Back to simplicity: Would carbureted ethanol-only cars pass new car emission tests?

[kennybobby]

If you are an electrical guy, then EFI appeals to your sense of simplicity and logic as a good solution that is easy to control.

If you are a mechanical guy, then carburetors appeal to your sense of design as a clever and beautiful solution in a compact package.

i like, use, and repair both types of systems. Both systems use circuits to route input information and control output response: EFI is obviously electron circuits; Carburetors have air, fuel and mixture circuit paths. EFI uses resistors, capacitors and inductors to regulate and control electrical currents, Carburetors use precision orifice holes and needles in tubes to meter out the fuel mixture.

But i love working on carburetors. There is an immense satisfaction from perfectly tuning a rack of carbs to run at the optimum mixture and deliver great gobs of power with a twist of your wrist. Long live the Venturi.

[elhigh]

Originally Posted by Big time

Now compare the resale value of the 59 Bug eye Sprite with the Kia.
Resale value / depreciation is often an indicator or very long term (10+ years) maintenance costs.

Unlike the Kia, Sprites' values are on the rise. And while I would jump at the chance to pay full price for a Bugeye (if I had the money), I wouldn't take a Kia if you gave it to me.

Original purchase price on a Bugeye in 1958: 680 pounds.

2013 equivalent: $9020. That barely buys you the butt end of the Kia, and absolutely none of the style.

Current selling price on a nicely restored Bugeye: $11,000. So you can plainly see that they are indeed going up in value; the example cited is not perfect, needing some minor body work but enjoying a few subtle mechanical upgrades.

And it's carbureted.

[Ecky]

I don't understand the fascination with carbs. EFI isn't necessarily more expensive or more complicated, and it's definitely more reliable outside of nuclear war.

For EFI, you need:

1. A computer - it's possible to do the processing needed on a <$10 computer so they're practically disposable

2. O2 sensor

3. Spark, be it direct ignition or distributor

4. Injectors


Some added niceties that help clean up emissions and improve efficiency/power but are not strictly necessary:

4. MAP/MAF sensor

5. Engine/coolant temperature sensor

6. TPS

7. Knock sensor


You still need a distributor with a carburetor, and I have no idea how a knock sensor would work without a computer. It's practically impossible to destroy a modern vehicle via detonation, so engines can be less overbuilt (saves on materials costs). As for tuning/tweaking AFR, it's certainly possible, it just requires a different set of tools. There are $5 bluetooth dongles on eBay that can plug into an OBD port and adjust things like timing and mixture from a cellphone or tablet, assuming manufacturers don't lock it down, which they could do with a carburetor too (something like requiring a special tool to make adjustments or gluing them down upon leaving the factory).

[niky]

Knock sensing, might be difficult to do without any electronics whatsoever, considering how short the duration of the knock is.

As for tuning AFRs... errh... a quick-reacting bimetallic strip temperature sensor that opens fuel flow to an extra jet in the carb when the temperature gets too high or closes off one of the jets when it gets too low? Could even have a series of jets, allowing for finer control.

[kennybobby]

Haha, you pitched an easy homerun...lol

Originally Posted by Ecky

I don't understand... carbs.

Several years ago i had a young fellow tell me it was too easy to write software--and he should know 'cause he could really rock at playing games on xbox and could surf the internet faster than all his friends...

If you think EFI is easy then go tell that to all the Nissan owners who have or will end up pulling everything off the top of the motor just to get to the clogged injectors.

i've repaired hundreds of Bosch Motronic units, aka DME digital motor electronics. It was easy for me because i had traced the boards and drew up the schematic, and also knew every line of code in the processor--seems trivial to reverse engineer something if you've never done it before, but anybody who knows basic electronics could do it.

i've cleaned and repaired hundreds of motorsickle carburetors, mostly for Honda V4 and twins, but all makes and models. Anybody with basic mechanical skills could learn to do it--you don't have to be a rocket surgeon.

To the OP: go for it and don't worry about emissions. If you really want to get something done--you will find a way. If not, you will find an excuse.

[niky]

Must be Vee motors. On a port-injection inline four , checking for a clogged injector is as simple as unbolting the entire fuel rail and cranking the car to see which injector doesn't spray.

Granted, some of the wiring is needlessly complex, but with newer systems putting the ECU in the engine bay, it's becoming less of a hassle.

Still need a hell of a lot of patience (and schematics) to wire up a custom job. More than most of us (including me) will ever have.

[cRiPpLe_rOoStEr]

I'd still rather work on a carburettor than in an EFI, altough I recognise EFI has its advantages regarding a more accurate control of the combustion process.

[Gasoline Fumes]

Unless something was replaced in the first 75k miles, my 23 year old Civic with 212k miles is on the original injectors, fuel pump, ECU and all sensors except the oxygen sensor. I replaced the fuel filter once, only because I thought it might be a good idea. And the tank rusted out, so that's been replaced. I like my complicated EFI.

I don't miss the 3000 RPM cold idle of my carbureted 1984 Civic!

[elhigh]

I'm not knocking EFI. I understand that in the more tightly regulated emissions paradigm of modern motor vehicles, EFI is pretty much a necessity. It's flexible, scalable and like many others have said, reliable.

Outside a nuclear war. There is that little asterisk.

But I prefer carbs. That's where the thing breaks down for me. On an emotional level I prefer the non-electronic option, the one that, if I really really needed to, I could MAKE one from a block of wood. Or if I could scare up the materials in an emergency, I could make one from assorted bits of scrap metal.

Granted, the wooden one wouldn't work very well. But how many wooden EFI systems do you see?

[jamesqf]

Originally Posted by kennybobby

If you think EFI is easy then go tell that to all the Nissan owners who have or will end up pulling everything off the top of the motor just to get to the clogged injectors.

That's not really an issue with EFI, though, but with designers who didn't take repairability into consideration when they were deciding where to put stuff. By the same token, I've lost a good bit of skin off my knuckles, trying to remove badly-located carbs. And starters, alternators, clutch slave cylinders, exhaust manifolds...