I was expecting this to happen. The engine in question is a 377, with aluminum heads & a Comp roller (XR282HR-10) with 1.6 roller rockers, & a Speed Demon 650 double pumper. Idle speed is about 850. On the loaded (cruise) test, it was excellent (HC 97 - max 450 & CO 1.04 max 3.75). The failure came at idle (HC 473 - max 450 & CO 5.43 - max 5.00). It isn't too far off, but I am wondering if this is strictly due to the mixture setting on the carb or if it will also entail a little timing adjustment (it is currently set at 18 & runs awesome). It does not have any symptoms of a misfire & the engine has less than 3,000 miles on it (9.8:1 compression). I do have a 770 Street Avenger waiting to go on (I'm just being lazy & don't feel like doing it yet) & it might be easier to tune for emissions, due to only having an adjustable primary circuit. Any input will be greatly appreciated. Thanks in advance.

retard the timing and if it gets you past leave it there until you get home then change it back

I had a 82 GMC 350 holley and headers unilite. I would just lean it out till it barley would run. It would stumble and sound like it was going to die. It always passed with flying colors. Then to show how defiante I was as soon as I pulled out of the testing station building I would get out, open the hood take out a screw driver and reajust it till it ran good again. And of course burn rubber out of the inspection station. Did I mention I hate testing stations.

Tuning will probably get you there but I seem to remember when I lived in Tempe that there was a magic can of additive at most of the parts stores that guys used to pass the test. The counter guys/gals will know what you're talking about.

I don't think I want to be running any stuff like that through a brand new engine. When I went to change the settings, I noticed that the secondary squirters were dripping, which would cause the idle failure. The rebuild kit for my Demon is on its way & the tech at Barry Grant told me what to check when I have it apart. I am going to take it to the waiver station when I get the Demon back on it, as they will actually sit there & tune it until they get it to pass - as many tests as it takes for only $15 (after which I can promptly reset it to where it runs the way I want it to). I think it will be fine.

Like already suggested, lean out the idle mixture as much as you can and reduce the timing. Also heat the engine up as much as you feel safe doing before the test. My `72 402 won't pass with it's normal 16º initial and 180º temps. With 6º initial and temp at 210º it flies through the test. Last test was 185 HC, 1.62 CO.

I was expecting this to happen. The engine in question is a 377, with aluminum heads & a Comp roller (XR282HR-10) with 1.6 roller rockers, & a Speed Demon 650 double pumper. Idle speed is about 850. On the loaded (cruise) test, it was excellent (HC 97 - max 450 & CO 1.04 max 3.75). The failure came at idle (HC 473 - max 450 & CO 5.43 - max 5.00). It isn't too far off, but I am wondering if this is strictly due to the mixture setting on the carb or if it will also entail a little timing adjustment (it is currently set at 18 & runs awesome). It does not have any symptoms of a misfire & the engine has less than 3,000 miles on it (9.8:1 compression). I do have a 770 Street Avenger waiting to go on (I'm just being lazy & don't feel like doing it yet) & it might be easier to tune for emissions, due to only having an adjustable primary circuit. Any input will be greatly appreciated. Thanks in advance.

Can't be much help on the emission question, but I did notice your engine is similar to my new 385, ..so I chimed in. Same exact cam, except w/ 1.5's, around 10 to 1, aluminium heads ( "old" AFR 190's) , Holly 770 Street Avenger. Currently less than 400 miles on it. It sounds and runs good. Good luck on passing emissions on the 2nd try.

I was expecting this to happen. The engine in question is a 377, with aluminum heads & a Comp roller (XR282HR-10) with 1.6 roller rockers, & a Speed Demon 650 double pumper. Idle speed is about 850. On the loaded (cruise) test, it was excellent (HC 97 - max 450 & CO 1.04 max 3.75). The failure came at idle (HC 473 - max 450 & CO 5.43 - max 5.00). It isn't too far off, but I am wondering if this is strictly due to the mixture setting on the carb or if it will also entail a little timing adjustment (it is currently set at 18 & runs awesome). It does not have any symptoms of a misfire & the engine has less than 3,000 miles on it (9.8:1 compression). I do have a 770 Street Avenger waiting to go on (I'm just being lazy & don't feel like doing it yet) & it might be easier to tune for emissions, due to only having an adjustable primary circuit. Any input will be greatly appreciated. Thanks in advance.

I thought arizona didn't have any smog laws? I sold a vette to a guy out there and told him it probably wouldn't pass smog and he said it didn't matter as there weren't any smog restrictions in AZ.

Ordinary rubbing alcohol will help things out (dry gas, heet) as will running gas with 10% ethanol or oxygenated gas.

Phoenix and Tucson areas have testing........ the boonies are still free to roam. When I lived in Tempe I had to have the '33 "tested". What a crock, just pay the money then they say that they don't test. You get a piece of paper that says you're exempt....... can you say tax resource!

On the loaded (cruise) test, it was excellent (HC 97 - max 450 & CO 1.04 max 3.75). The failure came at idle (HC 473 - max 450 & CO 5.43 - max 5.00). It isn't too far off, but I am wondering if this is strictly due to the mixture setting on the carb or if it will also entail a little timing adjustment (it is currently set at 18 & runs awesome). It does not have any symptoms of a misfire & the engine has less than 3,000 miles on it (9.8:1 compression).
Yor idle mixture is a little too rich, that's all. Turn the mixture screws in a little and it should pass OK. The cruise test readings show that your carb is jetted properly. If you were having a misfire the HC (hydrocarbons) would be way high. HC is simply unburned gasoline. Leave the timing where it is too.

Yor idle mixture is a little too rich, that's all. Turn the mixture screws in a little and it should pass OK. The cruise test readings show that your carb is jetted properly. If you were having a misfire the HC (hydrocarbons) would be way high. HC is simply unburned gasoline. Leave the timing where it is too.

I agree that it's only idle mixture issue.