LPG injection

LPG injection.

Has anyone ever tried this before?
With what values?
What percentage of intake air can be mixed in before it starts to ignite during compression? (I seem to recall something around 2%?)

Does it make a difference whether it's methane, propane, or butane? Specifically, from the perspective of compression ignition?

Does anyone offer components for it?

And: Would reducing the diesel injection amount reduce the soot content?
'Natural gas doesn't produce soot itself, but it could potentially help burn off the diesel soot that accumulates, as long as there is still oxygen present.'

Opinions?

Hi,
Alkanes, including propane, are quite resistant to knocking or, conversely, reluctant to ignite. Without diesel injection, not much will happen. Quantity restrictions would likely have other causes. Try searching online for natural gas buses; perhaps you can draw some conclusions from that.

I can just imagine the intercooler entering a geosynchronous orbit at Mach 20... *LOL*

"@garth: If you're really planning to do this, you should inject the substance after the EGR valve and use valves that are known for their reliable sealing."

In my opinion, without adjusting the boost pressure to match the additional amount of fuel, not much will happen.

Please tell me how it turned out.

Best regards, Rainer.

Hello Rainer and Christians,

I've already looked into gas buses, but it wasn't very informative. They inject the gas like diesel fuel.

Daß Gas recht zündunwillig ist und hochverdichtbar weis ich auch. Auch daß es von dem Mischungsverhältnis mit Luft und dem Druck abhängt, wann das Zeug hochgeht. Das wann/wieviel wäre interessant um vorher abschätzen zu können ob und wieviel es bringen könnte. Denn die normale Zündtemperatur von einem normalen Gas/Luftgemisch( 1/12 Vol.) erreicht der AFN beim Verdichten mit 1,2Bar Ladedruck ganz sicher. Ich muß also unter einer kritischen Grenze Gasanteil bleiben, nur wo ist die ? Ich hab in Chemie immer nur aufgepasst wenns um Dinge ging, die sich schlagartig 'verändern', weniger wenn darum ging das zu verhindern. DTherefore:

Can this be calculated, and how?

If the increased compression leads to knocking before it provides any noticeable benefit, then it's pointless. From my research papers on Otto cycle gas engines, I know that with increasing compression, knocking typically starts at a compression ratio of around 14-16.
In addition, diesel engines have glowing soot deposits in the cylinder that act as an additional ignition source.

That idea about using the AGR system is good; I could use it to inject something directly. It doesn't really have any other function, does it?
( A G R = Automotive Gas-powered Reinforcer ??? )

It's clear that the boost pressure needs to be increased – and that's not really the problem. The whole thing was anyway only intended for bursts of acceleration.

If you suddenly stop hearing from me, please refrain from making any attempts on your own.

Hello,

warum das Klopfen beim Diesel ein Problem sein soll verstehe ich nicht ganz, das ist doch das Prinzip des Diesels. Da Propan bei Raumtemperatur unter mehreren Bar Druck steht, würde ich es nach dem Turbolader zumischen. Dann machst Du aus dem Verdichter im Zweifel auch keine Gasturbine . Allerdings ist mir nicht so klar was der ganze Aufwand soll. Zum Verbrennen benötigst Du Sauerstoff sprich Luft. Eine Gaszumischung dürfte auch keine bessere Wirkung haben als noch mehr Diesel. Wenn dann nimm doch gleich NOS. ( laut Spiegel gibts jetzt auch NOS Flaschen Attrappen wenn nur nach 2fast and 2furious aussehen soll). LOX dürfte doch auch ganz gut wirken und braucht nicht umständlich vom Turbo verdichtet zu werden. DYou can also save money on LLK (medical supplies).

Best regards,
Christian.

Hi,

"Maybe contact AMG; they once converted an A-Class CDI engine to run on a propane-diesel combination (I believe it's installed in the SBARRO with variable vehicle length). I think I saw a report about it somewhere."

Hello Chris,

More diesel fuel would also work; more oxygen can be achieved through increased boost pressure.

