2-Stroke Diesel Engines: The Sequel

Hi, I need your help again. I previously asked if 2-stroke diesel engines actually exist, and we agreed that they do. However, a colleague doesn't believe me (his arguments: the internet is full of nonsense, his mechanics who have worked in the automotive industry for decades say no, and he claims that the two principles cannot be combined).
I can find him as much information as I want, but it's all nonsense. He would only believe it if a 2-ton diesel engine was right in front of him, running. Where else would you find something like that (in Germany)?
And does anyone perhaps have a link where the work steps are described in detail in German, with pictures, etc.?
I'm getting too much of this.

hello,
I remember seeing a picture once, but I don't remember where.
As far as I know, these are all ship diesel engines, so they have a very large displacement.
I recall that the engine had exhaust valves in the cylinder head and intake channels in the lower part of the cylinder.
Fresh air is blown into the intake channels by a fan, while the exhaust gases are simultaneously pushed out through the exhaust valves at the top.
The intake ports are angled in such a way that a spiral-shaped 'vortex' is created, which improves the filling process.
Basically, it's not a bad idea.
because it then has a 2-stroke engine instead of a 4-stroke engine, and more exhaust valves.
I don't think it would be suitable for a car, as the rotation speeds are likely to be around 50 to 100 RPM.
It's not a 2-stroke engine like the Moded.
However, it also only has 2 valves and one intake channel.
greetings

Show him a model-making catalog; you'll find a wide variety of those two-stroke engines there! Even though they run on alcohol, they still operate on the diesel principle.

Hi,

You would be surprised at what all existed or exists. Would you have thought that there was a two-stroke, naturally aspirated diesel engine with 3 cylinders and a distributor pump?

In a two-stroke engine, the intake stroke is missing, which is why it MUST be mechanically supercharged. Otherwise, the 2-stroke principle should be clear. That's the only drawback.

Actually, the 2-stroke principle is far superior to the 4-stroke principle because each piston stroke generates power, whereas in a 4-stroke engine, only every other stroke does.
So, after each kilowatt-hour rotation, there is an ignition!

Almost every major car manufacturer has, at some point, experimented with two-stroke diesel engines, but they stopped pursuing this technology because the piston rings wear out quickly due to the openings in the cylinder, causing oil to escape with the exhaust gases.
Well, that was one of the problems...

I can take a look, but I definitely still have drawings and pictures of parts like that! I bet there's one of those things sitting around at the VW museum.

Greetings.
Thomas.

profcosta wrote:

Show him a model-making catalog; you'll find a wide variety of those 2-stroke engines there! Even though they run on alcohol, they still operate on the diesel principle!

No. Definitely not. The current engines are glow-plug engines, meaning that the ignition of the fuel-air mixture is triggered by a platinum coil that maintains its temperature through a catalytic reaction during the fuel change. The diesels that existed in the past ignited through high compression and the addition of ether. However, a mixture based on petroleum was drawn in.

hello
Around 1980, the German armed forces (Bundeswehr) had a tracked vehicle called the MTW.
(troop transport vehicle). It definitely had a two-stroke diesel engine!
best regards
gerrit

Hi,

In the thread discussing the use of a TDI engine as a combined heat and power (CHP) system, links were posted to large industrial and marine diesel engines, most of which were two-stroke engines.

By the way, I would strongly disagree with the statement that two-stroke engines cannot operate without forced induction – or was that only meant in reference to diesel engines?

I have, in fact, already driven at least 15,000 kilometers with a two-stroke gasoline engine that was not turbocharged .

I don't believe that forced induction is necessarily required for diesel engines either.

Best regards,

Jan.

Hi,
It's not necessary to charge the mixture to 100%. With single-cylinder engines, the crankcase is used quite successfully for scavenging. With multi-cylinder engines, you would then have to create a separate chamber for each cylinder. In that case, a scavenging blower would probably be the lesser of two evils.

