Meeting CT Emission Standards

[Don]

The current/revised emission standard for CT Composites ( Kit cars, replicas etc ) :

220 ppm HC and 1.2% CO

For any size, SB or BB, engine, has anyone been able to meet these emission requirements ?

A. With or without catalytic converters
B Using a carb or FI
C. Combination of above

In CT, the year first registered in the state becomes the model year for the Composite

[ByronRACE]

My EFI Blown 435" sniffed at 35ppm HC and .4% CO with an agressive cam. No cats. No EGR. No PCV. No Nothing.

But...it's EFI. You can tune a carb to do this too...but without instrumentation, it's hard. Buy a UEGO wideband system and use it to tune. See http://www.innovatemotorsports.com for a good one.

Byron

[Don]

Byron......many thanks, 3 dealers in CT and the initial contact has been made with Tuner Tools.

Have you actually used the UEGO wideband system ? Any specific tuning advice ?

[ByronRACE]

Originally Posted by Don

Byron......many thanks, 3 dealers in CT and the initial contact has been made with Tuner Tools.

Have you actually used the UEGO wideband system ? Any specific tuning advice ?

Yes, I've had the opportunity to use a variety of wideband systems. I was heavily involved in the bay-area EFI tuning scene for about 10 years, and still do this once in a while for friends.

I'd be happy to offer specific tuning advice, but for what kind of induction?

In general, you're shooting for 14.7:1 ish AFR at idle/cruise (lean), and 12.5:1 AFR when applying/desiring power out of the engine. With a carburetor, achieving this will involve specific adjustments (jetting) and possibly more modifications to the carburetor...but in general, they should be close out of the box.

Since you're just starting, AFR stands for Air/Fuel ratio which is literally Air Mass divided by Fuel Mass. In other words, for every 12.5lbs of air entering your engine, you want 1lb of fuel to go with it at wide-open-throttle (WOT). In an ideal world, you'd like the ratio to taper back to a nice lean 14.7:1 at idle and very light throttle cruise...and be just about linear in relationship to your foot from idle/cruise to WOT. Richer on your way up, leaner on your way down. You can see why it's easier to use a meter that gleans this information from spent exhaust gasses than it is to measure what is entering the engine. Thank god for the cheap UEGO sensor...that's a relatively recent invention that has made life a whole lot easier.

[Cashburn]

BTW we have one of these already. Will have to play with it some for this purpose.

[Don]

Byron:

Recent history of CT Emissions max standards based upon year registered:

2000: HC 484, CO 5.09
2005: HC 800, CO 4.00
2006: HC 220, CO 1.20
2007: HC 220, CO 1.20

In CT the year of first registration in the state becomes the Model year, called a Composite, i.e. kit car, replica. While all is never fair, you can see how the Composite emission standards have changed from 2000 to 2007 even though the identical engines are being used. I am registered as a 2000, but now have to conform to the 2005 standard: HC 800, CO 4.00

Any thoughts regarding my specific engine:

351W .030 over
Edlebrock Performer Intake
Holly 600 carb
9.5 Compression, 1.94 intake
Ford GT heads
MSD 6A Ignition
MSD Distributor
Cam: I do not have the specs, not radical, from the old days, probably a 3/4 race cam.

Used for normal street driving only, aggressive performance not required.

............thanks for the guidance

Don

[ByronRACE]

Originally Posted by Don

Byron:

Any thoughts regarding my specific engine:

351W .030 over
Edlebrock Performer Intake
Holly 600 carb
9.5 Compression, 1.94 intake
Ford GT heads
MSD 6A Ignition
MSD Distributor
Cam: I do not have the specs, not radical, from the old days, probably a 3/4 race cam.

Unfortunately, the most critical part listed in regard to emissions is an unknown. The cam will make or break you...the rest of the parts are fine, provided you tune the mixture in so it's running 14.7:1 AFR during the test conditions, and the engine is hot and not too advanced. I'd recommend 15-20deg BTDC of spark during test conditions (lock the distributor if you must), and 14.7:1 AFR, factory heat-range plugs and a 180+deg thermostat. Run the test on a thorougly warm engine...water temp 180+. If the cam doesn't have much overlap, it will pass as long as the engine is not misfiring. If the cam has considerable overlap, it won't pass...period.

