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Old 01-06-2012, 10:56 PM
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Running Rich Will Not Pass Emissions

Im having an issue passing emissions no matter what I do to timing or try to adjust carb, HC readings are threw the roof! I have a 69 camaro with a rebuilt 350, not sure what pistons are in it but im assuming something stock. I bought a set of heads from a friend who had the heads(76cc) port and polished on the intake runners only, and had them opened to 2.02,1.60 with srew in studs and guide plates. I have a Edelbrock Performer RPM intake with a 1" spacer and running a Edelbrock 1406 600 cfm carb on top.When i bought the heads and cam from him I didnt realize the cam is a XE 4x4 hydro cam with 480/498 lift 270/278 duration with LSA @ 111 any suggestions thanks Ruben

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Old 01-07-2012, 01:27 AM
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Quote:
Originally Posted by 6D9CMRO
Im having an issue passing emissions no matter what I do to timing or try to adjust carb, HC readings are threw the roof! I have a 69 camaro with a rebuilt 350, not sure what pistons are in it but im assuming something stock. I bought a set of heads from a friend who had the heads(76cc) port and polished on the intake runners only, and had them opened to 2.02,1.60 with srew in studs and guide plates. I have a Edelbrock Performer RPM intake with a 1" spacer and running a Edelbrock 1406 600 cfm carb on top.When i bought the heads and cam from him I didnt realize the cam is a XE 4x4 hydro cam with 480/498 lift 270/278 duration with LSA @ 111 any suggestions thanks Ruben
At what engine speed/load are the tests being done? What jurisdiction still tests 1969 vehicles?

If the engine has a lot of blow by there's not much you can do except to freshen it up. You don't have enough CR most likely, and the quench distance is likely way too wide. The combustion chamber your heads have suck big-time. Swapping over to a fresh set of Vortec heads will help in that regard, along w/giving you 40 HP or so more power. But that's for another thread.

If the spacer is an open type, remove it. You want to keep the plenum divided. Hopefully the RPM isn't the air gap, if it is, the engine has to be FULLY warmed up- and I'd recommend you use a 190 degree thermostat regardless. PCV system needs to be functioning properly.

You need to use a lot of initial timing, but w/o causing the total timing to be higher than 36 degrees or so. Use a vacuum advance limited to supplying about 10 degrees and hook it to manifold vacuum. A complete tune up including all things related to the ignition should be performed. A MSD box could help. Advancing the cam might help.

The carb needs to be set up correctly for the amount of vacuum the engine makes. If the step up springs are too strong, they will cause the engine to be pig rich. Set the float level to factory setting and not a bit higher. Keep the fuel pressure from going over 5-6 psi.
All else fails, refresh the engine and/orswap the cam and retune it, or slip the dude a dove or two.
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Old 01-07-2012, 07:29 AM
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High hydrocarbons is unburnt gas. A common cause is too lean, causing a slight misfire, or incomplete combustion.
If you are too rich, the CO (Carbon Monoxde) will go up.
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Old 01-07-2012, 08:39 AM
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You need to get the motor fully warmed up as others have suggested. Try installing a 195 degree thermo, and retard the timing a lot, almost to the point of undrivability.

Bring your timing light so you can adjust it back after the test
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Old 01-07-2012, 08:45 AM
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Retarding timing and higher stat will raise the cylinder temperatures, are you thinking that this will effect the combustion process to improve the test readings?
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Old 01-07-2012, 08:55 AM
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Retarding the timing cuts down on the power output, which helps lower emissions across the board.

Make sure you have new plugs in it too. Also, they sell fuel additive that can help pass the test.
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Old 01-07-2012, 10:59 AM
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First, make sure all your cylinders are working well, as in compression/electcical tests if needed. Then make sure the idle is up to near 1,000 rpm or as close as they will let you get away with. They have become smarter so don't go in with it abnormally high or you'll fail right away. You didn't say what the HC read is but, as I recall, the limit is 450ppm. But DanielC might have hit it on the lean miss. Once again, I "think" the CO is about 4.5. If your CO reading is low, fatten it up with the idle screws. You will need to get as close to the CO limit as you can to get the HC acceptable if it is a lean miss. Timing is a crap shoot as the engine/cam want lots of advance but emissions like it retarded some. You just need to find a medium. I've also squeeked by using some methnol added to the fuel for the test. There are a few places that sell E-85 in town. You could experiment with a coctail for the test, but don't leave it in for a long time as it is detrimental to hoses and carbs in older vehicles. And whatever you do, make sure your test comes in the winter as you won't have a chance in the summer months unless it's early morning. It might be worth your investment to go to a shop with an emissions tester and do the adjusting there as they can see results in real time. There are a few shops in town that know how to help your problem. There are other tricks to try if you're on the edge, if this doesn't help.
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Old 01-07-2012, 01:36 PM
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Quote:
Originally Posted by 6D9CMRO
Im having an issue passing emissions no matter what I do to timing or try to adjust carb, HC readings are threw the roof! I have a 69 camaro with a rebuilt 350, not sure what pistons are in it but im assuming something stock. I bought a set of heads from a friend who had the heads(76cc) port and polished on the intake runners only, and had them opened to 2.02,1.60 with srew in studs and guide plates. I have a Edelbrock Performer RPM intake with a 1" spacer and running a Edelbrock 1406 600 cfm carb on top.When i bought the heads and cam from him I didnt realize the cam is a XE 4x4 hydro cam with 480/498 lift 270/278 duration with LSA @ 111 any suggestions thanks Ruben
How about the complete analysis of exhaust products, knowing HC's alone in not sufficient information to shrink the candidate problem list.

