Efficient Carburetor designs

[dutchdivco]

I'm not a chemist, or an engineer

My understanding is that jetsis is talking about catalyctically cracking the fuel, to turn it into a gaseous mixture of hydrogen and methane, and then run the engine on that.
My understanding is that any petroleum product; Gasoline, diesel, propane, kerosene, etc. will catalyctically crack.
If the cracking is done in the presence of oxygen, it will ignite.No oxygen, its a gaseous vapor, which could then be fed to the engine thru a propane carb.
jestis plasic to fuel project produces 3 products; a gasoline type substance, a Diesel type substance, and a propane or butane type flammable gas.
So, I can see where having a car that 'cracked' the fuel would be good, as he could run all 3 fuels, or at least the 2 liquid ones, interchangeably.
Anyway, I was just talking about catalyctic converters in that context.
Actually, since the plastic to fuel process is anerobic, you could pipe the gas off from the reactor vessel with exhaust pipe diameter pipe, to a catalyctic 'converter', heat it with an external burner to get it up to 1000 degrees F., and crack it right there.Might be great for a stationary generator type set up.
However, I suspect for a car your wanting to fill the tank with a liquid fuel, and crack it onboard, using waste heat from the engine.Otherwise too much energy in compressing it, etc.Jim

[dave_cahoon]

@dutchdivco

yes jetijs is referencing cracking but more of a thermal cracking not so much a special catalytic cracking, the hot iron plumbing is a nice catalytic material.

HEAT, water and hydrocarbons, together in correct ratio to the min temp or more and chemistry happens.

This will not happen in an automotive catalytic converter/combustor.

I must add as the reaction begins the blowtorch from the exhaust port shortens, sometimes so much that the reaction stops.

The distance from the exhaust valve is a critical dimension.

Dave

[maxc]

I used a converter as a preburner too vaporize fuel. It worked well. It needs large outlet tube too intake too work well (1inch and 1/2). It would work better if I welded a jacket around the converter for exhaust heat.

[Guest]

video

I've found a video posted by someone who has set up what could likely
be the most basic form of using fuel vapor to power an engine that is
thinkable... fully working, although looks like it might be a candidate
for miniaturization.

[ Engine running on fuel vapors ]

[dutchdivco]

Dave

Not sure i understand what your saying here;
"yes jetijs is referencing cracking but more of a thermal cracking not so much a special catalytic cracking, the hot iron plumbing is a nice catalytic material."

Is hot iron pipe acting as a catalyst, in which case its catalyctic 'cracking', or is it just cracking with heat? One or the other, but not both.

From my admitedly limited understanding of catalyctic 'cracking', heat is always one of the elements, a catalyst and petroleum product being the other 2.Oxygen being an optional 4th, depending on whether you want simultaneous ignition or not.

Is it possible to 'crack' petroleum products, converting them to hydrogen and methane without a catalyst, and just using heat? May well be, just not something I've heard/read about?

As far as the video of someone running an engine on 'vaporised gasoline', (I am not able to view video's on my computer; very frustrating, but thats the way it is ) However,many have got an engine to run on vaporised gasoline; run with any power, run for very long, run without leaving behind a residue of heavier fractions, or getting clogged up with heavier fractions, thats another story.Again, if thats what the video is 'demonstrating', already been discussed.

Cracking the fuel into hydrogen and methane, and running the engine on that is what we're talking about.Would like to hear more from jetsis on exactly how he's planning on doing that.Jim

[FRC]

dutchdivco

If you can not watch videos because of slow speed, get Mozilla Firefox and the
add on download helper, then you can download youtube videos and watch them later.

FRC

[dutchdivco]

Thanks, FRC

But I'm a real Luddite; this is a 17 y.o. laptop, on a landline connection.Even if I did what you suggest, i get 'bumped off' and have to reconnect every so often.On the one hand, its frustrating when others communicate using videos.On the other hand, the system is fustating enough to use, that its use is self limiting; I only stay on long enough for IMPORTANT stuff, like this. If I had a newer, faster system that could streamline videos, etc. I would probably be wasting a lot of time. Jim

[Guest]

The carburetor seems as though its performance is dependant on the ambient
temperature of the localized metal surfaces. Wouldn't it be great if heated
steam was piped around the gas line with a spiral copper tube?

[Cherryman]

The carburetor seems as though its performance is dependant on the ambient
temperature of the localized metal surfaces. Wouldn't it be great if heated
steam was piped around the gas line with a spiral copper tube?

This would be in the direction of GEET now...

Or My Little test design:



Large version: Klik

[faramog]

wow.... very cool picture. Lookes a nicely engineered model.

Got any more details: like what is in the flasks - only looks like a fuel feed from one of them.

[Cherryman]

wow.... very cool picture. Lookes a nicely engineered model.

Got any more details: like what is in the flasks - only looks like a fuel feed from one of them.

Tnx, As i wanted not to pollute this topic too much i changed the above pic with a description one.

The goal was to design an easy set-up to test the different fuels or fuel combinations.

I choose a pulse-jet as an "engine" because it has no moving parts.

PS Keep in mind it is a design only.

[Guest]

I'm seeing this new idea of yours Cherryman. What an astounding concept.

The spiral GEET... seems as though it would work!

[Discovery101]

My Next Attempted

Okay, last time I showed everybody me using a bubbler to lean out fuel mixture in my engine. But ran into a few problems and found out I couldn't run it right in that configuration. so I have scrapted that idea and am now working on making my EFI engine, and converting it to carbureted, only because I can't get my car to lean out with any of the EEFI enhancers hooked up to it. so once I have it fix with a carburetor only then will I try leaning out the mixture of my engine to where I get better mileage out of it! the only problem with this idea is getting a good spark plug to ignite that lean mixture. I will be adding also a HHO system with it to help increase the power out put and mileage if any. I will be posting my video and results on youtube when I get a chance, hopefully soon!

[dutchdivco]

Discovery 101

Yeah, could have told you the bubbler wouldn't work, unless you came up with something different than the umpty-jillion other people that have tried it.
Hate to see you going to all the trouble to convert from EFI to carb.If you lean it out, watch your exhaust temps, or you'll melt the pistons.The liquid gas going into the cylinder provides cooling.Lean it out too much, loose that cooling and things get hot real quick.
Can run leaner, by closing the intake valve well before BDC.That way, A) Less of a fuel charge, and B) Fuel in cylinder is subjected to additional negative pressure, after valve closes and cylinder continues down, which causes additional vaporisation. And when fuel vaporises, it sucks up heat like crazy.This 'absorbs' heat from pistons, valves and cylinder walls, 'cooling' cylinder.This in turn means that you can go for higher compression ratios, without having to worry about detonation, or pre-ignition.But, its a very sophisticated system.Could try water injection, so that the water will absorb some of the heat, in leiu of the fuel, since your leaning it out. Might at least keep you from grenading it.Would strongly reccomend you install an exhaust gas temperature sensor and guage.Before you try running 'super' lean.Jim

[Michelinho]

nice conversation and nice concept. i guess if the concept that's been discussed in this post. anybody here aware of this Rochester Quadrajet? i just seen this carburetor in a GM make car. when one of my customer brought his car. so what you think about the design i mean the carburetor of every GM car?

The Rochester Quadrajet is a good and rugged design that is easy to rebuild with a cheap kit. It comes in 2 sizes, 535(?) cfm and 685 CFM. The Carter carburetor was a notch above the Quadrajet. The favorite of Hot Rodders is the superb Holley (a pain to overhaul) carburetor in Chrome finish that matched the Carter design in many ways.

Hope this helps,

Michel