I have a 355 with stock GM crate engine heads, long tube headers, edelbrock 5002 cam (supposedly, though it doesnt sound big at all), no emmissions stuff (air pump), i'm buying a 3" converter from summit (cheap universal one) cause not only will I have to pass emmissions, but both tickets i've gotten (one for exhaust, one for something else), the cop has either mentioned the lack of cat, or been checking out the car (i'm sure hoping to find anything else to bust my ***** for, LOL), and I've got an edelbrock 600cfm carb on there now. How should I tune the car so I can pass the sniffer test? How should I tune the carb, what should I do with the timing, what type of gasoline should I use, etc.? This is in MA btw
-Chris

 

Tune it a lean as possible without missfire. If I were going to keep the car I would buy a used exhaust gas analyzer. One trick I have used is to put alcohol in the tank for the test 10 to 1. The car ran crappy but it passed. Also be sure you have a strong spark, a MSD 6AL box might help. Getting this car to pass is going to be difficult, can you register it somewhere you don't have emmsion tests? Good luck.

 

I actually have a 6AL sitting in the garage, how difficult is it to install?

 

It's fairly easy, just use soldered connections and shrink tube. I thought of something else that might help. The new cat you are going to put on has a tube that shold go to the air pump, it needs more O2 in the cat to burn off excess HCs and CO. You might put a small 12v compressor or a tank of compressed air to supply the cat. You will have to play with it to find out how much to add. If you pump in too much it will fail for false air(too much O2 in the exhaust).

 

connect a vacuum guage or a tach and set the idle mixture to where the vacuum or the rpm’s just start dropping off (get to the highest point on either and go just barely past it, the point where the idle sounds the best/is the strongest will show up as rich on an exhaust gas analyzer, correct will almost feel like you have a very slight misfire). If you go too far you’ll start having problems passing NOx and if you go way too far that misfire will start increasing your HC counts.

stoich for alcohol is much lower then for gas (you need more alcohol per mass of air for a correct mixture) and no matter what the mixture the byproducts are usually less noxious (easy to get almost pure combustion byproducts, H2O + CO2), so adding just a little will tend to clean things up so. The old trick is 2 bottles of “drygas” (usually methanol) to a tank of gas.

tune almost anything reasonable correctly and add a correctly working cat and you can get it through emissions

 

Your screwed MA has emissions testing like CA. Not having the emissions stuff and long-tube headers are gonna get you.

 

Yea, well, if you have to pass a visual then you're stuck making it look like everything that is supposed to be there is there and that nothing that isn't is there...

 

Just go to a wrecking yard and buy the distributor,carb air pump, egr and all the little vacuum and smog tube crap off any third-gen and hook it all up. (Provided you still have a computer.) They won't know the motor isn't a 305, provided it looks like one with all the junk on it and a stock air-cleaner with a thermac heat tube hooked to your header.
Good luck.

What were you thinking?
These cars won't be smog exempt for another ten years!!

 

I'm not worried at all about the visual inspection, I know a few places that are cool about that sorta stuff as long as it passes the sniffer. What should I do about the carb tuning and the timing? Thanks,
-Chris

 

Start by running out most of the fuel. Buy a crap load of fuel injector cleaner or stabil. Stick a water hose up the tail pipes and flush the thing. Pour in the fuel additive run it up to the shop and pass the sniffer

 

I bought a catco 3" universal cat. at summit yesterday, any more advice?