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Emissions over the years

Years ago when I was in high school (ok, 1991 - 1995) I remember in auto mechanics class, we were on the topic of emissions and how it has improved over the years.

The instructor, knowing my family was (and still is) involved in antique and classic cars. For the class that day, he borrowed 3 of our vehicles: a 1928 Chevrolet Grain truck (not restored), my 1959 Ford F-100, and our 1991 Ford Explorer.

As it goes, he stuck the sniffer of the emissions tester up the pipe of the newest vehicle making a point of how good the CO and O2 and all that other junk was. He then proceeded to stuff it up the pipe of the '59 (all original, engine never rebuilt) turn on the tester, and eat his words. That truck did better than the “New” explorer. Knowing the Chevy truck would not do good at all, he shoved the sniffer up the pipe. Guess what, it did better than BOTH of the newer vehicles.

Knowing this could possibly open a can of worms, what has modern smog gear done for us other than to add more crap under the hoods of the vehicles we drive and often have to work on? Personally, I can take that same 1959 Ford truck, and get it to pass current emissions WITHOUT adjusting the distributor or carb. I recently did it with my Father-in-laws 1965 Ford F-350 with a 390 V8 and more performance garb than you can shake a stick at. It just passe under 2009 emissions standards (I replaced the air filter…)

Complete and utter BS.

  1. I can’t imagine how a “non-cat” car could ever be cleaner than a “cat” car.

  2. That aside, given that the “sniffer” test is given at (where I live) two, “steady-state” RPM settings, couldn’t one make a simple carb’ed car do well on the test, yet still pollute in the real world?

  3. I could see how this might happen if the Explorer had something major wrong with it (i.e. dead plug(s))

We still get a chuckle out of it. Including the instructor and some of my class mates that I am still in contact with. The way we figure it: The Chevy had adjustable advance on the dist. (a short lever on the side of the steering column you could sdjust it while moving from inside the cab) and was retarded enough (or was that advanced?) to make it pass so well. We still don’t know on the Ford truck. The explorer had less than 25K on the clock at the time with no major (or minor) engine issues. I still have the '59…

Why BS? Because you don’t think it’s possible? Explain? I’ve done it. The local emissions testing station doesn’t believe it either but their official little piece of paper proves different.

If you sniff a car of today the needles for your HC and CO will barely move. A typical no emissions gear car (lets pick a 1970 VW Bug) is allowed here in AZ to run at 4.5% CO and 450ppm HC. These figures for the “Bug” are very close to what would be require and result with your 59 FORD and your 28 Chevy would probably have to run even a bit richer (the higher the CO number the richer the mixture and the higher the HC number the more incomplete the combustion). You are not dealing with a bunch of bumpkins here, this stuff has been my lifes work.I have “smogged’ hundreds of cars and been to all the classes. In one we had the analyzer on a V-8 with a cat. converter, the instructor pulled a spark plug wire off and even with this cylinder not burning the fuel the HC needle did not rise,such was the effect of the cat. This demostration was given to show us you must 'sniff” upstream of the cat to tell how well the engine is running.

What you can do is get a chart of the allowable emissions and compare what is allowed for older and newer cars. The older cars can not even begin to run as lean as newer ones. The exactness of electronic controls and the addition of cat converters make todays cars much less polluting. If you tried to set that 59 at under 1% (they really like 3.5% much better) CO you would get into what is know as a lean misfire and this would send the HC way high,same thing with your 28 chevy.

I won’t dismiss this yet but would like to see a copy of the paper. Any way of posting that?

It’s possible to have a carbureted engine with the same CO/HCs as a fuel injected engine. The big difference would be that the FI engine would be far more consistent through the range of operation. In other words, at idle the readings may be indentical. When the throttle plate on a carbed engine is opened and the accelerator pump starts dumping fuel in things can drastically change.

It’s funny, but back in the mid 80s when Subaru was converting from EEC controlled carburetors to fuel injection there was a huge disparity in fuel economy. The carbureted model would tick off 40-41 MPG and the fuel injected model (same size car/weight with the same size engine) would get about 30 MPG.
It would seem to me that since the carbed model will go 10 miles further on the same gallon of fuel it’s far more efficient than the injected one.

I thought of trying to post a copy of the results for the '65… No good excuse other than I looked at the results, then the emissions tester guy took it back and ??? Mind you the '65 does have a rebuilt engine, a Holly 650 CFM 4BBL carb, very very mild cams, and an Eddlebrock Performer aluminum intake and god only knows what else (I have only been keeping it running recently. I replaced the air filter because the K & N would NOT let it pass emissions so we put a regular old paper filter on it.

I can’t imagine how a “non-cat” car could ever be cleaner than a “cat” car. Think cold car. Converter does nothing until it is warmed up.

I’m skeptical of the results, but I’d also add that pollution controls do a lot more than keep the CO down. There are nitrogen and sulfur compounds to consider as well. Plus if all three vehicles weren’t warmed up, I further question the validity of the test. A modern vehicle has to warm up to go into ‘closed loop’ operation for the test to be meaningful.

Then there’s the ‘sniff test’ I can immediately tell if I’m behind an older vehicle that’s not catalytic converter equipped or has had its removed. You can actually smell the unburnt hydrocarbons emanating from older vehicles. It makes you wonder why people didn’t notice it all the time prior to the 80s. I guess we were all just saturated with it.

