2-stroke diesel is the (near) future?

You have most of it right. Some things you have wrong,

1. Desiel injection timing is differant than on an Otto engine. The
fuel is injected during the intake cycle on the Otto engine and the
fuel is injected during the ignition cycle on the Desiel. On the
Desiel the fuel injection cycle starts just before TDC and ends well
after TDC. The fuel ignites as soon as it hits the hot air.

2. The parts count is not less on a two stroke Desiel, It is higher
because of the need for a supercharger and a way to port the exhaust.

I don't think you would want a four stroke Desiel in an aircraft
because of the increased weight and low power. Desiel engines don't
really produce more torque as a gas engine, its just that the fuel
burns slower and thus the engine cannot rev as fast, but it can produce
the same or slightly more torque at lower speeds, and at much lower
fuel flow rates. Because of this they should be ideal for an aircraft
engine that doesn't need to turn at a higher speed.

You do lose one advantage of the Desiel engine on an aircraft. Because
of the lack of a throttle and the fact that they can burn extreamly
lean at idle, Desiel engines are extremely efficient in stop and go
traffic. But we don't idle aircraft engines that much.

Wandering aimlessly about the Web, I heard Sport Pilot say:
You have most of it right. Some things you have wrong,

1. Desiel injection timing is differant than on an Otto engine. The
fuel is injected during the intake cycle on the Otto engine and the
fuel is injected during the ignition cycle on the Desiel. On the
Desiel the fuel injection cycle starts just before TDC and ends well
after TDC. The fuel ignites as soon as it hits the hot air.

etc., etc. --- SNIP ---

It's Diesel, not "Desiel".

--
Andrew P.

[Post replies to this message on forum only]

"Andrew P." wrote in message
ink.net...
Wandering aimlessly about the Web, I heard Sport Pilot say:
You have most of it right. Some things you have wrong,

1. Desiel injection timing is differant than on an Otto engine. The
fuel is injected during the intake cycle on the Otto engine and the
fuel is injected during the ignition cycle on the Desiel. On the
Desiel the fuel injection cycle starts just before TDC and ends well
after TDC. The fuel ignites as soon as it hits the hot air.

etc., etc. --- SNIP ---

It's Diesel, not "Desiel".

--
Andrew P.

Well if you're going to get picky, it's "Auto" engine, not "Otto" engine.

MJC

MJC wrote:
"Andrew P." wrote in message
ink.net...
Wandering aimlessly about the Web, I heard Sport Pilot say:
You have most of it right. Some things you have wrong,

1. Desiel injection timing is differant than on an Otto engine.
The
fuel is injected during the intake cycle on the Otto engine and
the
fuel is injected during the ignition cycle on the Desiel. On the
Desiel the fuel injection cycle starts just before TDC and ends
well
after TDC. The fuel ignites as soon as it hits the hot air.

etc., etc. --- SNIP ---

It's Diesel, not "Desiel".

--
Andrew P.

Well if you're going to get picky, it's "Auto" engine, not "Otto"
engine.

MJC

Actually, it is Otto, as in 4-stroke spark ignition.

nate

N8N wrote:
MJC wrote:

"Andrew P." wrote in message
hlink.net...

Wandering aimlessly about the Web, I heard Sport Pilot say:

You have most of it right. Some things you have wrong,

1. Desiel injection timing is differant than on an Otto engine.

The

fuel is injected during the intake cycle on the Otto engine and

the

fuel is injected during the ignition cycle on the Desiel. On the
Desiel the fuel injection cycle starts just before TDC and ends

well

after TDC. The fuel ignites as soon as it hits the hot air.


etc., etc. --- SNIP ---

It's Diesel, not "Desiel".

--
Andrew P.

Well if you're going to get picky, it's "Auto" engine, not "Otto"

engine.

MJC


Actually, it is Otto, as in 4-stroke spark ignition.

nate

A 4-stroke diesel is still an Otto engine. An Otto cycle engine is one
with four strokes, intake, compression, power, and exhaust. Doesn't
care whether SI or CI.

Don Stauffer wrote:

A 4-stroke diesel is still an Otto engine. An Otto cycle engine is one
with four strokes, intake, compression, power, and exhaust. Doesn't
care whether SI or CI.

