308 smog

I have a 1978 308 also and am almost ready to take it down to the smog shop in San Diego. I'd be interested in what you discover. I did talk with someone at DMV here in San Diego. He mentioned a referee at one of the smog stations that is “Ferrari” friendly. I will try to look up his information.

Dan

 

I had an issue smogging my '76 in Las Vegas last spring. When I first brought it in, I did not have the air pumps installed, the oil had no been changed within the past couple of months, jets were tuned for performance, and the plugs were not 100% fresh. It blew about 550 hydrocarbons at idle and 110 at 2500rpm with CO numbers ranging from 1.4% to 5% at various speeds. Here's what I did:

Make sure the air pumps were hooked up and working properly. Remember '77-'76 cars had no cats, the cams were hotter, and I personally have an Ansa exhaust rather than the thermal reactor. I installed stock jets, which for this year car were 135 mains and 220 a/c with 55 idles (I use 55 idles anyway). Make sure the timing is correct and you have adequate dwell and gap from the points so you are getting as much spark to the chamber as possible. New sparks plugs. I use NGK BP6ES, but some say they use BP5ES when they go to smog cause they run a little hotter (I used BP6ES and was fine). CHange the oil. Get the car fully warmed up. SOme say to get it *really* warmed up and drive it hard. I did not find that necessary.

I took the car back to the smog station where Billybob Redneck and his Chebby loving buddies were dying to fail this Ferrari. The car blew 42 hydrocarbons at idle and 97 at 2500rpm test. CO% was below .69% on both tests. In Nevada, the test is done with the car completely stationary with no load. My car passed with flying colors and Billybob and Bo'Bob ate their trucker hats. Remember, this was done with a '76 with no cats, hotter cams, no thermal reactor. Just air pumps and proper tuning.

Good luck. Hope this helps.

 

Check your plugs/wires. When I lived in MD I had an old Cadillac that didn't pass on the roller test and it was ultimately plugs and wires which were the problem. Retest passed.

I would run it pretty hard before taking it to the station myself. Get that exhaust nice and hot and the car nice and warmed up. I also did that with my old Cadillac though I do believe that the plugs and wires were the main failing point.

I don't know if anyone here has tried those "guaranteed to pass smog" gasoline additives. Probably just something like Techron? I am always hesitant adding anything to my fuel without knowing exactly what is going on though...

 

I don't know if anyone here has tried those "guaranteed to pass smog" gasoline additives. Probably just something like Techron? I am always hesitant adding anything to my fuel without knowing exactly what is going on though...[/QUOTE]

Having fresh gas is very important. A couple of years ago I barely passed with an old tank of gas, but after running out the old fuel it passed with flying colors on a fresh tank. The old fuel will give a high HC reading.

 

Fresh gas, oil and plugs are VERY important to the readings, IMO.....

 

I have a 1979 carbureted 308. I live in California and have had to take the test every 2 years for the past 10. Here is what I do to get ready. Make sure it is tuned up properly and the cats are in good working order. Then you need to go through the entire air injection system. Make sure the smog pump is pumping and the diverter valve is working properly. They are two back flow valves that can rust out and clog. Finally check the rail into the manifold. If the pump air is not getting into the system your cats will not work properly. This is the area that is most often overlooked . Finally I run 125 mains and 52 idle jets. The mains do not have much effect on this test but it is real sensitive to the idle jets. I have taken the test with 50s but found it to run much better with the 52s. Good luck with you next test.

 

Drove the 308 from the mechanic's to the muffler shop to have the cats installed today. My mechanic told me the diverter valve was "stuck open". He also said that this a part that GM no longer manufactures and there is scarce availability. Since California requires this as part of the original smog equipment I would like to replace this device. Any ideas where it can be found would be greatly appreciated.

Dan

 

My 308 passed with flying colors (well Red anyway) today. I went with MAGNAFLOW hyper flow cats that a local shop installed. The diverter valve still isn't working. I'll take it off and head down to the local NAPA and see what they can find. Should be back on the road tomorrow. I'll post pictures soon.

Dan

 

Any value in extra smog pump and pair of cats.

