2T Diesel: The Sequel | Posts 16+

Avenga wrote:

Hi, I need your help again. I already asked before if there's such a thing as a 2-stroke diesel engine, and we agreed that it does exist, mainly because a colleague doesn't believe it (his arguments: the internet is full of nonsense, his mechanics who have worked in the automotive industry for decades say NO, it doesn't exist, and he says 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 here

.

Hello,

Ask him if he served in the military and if he is familiar with the M109 self-propelled howitzer or the M107 cannon (photos: http://www.hunsnet.de/artillerie/german/art/ghist7.htm). They have a turbocharged two-stroke diesel engine, just like the personnel carrier (MTW, already mentioned by Gerrit). These are probably American engines, and it was always a hassle with the customs tools . Once, when we had to replace the head gasket on an MTW, you could clearly see the individual valves.

Best regards, Uli (former maintenance technician with fully completed military service, but recognized as a conscientious objector).

@christians:
Isn't it sufficient for the declaration 'diesel engine' if the mixture ignites solely due to the compression heat, regardless of whether it's injected at TDC, pre-vaporized, or prepared in any other way? In my opinion, that's the case!
The glow plug in the head of model engines is also heated by combustion.

The glow plug in the head of model engines is also heated only by the combustion!

No, that's not how it usually works (or, actually, almost never works). They preheat the thing and then try to start it.

Best regards, WarLord.

@WarLord:

Quote:

No, that's not how it usually is (or actually, always is).

They pre-glow the things and then try to start them.
And is it different with our tractors }?

WarLord wrote:

profcosta wrote: The glow plug in the head of model engines is also heated only by combustion! No, that's not how it usually works (or actually, almost never). They preheat those things and then try to start them.

That's only half the truth. While it's true that the glow plug is activated at the start, why doesn't the glow plug cool down when the spark plug is disconnected? This also applies to four-stroke engines.
The science behind glow plugs is quite complex. In the late 1970s, HB, through the Graupner distribution network, also produced a glow plug with a glass insulator, allowing users to observe the heating element.
These engines do not ignite through compression alone, and are therefore not diesel engines.
I'm not sure if an injection is really necessary for the diesel term, but at least I've only encountered it used that way.

In the instruction manual for such a model engine, it stated that the glow plug would be sufficiently heated by the combustion after starting, providing enough energy to support the next ignition.
And on warm days, they would often start without any initial external heating, simply by turning the starter, relying solely on the compression heat!

A catalytic reaction takes place at the coil, which releases heat. If the coil were made of steel or tungsten, nothing would happen.

The model engines are also referred to as "glow ignition" engines.
Diesel engines, on the other hand, are "compression ignition" engines, although some, like IDIs, still require preheating.

Regards,
Alex.

Ugh...

for clarification:

The model engine draws in a flammable mixture and compresses it. At some point, it ignites on the hot glow plug. These engines require relatively high octane ratings; otherwise, they won't run (they run on methanol!). The ignition timing cannot be controlled, and this type of engine won't run on diesel.

The diesel engine draws in air. Fuel is then injected into the cylinder, and it ignites due to the high temperature.

There are also mixed-combustion engines: the famous LANZ has a glow plug, but a single injection system.

CU Gremlin.

That's only half the truth, though.

In model engines, there are glow plug engines, where the mixture ignites on the hot glow plug and is "heated" by the combustion process.

Furthermore, there are also genuine diesel model engines available as two-stroke engines.
without filament.
The key feature is that a mixture of ether, petroleum, and castor oil is vaporized through a carburetor.
The construction is identical to that of "conventional" 2-stroke engines, except that instead of a spark plug or glow plug, there is a type of adjustment screw in the cylinder head that allows the compression ratio to be varied.
The specially formulated mixture ignites at a very low temperature, which is generated solely by the heat produced through compression.
To adjust the auto-ignition timing (as the outside temperature is not always the same), this screw can be turned in or out, which slightly reduces or increases the combustion chamber volume.
"However, these model engines are no longer manufactured today because the rough, self-igniting combustion process transmits excessive vibrations to the delicate model airplanes and their electronics."
I also have a similar engine lying around.

Hello!

In East Germany, the main goal of engine development was a two-stroke engine with a crankcase pre-compression system that would not require cylinder lubrication. There were also plans for two-stroke diesel engines.
A neighbor who lives very close by has, for many years, researched ceramic materials for engines as a professor.
At that time, the goal was to manufacture the sliding components using ceramic materials, so that the engine could operate without piston lubrication.
In 1990, due to political circumstances, this research was terminated.

a dancer wrote:

but that is only half the truth.

Why? I wrote it almost the same way 3 years ago, but not exactly.

@ Christians:

Sorry, I probably missed that.
I only skimmed the thread...

The idea of designing a ceramic inner wall for a cylinder sounds interesting!
"But completely without lubrication?! I'll talk to an acquaintance who is currently researching the use of ceramics in technology at ETH Zurich."

but that is only half the truth.

In model engines, there are glow plug engines, where the mixture ignites on the hot glow plug and is 'heated' by the combustion process.

Furthermore, there are also genuine diesel model engines available as two-stroke engines.
without filament.
The key feature is that a mixture of ether, petroleum, and castor oil is vaporized through a carburetor.
The construction is identical to that of 'conventional' 2-stroke engines, except that instead of a spark plug or glow plug, there is a type of adjustment screw in the cylinder head, which allows the compression ratio to be varied.
The specially formulated mixture ignites at a very low temperature, which is generated solely by the heat produced through compression.
To adjust the auto-ignition timing (as the outside temperature is not always the same), this screw can be turned in or out, which slightly reduces or increases the combustion chamber volume.
'However, these model engines are no longer manufactured today because the rough, self-igniting combustion process transmits excessive vibrations to the delicate model airplanes and their electronics.'
I also have a similar engine lying around.

http://www.modell.portali.de/webra1.jpg

The engines with the compression screw are called Cox engines. I also had one at home a few years ago (model engine). The other model engines (I have 5 of them, 4 are installed in 1:10 or 1:8 scale models ) ignite the methanol-air mixture using the still-glowing heating element of the glow plug from the previous combustion. There are, for example, cold, warm, and medium glow plugs. The warm plugs (for a lower nitro-methane content) have a thinner heating element, so they heat up faster during combustion and therefore have a higher overall temperature for the next ignition than, for example, a cold plug. Depending on the engine size, air temperature, speed, and nitro content, you choose the appropriate plug.

I just wanted to add this, for the skeptics.

Another link http://www.gollemotor.ag/geschichte.htm.

However, the Jumo diesel engines also had their reliability issues.
http://de.wikipedia.org/wiki/Junkers_Jumo_207
http://de.wikipedia.org/wiki/Jumo_205

Best regards,
Christian.

Of course, there are two-stroke diesel engines. These are the most powerful combustion engines available! On container ships, there are two-stroke diesel engines with a power output of up to 80,000 kW.

greetings