Whoops

Before everyone jumps on me, I left off an important qualification. I
was specifically talking about cars, airplanes and highway trucks.
Large Diesels, (stationary, large ship, etc) do run a different cycle-
the true Diesel cycle.

However, even the true Diesel cycle of larger engines is not the true
cycle Diesel really wanted. He couldn't develop the true cycle he
wanted (constant enthalpy), and a large Diesel comes somewhat close. A
high speed (vehicle) engine doesn't even come close with even today's
technology. It is pretty close to an Otto cycle, though still not
exactly. Otto cycle has infinitesmal fraction of cycle for ignition and
burn, while even a high speed Diesel (and even the SI engine) still
ignites and burns over a finite angle of crank rotation. Still, the
result, as I say is MUCH closer to Otto than the cycle Rudy had
intended. Still makes a good engine, however :-)

Don Stauffer wrote:

Don Stauffer wrote:


A 4-stroke diesel is still an Otto engine. An Otto cycle engine is
one with four strokes, intake, compression, power, and exhaust.
Doesn't care whether SI or CI.


Whoops

Before everyone jumps on me, I left off an important qualification. I
was specifically talking about cars, airplanes and highway trucks. Large
Diesels, (stationary, large ship, etc) do run a different cycle- the
true Diesel cycle.

However, even the true Diesel cycle of larger engines is not the true
cycle Diesel really wanted. He couldn't develop the true cycle he
wanted (constant enthalpy), and a large Diesel comes somewhat close. A
high speed (vehicle) engine doesn't even come close with even today's
technology. It is pretty close to an Otto cycle, though still not
exactly. Otto cycle has infinitesmal fraction of cycle for ignition and
burn, while even a high speed Diesel (and even the SI engine) still
ignites and burns over a finite angle of crank rotation. Still, the
result, as I say is MUCH closer to Otto than the cycle Rudy had
intended. Still makes a good engine, however :-)

I pretty much agree, although today's high-speed diesels are doing a lot
better at approchin the constant-enthalpy cycle than they used to,
thanks to being able to divorce the injection profile from crankshaft
position via electronically-controlled injection systems.

Don Stauffer wrote:
Don Stauffer wrote:

A 4-stroke diesel is still an Otto engine. An Otto cycle engine is
one
with four strokes, intake, compression, power, and exhaust.
Doesn't
care whether SI or CI.

Whoops

Before everyone jumps on me, I left off an important qualification.
I
was specifically talking about cars, airplanes and highway trucks.
Large Diesels, (stationary, large ship, etc) do run a different
cycle-
the true Diesel cycle.

However, even the true Diesel cycle of larger engines is not the true

cycle Diesel really wanted. He couldn't develop the true cycle he
wanted (constant enthalpy), and a large Diesel comes somewhat close.
A
high speed (vehicle) engine doesn't even come close with even today's

technology. It is pretty close to an Otto cycle, though still not
exactly. Otto cycle has infinitesmal fraction of cycle for ignition
and
burn, while even a high speed Diesel (and even the SI engine) still
ignites and burns over a finite angle of crank rotation. Still, the
result, as I say is MUCH closer to Otto than the cycle Rudy had
intended. Still makes a good engine, however :-)


You can only get so much speed when you inject the fuel through the
combustion or expansion cycle. High speed diesels get more speed by
injecting more of the fuel early. But an aircraft engine doesn't need
to turn more than 2500 RPM so we should be able to get the benifit of
the longer burn time.

Actually, it is Otto, as in 4-stroke spark ignition.

nate

A 4-stroke diesel is still an Otto engine. An Otto cycle engine is one
with four strokes, intake, compression, power, and exhaust. Doesn't
care whether SI or CI.

No, it really isn't, at least not in common usage. If you want to be
ridiculously pedantic, then the "Diesel cycle" is an Otto cycle with
constant-pressure combustion under varying cylinder volume, whereas what
is commonly just called the "Otto Cycle" is a spark-ignited Otto cycle
with constant-volume combustion under varying cylinder pressure.

Neither cycle attains that ideal, so there's some overlap, but if you
look at real-world pressure-volume diagrams for Diesel and
spark-ignition engines, the difference is obvious.

Actually, it is Otto, as in 4-stroke spark ignition.

Dude, MJC was Joking