Valve bodies still have plenty of the old school springs, valves, check balls etc. All the electronics does is take the place of throttle position input and governor or speed input. Shift solenoids in some just direct fluid to activate a shift valve. There are no one size fits all valve bodys for automatic transmissions, that I can think of.
Cant we invent carburetors that atomize fuel as good as fuel injectors by now?
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Atomizing not an issue? It is a huge issue fuel needs O2 to burn, the more little tiny blobs of fuel that have air/O2 next to them are going to burn. IMO FI is not the greatest at atomizing fuel.
Fuel injectors atomize fuel fine. Go find me a carbureted engine running 14.7:1 stoic ratio under all conditions. Doesn’t exist.
No they don’t, why do you think DI has fuel dilution issues?
And why would you desire to have 14.7 under all conditions? That is not good for power demand, nor good for best economy!
Thanks to KrisZ for answering the first part.
Not all GDI has dilution issues. There are occurrences associated with some shortcomings of sizing a single high pressure injector working under all conditions. The fix is the move the injector to the plenum, or use 2 injectors.
Atomization isn't the issue to discuss - open vs closed loop control is. If you want to actually close the loop you need to be able to precisely control one of the inputs - fuel or air. Carburetors allow neither because you get x amount of fuel for Y volume of air , there is no way to immediately compensate for amount of 02 in the air or quality of the fuel in real time. Carburetors are open loop or at best partially open loop. Arguing otherwise simply means you don't understand closed loop control theory.
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From what I've read the problem is condensation of the atomized fuel on the cylinder walls, not a lack of atomization.
But it's true an injector is more sensitive to dirt / deposits causing a problem resulting in poor atomization.
14.7 : 1 is an ideal burn. If there were a reason to have something different, for example a cold start - EFI can also be manipulated better for that condition in real time as well - again something a carb can't do.
I think because its sprayed directly in the cylinders, on carbed cars the fuel pooled in the intake runners until the engine got hot.
Who is arguing open vs closed loop here?
Modern system hit closed loop operation in under a minute, or something like that. Yet the fuel dilution issues aren’t caused by open loop operation. They are caused by excess fuel which isn’t atomized.
The problem with these types of discussions is that carb development essentially stopped once FI became mainstream. Like I mentioned earlier, motorcycles used carbs the longest because they provided the best power and throttle response and were not saddled by emissions for far longer than cars were. And a lot of motorcycle carbs don’t experience problems you’re describing. They can be run pretty much year round without the need for adjustments.
Had FI not taken off, o think a lot of the electronic controls would’ve made to the carbs, but at this point it’s all “what if”.
The technology has existed for decades but the car companies are in cahoots with big oil and won’t let them be used. I know this because my neighbor knew a guy who knew another guy who said one accidentally got installed on his 66 Oldsmobile that got 300 mpg. Men in suits came from Detroit and confiscated it.
I think every person over 50 has heard this story at least twice from two different people.
I think every person over 50 has heard this story at least twice from two different people.
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That was my entire point on why atomization was not the issue - closing the loop was. I can atomize fuel with a carb or a EFI - but only one allows closed loop control. Fuel delivery was not the reason manufacturing went away from carbs - it was the inability to close the loop that did. Closed loop is the reason as to why carbs are no more.
Then we can go off on a tangent to discuss why some GDI engines dilute (recondensing on a cold cylinder wall, high pressure injectors are hard to make atomize fuel at low volumes (similar to some carburetors idle jet), staying in open loop too long, going into closed loop before the A/F sensors are hot enough to be accurate, and many other speculated reasons). Clearly not all fuel injectors were created equal nor were all carbs, but only one allows closed loop.
We could stray off into motorcycles. I don't know why they continued using carbs, not my area of expertise. I suspect at least one reason is the same reason my $400 inverter generator also has a carburetor - cost?
At the end of the day OEM's went to EFI to close the loop. No one continued development because atomizing fuel via an injector when properly implemented works just as well.
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There were feedback controlled carbs during the transition to EFI, but they weren't ideal.
Feeding multiple cylinders from a central location, is never ideal. Multiple carbs are much more complex than multiple injectors.
The title of this thread is answered - we can make a carburetor that atomizes fuel as well as injectors, but that would not be ideal.
Feeding multiple cylinders from a central location, is never ideal. Multiple carbs are much more complex than multiple injectors.
The title of this thread is answered - we can make a carburetor that atomizes fuel as well as injectors, but that would not be ideal.
If you mean closed loop for the purpose of emission control, then yes I agree.
More power per cube, more efficiency, broader power band. Could you even do VVT with a carb, sounds hard? You for sure couldn't run a quasi Atkinson cycle.
Possibly there are some obscure applications somewhere that carbs outperform, but not for a daily driver.
The beauty of America is you can go open a carburetor company and prove me wrong though. I like being proven wrong by creative people.
The advantages are obvious when comparing modern FI to carbs. These advantages, even open loop, weren't there when FI started to be implemented in mainstream vehicles. But the emission control advantage was apparent. That is why certain European models stayed with carbs longer, because their emission regulations lagged behind California, and they didn't want the performance hit.
Lots of people make carbs out to be some very archaic, low tech contraptions, but in reality they are very sophisticated, were very capable of making good power and torque, and if it weren't for emission regulations, they would likely be used much longer and who knows how far they would've come.
And finally, as much as I like carbs and tinkering with them, in no way am I advocating for their comeback. Not sure where you're getting this idea from. Just because I'm clarifying some misconceptions about them, doesn't mean I think of them as superior tech or that I want them back.
Don’t you figure not having a battery to energize the EFI computer is at least part of it? Booting up a controller, even one that is 100% ROM-embedded code is probably really tough to do reliably from a hand cranked magneto.
My very first post on this thread was simply "Even if you could build a better carb it would be of no value....(paraphrasing - due to lack of ability to close the loop)
Many people took exception to this comment for some reason. I thought you were one of those - but if not I apologize.
The premise of the thread is flawed. The "can we build a better carburetor" question is likely yes, but likely not of great use. We could probably build a better horse saddle, or buggy whip while were at it.
Trust me the ingenuity of a carb is not lost on me. I have fiddled with many - mikuni, holley, quadraject, carter. Some were definitely better than others. I would rather have a ECU and PWM controlled injector - preferably in the plenum.
Probably. My guess though is if they could install a ECU, battery and EFI cheaper than they could a carb, they would. Design teams don't think in terms of complexity / simplicity. They think in terms of meeting a design objective within allotted time and budget, that makes it through the warranty period.
