TTop Tony

What makes a motor emmission legal or not. What I mean to say is I've been thinking about a crate mtor for my 75. They don't do physical inspections and the emmissions standards ain't too bad. 500hc 5.0 co. But I know theres that whole EGR thing but mine wasn't working (unknown to me at the time) when I went through and it passed fine. I was thinking of the ZZ4 crate but is it the compression of the engine or the cam that really makes a car fail emmissions. I know the 350 HO motor is only 9:1 wheil the ZZ4 is 10:1. I like the fact that the ZZ4 has a steel crank and better pistons while the HO has iron and cast pistons (which is what I have now). Several people tell me any car can be made legal with some detuning but I'd hate to spend big bucks and fail. Sorry for the long post but I would appreciate everyones thoughts on this. :confused:

79MakoL82

"Technically" to be legal, your car must have ALL the emmissions crap it had on it when it came from the factory. So, if your car had A.I.R. and EGR, and EFE, Cats, 2-1-2 exhaust, etc., to be "legal", it would have to still have those on it. HOWEVER, if your state only does a sniffer test and not a visual inspection, you can pretty much do whatever you want provided you keep your numbers below the acceptable limits. "De-tuning" can be as little as retarding the timing temporarily to get it through the sniffer, so it's not necessarily a big deal.


[Modified by 79MakoL82, 12:08 PM 11/16/2001]

TTop Tony

Thats cool. I guess I'm being paraniod. Since they don't do the physical inspections, my car doesn't have an AIR pump (previous owner emoved) and the egr didn't work and it still passed. I was just curios as to what makes the car spit out all those bad emmissions.

trs77

I'll just throw in two things about emissions.

1) EGR only works off-idle and can actually be beneficial for an engine by reducing combustion chamber temperatures with the result being reduced NOx gases. If all you have to pass is an idle test, then don't worry about the lack of EGR.

2) If you are running with a catalytic converter now (your car would have come with one), and are thinking about removing it, then you may have a problem with the test, regardless of engine, since the cat is used to reduce CO and HC emissions substantially.

I'm no expert, thats for sure, but I think the cat is your best insurance to passing idle emissions. I actually swapped my 2-1-2 cat exhaust on for the test and then switched back to true duals after I passed. :D

tom


[Modified by trs77, 2:20 PM 11/16/2001]

TTop Tony

Oh no I wasn't planning on taking my cat off. They do check that and the test is at idle. It's just that whenever you ask if this or that will pass emmissions its always "theres no egr" or "it depends on local laws". Which I understand is what they have to say. But I've never understood what part of the engine makes the emmissions. I know people who said they know people who have 383 engines or big blocks or whatever which are "off road" and have passed the test. But they never explain how. I guess It's just over a newbie like me's head. :D

79MakoL82

Going back to technicalities, things are called "off road" if they are not technically legal for your application. i.e., a dual exhaust in post 1974 cars is considered "off road" because it is technically illegal to replace the 2-1-2 exhaust with a true dual system because it was never offered for those cars. So they have to advertise them as "Not legal for street use". You can however get a true dual exhaust system and put dual cats on and pass the sniffer test. There are muffler shops that will not install a true dual exhaust on a 2-1-2 car because it is technically against the law for them to do so. However, this does not mean that "off road" equipment cannot pass the test. I am not condemming or condoning the removal or use of ANY emmissions equipment, and some of it is beneficial, but this is what is meant by "off road" and "street legal".

P.S. What causes excessive emissions is generally a poorly tuned car or damaged parts like rings and gaskets. As long as these thing are in good order, generally you can pass these tests with a properly tuned car.


[Modified by 79MakoL82, 2:42 PM 11/16/2001]

TTop Tony

I didn't know that. Thats interesting how they get around certain things. I tried the dual cats thing and I couldn't get any of the exhaust shops to do it. So I used a 3 inch version instead.

I wonder if anyone on the forum has tried either of these crate motors and got them to pass emmissions. Maybe a question for after Christmas when I'm closer to actually doing it :D

79MakoL82

I am positive that the ZZ4 can be made to pass the test. I have a 10.5:1 CR 383 making 420HP in my Z28, and it passed the test in CT. That's a more radical engine than the ZZ4. Again, when properly tuned and in good repair, they can pass the tests.

TTop Tony

That Z28 in your sig passes!!! That must be a blast to drive. Thanks for answering my crazy ramblings 79mako.
Nothing ventured nothing gained right?

79MakoL82

Yes, it is. :D

And it's not done yet!!!!

TTop Tony

Just rub it in why don't ya :D

BSeery

I have a ZZ4 and have passed the visual inspection and idle test. I just failed the loaded test, and that is carburetor related, it has nothing to do with the motor. I am 100% my ZZ4 will pass after I get the carb. tuned to that motor. For more information on the ZZ4 swap project, see my ZZ4 swap information pages at http://temp.corvetteforum.net/c3/bseery/zz41.htm

TTop Tony

Dude you da man!! I know what I want for Christmas. Now comes the hard part: Paying for it.

e3pres

Tony,
My old roommate lived in Nashville when he had his '78 SA. He passed emissions by 4ppm... Oh yeah, did I mention they only sniffed one of the mufflers on his dual exhaust setup? :) I think they check both simultaneously now.

Good luck,

BTW... I'm moving back to school in Cookeville (Tennessee Tech) in January. We should get together and cruise this spring.

TTop Tony

I don't remember them checking both out. Hey Tech's my old school. Its pretty nice there now that they have beer. They were a dry county when I went (Beleive me that sucked). I'm at Center Hill lake alot during the summer. If you ever do the shows in the area (Bowling Green included) let me know it would be nice to put the face to the name.

joshc

I can absolutely guarantee that the ZZ4 will pass emissions standards in AZ.
I failed the first time, retarded the timing, leaned out the carb, and bam, passed with flying colors.

Dave68

If your state's emission-tests require a visual inspection and you have everything you need in that regard, I know your car will pass the sniffer test. My (up until last Summer) 68 had a ZZ3 with no emissions attachments except the AIR tubes to the Doug Thorley headers and it put out a very clean 70 ppm HC. This is cleaner than many 1995 vehicles!

Generally, if a car fails, it fails the HC (Hydrocarbon) test, which measures unburned fuel. The biggest contributor to excessice HCs is a big cam.

By the way, I recommend the ZZ4 highly. It's a super-potent engine that'll make you think that you're driving a 427 big block - great torque!

TTop Tony

There's no physical inspection in TN except the cat conv. Yeah the ZZ4 sounds sweet.

81vette

My 290HP 98' Regal GS Supercharged family car passed with a 2ppm at idle, and a 1ppm at 2700rpm. I still can't believe it. My 81' Corvette was :U a 210ppm without the cats installed.


Bserry, I wonder if your vacuum secondaries might be opening too soon for the load test causing the high HC...provided you are running the QJ with vacuum secondaries?