California emissions 1970

[Robert C.]

I recently bought a 1970 base motor convertible. Originally delivered to California from factory. It has an aluminum heat shield under the q-jet carb. I understand that this was required for cars shipped to California. Are there any other emmission add ons for this car? Thanks

[Mark E.]

Re: California emmisions 1970

Yes. RPO NA9 consists of that heat shield, a special Quadrajet, a charcoal canister, and the vapor lines to connect these to the fuel tank.

It probably also consists of special fittings and no vent on the gas tank; others can confirm.

The 5th digit of the NA9 Quadrajet pn is "5", versus "2" for 49-state. It has an extra vacuum port on the front for the evaporative emissions connection, a sealed front fuel bowl vent, and probably different jetting (the jetting difference is a guess).

A new member posted over the past 2 weeks asking for a photo of a 1970 with its heat shield. You might post a photo there or here.

[Robert C.]

Re: California emmisions 1970

Thanks for the reply. The carb number is 7040502 ET. The fifth number as you said is a 5. The NCRS book list this number as equipment on a 300 base Auto & ECS. This is a 4 speed car. The 4 speed should be 7040513 as I read it. It appears it's not the original carb.
I did find the charcoal cannister. It is plugged as are several vacuum ports on the carb.
I'm posting a photo with heat shield shown. I haven't checked the fuel tank yet.heat shield.jpg
I

[Tim G.]

Re: California emmisions 1970

I had to pull my carb today to fix a stuck float, I got a good picture of the part number. This is a base motor four speed 49 state car. I'm still trying to figure out all the letters and numbers. 7040213 is the part number.

[Brady C.]

Re: California emissions 1970

Here is my California Emissions (NA9) 1970 with an automatic so with the 502 carb. You will also need the yellow emissions sticker on driver side firewall.
. IMG_5911.jpg

[Robert C.]

Re: California emissions 1970

Thanks. Thats what I thought. My carb came from an automatic car at some point. At least it's a 1970. It doesn't have an emissions sticker. I'll have to get the yellow one like you said.

[Mark E.]

Re: California emmisions 1970

Thanks for the reply. The carb number is 7040502 ET. The fifth number as you said is a 5. The NCRS book list this number as equipment on a 300 base Auto & ECS. This is a 4 speed car. The 4 speed should be 7040513 as I read it. It appears it's not the original carb.
I did find the charcoal cannister. It is plugged as are several vacuum ports on the carb.
I'm posting a photo with heat shield shown. I haven't checked the fuel tank yet.[ATTACH=CONFIG]121344[/ATTACH]
I

Unlike the carburetor shown, the original doesn't have a vacuum port coming out the right side, and has a sealed front fuel bowl vent.

Originally, TCS (missing on your car) connects to the vacuum port on the right front (plugged on your car), and ECS connects to the left front port (where your vacuum advance is currently connected).

[Robert C.]

Re: California emmisions 1970

Thanks. I'm not that familiar with all of the vacuum lines but it runs and idles very smooth. Guess I will leave it alone.
Any idea how many 1970's were shipped to CA in this configuration?

[Joe L.]

Re: California emmisions 1970

Thanks.

Any idea how many 1970's were shipped to CA in this configuration?

Robert-----


1,758 including all engine options. No way to know how many were base engines.

[Mike E.]

Re: California emissions 1970

Thanks. Thats what I thought. My carb came from an automatic car at some point. At least it's a 1970. It doesn't have an emissions sticker. I'll have to get the yellow one like you said.

What is the date on your carb? Does it fit the build sequence of your car?

[Mark E.]

Re: California emissions 1970

What is the date on your carb? Does it fit the build sequence of your car?

Mike,

Even if the date fits, this one is a non-Corvette Q-Jet assembled from a mixed bag of parts. It has an NA9 vacuum port on the front of the bowl but sports a 49-state airhorn and a vacuum port on the side used for either an AIR system or vacuum operated door in the air cleaner snorkel (which 1970 Corvette Quadrajet engines do not have),

[Justin S.]

Re: California emissions 1970

If you lived in a non smog participating county, couldn't you have ordered a car without NA9?
There are still several counties that don't participate in the program.

[Joe L.]

Re: California emissions 1970

If you lived in a non smog participating county, couldn't you have ordered a car without NA9?
There are still several counties that don't participate in the program.

Justin------


Nope; you could not. All cars delivered to California had the NA-9 "option". GM also specified that it was only available for cars delivered to California.

[Robert C.]

Re: California emmisions 1970

Thanks for the info.

[Robert C.]

Re: California emissions 1970

Good to know. Maybe I will have to find a correct one.