Yep, those are really ugly readings. I see you getting a lot of responses aimed at getting you past the test. Add alcohol to the gas, put on a catalytic converter for a day, etc. From where I sit, these are pretty silly and unhelpful.

For one thing, a catalytic converter is not a magical device. It will NOT swallow that much HC and CO, or anything near that much. A catalytic converter only oxidizes HC and CO when the mixture is stoichiometric (14.7 parts air, 1 part fuel). With your 9% CO and 1429 ppm HCs, you're not even in the same postal zip code as stoichiometry, so a catcon will do you zero good (and will promptly overheat, internally melt and clog with that much HC entering it).

The alcohol trick sometimes works in borderline cases. Yours isn't a borderline case, it's a gross polluter. Ten bottles of alcohol wouldn't get you past the test.

But more fundamentally, the people making these suggestions are looking at the test as a game you should cheat at just to get your sticker. Sometimes it feels that way, especially in places like CA where the rules really are ridiculous (doesn't matter if pure, fresh mountain air is coming out of your tailpipe; you don't pass the test if the carburetor isn't the one the factory installed).

Fact is, though, cars with filthy exhaust like yours are exactly why the tests exist. Everyone has to breathe what your car's putting out (it doesn't just go "away"), and we all have to breathe. Some people are too selfish and/or thoughtless to make sure their cars run cleanly, so the state steps in and does it. The numbers are telling you something, if you're willing to listen. They're telling you you're running very rich, but you already knew that from the fact you can't adjust your idle. And your black spark plugs.

Your inability to make the engine ping even with 20° of additional initial advance is further evidence you're running rich, but it also tells us about the elephant in the living room: Your Isky 264° is probably too much camshaft for your street-driven car. What was the original goal? How did you happen to pick the Isky 264° cam? Where did you install the cam (straight up, advanced, retarded, did you centerline it at all)?

Don't futz around trying to cheat pass the test. Spend your time and effort making the car run right. It can be done. It has been done. You may have to keep working on the carb until you can get it to adjust.

Your valve lash settings may well be too tight/small for that camshaft, which would greatly aggravate the conditions you mention (can't adjust idle, flunk emission test). You may want to pop the valve cover and loosen the tappet adjustments. Back them WAY off (at least a full turn on each adjustor, all intakes the same amount and all exhausts the same amount) and see if some of the idle adjustability returns (and some of the skipping and misfiring at idle goes away). The engine will make a racket, but it's a valuable diagnostic and won't hurt anything.

Don't see anything in your setup description about the ignition system. What have you changed/kept? Any distributor recurving? Your 22 degrees' total advance doesn't sound like enough from where I sit.

Your engine will seal better once it's broken in, but engine breakin is not going to make the difference between "gross polluter" and "Here's your new emission sticker, mister.". It's false hope to think that it will. What's more, your engine is probably much farther along in the breakin procedure than your mileage would indicate. Running that rich, oil's getting washed right off the cylinder walls. Bet your oil smells of gasoline by now.
Carbs do not like sitting for a long period of time. Go through it with a kit.
Well...yeah, because your car's spittin' out HC at a rate that was considered unacceptable by the very first, very lax emission test standards forty years ago!
Probably at the intake-to-exhaust manifold junction. It's very hard to find the good gasket for this junction any more; the crimped sheetmetal ones don't seal very well. I've had some success coating the sheetmetal gasket with high-temp RTV silicone and letting it cure before installing it.

Let's post factual and correct information here. You don't need 14.7:1 A/F for a cat to work. A cat will oxidize any quantity of unburnt hydrocarbons present in the exhaust. However, if you are running very rich, you need an air pump to introduce oxygen into the exhaust and without it, you won't gain much by simply adding a cat. Almost every car equipped with a cat also had a pump. What you really need to do is straighten out your carb. You may need to rebuild it, but it sounds like you certainly have to tune it. You'll probably be able to get under the limits even with the cam you have which, incidentally, is not larger than many factory high performance cams used since the inception of the smog test. Get the tune right on your engine and you should pass. BTW, I have seen many cars with much more radical aftermarket cams pass the smog test with flying colors, albeit, with a functioning emmission system.

Mitch

Thanks for these great rplies. I agree wholeheartedly I need to make it run correctly before my next test. I am looking locally for a carb rebuild kit today. If I find one I will rebuld it this weekend. I agree it's likely anything rubber in this cab is suspect. So I'll fix that first. As far as the cam goes I went with that cam as a performance upgrade without going too radical. I realize it's not stock but it's in there and it's gonna have to do for now. I did a lot of reading on this site and others about this cam and it seemed the right thing to do at the time.