@avenga

Almost all large diesel engines are two-stroke engines. This ranges from the commercial vehicle sector (e.g., dump trucks and, of course, locomotives) to ships. In some cases, these two-stroke engines achieve efficiencies exceeding 60%!

Take a look at MTU. Also, MAN also manufactures two-stroke engines.

The Ford Transit, for example, was available in 1955 as a 4-cylinder, 2-stroke diesel engine with 80 horsepower!

And the world-famous LANZ also had a two-stroke engine, as did some Hanomag tractors.

Two-stroke diesel engines were also used as aircraft engines (by Junkers) and proved to be excellent in that application.

As mentioned before, a 2-stroke diesel engine absolutely requires a scavenging blower (Jan: forced induction is not necessarily required, but a scavenging blower is essential!).
This could be a mechanical supercharger, and often a piston pump is used as an air pump, powered by the crankshaft.

Otherwise, Google is your friend!

CU Gremlin.

Hello.

http://www.einachser.com/eigene.html

My former neighbor in Selb had a small, red tractor (with two axles) from around 1950. It also had a two-stroke diesel engine.

My Kawasaki doesn't need a turbocharger, even though it only produces about 58 horsepower from its 250cc engine <sup>.
Simple reverse flush system with membrane inlet.

"A problem with two-stroke diesel engines using scavenging, i.e., without a turbocharger, is that the connecting rod, cylinder liner, and crankshaft bearings must be lubricated. By pumping the combustion air through the crankcase, lubricating oil is inevitably drawn along with it. To minimize these losses, roller bearings are used instead of plain bearings."
If sliding bearings had a high oil consumption, the engine would run on lubricating oil instead of diesel.
Here, the advantage of higher power output is offset by roughly two disadvantages:
- Co-combustion of engine oil, loss of lubrication.
- Rolling bearings are less durable than plain bearings for the same size. Therefore, the lifespan of a lower connecting rod bearing using rolling bearings is significantly shorter. This is likely the main reason why there are very few two-stroke diesel engines with reverse scavenging systems today.

Best regards, Rainer.</sup>

My Kawasaki doesn't need a turbocharger, even though it only produces about 58 horsepower from its 250cc engine.
Simple reverse flush with membrane inlet.
I hope it's also painted a bright green color?


- Rolling bearings are less durable than plain bearings for the same size. Therefore, the lifespan of a rolling bearing in the lower connecting rod bearing is significantly shorter. This is likely the main reason why there are very few two-stroke diesel engines with reverse scavenging systems today.


'Partially. The main reason is that valve-controlled exhaust systems allow for asymmetrical valve timing, which significantly improves the scavenging process in the cylinder. Furthermore, the thermal load is shifted to the cylinder head, which is easier to manage and, of course, benefits the piston rings (as exhaust ports are eliminated).'
Ultimately, large diesel engines are only built with crosshead designs, which inherently eliminates the possibility of using the crankcase as a scavenging blower.
I find it amusing: 6 valves per cylinder and then two-stroke .

CU Gremlin.

Gremlin wrote:

Rainer K. wrote: My Kawasaki doesn't need a turbocharger, even though it only produces about 58 horsepower from its 250cc engine . Simple reverse flush with membrane inlet. I hope it's also painted a bright green color? Logo When my little house is finally finished, I'll show the seniors what a rake is

.
Currently, she unfortunately only digs trenches in the family's meadow 2-3 times per year.

Avenga wrote:

... I can find him as much information as I want, but it's all nonsense. He would only believe it if a 2-ton diesel engine was right in front of him, running. Where else would you find something like that (in Germany)? And does anyone perhaps have a link where the work steps are described in detail in German, with pictures, etc.? ..I'm getting too much here

.

Sure:
http://de.wikipedia.org/wiki/Zweitaktmotor

The main difference from a four-stroke engine is that the "strokes" for drawing in fresh air and expelling exhaust gases must be performed externally, which saves two strokes.

