[DeTomaso] Passing emissions - or anyone got a carb for me?

[Julian Kift]

Here's what I think I know....By retarding the ignition you cause the burn to start with the pistons already on their downstroke, exposing more of the cylinder walls to the flame front and causing a longer, hotter burn. After reatrding ignitin, bring the idle back up with the mixture screw which will lean out the mixture further. This will increase NOX, but reduce HC and CO.

 

If NOX is close to the limit then taking your car for smog on a rainy day can lower NOX by up to 30% simply from mositure in the air.

 

Make sure you use a high octane fuel and you can also cut the gas in your tank with some denatured alcohol which is cleaner burning and reduces emissions.

 

Good luck,

Julian
 


Date: Wed, 14 Oct 2009 22:46:27 -0700
From: davel at emspace.com
To: julian_kift at hotmail.com
CC: asajay at asajay.com; detomaso at realbig.com
Subject: Re: [DeTomaso] Passing emissions - or anyone got a carb for me?

Hey but I'm interested in this Julian.

Seems to me that retarding the ignition should cool the peak temp and take the NOx number down (not my problem).
But the cool temp should also reduce combustion completion and so raise CO and HC.
Have you another viewpoint on this?

I'm going to switch to hotter plugs and cut the gap.
This should light a very lean mixture better - I get that.
dave

Julian Kift wrote: 


When I had to go through this I retarded the ignition as far as it would still run and leaned out the mixture.
 
Hate to say I tossed an OEM cast iron manifold as it was kicking around for ages and I couldn't even seem to give it away as the damn thing weighed so much for shipping.
 
Julian
 
> Date: Wed, 14 Oct 2009 19:42:02 -0700
> From: asajay at asajay.com
> To: davel at emspace.com
> CC: detomaso at realbig.com
> Subject: Re: [DeTomaso] Passing emissions - or anyone got a carb for me?
> 
> Dave,
> 
> Sounds like you are really close, have you:
> 
> - Changed oil to make sure it's fresh for the test
> - Changed the air filter to make sure the best air gets in and enough of it
> - Run the snot out of the car right before testing (do -not- wait in 
> line idling for more than a few minutes)
> 
> These three items (and possibly others I forget) can have a huge impact 
> on passing.
> 
> Asa Jay
> 
> Asa Jay Laughton, MSgt, USAFR, Retired
> 
> & Shelley Marie
> Spokane, WA
> 
> 1971 Mach I Mustang [ASA JAY]
> 1973 Pantera L 5533 [ASASCAT]
> 
> ****************************** 
> http://www.asajay.com
> http://www.teampanteraracing.com
> 
> 
> 
> 
> Dave Londry wrote:
> > I've got my 800cfm carb and HiPro cam within a hair of passing emissions 
> > testing now.
> > (only because they've been pretty relaxed about the idle speed I've been 
> > coming in with)
> > The basic issues are too much overlap and too big primaries, so I lose 
> > out on one of idle HC or CO.
> >
> > I don't feel like pulling the cam out and having to match the rest of 
> > the valve train.
> > This one runs pretty nicely when I haven't brutalized the A/F ratios for 
> > testing.
> >
> > So, has anyone got on original Ford manifold and a Motorcraft kicking 
> > around they'd give me a deal on?
> > Or Dave Nunn was suggesting an Edelbrock Performer (dual plane) manifold 
> > and Edelbrock 600cfm carb?
> >
> > I'd change for testing and put the 800 back on after.
> > tks
> > dave
> >
> > 
> > ------------------------------------------------------------------------
> >
> >
> > No virus found in this incoming message.
> > Checked by AVG - www.avg.com 
> > Version: 8.5.421 / Virus Database: 270.14.16/2435 - Release Date: 10/14/09 06:33:00
> >
> > 
> _______________________________________________
> 
> Detomaso Forum Managed by POCA
> 
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
> 
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso



Hotmail: Free, trusted and rich email service. Get it now.
-- 
Dave Londry
Embedded Spaces Inc. (ESI)
davel at emspace.com

604 589 9183 phone/fax
604 721 2278 cell
Skype:embeddedspaces 		 	   		  
_________________________________________________________________
Hotmail: Powerful Free email with security by Microsoft.
http://clk.atdmt.com/GBL/go/171222986/direct/01/