 

The smog pump comes out of a Jeep Cherokee; they just change the boxes and ADD the Ferrari 'Tax.'

The cats might be worth something to someone though.

A Restorer or a Precious Metals guy. People here were cutting cats outta cars in the middle of the night for the goodies inside that make them work.

I wouldn't dare 'throw them out.'

 

Thank you

 

There should be a part number on the diverter valve. It is usually cast into the area surrounding where the diverter hose connects, looking straight towards the hose side. I replaced both diverters valves on my 85 Ferrari 308, and they were GM diverter valve 4974965. I am not sure what the ealier 308's used.

 

I just got my 78 through Calif smog. Last year I when I passed smog it passed with flying colors. I put all the stock smog stuff on it including the r2 points and micro switch. It had sat since 1992 and still passed with no more than fresh plugs. (I did the belts before starting it). I had to get it through smog again this Dec. I had done some major work to it including replacing all the valves in the rear head, installing Derek White's round tooth belts, increasing the cam lobe centers a little, Hill tensioning pulleys, plugs, wires, plug extenders, dizzy caps and rotors and last but certainly not least Pertronix electronic pickup ignition and coils. With all that it barely passed. As I had been fighting a high speed miss for months now I finally switched out the Pertronix stuff and reinstalled the stock points (R1 and R2), coils and micro switch. I took it back to the smog station just for grins and it passed with flying colors. Much better than with the Pertronix. I believe the r2 points help a lot as it retards the timing when between idle and about 2.5K which makes adjusting the carbs a lot easier.

I did use CRC smog guaranteed to pass although I don't know if it makes any difference. In Calif you have to have all smog equipment installed including OEM cats. My smog guy took a picture of the cats (I had the bottom heat shield off) and compared it to a picture he had of OEM cats. One of mine has a flaky core but passed.

According to my understanding there are no after market cats that are legal on a 308 in Calif. If you look at the web sites for the after market cat suppliers everyone I've checked will not sell to Calif.

I only run the air pump and cats for the test as they are difficult to replace.

Syncing the carbs is really important as it affects the overall idle mixture as well as transition to the main jets.

Since I don't have anyway of actually measuring the mixture I adjust the carb idle mixture with a large scale 0 to 1200 RPM tach and can see when it's getting lean as the RPM falls off.

If everything is right or very close you shouldn't have any problems passing smog.

BTW I run 60 idle jets and 130 main jets.

Barry

 

You do not need OEM cats, you can have generic cats. Aftermarket cats are legal. You can find the correct information if you dig around on the CARB website. From memory any PC1 cat is legal on a 308. Also don't rely on a smog shop or muffler shop to know the laws for older cars. I had to involve a referee not because I didn't know the laws but because the shop didn't know the law. Complicating this is that several years of 308 are missing from the replacement catalytic converter look up book. But the look up book is a guide, not the law. And pre-OBD cars can use aftermarket generic cats of the right type depending on the exhaust system configuration.

 

Brian
Would you direct me to a web site that has Calif legal aftermarket cats for a 1978 GTS. I was unable to locate any even though I did see a couple of "direct fit" but when I checked with the supplier they would not ship to Calif. What about the temperature probes? I assume they are a safety issue. I ended up finding a couple of used OEM cats that were good enough.

There is an effort, again, to pass a Calif assembly bill to exempt 1983 (its currently 1976) and earlier vehicles from smog testing. Its Calif bill AB220 and comes up (hopefully) for an initial vote the 17th of Feb. There is a face book group Californians for Classic Cars https://www.facebook.com/groups/162183124714856 which is trying to push this through. It would be great.

 

https://ww2.arb.ca.gov/pre-obd-ii-catalytic-converters-verification-list
You have "PC-1 - Pre-OBD II passenger cars with one catalytic converter per exhaust bank"
So you could use a " 36000 PC-1 Car Sound(DBA Magnaflow) (949) 858-5900" Autozone seems to sell them amongst others.

You might have to buy it through a muffler shop, there might be some law that requires professional installation. That might be your shipping issue. I made up a new bung for my probes and the muffler guy welded them in. Same with the air injection.