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SIX STROKE ENGINE
How six stroke engine works
Specification of six stroke engine
Comparison of six stroke engine with four stroke engine
Malcolm beare built an innovative hybrid design of the I C engine , by combining a two stroke with a four stroke engine.
The Beare Head is a new type of four stroke engine head design known as the “Beare Head”
The Beare Head uses a piston and ports very much like a two stroke engine to replace the over head valve system that is found in four stroke engines today. The four stroke block, pistons and crankshaft remain unaltered. This combination of two stroke and four stroke technology has given the engine its name – the “six stroke engine” (2 + 4 = 6).
Key attributes of the Beare Head are:
Fewer, lighter reciprocating parts,
HOW SIX STROKE ENGINE WORKS
Fuel ignites with piston at the top dead center.
Rotary valve opens, allowing exhaust to escape
Exhaust stroke begins when the piston is at bottom dead center
Exhaust stroke ends, intake begins. rotary valve cuts exhaust .intake of charge into cylinder due to pressure difference.
The intake stroke happens when the piston is on its downward path with the intake valve open. This action creates suction, drawing atomized fuel in this case gasoline mixed with air, into the combustion chamber.
Top piston nearly closes complete inlet port and The compression begins.
Combustion chamber completely sealed and ready for the combustion.
The power stroke begins at a critical moment, just as the air-fuel mixture is at its most compressed. A supercharged voltage is delivered to the spark plugs from the ignition coil, at that point it ignites the fuel mixture. The valves in the engine are still closed during this period. Thus the explosion forces the piston down to turn the engine's crankshaft, delivering the power via the gearbox and clutch to the driving wheels.
SPECIFICATION OF SIX STROKE ENGINE
The piston is half way up on the exhaust stroke. When the piston reaches TDC with the ports fully open, the disk will begin to cut off the exhaust. The valve runs clockwise
The intake begins at 0 degrees on the X-axis. The effect of the additional volume changes that the upper piston has on the volume of the engine is all positive from a thermodynamic point of view. If the engine were a normal 4 stroke the cylinder capacity would be 340cc. Of note - maximum volume at the end of the intake stroke occurs at 173 degrees instead of 180 degrees- the change in volume is 308cc which is less than a 4 stroke (340cc)- yet the total volume at the end of the intake stroke is 415cc as opposed to 375cc for a conventional stroke.
The change in volume during the compression stroke is slightly greater than a 4 stroke after the ports are closed.
The expansion stroke is much greater than a 4 stroke, both from T.D.C. to B.D.C. and from T.D.C. till the exhaust port is open.
It is possible to leave the opening of the exhaust port later than in a 4 stroke because maximum volume is not reached until after B.D.C.-548 deg. Instead of 540 deg .
In a six stroke engine the energy absorption is less because of slower acceleration of reciprocating parts The piston speed of the upper piston is about a quarter of the main piston; therefore its service life should be at least twice that of the main piston.
In the Beare design, per single cylinder, the number of parts is 15 compared to a four stroke of approx 40 to 50 parts. Also, to reduce manufacturing costs the head and block can be machined in one piece.