By the way, small, two-stroke diesel engines are also often used in extreme fuel-efficiency competitions.

Hi,

Here are some pictures.

And for those who still aren't satisfied, they should visit the Deutsches Museum in Munich.

For example, in a submarine from World War I, there were two 2-stroke ship diesel engines.

There's also a piston with a displacement of 2 cubic meters mounted on the wall. It's a 2-stroke engine!


Regarding the images:
You can clearly see the lower inlet, and only the outlet on the top.
I am still missing a picture of a large 2T ship diesel engine with a displacement of 2 cubic meters per cylinder.

The oil consumption isn't actually that high, because these engines use an oil scavenging system. When a blower is attached, it also prevents flushing through the crankcase. This reduces the oil consumption to less than that of a 4-stroke engine, because there are no valve stem seals.

@Garth:

Sure, here's the translation:

"It's a bit off-topic, but what did you use to create the images?"
The flash technology seems very well-balanced. It doesn't look like a small, cheap digital camera at all...

That should be enough for the last of the doubters. Those who still don't believe should consult their pastor due to a crisis of faith.


http://www.brekina.de/Krupp.html

http://www.elsbett.com/Ludwig%20Elsbett.pdf



And what about the big ones: *********************************

http://www.manbw.com/web/files/news/filesof3077/techarticle09-12-03.pdf

and what about those small, modern ones: (Daihatsu car engine) ******

http://www.daihatsu.com/motorshow/frankfurt03/ai/ai_g.pdf

On the rails, with a 12-cylinder, 2-stroke engine, a 'Taigatrommel' (Taiga drum).

http://www.grueneliga.de/berlin/informieren/rabe_ralf/rabe_archiv/12_2000/pflanzenoel.html

And new developments for aircraft, successors to the Junkers engines: **********

MAGAZINE.

Mini-turbines, diesel engines, and Wankel engines.

Various new propulsion systems for general aviation are being developed. When they will be ready for the market is still uncertain, but it is certain that they will eventually arrive.
Williams International, for example, is now also aiming to gain a foothold in the market for propeller turbines. Recently, the company presented the TSX-2 turboprop engine. Also, within the framework of the GAP program, a 200 horsepower two-stroke diesel engine is being developed under the leadership of NASA and Teledyne Continental Motors (TCM). It is designated as the CSD 283.
DeltaHawk, a company based in Racine, Wisconsin, also believes in the two-stroke diesel engine as the future of propulsion. Their engine, a V4 called the EagleHawk, with its two cylinder banks arranged at a 90-degree angle, also produces 200 horsepower. Michael Zoche has been involved with two-stroke diesel engines from the very beginning. For 15 years, he has been developing two engine versions: the ZO 01A, an 84 kg, 150 horsepower V4 radial engine with a 2.66-liter displacement and turbocharger/supercharger, and the ZO 02A, an 8-cylinder radial engine with a 5.33-liter displacement, producing 300 horsepower and weighing 123 kg. A 70 horsepower, 55 kg ZO 03A with a 1.33-liter displacement is currently in development.
The French company sma and Textron Lycoming from the USA are focusing on four-stroke diesel engines. Since Snecma's acquisition, the current engine version at sma is no longer called MR 200, but SR 305. The initial power output is 230 horsepower. Surprisingly, European certification is expected to be obtained by the end of the year.
Lycoming is developing a turbocharged four-cylinder, four-stroke engine. The claimed power output is 205 horsepower. The basic design of the engine originates from Italy and was acquired many years ago by the Detroit Diesel Corporation (DDC).
Since October 13th, the new Zöllner aircraft engine has been undergoing testing at HK Aircraft in Haßfurt. The air-cooled, two-liter boxer engine with dual ignition and 120 horsepower is designed for installation in a Vega Ex.


@avenga: Is that enough now?
@Roger: Everything is the internet.