However, with the AFN engine, the amount of diesel I can inject is simply limited by the injection duration. Not only would I need larger and very expensive injectors, but also an ESP (electric fuel pump) that delivers more fuel in a shorter time, and those don't even exist.

Therefore, the question of alternatives arose.

I didn't plan on making any major modifications to the car; I need to use it every day. So, I'm looking for a relatively simple solution, and that might be possible with gas.

Hi there,
Assuming a 20% excess of air at full throttle, it's possible to calculate how much fuel can be burned with that amount of air. If that value remains below the critical limit, I don't foresee any major problems.
Biogas plants with combined heat and power (CHP) systems work in a similar way. They only need diesel for ignition, which is the idling amount. The biogas is then mixed into the intake air to generate power. However, I don't have any information on how to compress such engines. It probably wouldn't be much different from compressing a diesel engine, otherwise it wouldn't ignite.
On the other hand, in a diesel engine, the flame does not fill the entire cylinder. The question then is: what happens to the air-fuel mixture on the cylinder walls? Does the gas continue to burn even after the ignitable concentration has been exceeded?
And what about the diesel flame? It's not burning in pure air anymore. At that point, gas is also being burned. Could this lead to soot formation because the local, relative oxygen content of the air has decreased?

Perhaps it would be worth trying to gradually increase the amount of fuel injected into the intake manifold at a constant speed and see what happens. I suspect that the sound of the combustion will change noticeably before reaching the critical limit.

Regards,

Eike.

'P.S.: What might happen if you inject enough gasoline into the intake manifold without reaching the critical threshold where pre-ignition occurs? Perhaps this could even be used to achieve a temporary boost mode...'

but also an ESP that promotes more in a shorter amount of time, and there is simply no such thing.


Sure, they are available.

The VP37 is built with pistons up to 12mm in diameter and can easily displace 100-150 mm³ per stroke.

You just have to invest a little bit .

CU Gremlin.

Sure, here is the translation of the text from German to English:

"Hi Gremlin,"

What kind of pump is that? Do you have any part numbers?

As far as I know, the VP37 automatic pistol from ALH has an 11mm piston.

Greetings.
Thomas.

Hi,

I also found something about propane injection:

http://www.usdieselparts.com/bullydog.cfm

Hello everyone,

After watching the link from Bertil (great information, thank you!), I tried the following.

Take a lighter refill canister (likely mostly butane) and an engine running at idle.

1. A short, forceful burst of gas into the intake manifold (i.e., before the air filter).
Reaction: After approximately 0.5 seconds, a brief increase in speed accompanied by very loud knocking sounds.

Observation: As expected, compression ignition is occurring.

2. Limited light gas supply. The engine noise becomes very soft and quiet, similar to a good gasoline engine. After a short adjustment period, the RPM remains constant.

Translation:

Insight: It's all about the dosage; the right amount can even contribute to a smoother combustion process in the engine.
I'll try it out while driving sometime soon.

And another bill for gas consumption:
I want +20 horsepower - diesel consumption is approximately 210 grams per horsepower per hour, which equals 70 grams per minute.
(Assumption: The calorific value of diesel is approximately equal to that of gas, based on weight. I didn't feel like looking up the exact figures.)
With a 150g can, I could accelerate for about 2 minutes, and that's the only reason I want it.

For testing purposes, this is sufficient for now.

Are you sure you won't damage the engine doing that?


If not, your pioneering spirit is highly commendable .


Regards,
arne

because they don't know what they're doing...

To the best of my knowledge, Startpilot is nothing more than butane and a few other carbon-hydrogen compounds.

I once jump-started my old car using a jump starter.

Wow, he nailed it and totally went wild!

Since then, I've been a bit skeptical about inhaling anything other than pure air!

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Hi,
"Startpilot contains substances like ethyl ether, which has an extremely low flash point. This means it's really only suitable for starting engines."

Seriously, does it contain aether?

Okay, then it's clear why he's getting so upset.

It wouldn't start with the starter motor due to insufficient compression; it only started when push-started.

To the best of my knowledge, Aether has a flame temperature of 180 degrees Celsius.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.