About the emissions. I agree I'm way out and it needs to be brought in. I have also been researching an O2 sensor instalation for tinkering to get it leaner. Seems like a decent diagnostic tool for on the fly measurements at least gross measurements.

As far as the seal between the manifolds, I'll check that again but when I felt around it with my hand I didn't notice any leaks but I'll check that again. I did find exhaust leaking out of small hole near the right side of the flapper shaft. I put a screw in it just to plug it but it's still somewhat noisy.

Also I noticed the warm air valve on the air cleaner isn't closing so I'd like to get that warm air intake working for better cold conditions. Also I don't know if the EGR is doing it's job either.

Most of these things will have to wait until I get the carb straightened out.

Thanks

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Sweet Emotion

Yes, let's. It looks like you might not have a completely solid working knowledge of the causes and control of engine emissions. There are numerous good texts on the subject; if you want to get up to speed quickly I recommend the Stockel text. Any post-1981 edition will contain most of the relevant info.
That is exactly what you need for a catcon to work. It's why fuel and ignition systems (and, later, engine management systems) got a great deal more complex with the introduction of the catalytic converter. The older carburetors and distributors were generally not capable of providing the much more precise, tight control over fuel metering and spark timing necessary to give the catcon something it could work with. The pre-catalyst way of calibrating driveability at the factory, at the engineering stage, was to throw more fuel in to cover up myriad problems (big and little hesitations, big and little surges, etc.). From the driveability standpoint, this works, but fuel economy and emission control go right out the window. Tighter, more precise control of engine operating parameters was what was needed, and that's what happened -- and that's why.
Nope. It won't. It's not a magic HC eater.
The above is a mix of information that you've misunderstood, and just plain incorrect information. The need for (and configuration of) secondary air injection is NOT determined by whether or not the engine is "running very rich". It is determined by numerous factors including the efficacy of the upstream reduction catalyst if present, the ability of the engine management system (of whatever type exists) to maintain a stoichiometric mixture, the physical placement of the catalyst relative to the engine (thermal management) and others. It's definitely NOT the case that "almost every car equipped with a cat also had a pump". There exist lots of cars that have no air pump. Some of them, including many \6 vehicles, have a "pulse air" system that uses no pump, but relies instead on negative-pressure pulses within the exhaust ports. Some of them have no secondary air injection at all. All of these different designs passed the Federal emission certification tests (a 3-day, multiple-thousand-dollar test VERY much tougher than any state's periodic emission test, which every car design must pass in order to be legal for first sale). And all of these different designs, when properly maintained and not thoughtlessly altered, pass state emission inspections.
No, the largest factory cam used on \6 engines (excluding the '60-'61 Hyper Pak cam) was the 244°/244°/26° item used on all 1971-1980 \6 engines. The '81-up hydraulic cam was a 228° unit. The Isky 264° cam is quite a bit "larger" in all the relevant parameters than any factory cam. Remember, it's not just the added duration, but also the different lift characteristics and lobe centers/overlap.
Seen which cars pass *which* smog test, exactly? There are many.
In this case, the functional EGR system is aggravating the HC/CO failure of the 35mph treadmill test. That Isky cam, if I'm looking at the specs for the right one, has more overlap than any stock cam did. Increasing the cam's overlap does several things, but the relevant thing it does in this case is greatly increase exhaust dilution of the intake charge within the cylinder, at low RPMs. This is a very effective form of built-in EGR, and is one of the main reasons why "big" cams tend to idle poorly and reduce low-end torque and driveability. It is also why the stock camshaft went from 16° overlap to 26° overlap in 1971 when control of NOx emissions was mandated. (quickly: EGR's job is to reduce the formation of NOx by reducing peak combustion chamber temperatures.)

By leaving the EGR hooked up, additional exhaust gas is routed into the intake tract, further increasing intake charge dilution and aggravating low-rpm misfiring. With this cam, an external EGR valve is not only uncalled-for, it's hurting matters.

Nobody said you have to have a stock cam to pass emissions. I'm just suggesting you might've overdone it. If that turns out to be the case, you probably won't be entirely happy until you swap in a "smaller" cam. (That unhappiness could manifest as failed emission tests, or poor gas mileage, or an engine that doesn't run the way you wanted it to, or a rough idle, or any combination of these.) Note that slacking off the valve adjustment will simulate a "smaller" cam.
An O2S can be a very useful diagnostic tool, but a few caveats apply:

1) No O2S is going to help when you're this far out. It'll just read "full rich" until it quits working from carbon contamination.

