Calif smog with rebuild

Don W.

Don W.

Stab it and steer it
Not sure how to title this thread??

Starting to help a fellow owner who needs a rebuild and the question is how far can he modify a Calif truck and still reliably pass smog. Stock? - of course. but what about, for example, a 412 cam and L35 heads with stock exhaust, injs and chip. (Will L35s work with a stock chip?)

TIA
 
wildphil

wildphil

I Love My Ty's
Re: Calif smog with rebuild

I don't know how much more strict California's smog test is than Tennessee. But I can get my truck to pass here with L35 heads and a 412 cam. Sometimes I have to tweek the tune to get it to pass.

If L35 heads and a 412 cam are used. The stock chip will not work well. The engine will have to be tuned for them.
 
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berzerker

berzerker

wookie
Re: Calif smog with rebuild

i ran stock inj.s with votecs and 412 cam , pitbull 2 bar chip and my truck passed with flying colors on the road simulator rollers we have to do here in colo . my truck does run pretty lean with this set up though . to pass the visual i just dummy bolt the egr valve on top off the block off plate and run a couple fake vacuum lines around the back of the engine .
 
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Calif smog with rebuild

A 412 cam and a stock chip do not work together.

I would imagine that you can get a 412 cam and L35 to pass a CA emission with a custom chip. I thought when I was build my Syclone I could get my Syclone to pass MA emission (idle and 2500rpm in Neutral) with something slightly more aggressive than 415 cam and Vortec heads as long they didn't test my EGR operation. Fortunately they did away with ODBI emission tests.
 
It's just a six

It's just a six

Super Member
Re: Calif smog with rebuild

The L35 heads won't be a problem but going w/a cam anything more than roughly 204 degrees duration @ .050 will be a problem to pass a smog test in Cali,they are strict here.

It will need custom tuning like retard the timing quite a bit @ the minimum if running a bigger cam than 204 .
 
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dgoodhue

dgoodhue

BuSTeD 4.3
Re: Calif smog with rebuild

It's just a six said:
The L35 heads won't be a problem but going w/a cam anything more than roughly 204 degrees duration @ .050 will be a problem to pass a smog test in Cali,they are strict here.
Click to expand...

We used to have strict emission testing in MA up until recently (The weren't CA strict on inspection though), so I have been aware of what is need to pass sniffer test. I don't believe that 204 duration is the limit. Lobe seperation plays part in how much duration it will tolerate.

I had read that too much lobe overlap was what cause problems with emissions. Back from when I had a SBC, Lingenfelter had a 50 state legal package for fuel injected 350 that used a 219/219 cam with a 112 lobe speration. I and many other used this a bench mark of cam for passing emisions.

The 412 is 206/210 with 110 lobe seperation. If you want to make it more emission friendly have it custom ordered with a larger lobe seperation. You could also swap the lobe to make it more turbo friendly, I bet a 210/206 and 112 lobe seperation using the 412 lobes would more power on a SyTy.
 
Don W.

Don W.

Stab it and steer it
Re: Calif smog with rebuild

All very interesting guys. Thanks much for the input. It'll be interesting to see how this all pans out.
 
It's just a six

It's just a six

Super Member
Re: Calif smog with rebuild

I am just thinking w/our speed density it is harder get the engine to run as well (idle smooth) as a car w/mass air flow when running bigger camshafts w/more overlap. Just me thinking to myself.

I think KB did experiment w/cams & they had to pass smog here in Cali, & there first step up cam from stock had 204 degrees duration @ .050.

I think you could go as high as around 210 maybe 212 w/a lobe center of 114 or wider but will need a custom tuned chip to pass.
 
Don W.

Don W.

Stab it and steer it
Re: Calif smog with rebuild

Nope, not from me. I wuz just trying to help someone and he hasn't been in touch so I dropped it. I know that in the past, for me, it took a new cat to pass.
 
EcSy#2671

EcSy#2671

Si vis pacem, para bellum
Re: Calif smog with rebuild

I pass smog siffer test with RPM Chip, stock injectors, Stage 2 turbo, Vortec heads and 412 cam. Visual and EGR operation test I would fail, because of the Vortec and I have the EGR removed.

Side note. With this set up and stock chip and injectors with extra 10 degrees of timing she passed the sniffer tests with flying color
 
SY2455

SY2455

70's Veteran
Re: Calif smog with rebuild

EcSy#2671 said:
I pass smog siffer test with RPM Chip, stock injectors, Stage 2 turbo, Vortec heads and 412 cam. Visual and EGR operation test I would fail, because of the Vortec and I have the EGR removed.

Side note. With this set up and stock chip and injectors with extra 10 degrees of timing she passed the sniffer tests with flying color
Click to expand...

How did you get it to run with the stock chip? Add the 10* at the Dis?
 
It's just a six

It's just a six

Super Member
Re: Calif smog with rebuild

Normally retarding the timing helps pass smog,like unplugging the brown wire in the pass floorboard area..
Maybe advancing the cam 10 degrees?
 
EcSy#2671

EcSy#2671

Si vis pacem, para bellum
Re: Calif smog with rebuild

At start up, I just f-with the timing at the cap to get to start with out the brown wire plug in. After i ran low boost and 50 psi fuel press and watched my AFR like a hawk. She ran ok, but she did run.... I even race a blown mustang like that..... (not my fines hour) haha
 
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