2-stroke diesel is the (near) future?

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.

Originally Posted by Smitty

... the pervasive ignorance of spelling, grammar, punctuation, homonyms, sentence construction, ad infinitum, makes me ****ing sick. And it isn't just usenet, it's everywhere, even in your ten million dollar report, because your computer can't fix everything and your coworkers are as apathetic as you are. We're becoming a nation of ignorant idiots. I think that's a bad thing, and a dangerous one. If we knew as little about airplanes as we did the English language, and flew them as carelessly as we write, we'd all be dead by now.

Here here! (Not "hear hear" idiots.) I can't believe I read that the other day on studentpilot.com.

"Don Stauffer" wrote

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.

And some of the operations are happening simultaneously.

"Morgans" wrote in message
news

"Don Stauffer" wrote

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.

And some of the operations are happening simultaneously.

There is one very efficient 2-stroke variant that does have separate and
distinct intake, compression, combustion and exhaust functions - the
opposed-piston 2-stroke diesel with the pistons driven by cams, not
crankshafts.

As the pistons move apart (power), the exhaust port is uncovered first by
one piston (exhaust) and then the intake is opened by the other piston so
high pressure air from the supercharger can scavenge the last bits of
exhaust gas from the space between the pistons. After the cylinder is
scavenged, the first piston closes the exhaust port leaving the intake port
open so the supercharger can charge the cylinder with air (intake). Then
both pistons move together closing the intake port (compression). Fuel is
injected directly into the space between the pistons which forms a spherical
combustion chamber (ignition). The cams are designed to optimize the timing
and duration of the port openings as well as contour the compression and
power strokes.

This design makes extreme demands on metallurgy and lubricants so is just
now becoming practical.

Bill Daniels

In article ,
Fisherman wrote:


Here here! (Not "hear hear" idiots.) I can't believe I read that the
other day on studentpilot.com.


Uh, actually, "hear hear" is correct.

("Smitty" wrote)
Uh, actually, "hear hear" is correct.


http://snltranscripts.jt.org/84/84mcourt.phtml
Here ye, here ye!

http://www.rootsweb.com/~nyrgs/hearye/
Hear Ye Hear Ye

Which is correct? Why? Curious.


Montblack

On Tue, 12 Jul 2005 23:36:13 -0500, "Montblack"
wrote:

("Smitty" wrote)
Uh, actually, "hear hear" is correct.


http://snltranscripts.jt.org/84/84mcourt.phtml
Here ye, here ye!

http://www.rootsweb.com/~nyrgs/hearye/
Hear Ye Hear Ye

Which is correct? Why? Curious.

Lemme get this straight: You're citing a Saturday Night Live script as a
reference? :-)

http://www.straightdope.com/mailbag/mhear.html

Ron Wanttaja

In article ,
"Montblack" wrote:

("Smitty" wrote)
Uh, actually, "hear hear" is correct.


http://snltranscripts.jt.org/84/84mcourt.phtml
Here ye, here ye!

http://www.rootsweb.com/~nyrgs/hearye/
Hear Ye Hear Ye

Which is correct? Why? Curious.


Montblack

Imagine it's 150 years ago. (For you youngsters, that would put us way
back in pre-internet days, when people conversed instead of pecking.)
We're sitting around enjoying some refreshing non-alcoholic beverages
and talking about various things. Some brilliant thinker among us begins
to orate in a particularly eloquent fashion. More and more people break
from individual, localized conversation to listen to the man (or woman)
speak. To encourage serious attention and to show his support for the
ideas being presented, a listener pipes up with the admonition "Listen
to the man speak, my friends. What astounding thoughts he has, and so
well spoken." In other words, "Hear, Hear!"

Thinking a very large version of that was used before?

On Wed, 13 Jul 2005 06:09:56 -0700, Smitty
wrote:

Imagine it's 150 years ago. (For you youngsters, that would put us way
back in pre-internet days, when people conversed instead of pecking.)
We're sitting around enjoying some refreshing non-alcoholic beverages
and talking about various things.

You'd have to back up a few more than 150 years to find a gathering
where people are drinking non alcoholic beverages...

Corky Scott