Full atomization?

The "technology" to produce any size droplet is now over 100 years old.
As I said - is that what you want?

Direct Fuel Injection allows you to control the timing of the fuel, and since the injector is downstream of the intake valve (directly into the cylinder) you have more flexibility with cam profile and compression ratio. No worries about pre-ignition when there's no fuel present.

I did a study on fuel atomization at Chrysler and the main factor was pressure

Which technology was that?

Polyspheric, I find your posts excellent and informative, but I do not understand your question here.
Why would it be desirable to have poor fuel atomization ?
The more vaporized the fuel, the more complete the combustion, unless of course the mixture is stoichiometrically rich.

The fully atomized fuel displaces its equivalent volume of air in the charge mass; gasoline as a gas is many, many times larger than as a liquid. In engines with poor breathing (DV was specifically referring to the BMC Mini) air is more important.
A hemi would have the opposite argument: large intake port means fuel drop-out may occur if they're too large.

OK I see now.

Can anyone please explain how a carb atomizes fuel better than fuel injection.

For the sake of my question both the carb and fuel injection are tuned properly.

The fuel in MPFI is injected onto the back of the valve while it is closed so the fuel is the first thing in as the valve opens. Think of it like putting cream in your coffee, if you add the cream to your cup first(small amount) then add the coffee(larger amount) then just the act of pouring the coffee in will mix it all up and you don't need to stir it at all, on the other hand you pour the coffee first then squirt in the creamer you are gonna have to stir it because it won't mix on it's own.

Carbs on the other hand spew the mix in the chamber at the same time, it also has more time in the runner to evaporate a little more or for the fuel to seperate out if the manifold or port is poorly designed.

EFI also comes out at a much higher pressure and this also helps to atomize so 6 of 1 or 1/2 dozen the other way.

Direct injection is more about MPG and emmisions than power or even atomization, it allows the whole combustion chamber to filled with a homogenious mix under WOT or more importantly, part of the chamber can be filled with a real good mix near the spark plug while the rest is just air, this minimizes heat rejection into the metal because the air acts like insulation, you can intentionally have lean and rich areas at the same time in the chamber to improve MPG and emmisions, this is not really utilized under WOT because a carb or port injection both can do a fine job of filling the entire chamber with a good mix.

In my personal opinion if MPG were the primary concern you would want all the fuel vapoorized and evenly mixed so you would want the high pressure fuel atomization of MPFI and a longer time in the manifold that you get from injectiing it at the beggining of the runner instead of at the valve, my TBI motors I have owned always got the best MPG, chevy, dodge both got better MPG with throttle body injection than MPFI magnum and vortech style engines at the cost of power.

I don't think anyone on this thread knows the answer to that question. That is a very complicated technical question and nobody would be able to prove it one way or the other without a lab full of equipment. A carb works opposite of injection so the behavior is totally different. In a carb the low pressure area in the venturi sucks the fuel out of the bowl. The pressure differential in a carb is only 5 or 6 psi while an injector operates around 50 psi. The metering block in a carb adds air bubbles to the fuel which helps. There is no air bubble system in an injector.

If someone really wants to know the answer to this question they would need to talk to an injector engineer at Bosch. My guess is that they know how to measure it and and could explain it.

Thats the issue here... if you look at the question you can have 2 answers.. a injector by itself will atomize
better but in a full system as in TBI you have a intake(mixer area) a MPI has higher pressure than a TBI
and the MPI will atomize better
EDIT
I had 10 years of flowing injectors and building the flow stand

I was surprised with the level of uncertainty in this thread.

Liquid fuel does not burn. It has to be vapor to burn. New cars are all about low emissions. Our favorite classic mopars had high emissions because carburetors while good at making power are not so good at low emissions. If a carburetor could atomize fuel as well as fuel injection - new cars would sport carbs.

The smaller the fuel droplet the more surface area for evaporation. Carbs drip the fuel, fuel injection sprays in a fine mist. The mist has more surface area resulting in better mixture with the air. Fuel injection is also constantly "jetting" the injectors. Making small adjustments in pulse width for any throttle position or engine load. A graph of the oxygen sensor signal on a properly running engine will cycle just above and just below stoichiometry. If the oxygen sensor signal spends too much time rich or lean it flags a code. If the fuel trims get too far rich or lean they flag a code. Carburetors are good but they are never as good as injection.

Carbs always run rich - especially on choke. That extra fuel is what wore out old engines. It washed the oil off the cylinders causing the ring ridge. It then ended up in the oil pan diluting the oil wearing out the bearings. Modern engines are barely broke in at 100,000 miles. It's because of the fuel injection mixing the air/fuel well enough that after combustion minimal fuel is left over.

Plus the blocks are much harder now days

Aren't most of the modern retrofit throttle body EFI systems now running basically 8 MPI injectors bunched together and running high pressure (50PSI or so) and squirting it in the throttle body?

Another benefit for modern cars is that a dry manifold can be made more effective at ram tuning and physically fitting into any given engine compartment than one designed to carry a mix of air with fuel suspended evenly into it. The beer barrel intake on a magnum or modern hemi is a perfect example, they have even length and shape from one runner to the next as well as a long length that would let fuel drop out at low velocipy. They would both have terrible distribution with a carb (either a down draft on a magnum or side draft on hemi).

The last time I work with either system the TBI was 14# and multi point was 55#.. I started out flowing
single injectors at multiple voltages and seeing the differences in the area around each zone of
the flow pattern and the different duty cylcles/pulse width

Holley Sniper runs at 58 psi while Holley MPFI runs at 43 psi. But the Sniper injectors fire into an annular ring and then the fuel dribbles out of there. So it isn't really injecting directly into the air. I have no idea how a Sniper compares to a carb in terms of atomization since the dynamics are very different. The average guy has no way to measure this stuff.

I have no way to measure that stuff now days without that flow bench I built up

Or whole factors of normal sea level atmospheric pressures.

There's really no debate to be had on which technology atomises better. You've had at least two people who have worked in the industry say the same thing (Mr P Body and myself). Higher pressure gives better atomisation. EFI is ALWAYS higher pressure therefore, leaving the carb or injector, better atomisation, every time, period.

Per my original reply - what you do with it after that is getting a lot of good discussion here, but there's no uncertainty about which device atomises better.

I am still in doubt about which system, EFI or a dual quad tunnel ram set up, is better for a all out drag race motor Hence NHRA Pro Stock not going faster now with EFI than they did with dual carbs on a tunnel ram intakes
I remember several different mechanical fuel injector companies testing the location of the injectors heights in there all out race set ups for dirt and asphalt track roundy round all out race cars