Doubt: Is 3 Stroke Engine Possible?

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Discussion Overview

The discussion centers around the feasibility of a three-stroke engine, exploring the mechanics and principles involved in engine cycles. Participants examine the implications of reducing the traditional four-stroke cycle to three strokes, questioning the viability of such a design from both theoretical and practical perspectives.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Exploratory

Main Points Raised

  • Some participants question whether it is possible to have a three-stroke engine while maintaining all necessary cycles of intake, compression, power, and exhaust.
  • One participant suggests that if the first stroke is for intake, the second for compression and ignition, then the third must handle both expansion and exhaust, raising concerns about the mechanics of exhaust gas removal.
  • Another participant argues that the piston would not be able to force gases out during the third stroke, suggesting that additional mechanisms would be required, which could reduce efficiency.
  • There is a proposal to combine a two-stroke and a four-stroke engine on the same crankshaft to achieve an average of three strokes.
  • One participant asserts that real reciprocating engines require an even number of strokes, emphasizing that the traditional cycles cannot be effectively altered without compromising function.
  • Concerns are raised about the implications of high-pressure gases during combustion and how they would behave in a three-stroke design, with some suggesting that such a design would not produce power effectively.

Areas of Agreement / Disagreement

Participants generally disagree on the possibility of a three-stroke engine, with multiple competing views on how engine cycles could be modified or combined. The discussion remains unresolved, with no consensus on the feasibility of the concept.

Contextual Notes

Participants express uncertainty regarding the mechanics of exhaust in a three-stroke engine and the implications of modifying traditional engine cycles. There are unresolved questions about the efficiency and practicality of any proposed designs.

vyas.sr
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Is 3 stroke engine possible??if not why?
 
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what are you going to give up , intake compression, power or exhaust stroke?
 
no change in the cycles...want all the cycles in 3 strokes...is that possible??
 
imo NO
 
y is that so?y can't there be an cyle where 1st stroke intake 2nd stroke compression and ignition(as in diesel) and 3rd stroke with (expansion and exhaust)?
 
but how will exhaust take place? Piston is leading towards inner dead center in 3rd stroke, then it can't force the gases out. If you fill fuel right here to move gases out, it will become a two stroke engine. Perhaps, you have to add an extra device to move the gases out. Thus you will have to do extra work. This will reduce efficiency.
 
still...cant there be any combination of stroke that could make a 3 stroke engine possible?
 
Put a 2-stroke and a 4-stroke engine on the same crankshaft, and they'll average out to 3 strokes!
 
A stroke of an engine is either from TDC to BDC or BDC to TDC. On a three stroke engine one cycle would start at TDC the next at BDC, Escher might be able to come up with a workable design but I can't.
 
  • #10
Real preciprocating engines, need an even number of strokes. You must ALways have at least the INTAKE, COMPRESSION, POWER, EXHAUST stokes.

They require a down, up, down up movement of the piston. You can combine the 2 upstrokes and 2 downstrokes to make a 2 stroke engine.

As you suggested of combining the power and exhaust phase, not only does that require the pison to be moving in opposite directions, but it also has an engine that producec no power what so ever.

After combustion you have high pressure gases, that push the piston down. If you opened the exhuast (had any gas removal system) then the high pressure gases would simply go straight out the exhaust as a path of least resistance.

All odd numbered stoke engines are all pseudostrokes, basically they are 2 or 4 strokes that are slightly modified.
 

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