Has anyone passed a tailpipe/sniffer test in their state with a Vortec head engine swap?

If so, could you post your results please?

 

Vortec heads have nothing to do with passing a sniffer test.
What are you really asking?

 

Well, actually they do. The Vortec heads have no provisions to route exhaust gas thru the intake.
So the question is does anyone have test results from a Vortec headed engine with no EGR set up on it?

 

OK, now I understand where you're coming from.
That would be a factor for cold startup emissions.
Sniffer tests should be done on a warm engine. You didn't say factory/EPA cold startup testing.
It's a non-issue.

 

Yeah I'm just asking if anyone's passed a sniffer test with no EGR setup.
I don't know exactly when EGR is active. From what I read its not at idle or WOT. So cruise/part throttle is when its active?
The test I have to pass is at idle, and again at 2500 rpm.
'89 IROC in this case.

 

My 1983 G20 van with a TPI Vortec 350 blew practically ZEROS on the emissions tests and that was with exhaust cooling Tri-Y long tube headers before the cats.

 

So no EGR rigged up?

Would you happen to have the results you could post?

 

No EGR hooked up and it was disabled in the tune. No air injection either.

 

Awesome, THANK YOU!

Anyone else?

 

Pretty much. EGR effectively lowers the size of your engine by letting in "air" without much, if any, oxygen. So the intake charge that is coming in combined with the EGR gas has total less oxygen for the volume, so you can inject less fuel. It's not for emissions as much for economy

 

EGR also lowers NOx by reducing peak combustion temperatures at cruise.
Although even without EGR, Fast355's results above show only 2-3% of allowable NOx !

 

The EGR is more an emissions device but happens to help fuel economy in some applications. My Express van got better mileage with the EGR disabled. From the factory the Vortec 350 uses very little EGR at crusing speeds. The valve has a much higher opening % under acceleration at part-throttle than steady cruise.