Thread: Emissions legal 350?

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Okay, I'm about to rebuild a 350 to go into my '79 Camaro, and I live in Oregon where they require emissions testing every 2 years. I need some advice.

The engine is out of a '76 Vette that I recently donated to a charity auction. I know it's the original '76 engine, because the charity was VERY reluctant to let me keep the motor, as it made the Vette a numbers matching car (long story). I was told the engine was rebuilt about 30K miles ago, so machine work should be minimal (yeah, I know). It has a non-emissions intake, and I haven't torn it down to see what cam/rocker/piston package the previous owner put in. I got the Vette from an estate sale, so there was no one I could ask about the rebuild.

My question is, who makes emissions legal headers with EGR fittings, that would fit in without having to bang on them with a hammer to make them fit well. Also, what kind of top end kit/package could I look for to still be able to pass emissions? I've looked at the Holley and Edelbrock packages, but they say "for off road use only", which I take to mean they won't pass emissions. I plan to remove the cats, and plug up the EGR ports on the intake manifold/headers, and remove the A.I.R. pump in the time between emissions inspections, but I need to be able to take it back to emissions-legal status relatively easy.

I also have no idea what kind of carb is on the engine. It's looks like an Edelbrock or Carter, but there are no numbers or data plate on it. The local speeed shop couldn't tell me what it is. They just said, "We can sell you a rebuild kit for it, if you want." How do I know if I want to rebuild it, if I don't know what it is?!?

I'm not looking for a "Torque Monster" or "Killer HP" engine. I only want about 350-400HP and appropriate torque. I know this a very general question, but I ned a starting point. The results of the searches I've done through the forum archives all seem like they're not concerned with passing emissions, so not very helpful to me.

The Camaro is going to be a daily driver, but one that I romp on once in a while just for fun. I have no desire to take it to the track to run quarter miles, I'm 42 and that thing just doesn't excite me anymore (besides, if I did want to do the track thing, I'd sneak out my wife's '01 Vette for a few runs). I only drive 4 miles to work, so gas mileage is not a concern for daily driving, and on the weekend when I run around, it'll be for fun, so having a little extra horsepower to play with is a plus.

Mark

it only has to pass emmisions for the '79 Model year, which is the same emissions test as '76, cat converters are mandatory, put them on every 2 years. if the intake is original and it is non emmisions, that will pass. another option, is get a newer 305 that will pass emmisions, put identical headders on it and then when testing comes around, it only takes approx 45 minuites to change out a small block if you have done it b4.

So Matt, with my 305 from the 85 pickup, do I have to buy some kind of EGR headers then? I didn't know there was such a thing.... Sorry to take over the thread but thought I'd ask while on the subject here.

Unfortunately, I have never done an engine rebuild and swap. I'm doing this one first, and doing it slowly. Also, I have no place to do the swap. I have a little room in the garage to do the build, but I'll have to find someplace to take the engine and car to do the install. I was hoping for a way to build the 350 to pass emissions, but still put out a decent amount of HP.

Originally posted by FMXhellraiser
So Matt, with my 305 from the 85 pickup, do I have to buy some kind of EGR headers then? I didn't know there was such a thing.... Sorry to take over the thread but thought I'd ask while on the subject here.

there really isn't. GM had a sloppy type of EGR thinggy on approx '79 to '81 small bore motors, some 350's. basicly it is special manifolds that run a hose into the air cleaner, that recirculates the gasses that way along with a standard egr valve. he may be thinking of this type setup. all you need is a egr equiped intake manifold to pass emssions, along with cat converters, I don't think your truck would be sniffed so you could probably drill them out.

That isn't EGR. EGR takes small amounts of exhaust gasses and reinserts them into the intake manifold to help keep combustion temperatures down. What you are thinking of is an intake air heater. No exhaust is actually directed into the air cleaner or your air cleaner would be black with soot within 5 minutes. There is a butterfly valve in the air cleaner that closes when the air cleaner is cold. That means air has to be drawn in through that hose and it is drawn in from around the exhaust manifold where it is very hot. This heats the air inside of the air cleaner to an approximate temperature of 125 degrees F. This allows for leaner fuel/air mixtures and was thought to increase milage slightly as well as reduce NOx emissions because higher intake air temps mean lower combustion temps.

Originally posted by 76GMC1500
That isn't EGR. EGR takes small amounts of exhaust gasses and reinserts them into the intake manifold to help keep combustion temperatures down. What you are thinking of is an intake air heater. No exhaust is actually directed into the air cleaner or your air cleaner would be black with soot within 5 minutes. There is a butterfly valve in the air cleaner that closes when the air cleaner is cold. That means air has to be drawn in through that hose and it is drawn in from around the exhaust manifold where it is very hot. This heats the air inside of the air cleaner to an approximate temperature of 125 degrees F. This allows for leaner fuel/air mixtures and was thought to increase milage slightly as well as reduce NOx emissions because higher intake air temps mean lower combustion temps.

I knew EGR is exzaust gas recirculation, I thought that hose was recirculating gasses, guess not. it could still very well be what the guy is thinking of tho.

Didn't the tubes to the headers just pump fresh air from the air pump into the headers to clean up the exhaust??? I'm not a chebbie guy, but I thought that is what the tubes were for. I've seen the headers with the fittings for the tubes from various manufacturers, I believe Edelbrock has a set of them in their catalog.

That's what us Chevy guys like to call AIR injection, the precurser to the catalytic converer. An AIR injection system is simple enough in concept. There is a belt driven compressor that compresses air and injects it into the exhaust port just above the valve. Temperatures are very high at that point, 600-1500 degrees F depending on operating conditions. Ideally, they are hot enough that whatever combustible gasses are still present in the exhaust system will reignite when exposed to fresh air. These gasses include unburnt hydrocarbons, they combust to form carbon dioxide and water. Carbon Monoxide is combusted to form Carbon Dioxide. NOx's can be combusted to form Nitrous Oxide. All of which are realatively inert in every way except that they are considered greenhouse gasses (bullpoop). CO and NOx require very high temperatures to react with just oxygen and the temperatures were not always high enough in the exhaust port as they depended on operating conditions. A catalyst is used to reduce the temperature required for the oxidation reaction to occur to around 500 degrees and the catalytic converter was born.