Don Stauffer wrote:
> Sport Pilot wrote:
> >
> > Don Stauffer wrote:
> >
> >>Sport Pilot wrote:
> >>
> >>>Completely wrong, the Otto cycle has nothing to do with four stroke
> >>>engines. Don is right its not four cycle, I used it incorrectly. The
> >>>Otto and Diesel cycles are actually refering to the thermodynamics
> >>>chart of temperature pressure and volume, they invented their cycles on
> >>>paper and books, the engines we use are only close approximations. The
> >>>two stroke ignition engine uses the Otto cycle as it is has the four
> >>>phases of intake, compression, power, and exhaust, and the pressure is
> >>>not constant. The Diesel two stroke is a Diesel cycle because it also
> >>>includes the same phases and the fuel burns at a fairly constant
> >>>pressure.
> >>>
> >>
> >>I guess I'd quibble with the statement that the Otto cycle has nothing
> >>to do with four-stroke engines- it was the first successful cycle to
> >>incorporate four strokes. yes, there are other four stroke cycles, but
> >>the Otto cycle is still by far the most common. There have been several
> >>other four-strokes, several two-strokes, at least on six stroke- I
> >>suspect several also.
> >>
> >>New IC engine designs are among the most numerous US patents. Just
> >>because something is patentable, of course, does not make it good or
> >>successful, and most of these patents were for approaches that offered
> >>insufficient advantages.
> >>
> >>BTW, as I understand the new Miller cycle, I don't consider it a truly
> >>new cycle- just a clever mod on the Otto. I don't consider the Otto
> >>cycle to require valve openings at closings at the top or bottom dead
> >>center, exactly.
> >
> >
> > The confusion is that Otto invented the first four stroke engine and
> > called it the Otto cycle, not because of thermodynamics but because he
> > put it in a motorcycle. However the thermodynamic cycle can be
> > reproduced with a two stroke engine. Its just that the intake and
> > exhaust cycle's are much shorter.
> >
>
> I am not sure what you mean by exhaust and intake "cycles". There is
> one cycle- the actions that the engine goes through before everything
> repeats. Do you mean the portions of the cycle during which the exhaust
> and intake take place- they definitely take less crankcase revolution angle.
>
> In the Otto cycle it is easy to break it down into four operations, each
> lasting one stroke. A two-stroke is more complicated, because it still
> has (existing, contemporary ones, do anyway) four seperate functions of
> intake, compression, combustion and exhaust, but have to do it in two
> strokes.

Sorry for the confusion, the two stroke doesn't take a stroke for those
functions so I used cycle, can't think of anything else to call it.