Vortec V6 head swap

[4C FED]

Syclone w/ FAST.

Vortec's lack an EGR passage compared to stock LB4 heads.

To make the EGR at least visually/audibly functional, I was thinking of drilling a hole into the exhaust manifold & running a stainless hard line to a newly tapped hole before the EGR valve. This will at least cause the idle to drop when the SMOG tech depresses the dashpot.

Do you think they'll fail it for a visual?

I don't want to drill any extra holes if it's not going to get me anything.

I always have the stock heads I could put on, but that's a real PITA.

 

[gofstbuick]

Vortec's lack an EGR passage compared to stock LB4 heads.

To make the EGR at least visually/audibly functional, I was thinking of drilling a hole into the exhaust manifold & running a stainless hard line to a newly tapped hole before the EGR valve. This will at least cause the idle to drop when the SMOG tech depresses the dashpot.

IMHO, I would not affect additional air (via modified EGR system) into the induction system. May cause more harm than you think, with other gasses (specifcally HC and CO)


Do you think they'll fail it for a visual?

Yes, to a technician that is aware of the vacuum hose routing

I don't want to drill any extra holes if it's not going to get me anything.

I always have the stock heads I could put on, but that's a real PITA.

IMHO, I don't want to sacrifice passing smog check on a basically street car / truck. It should pass all the time and if I want to go to the track, I'll make the changes for the track. But my car is driven exclusively on the street. Eventually, a contractor will produce a reliable remote sensing device, to monitor vehicle emissions on daily drivers. What will your smog check configuration look like then and will you want to randomly change your cylinder heads to accommodate a vehicle that is mostly driven on the street?

__________________

 

[Mac in SD]

Originally posted by gofstbuick

IMHO, I don't want to sacrifice passing smog check on a basically street car / truck. It should pass all the time and if I want to go to the track, I'll make the changes for the track. But my car is driven exclusively on the street. Eventually, a contractor will produce a reliable remote sensing device, to monitor vehicle emissions on daily drivers. What will your smog check configuration look like then and will you want to randomly change your cylinder heads to accommodate a vehicle that is mostly driven on the street?

__________________ [/B]

Gofstbuick, I'd like to say that I truly do appreciate your advice to all of us here. But I'm a bit confused. You often emphasize the importance of the smog check program, and how we really shouldn't do modifications that circumvent or jeopardize the smog check. Clean air, yadda, yadda.

Yet your signature shows several modifications to both your cars that appear, to me at least, to be unauthorized. I mean, do you change cams when you're up for smog? What about the alky injection? Granted, the alky doesn't affect emissions tests, but are you telling me it passes the visual? Or are you gaming the system just like the rest of us? Absolutely NO offense intended.

 

[gofstbuick]

No offense taken. Even though the chevy is out of the program, it really shouldn't be set up that way . But when building the 3.8, I kept the cam lobe center close to matching the factory configuration. I suspect that a larger lobe separation would possibly create NOx problems due to increased cylinder pressures. The cold air kit is a gray area (decision still being determined). Alky (water injection ) is a category 1 emission equipment (items not of concern). The AFPR definitely not legal. EGR system is still intact and working (I just changed the intake gasket from felpro 1200 to factory). I never realized the 1200 gasket did not have provisions for EGR passage and if I had noticed during the build, I would have cut open the port to allow EGr function. The downpipe is also a gray area. The catalyst is CARB approved. One reason I chose the ATR DP over the Terry Houston was that the cat available with the DP was a three-way-cat (controls NOx emissions). The intercooler with the Duttweiler neck is also a category 1 emission equipment. The chip and injectors are not legal (though I did request that Jim Testa burn the chip so that it would not sacrifice emissions for the sake of performance). I match ported the intake to the heads and the factory intake gasket, plus a balance and blueprint. Visually, it looks and runs mostly legal and I consistently pass. Is it right, not really. So there's the story. Hows that for an answer. Look here and
type in this license plate, 3hxb904
but the earliest test is when I bought the car.

 

[Mac in SD]

Soooo... you are a sinner? Welcome, Grasshopper.

I think what bugs a lot of us is that we know that we can make them pass the sniffer, but the bureaucratic "visual" drives us nuts. I don't want to get into my personal specifics (you never know who's lurking ) but what's the purpose? Limiting emissions, or harrassing hobbyists? For example - if through a combination of aluminum heads, calibration, and cat the NOx is within limits, why should the presence of an EGR system matter? Also, the BAR number thing for specific manufacturer's parts (but not functionally identical parts from another manufacturer) is nothing more than extortion by the State. Not that you can do anything aobut it - I'm just venting at a symbol of authority.

The only viable things I can think of for a visual is the evaporative emissions system and PCV.

BTW, you mentioned Category 1 equipment. Where can we poor slobs get a list or explanantion of what that is? Thanks again for your help to the board.

 

[gofstbuick]

ARB approval is a process. The more information the parts manufacturer provides to ARB, the less chance of scrutiny. The visual, functional and tailpipe, and Test-Only stations (satisfies the feds and) keeps the feds from possibly implimenting a fully centralized program. Ask Turbo Jim how he feels about NJ centralized program and think about the population of vehicles in CA trying to test at local centralized emissions stations. As for category 1 emissions equipment, I can email or fax you tomorrow. Send me an email or call 916-255-4217 (7:15-4:15PST).

 

[terryk]

I never thought of it that way. It could be alot worse.

 

[ijames]

Joe, a question about your comment about atr vs th downpipes. Do you mean that the cat that comes with the thdp is only a two-way, and does not reduce NOx? I innocently assumed that it was a three-way like the original stock cat.

 

[gofstbuick]

When I called to inquire about the THDP, I asked the salesperson about the cat (supplied with the THDP) and was told it was a two-way-cat and that if I opted, i could purchase the TWC for an additional fee. ATR said the cat supplied with their DP was a TWC and I matched the part number to their catalog and it matches to their 3 inch race TWC.

 

[ijames]

Hmm, guess it was a good thing I passed the nox part even without a cat. I wondered why the nox didn't go down when I put on the cat. Thanks for the info.

 

[4C FED]

Well, I 've found a way to circumvent any problems with my combo.

Just need to get the rotating assembly balanced and I can start assembling it.