Passed CT Emissions: third try. Details within.

94-302-vert said:

Well quite a few of you offered opinions on how to pass emissions. Here is what we did and how it worked:

first time (re installed my high flow cats, hole in air pump supply to cats, no egr): HC 27 of 60, CO .02% (not sure limit), Nox 1370 of 700 : FAIL

2nd time (re-connected EGR (actually plumbed it to manifold vacuum to be sure it stayed open), ran CRC guaranteed to pass, and put some isopropyl alc in the tank): HC: 189, CO 6.4%, Nox 132: FAIL

3rd time (disconnected spout): HC 29, CO: .01%, Nox: 135 : PASS

So all in all it cost me $40 for the 3 tests (one was a free re-test) and then about $25 in misc fittings for the EGR and the G2P. So I am happy.

Off-Road H goes back on tonight...

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How often do you guys have to get inspected up there

Its yearly for us down here

Grady

2 years for MD.

"2nd time (re-connected EGR (actually plumbed it to manifold vacuum to be sure it stayed open), ran CRC guaranteed to pass, and put some isopropyl alc in the tank): HC: 189, CO 6.4%, Nox 132: FAIL"

WOW! First time I heard GTP didn't work!

anybody know of any reports/information that shows emission information for engines with large cams?

it'd be interesting to see what the tweecer could do to pass an engine on a smog setting...

especially if it had a big cam

Therian said:

anybody know of any reports/information that shows emission information for engines with large cams?

it'd be interesting to see what the tweecer could do to pass an engine on a smog setting...

especially if it had a big cam

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Seems to me the spec that might be the most critical to consider for emissions would be lobe center
but
I wanna make it clear that is only a guess on my part

If that is so

Would that mean a more narrow lsa is gonna produce more duration
and therefore
more of a dirty idle condition

Just trying to futher define the word ... "big"

Anyone have any comments

Grady

tighter LSA is indeed the key I think.

I never read enough to fully understand the relationship between the lobe angle and duration, but it would make sense for a high RPM cam to have lower lobe angle, higher duration and a dirtier idle...


how to clean up the idle though...just for passing smog once a year...that is the question

grady what do you know of rhoades(sp?) lifters? The theory sounds good, but where are the actual numbers?

How far would retarding the timing go to helping a tight lsa, high duration cam pass emissions?

hmmm

JT?

We have really strict smog here (people keep bumping or referring to my thread from 5.0 Tech whenever an issue arises. I fail because of my aftermarket dual 3 way cats. ).............

How did it idle with the EGR running non-stop? EGR at idle can cause a lean misfire - HC's can go up.

Rhodes lifters were big back when Grady was a youngin' . They worked decently in old muscle (of those I've known who ran 'em - I never did). Kinda noisy though.

Therian said:

grady what do you know of rhoades(sp?) lifters? The theory sounds good, but where are the actual numbers?

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Like Jt said ...................

I have not thought about those since I was still drippin behind the ears.

IIRC, they were supposed to be an anti pump up lifter or somthing like that.

I never ran them or knew anybody who did ... anyway

Shifting gears and back to the original thread topic of emissions.

I don't claim to know a lot about cams other than general info so that is why I asked about the narrow lsa.

I will say my cam has a very narrow lsa.

When I first put the combo together ....................
It was just terrible with the basic tune on the GT pcm before I switched to the Cobra pcm.

I suspect the lsa had a lot to do with how it ran and the challenge it gave me to find the ever elusive stable idle after the pcm switch.

I know for certain, I never would have passed with the GT pcm.

I was lucky I had a while to get my tune together before emissions inspection time rolled around.

It has passed with clean results each year for the past several years.

Again ... don't forget ... I got all emissions stuff in place and functioning.

Grady