notable six stroke engine designs include Crower's six stroke engine, the Bajulaz engine and the Six-stroke engine (Trivandrum). The Beare Head engine is called a six stroke by its designer but stands apart from the others. It uses a second opposed piston in each cylinder which moves at half the cyclical rate of the main piston, thus giving six piston movements per cycle. It does not use any additional working fluid.


The Bajulaz six stroke engine is similar to a regular combustion engine in design. There are however modifications to the cylinder head, with two supplementary fixed capacity chambers , a combustion chamber and an air preheating chamber above each cylinder. The combustion chamber receives a charge of heated air from the cylinder and the injection of fuel begins an isochoric burn which has increased thermal efficiency compared to a burn in the cylinder. The high pressure achieved is then released into the cylinder to work the power stroke. Meanwhile a second chamber which blankets the combustion chamber has had its air contents heated to a high degree by heat passing through the walls from the burn. This heated and pressurized air is then used to power another stroke of the piston in the cylinder. The advantages of the engine include reduction in fuel consumption by at least 40%, two expansion strokes (work) in six strokes, multi-fuel usage capability, and a dramatic reduction in pollution.

The Bajulaz six stroke engine features:
1. Reduction in fuel consumption by at least 40%.
2. Two expansions (work) in six strokes.
3. Multifuel.
4. Dramatic reduction in pollution.
5. Liquefied Petroleum Gas.

In the six-stroke engine patented in the U.S. by Bruce Crower, after the exhaust stroke, fresh water is injected into the cylinder, and is quickly turned to superheated steam, which causes the water to expand to 1600 times its volume and forces the piston down for an additional stroke. This design also claims to reduce fuel consumption by 40%.

It was invented in 2004 by 75 year old American inventor Bruce Crower who holds a patent on the design involving fresh water injection into the cylinders.

Crower's six stroke engine features:
1. No cooling system required
2. Improves a typical engine’s fuel consumption
3. Requires a supply of distilled water to act as the medium for the second power stroke.

The term "Six Stroke" was coined by the inventor of the Beare Head, Malcolm Beare and sold to Jack Brabham Engines Limited in May 2004. The technology combines a four stroke engine bottom end with an opposed piston in the head working at half the cyclical rate of the bottom piston. The head piston works in a ported cylinder closely resembling that of a two stroke, thus 4+2= Six Stroke.

These were double acting, tandem engines and sold under the name "Kilmarnock". A major market for the Griffin engine was in electricity generation, where they developed a reputation for happily running light for long periods, then suddenly being able to take up a large demand for power. Their large heavy construction didn't suit them to mobile use, but they were capable of burning heavier and cheaper grades of oil. Only two known examples of a Griffin six-stroke engine survive. One is in the Anson engine museum. The other was built in 1885 and for some years was in the Birmingham Museum.


This six-stroke engine was developed by the students of College of Engineering, Trivandrum, India,...
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