2) An O2S can't tell you what any individual cylinder is doing, only what they're all doing together. The "all together" info is useful to an extent, but the \6 does tend to have mixture distribution issues that can get in the way of making the engine run right (for whatever definition of "right" you choose).

3) An O2S isn't really the right tool for large-scale initial fixes and adjustments with the car standing still. It's an excellent tool for finding rich and/or lean areas in the fuel curve while driving (or on a dyno) so you can then go in and tweak the relevant part(s) of the carb to bring those areas in line.

The really big-scale adjustments you can make without the use of any tool. It's not hard to tell when an engine's running grossly rich or grossly lean. Once you get it into the general ballpark, I recommend the use of a Gunson Colortune. This is a glass spark plug that is temporarily installed in place of a regular spark plug. It lets you see the color of the flame in the combustion chamber of whatever cylinder you install it in, which is a highly reliable, real-time and instantaneous indicator of how rich or lean that cylinder is running. You install it in one cylinder (or if you really want to spend money, buy three of them and install in cylinders 1, 3 and 6!) and do your tweaking and twiddling as you keep an eye on flame color. Extensive color charts are included with the Colortune. When the flame is a nice "gas stove blue", you've hit the target.
The really tiny hole, maybe 1/32" diameter? That's the only hole there ought to be...if there's another, something's missing!
This is a simple system to diagnose and repair. It has two working parts and two hoses! One hose runs from manifold vacuum to a bimetallic "air cleaner temperature sensor" (little round flying saucer looking device inside the air cleaner body). The other hose runs from this sensor to the "vacuum motor" (round can atop the air cleaner snorkel snout). The temperature sensor applies or withholds vacuum to the vacuum motor depending on the temperature of the air flowing over it. It tries to maintain an intake air temperature of 100°F to 130°F. This is one of the measures that was taken in '70 to exact tighter control over fuel/air mixture, by supplying the carb with a much more constant air intake temperature.
What cold conditions? You're in Tucson!

To diagnose the system, run a hose directly from the vacuum motor to your mouth and suck on it while watching the flap door. If you can continue to suck air and the door keeps returning to "open", you need a new vacuum motor. If the door closes in response to mouth suction and stays closed when you put your tongue over the end of the hose, the vacuum motor's good and you need a new temp sensor (Standard-Hygrade ATS-9). All of this assumes both hoses are hooked up correctly and working...if not, the system won't work even if both components are good!

Do you have a vacuum gauge? What's your manifold vacuum at idle?
See my other post in this thread. EGR won't help you with that big cam; it'll hurt things. You only posted HC and CO numbers, so it looks like Tucson isn't testing for NOx for 1974 cars at this time.

Slantsixdan, you certainly do not know my background, my credentials, who I have worked with, what I have done in this industry and what I do now. I did not hear you ask either. What you are telling this individual is mostly irrelevant with regard to his particular problem. I do not have the time to writeup a synopsis on what the topic really is which is how this guy is going to get his vehicle to pass an emissions test. He does not need to bring his car up to current EPA standards.

Textoad, the plain and simple fact is: you need to get your engine in tune with respect to your carb and you will probably need to install a catalytic converter. I have an 80 Aspen with a slant six, no air pump and one cat and my emmisions are way below the limits your state imposes. If I can do this, you certainly can. Simple as that.

Mitch

When you start saying things like "a catalytic converter will oxidize any quantity of unburnt hydrocarbons present in the exhaust" and things like "a 264° cam isn't bigger than a cam the factory used", it tells me everything I need to know about your knowledge of the topic at hand.
Textoad seems to have no difficulty speaking for himself, but I'm sure he'll let you know if/when he wants you to speak for him.

It's really not nice to "help" others by giving them incorrect information. Even if it makes you feel good to do so, it creates messes for other people to clean up, and that's not very neighborly.

That'll happen when the car runs right.

Cheating past the test is only worth considering when the car's clean but the test says "Dirty", or when the car's clean but the law contains silly provisions about which exact, specific carburetor or distributor, etc., must be used to make it clean.

It's dumb to try and cheat past the test when the car's actually as dirty as the test says it is. It's a lose-lose deal. The car still doesn't run right, you're still pissing away gasoline money, and you've wasted time, effort and money that could've been spent fixing the problem rather than trying to hide the symptom.

Let's "play nice", we want to help this Slant Six owner pass a smog test and not turn this message thread into a "who said what" contest.
MitchB, now you have everyone wondering what your background is.