Gut feeling on the cam might give you some idea...
What does it sound like at idle? (heavy lope, no lope, smooth idle)
What is the minimum idle rpm that it will stay running?
How much vacuum can you generate at an 800rpm closed-throttle idle?

If you can't get it to idle below 800rpm and/or it has enough lope that you can see the tach bouncing around, your odds are not so good. If the idle vacuum is much under 12" Hg, I'd worry some as well.

Additionally, there's a variety of bottle-products out there that can be added to the tank for just such a purpose that cause combustion to be far more complete. HC's are hydrocarbons...unburned fuel. If you fail the test by a narrow margin, the addition of this might be enough to push you over the edge.

Good luck with it.

Byron

[Cashburn]

Some more reading for you Don... http://www.ffcobra.com/cgi-bin/ultim...t/010084.html?

[Bob In Ct]

CO emissions (carbon dioxide) are a result of incomplete combustion and/or a rich mixture. By definition a rich mixture is not providing enough oxygen for complete combustion. Sometimes just adding a PCV valve will help.

HC emissions (hydro carbons) are due mainly to the fact that the wedge engines we all are running have the intake and exhaust valve right next to each other. Depending on the cam, these guys are open at the same time for a lesser or greater period. While they are both open part of the input charge simply goes right out the exhaust valve without ever taking part in a power stroke. The greater the overlap the greater the HC emissions. Cats are designed to burn these unburned hydro-carbons.

Bob

[Don]

Bob, any experience in the products sold by Innovate Motorsports or other vendor Tuning Tools

http://www.innovatemotorsports.com/index.html

CT Dealers:

Mongillo Motors
34 Fulton Street
New Haven, CT 06513
(203) 907-4443
www.mongillomotors.com

Marren Fuel Injection
91 Willenbrock Rd. Unit B2
Oxford, CT 06478
(203) 267-3835

Tuner Tools - the Inside Line
Ledyard, CT 06339
(888) 639-9750
www.TunerTools.com


Jay......thanks, maybe CT does not have the lowest emissions standards. A big " if ", the year registered was the year the kit or replica was modeled after, our vehicles would be over 25 years old and automatically exempted as Antiques. I have a Comp Magnum 280H cam in the 1969 AMX , Holly carb and idles approx 725/750 RPM . In the Spring, will have an off line test just for comparison purposes.

[Don]

Byron:

Appears the cam is a Crower, not more than a 280 duration and 526 lift , only data available. Within the range for tuning as mentioned earlier to meet the 1.20 CO and 220 HC ?

[ByronRACE]

Originally Posted by Don

Byron:

Appears the cam is a Crower, not more than a 280 duration and 526 lift , only data available. Within the range for tuning as mentioned earlier to meet the 1.20 CO and 220 HC ?

280 at .050? The industry standard is to measure duration starting at .050" lift. Assuming that's the duration number given, that's a pretty big cam. 526 lift, however seems to suggest it's probably not a .050" number.

So, I'll say it depends.... if it's 280 at .050, I'd say chances are NOT good...that's a pretty racey cam and would have rough idle/cruise characteristics. If it's 280 at .020, that's about a 240 duration cam at .050...and you'll most likely pass assuming the lobe center and overlap is somewhat normal/typical for a cam of that type.

So, I go back to my qualitiative statements about idle lope and rpm to determine how lumpy the cam is.

Here's a table of typical cam types...you can sort-of get a feel for duration and lift numbers as well as seperation by looking at what's been done in the past. Your cam PROBABLY doesn't deviate too far from one of these.

[Don]

Byron

Thanks for your time, information and patience regarding the cam data and tuning to meet the emission specs. My technical knowledge on cam specs and the relationship of the numbers = none.

I asked Don Scott, owner of CR II that built the 351W engine back in 1998 or 1999 for the first owner, I am the 2nd owner, if he could provide additional details. At that time Don was a dealer for CR and assembled the entire Cobra as well as building the engine.

Cam Specs for 351W

CT has had a history of lowering the emission specs for older engines, what night happen after 2007 is an unknown.