Smog Check Success - Sort of
01-19-2002, 12:56 AM
#1
Pro
Thread Starter
Smog Check Success - Sort of
The 383 rebuild is now complete - the car has passed the California Smog (*****) test!
The new 383 has a really mild cam in it (like a comp cams high energy) and still has all the stock intake and exhaust system. Should have been an easy pass - right? Wrong. Failed the first time, then I leaned out the mixture with smaller jets - better results but still a fail on Hydrocarbons. The last detail was the catylitic convertor... The smog check place is next door to the muffler placed so with another fail (at least this time I was not a gross polluter!) in hand I went next door and made arrangements for a modern convertor to be installed. Thirty minutes later the car was back on the **** dyno and the results were very impressive... a true "quick pass" (which for you lucky folks not subjected to this oppression - is when the sniffer determines a pass in about 15 seconds).
I saw results posted from Arizona so I will do the same for comparasion (for simplicity, I will only type the 15 mph results):
%CO2 %O2 HC(ppm) CO% NO(ppm)
Limits 194 1.26 1286
383 (no mods) 11.8 2.3 252 fail 2.49 fail 352 pass
reduce jet size 11.3 4.6 212 fail 0.12 pass 488 pass
install convertor 11.9 4.1 99 pass 0.02 pass 609 pass
One point to note is carbon monoxide - with the lean jets it almost disapears by percentage - the car runs but its just too lean. Does not feel strong - hesitates slightly pulling away from idle - Im going back to the stock size 77 jets in the morning. But the big lessons learned is about the convertor - when the muffler guy took off the old one and shook it - he said he didn't hear any pellets left in the canister meaning I was just haulling around dead weight! I wonder how many years ago the pellets ran out on that 25-year old convertor?
Next step - Install LARS advance kit and feel the power!
The new 383 has a really mild cam in it (like a comp cams high energy) and still has all the stock intake and exhaust system. Should have been an easy pass - right? Wrong. Failed the first time, then I leaned out the mixture with smaller jets - better results but still a fail on Hydrocarbons. The last detail was the catylitic convertor... The smog check place is next door to the muffler placed so with another fail (at least this time I was not a gross polluter!) in hand I went next door and made arrangements for a modern convertor to be installed. Thirty minutes later the car was back on the **** dyno and the results were very impressive... a true "quick pass" (which for you lucky folks not subjected to this oppression - is when the sniffer determines a pass in about 15 seconds).
I saw results posted from Arizona so I will do the same for comparasion (for simplicity, I will only type the 15 mph results):
%CO2 %O2 HC(ppm) CO% NO(ppm)
Limits 194 1.26 1286
383 (no mods) 11.8 2.3 252 fail 2.49 fail 352 pass
reduce jet size 11.3 4.6 212 fail 0.12 pass 488 pass
install convertor 11.9 4.1 99 pass 0.02 pass 609 pass
One point to note is carbon monoxide - with the lean jets it almost disapears by percentage - the car runs but its just too lean. Does not feel strong - hesitates slightly pulling away from idle - Im going back to the stock size 77 jets in the morning. But the big lessons learned is about the convertor - when the muffler guy took off the old one and shook it - he said he didn't hear any pellets left in the canister meaning I was just haulling around dead weight! I wonder how many years ago the pellets ran out on that 25-year old convertor?
Next step - Install LARS advance kit and feel the power!
01-19-2002, 01:09 AM
#2
Race Director
Re: Smog Check Success - Sort of (Carl in LA)
Same with my '78, when I had the high flow cat put in, the old one was just a big ugly piece of filth. Not to mention, heavy! Ah well, good job on beating Californiazikstan, I have a year from this April before my '78 goes in again. Hopefully, my dad will still have his smog license then...
-Steve
-Steve
01-19-2002, 01:34 AM
#3
Instructor
Member Since: Jul 2000
Location: CA
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Re: Smog Check Success - Sort of (Carl in LA)
congratulations... :yesnod:
i've just recently finished fighting with the smognazis myself,
and know how frustrated you must've felt
i've just recently finished fighting with the smognazis myself,
and know how frustrated you must've felt
01-19-2002, 03:18 AM
#4
Le Mans Master
Re: Smog Check Success - Sort of (Carl in LA)
Thats very close to my results just last july - me too i got a new convertor installed - you can see the big difference between the new convertor in my recent smog test and the old 4 year old convertor from the first test - the cars burns a bit of oil due to a bad valve guide so i go through convertors apparently
see the test results here http://earchitect.50megs.com/corvette/ofpower.html#smog
see the test results here http://earchitect.50megs.com/corvette/ofpower.html#smog