URBAN LEGENDS… Like the 55 MPG 4 bbl that GM let get away from them in 1959.

Andy, you can claim all you want, but emissions reductions from 1965 to now are a proven, documented fact. Your extraordinary (I would say unbelievable) claims require proof, not just claims.

Try running that carbrurated engine at 1% CO you will really like the idle quality. Tune a carbed engine for “best idle” and then take a sniff (pre cat), you will find it at about 3%CO. You can’t use the worst example and draw the conclusion that carbs are better than F.I. That"s just what you are doing when you use computer controled carbs as your example. This is something like a reverse strawman argument.

I’ll bet that the Studebaker electric made in the early 1900’s has everything beat as far as emissions are concerned.

One interesting side note on emissions: I have a smoke detector in my garage. I start my modern cars in the garage (with the garage door open, of course) and the smoke detector does not go off. However, if I start my 1978 Oldsmobile outside the garage and the wind is blowing toward the garage, the smoke detector will go off. The same thing happens if I start my lawnmower outside the garage, but the door is open and the wind blows the smoke into the garage. I suppose that the smoke detector picks up the carbon particulates and the old Oldsmobile and lawnmower engines emit more of these.

Personally, I can take that same 1959 Ford truck, and get it to pass current emissions WITHOUT adjusting the distributor or carb

Can you explain this further? All the sniff testing stations I have ever gone to will enter the year, make and model along with engine size and then the emissions limits are set based on those factors (along with derating based on the current age of the vehicle). A 2009 vehcile is going to have much tighter standards than a 1959. In fact, something that old was exempt from emissions testing and only had safety inspection because they were such gross polluters comparatively.

How did you ascertain it would pass 2009 emissions levels? Did you enter information for the same engine displacement for a 2009 truck? Or did you know the 2009 limits and just compare your test results to them? Is this an idle sniff only or a full dynamometer protocol? As mentioned, you might be able to sneak through an idle only sniff but I’d be very surprised if you could get it to pass once you get past tip-in. I’d be interested to see the test results too.

In 1968 the smog was so thick in Southern California that as you drove on the Santa Ana Freeway the visibility was less than 1/2 mile. The Big 3 in Detroit howled and bemoaned that it was impossible to meet the EPA standards for cleaning up automobile exhaust. Detroit said they were DOOMED if forced to meet the standards. In my recent trip to Southern California I could see the HOLLYWOOD sign clearly from the Hollywood Fwy. The air was as clear in LA as it was in Amarillo. Obviously the EPA standards were realistic and the decline or Detroit’s Big 3 was from corporate mismanagement, not emission standards. And the reduction in hydrocarbon and carbon monoxide emissions was considerable as a Callifornis tourist and years of working on cars. The original Sun Equipment Infra-Red Exhaust Analyzer had a scale for pre-emission and post-emission cars.

Detroit said they were DOOMED if forced to meet the standards.

Well, the combo of the gas crisis (that caused Detroit3 to put out horrible small cars that they really didn’t know how to build) and smog requirements (that robbed cars of HP and introduced drivability issues) put the Big 3 into a tailspin that they never really recovered from, leading to the recent taxpayer bailout.

…So, I suppose you could say that statement wasn’t far from the truth.

I’m going to stick to this specific case and suggest that it is possible under specific conditions.

First off, nitrogen oxides don’t become a problem until the cylinders become hot. The '59 was probably operating at a much lower temperature than newer vehicles, and in this case none of the vehicles had probably been for a good run and the cylinders in all were probably not very hot, added to the fact that they were at idle, which is easy on emissions.

Secondly, the newest vehicle in the test group was a 1991…19 years old…probably ont comparable to a new vehicle even under the best of circumstances, even though at idle it might be possible for it to squeak by current standards.

Thirdly, we don’t know the sizes, the miles, or the condition of any of these engines. A very old engine in great shape and with the carb running lean could. conceivably at idle, beat a 19 year old vehicle that has led a hard life.

I find this specific statement believable given the constraints and the unknowns, but I think it would be a miistake to infer from this that a typical 1928, 1959, or 1991 engine could produce lower emissions than a new engine, especially under dynamic conditions, even if all the engines were brand new.

I agree with Rod’s comments that the EPA has truely done a lot of good, especially in congested areas. But don’t infer from that that I agree with much of what they currently do. In many respects emissions testing has IMHO become a farce and I doubt if it truely reduces emissions beyond what just the manufacturing requirements would. Said differently, emissions would probably be not detectably different of the requirements to the manufacturers were kept at their current levels and the states’ emissions testing requirements were eliminated entirely. It’s time for the EPA to turn its focus on significant contributors, like diesel trucks. I’m pleased to see that they’re finally beginning to address this issue.

I’m also concerned that the courts have found that the EPA has a right to regulate emissions not in the Clean Air and Water Act, essentially bypassing the reviews and debates of the legislative process. This IMHO sets a bad precedent.

Was the cat converter on the '91 Explorer warmed up?

“how good the CO and O2 and all that other junk was”…“It just passe under 2009 emissions standards”

I would like to see some actual numbers.

Very good and substantiated post! I wanted to add that the original poster mentioned that the incident he reported happened 17 or so years ago when the 1991 Explorer was practically new.

But your explanations about operation in cold vs. warmed up state and in idle vs. higher revs makes a lot of sense.