C3 Smog equipment

[Shawn Woodend]

My 73 has all the correct smog equipment on it. I'm not going to enter any NCRS show, it's going to be a nice driver when I'm done. My question is should I keep all the smog equipment on it or take it off and save it in case i do decide to show it. What do you think? Thanks

[Harmon C.]

Re: C3 Smog equipment

Shawn I like to see the smog installed and it was not to be removed. In some states it needed to be their if checked. Lyle

[Chuck R.]

Re: Keep it

If and when the time ever comes when you decide (if ever) to either show or sell the car, the next potential owner might just be a by the numbers kind of person and want the correct emmisions equipment that came with the car. It's definately a re-sale enhancement to retain these parts.

I agree with Lyle, find out about the emissions standards in your state.

Chuck 32205

[Joe L.]

Re: C3 Smog equipment

Shawn----

1) First of all, it's a violation of FEDERAL law to remove it, regardless of whether or not it's a violation of state law in your area. Most states, though, do make it a violation of state law to remove it EVEN IF THE CAR IS NOT SUBJECT TO PERIODIC INSPECTIONS. In California, for example, pre-74 cars don't have to be inspected BUT IT'S STILL ILLEGAL to remove ANY smog equipment from such cars. If such a car is identified as a potential "gross polluter" by roadside sensing equipment, the vehicle will be inspected and appropriate action taken for a "tampered" emissions control system. The chances of getting caught under federal law are very slim (currently). However, if does happen, the penalties are very large (like 5 figure fines);

2) Very often, removal of the equipment produces a performance IMPAIRMENT, and NOT an improvement. Although more a problem for newer vehicles with completely "integrated" emissions control systems, it can be a problem with earlier systems, as well. Carburetor and distributor calibrations are based upon the emissions control system being present. If you remove it, you have to modify the distributor and carb if you are going to realize any performance benefit;

[Shawn Woodend]

Re: C3 Smog equipment

Thanks for the response. I live in Ontario canada, so I'm not sure what the legalities are, but I guess if it's there it should stay. I do know that many of these parts have been "lost" on alot of older Vettes

[Joe L.]

Re: C3 Smog equipment

Shawn----

Yes, many emission control systems have disappeared from the engine bays of old Corvettes, as well as other old cars. In fact, once-upon-a-time, I removed the AIR system from a 66 Chevelle SS 396 that I purchased new in 1966. I was young and naive and thought that taking the system off would improve performance. It just created more problems and NO improvement in performance. But, I learned my lesson and, with one minor exception, NEVER removed an emission control system again.

My "ZL-1" 1969 conversion will have a full emissions control system. In fact, I spent a LOT of money to assemble a complete NOS AIR system for the car and absolutely NOT for "originality" purposes as this installation will NOT be an original installation anyway.

[Duke W.]

Re: C3 Smog equipment

You can take several approaches. One is to leave everything alone. A second is to recalibrate the distributor to '65 specs - 300 HP if your engine is base and SHP if your engine is a L-82. Such recalibration will provide more low/midrange torque and maybe a little top end power depending on how much total WOT advance you run, better fuel consumption, and reduce any tendency to run hot.

As a rule, recalibration means more initial advance, a quicker centrifugal curve and less total vacuum advance, but a more aggresive curve. Suitable HEI springs and vacuum cans are available to provide the equivalent calibration of '65 single point and TI distributors.

The AIR pump takes about 3-5 HP at 5000 revs, so it's not costing you much power. If you do take it off, clean and preserve everything so it can be reinstalled in the future.

Once you recalibrate the distributor, emissions will be compromised, and whether you can accept this depends on whether you have to be emission tested or personal reasons.

Duke

[Tom R.]

Re: C3 Smog equipment

Shawn:

I have to agree with all that has been said and can only add that in the 21st century...it's the thing to do! That is keeping the emissions technology in place and tho limited in terms of its ability to control emissions...at its time it was state of the art. If you weight the pros and cons...there is not that much to gain but much more to lose. Sounds like you've got a nice original car 73...keep it that way. You'll have one and Lyle will have all the rest!