Carbs and Emissions?

[jamesjedi]

How much worse are the emissions from carbs? I know they fail emission tests, but how bad are they?

[Joe Bob]

It's not that they fail emissions it's that they fail the visual test in most states that test your particular model year. That is, if your 911 originally came with fuel injection.

In CA, they don't even bother with the tail pipe test. Any originally equipped carbed 911 is exempt in CA.

You would have to put the carbed 911 on an exhaust engine analyzer to specific numbers.

[jamesjedi]

I did not know anout the visual inspection. I wonder if the numbers are much higher. I have no idea of the differences.

[Joe Bob]

Fuel Injection was the answer to increased limits on smog emissions starting in 1970. Before that there were minimal controls.

By 1976 most if not all vehicles in CA had cats, FI, air pumps and were burning unleaded fuel. HP was down because the manufacturers simply added on control devices to meet the standards. It took many years before high performance came back.

The sports cars of the 70s were dogs.

Small engines up until recently have been exempt.

[RWebb]

- Aichle

[jamesjedi]

I would assume that from the chart, there is a very big difference if carbs are used. Thanks for posting.

I like carbs. but they look to be extremely dirty.

Thanks.

[island911]

One thing about carbs is that they usually dump extra fuel when blipping open, and then also lag, in pulling back the fuel, when closing off the air. So, if you need to run more cleanly w/ carb's slow throttle inputs are helpful.

[Lorenfb]

"So, if you need to run more cleanly w/ carb's slow throttle inputs are helpful."

Profound! But it gets the post count up, right.

[island911]

Nope; was just 2¢ worth. Not everyone considers the dirty throttle transitions of carbs.

btw, Why do you care? or are you just trying to get your post count up? Did you add anything?

Loren, maybe you're uncomfortable with me not being thoroughly annoyed with you, like most everyone else on this board.

btw, you seem to be okay with webbs 40,000 plus post count (he has a few log-ons) so I'll take it that this is personal. So, I'll make an effort to be more annoyed with you, like most everyone else on this board.

[Lorenfb]

"Not everyone considers the dirty throttle transitions of carbs."

Like that adds that much to the inherent problematic emissions.

[RWebb]

Loren is right, it does not add much; it does add some.

Why you people would want to increase your post count is beyond me.


James - the decision to run carbs re emissions will vary, depending on where you live. If you live in a highly populated, basin that holds in air, and is also very hot (LA), then a big no.

If you live in the middle of Alberta or the Yukon, then the emissions are not an issue, but you will be unhappy until the motor warms up.

EFI can give more performance than carbs, and lower emissions at the same time. All you need is money and/or equipment & skill to set it up. Lots and lots of money for the best ones.

[Eagledriver]

Carbs are much dirtier than modern EFI or even CIS. My car gets about 12MPG on the highway. It runs very rich at low throttle settings. I'd bet i puts out 100 times the HC pollution of my 2007 Sonata.

-Andy

[James Brown]

my lawn mower has carbs. that is the reason i don't cut the grass, if only Briggs & Stratton came out with a MFI for there engines...

[RWebb]

Honda makes the cleanest (and best) lawnmower powered by an infernal combustion motor -- the very dirtiest thing to run is a 2 stroke motor (leaf blower, chain saw, m/c, skidoo, etc.)

I used to use a push reel mower, but recently went with an electric one

a modern car can drive 200+ miles and produce less conventional pollutants* than mowing your lawn

* i.e. CO, NOx, HC's - not CO2 - the car will produce more gases that affect global warming