(I have met SS Dan and know his automotive background)

I think with all the knowledgable people we have here, we can get this problem sorted-out.
I need some key information:
1) What is the engine's cranking compression in psi. (run a compression check)
2) What is the manifold vacuum at idle? How high can you get the vacuum by cranking up the initial advance?

I think textoad needs to rebuild that carb. and recheck / loosen-up the valve lash a little. If manifold vacuum is still low, the power enrichment circuit may be coming-in at idle, that will need adjusting. One option is to try a different carb. before getting into a more systemic rejetting process.
DD

Manifold vacuum is about 15 in Hg measured at the port on number 6 intake. Haven't measured compression but I will tonight. I'm guessing around 9.2 based on .060 off the head. But I'll check. I'll be rebuilding the carb for sure this weekend. I have another thread on suggestions for a carb rebuild kit.

Thanks.

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Sweet Emotion

BTW I have the old single barrel 1920 and a rebuild kit for it but I have the 2 barrel intake installed right now. Getting the single on there would mean removing and replacing the intake or some sort of adapter. It's an option but lets go with the 5200 for now. The 5200 I have is from a Pinto or Mustang 1975. The Holley part number is R 7876 which the guy at checker was able to find a rebuild kit for it.

I do have some questions on the vac lines for this carb because I'm guessing a little on what is what. However I'm hoping the rebuild kit may have some clues.

There are basically 4 vacuum hookups.

One at the base which is the vac advance I'm pretty sure.

Another at the top right under the air cleaner flange. ( not sure about that one, smallish tube.

Another coming off the bowl, fairly large I assume is the vent for the charcoal cannister. ( not a vac line BTW)

Then another medium sized line coming from the middle of the carb and bent at about 90 degrees pointing upwards. ( Not sure what this one is for)

Thanks

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Sweet Emotion

The Gunson Colortune sounds like a really cool device. I'll look into that.

BTW it was 26 degrees F at my house last night. That's pretty cold for my Arizona blood. I'll duck the snow balls now. That's about the cooldest it gets around here. And there skiing natural snow on Mt Lemmon.

Question, when does the cold air intake activate? What temperature?

Thanks again for all the replys. Fruitful exchange. I love this site.

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Sweet Emotion

That may be rather low, but it also may be about all you can get with that camshaft. One reason why a carb that might bolt on and work great with a stock cam can give you fits with a non-stock cam is because different cams radically change the vacuum signal profile that the carb "sees". It's possible that the carb's power valve sees your 15" vacuum as an open-throttle/under-load condition (which it would be, with a stock cam) and is for that reason dumping in more fuel. I'm not very familiar with the Holley 5200, so others will have to offer specific assistance on that, but I know some Holley carbs are very customizeable in terms not only of jet sizes but also power valve calibration.
Remember, though, a compression test won't tell you the compression ratio (your 9.2 guess is probably about right). In fact, a compression test won't tell you much, at this point -- just whether there was a gross problem with the engine buildup, is all. You will probably find even pressure across all six cylinders. A cylinder leakage test would tell you with more precision if there were a problem with the engine buildup, but I don't think you have internal engine problems so much as you have a badly miscalibrated carburetor for the camshaft you're running.

Oof. OK, I was under the impression that you were using an aftermarket Holley carb. I don't think it would be helpful to swap the original carb and intake back on...that 1920 isn't going to see what it was designed to see (in the way of vacuum signal) with that camshaft, any more than the 5200 will! It'll be a pleasant surprise if you can make the 5200 work just by rebuilding it, but I suspect you will have some actual recalibration to do. It's a lonnnnnnnnnnnnnnnng way from a '75 Pinto to a modified slant-6. You might do better with a Carter BBD (or you might not).
The vacuum advance port would have zero (or near-zero) vacuum at closed-throttle idle, and would then jump up when you begin to open the throttle.
Impossible to say without seeing.
Yep.
Could be for charcoal canister purge signal. Could be for one of the vacuum-operated emission control devices Ford used in the mid '70s.

Your PCV valve has a hose connected to...???

In *TUCSON*?! What are you, halfway up the mountain or something? We usually visit Tucson every January, but can't make it this year. Go have a molé at La Indita at the top of 4th Ave for me, willya?
Not sure I understand the question. The system is always "active" in that it always regulates the intake air temperature. If the temp sensor sees that the intake air is below approx 100 to 130 degrees, it goes to the "heat on" position. If it senses the intake air is at or above 100 to 130 degrees, it goes to the "heat off" position. Some of them are calibrated to stay in "heat on" at idle regardless of intake air temperature.

What are you using for an air cleaner, by the way? I'm guessing a Ford item?