Can a 6stroke or a 5stroke engine be constructed?

  • Thread starter monty37
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  • #1
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Main Question or Discussion Point

can a 6stroke or a 5stroke engine be constructed?
as we have always known only of 3 atroke and 4stroke engines.
would 6 stroke or 5stroke engines be feasible?
 

Answers and Replies

  • #2
2,017
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6 strokes can, 3 and 5 cant.
 
  • #3
minger
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What about 2 stroke? To be honest I had to look up a three-stroke engine. Sure enough, there's a patent on it.
 
  • #4
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6 strokes can, 3 and 5 cant.
This is incorrect. I can think of at least two ICE engines that have 5 strokes, one being the Miller cycle. I'm think the Atkins cycle can be modified to have 3.

In the Miller cycle, the intake valve is left open longer than it would be in an Otto cycle engine. In effect, the compression stroke is two discrete cycles: the initial portion when the intake valve is open and final portion when the intake valve is closed. This two-stage intake stroke creates the so called "fifth" stroke that the Miller cycle introduces.
http://en.wikipedia.org/wiki/Miller_cycle
 
  • #5
2,017
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Both the miller and atkinson cycles have modified timing but are still considered to be 4 stroke engines. Atkinson with the exhaust timing and Miller with the intake. The piston still only moves up and down 4 times per cycle or 2 if its a modified 2 stroke.

Now this then depends on how you classify stroke, does a secondary intake on the miller cycle count as anther stroke, or does it count at just count at having a very long intake cycle that overlaps to comprression. The answer is up for debate really but both Atkinson and Miller still only have 4 stages to the cycle.

Intake Compression Power Exhaust.

You can break down those stages to magic up more stokes, the standard thinking is that although it has a two stage intake the second is a 'pseudo stroke' if you will.


EDIT: Just look at the quote you posted. the word fifth is in inverted commas and has the words 'so called' in front of it. Also just read the first line of that wiki entry.

"In engineering, the Miller cycle is a combustion process used in a type of four-stroke internal combustion engine"


As much as wiki is an unreliable source of information, its bang on with that one.


6 strokes have 6 discreet cycles.

Intake, Compression, Power, Exhaust, Steam/Air Cycle, Steam/Air Exhaust.
 
Last edited:
  • #6
brewnog
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A 'stroke' is movement of the piston from TDC to BDC or back again; Miller/Atkinson cycles are clearly still four strokes.

As has been advised, 6 stroke engines are definitely feasible.
 
  • #7
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can someone tell me why 6stroke is possible and why is 5and 4stroke not possible.
where is the 6stroke normally used?
 
  • #8
2,017
85


There has to be an even number of strokes, for every intake there has to be an exhaust.

The 4 standard strokes are listed above. For each of those 1 operation is done so a full cylce takes 720 degrees.

A 2 stroke does the compression/intake and power/exhaust at the same time.

A 6 stroke is a standard 4 stroke, then it adds a cycle at the end, that water is added during th next downstroke it expands as superheated steam down to BDC, this is then exhausted and the petrol cycle begins again.
 
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  • #9
brewnog
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If the piston goes down, it has to go back up again; there must be an even number of strokes.
 
  • #10
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well I own a 2wheeler which says it has a 3stroke engine ,but according
to what you say it has to have even number of strokes,but the technical
specifications of this 2 wheeler says 3stroke?
 
  • #11
2,017
85


Well like I said earlier it depends on what you classify as a stroke. It may say three stroke but it'll be a 2 stroke cycle with modified timing or it'll consider the exhaust scavanging to be an extra process in the cycle.

What strokes does it say it has? Can you give us more information as to exactly what engine it is.
 
  • #12
brewnog
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3 stroke engine in use? Show me.
 

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