Arizona, a state that keeps yelling about freedom, tests all the way back to 1966; even the Bolshevik of Washington state doesn't do that.

Off the top of my head I say the 76 cc chambers and big stick cam aren't doing this any good. Big chambers and a lot of cam makes for rather lazy combustion at the RPMs that emissions are tested at, so the exhaust valve is opening before combustion is complete. Add to that a lot of overlap where the incoming mixture just exits out the exhaust without even a pretense of being burnt. But keep in mind that without knowing the CO2 and CO numbers by RPM is just guessing so most any other stab in the dark could be just as valid.

A 1969 Camaro might qualify as a collector car, check with your insurance carrier. If they'll take it on as a collector vehicle they can notify the state and you'll get an emissions exemption.

Bogie
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Old 01-07-2012, 03:10 PM
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Quote:
Originally Posted by oldbogie

Arizona, a state that keeps yelling about freedom, tests all the way back to 1966; even the Bolshevik of Washington state doesn't do that.
That's crazy. Calif even changed their cutoff year to '75.
What sucks even more is that CA keeps nudging down the max limit. So what almost didn't pass last year will fail on the next test. I understand there needs to be testing, but to keep changing the rules in unfair.
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Old 01-07-2012, 03:17 PM
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Retarded timing is what we used to do to get them through.
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Old 01-08-2012, 03:10 PM
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Thank you all for your reply's. So this is exactly what I did. I purchased a 350 from a guy in Phoenix and it came stock except for the edelbrock performer cam and the performer RPM intake it passed with flying colors, so i am assuming that, and Im pretty sure, correct me if Im wrong with the 76cc heads and the cam its running rich because I am using the same carb same distributor same intake performer RPM, and I changed the cap and rotor new MSD 8.5 universal wires, new blaster 2 coil and new plugs and air filter and it still failed!HC readings were 2200 i believe and the O where passing! Now I was confused at first as to why it wasnt passing because before this engine I had a GM crate 350 and put a set of (I know they were big heads) DART IRON EAGLE 215cc with 2.05/1.60, 64cc chambers with a COMP CAM 477/480 lift, and a victor jr intake sitting on top and THAT passed with flying colors!

So should I purchase a set 64cc heads? I was looking at the Patriot heads 190cc/62cc exhaust,64cc chambers 2.02/1.60 aluminum heads drilled for both Vortex and regular intakes! I was also wanting a different cam also, looking at the XE 490/490. Ive been scratching my head, and all i would like is to have a 350 400+hp and 400+TQ. I have a 350 tranny with a 10 bolt 3.42 posi out back should I keep the gears or go lower gears? Again thanks for all your reply's
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Old 01-08-2012, 05:22 PM
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How do you know it is running too rich? I am going to suggest again you have a lean misfire. If the mixture is too lean, it does no matter if you have an actual lightning bolt from the sky, striking a lightening rod at exactly the right time, and have the wire straight to a spark plug. A too lean mixture will not burn. The unburnt gasoline goes out the exhaust pipe, and gives you a high HC reading.

You might want to do a leakdown test on the engine. A slightly burnt exhaust valve will also leak unburnt HC out the exhaust, or possibly an exhaust valve adjusted too tight.
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Old 01-08-2012, 05:33 PM
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I think you need to make you car pass the AZ emissions test the cheapest & easiest way possible. Replacing the heads is not cheap nor easy, & it's not a good option just to get it to pass. You will quickly find out that there's no easy fix. The smaller chamber heads might fix the HC issue, but it may push the NOX count up, and then you start chasing your tail.

Can you scan the complete test result and post it?

The best option is to find a hotrod friendly shop that will make the car pass the way it is now. Another option is to have the emission "system" worked on by a state certified shop, say having them rebuild your carb & fix the exhaust. Once you get up to $500 in repairs, you can get a waiver from the state.
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Old 01-09-2012, 04:52 PM
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Quote:
Originally Posted by DanielC
How do you know it is running too rich? I am going to suggest again you have a lean misfire. If the mixture is too lean, it does no matter if you have an actual lightning bolt from the sky, striking a lightening rod at exactly the right time, and have the wire straight to a spark plug. A too lean mixture will not burn. The unburnt gasoline goes out the exhaust pipe, and gives you a high HC reading.

You might want to do a leakdown test on the engine. A slightly burnt exhaust valve will also leak unburnt HC out the exhaust, or possibly an exhaust valve adjusted too tight.
When its running the exhaust fumes burns my eyes so I assumed its running rich.So what you suggest I do? will simply turning of the idle mixure srew out would help? or do i need to change the jets? again thanks for the reply's and suggestions!
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Old 01-09-2012, 05:08 PM
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Quote:
Originally Posted by 6D9CMRO
When its running the exhaust fumes burns my eyes so I assumed its running rich.So what you suggest I do? will simply turning of the idle mixure srew out would help? or do i need to change the jets? again thanks for the reply's and suggestions!
You would want to turn the screws in to lean the mixture not out.
What were the HC and CO readings from the test
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