Two- and four-stroke engines: Difference between revisions

Revision as of 01:10, 19 October 2022

Revision as of 20:28, 17 November 2022

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''' The M4+2 engine''', also known as the double-piston internal [[combustion]] engine, is a new type of [[internal combustion engine]] invented by a Polish patent holder Piotr Mężyk.<ref name="Piotr Mężyk">[http://izoling.beep.pl/www.izoling.pl/badania/czytaj/engine.html "Double pistons internal combustion engine"], Official site of the city of [[Myszków]], Poland ('''Polish'''). {{webarchive |url=https://web.archive.org/web/20170109041809/http://izoling.beep.pl/www.izoling.pl/badania/czytaj/engine.html |date=2017-01-09}}</ref>

The M4+2 engine took its name from a combination of the two working modes of the known engines, that is from the [[two-stroke engine]] and [[four-stroke engine]]. The two-stroke combustion engine is characterized by a simple construction and system of air load change, as well as a bigger index of power output. Unfortunately, its filling ratio is worse than in four-stroke engine. The ecological index of two-stroke engine is also unfavorable. The system of valves of the four-stroke engine is its disadvantage. The cylinders of both modules of double-pistons engine have been joined along one axis with common cylinder head - in the form of the ring. The pistons are moved with different speed and with appropriate stage displacement. The two crankshafts are connected with a special transmission. The four-stroke crankshaft is rotated with twice a speed of two-stroke crankshaft. The engine is named double-piston because of its construction - double pistons and crankshafts. In the M4+2, the advantages of both engines being connected are obvious; the [[piston]]s of the engine working in one [[combustion]] [[Cylinder (engine)|cylinder]] are set oppositely to each other, but in different modes. Although the projects of connecting two stroke modes in one cylinder were tried already a long time ago in the [[opposed piston engine]], the combination of the two different cycles had never been tried before. It turned out that the engine is not only able to work, but that the effects are very promising. The engine has a far greater efficiency over the break-even value known to combustion engines (about 35%) and closer to the one associated with [[steam turbines]] or [[electric engines]] (about 70%).{{Citation needed|reason=this should be in one of the already cited refs|date=April 2010}}

[[Image:proto.jpg|thumb|right|200px|The M4+2 [[prototype]] constructed at the [[Silesian University of Technology]], [[Poland]]]]

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The two-cycle modes are currently being researched at [[Ricardo Consulting Engineers]] in the UK. The concept consists in switching from one mode to the other depending on [[Revolutions per minute|rpm]] value. The four-stroke engine is more efficient when running at full throttle, while the opposite is the case for the two-stroke engine. When a small car under heavy load runs at half speed, the engine automatically switches to the two-cycle mode, which is then more efficient. The research on this showed a 27% reduction in fuel consumption.<ref name="genius">[http://www.theengineer.co.uk/Articles/305434/Stroke+of+genius.htm Engineer Online] Stroke of genius [[The Engineer (UK magazine)]]{{dead link|date=October 2021}}</ref><ref name="mit">[http://www.technologyreview.com/Energy/20494/ Nonelectric Hybrid Engines [[Technology Review]]/[[MIT]]] A novel hybrid engine could slash fuel consumption{{dead link|date=October 2021}}</ref>

Since the shaft of the four-stroke piston in the M4+2 engine always rotates twice as fast as the shaft of the two stroke piston, meaningand the two-stroke part always runs at half speed, both parts work in optimal conditions regarding fuel consumption at all times. The same principles are involved as with having 2 distinct engines, but the design of the M4+2 is much simpler.

==See also==