Swapped out my LO3 for a 383. Specs are in the sig. Im really wanting to get a tag put on this thing, so I have to pass emissions. The shop I work at can only test 96+ OBDII cars, but it can "inspect" older cars with the sniffer, just now pass or fail em. I just wanna know where to start to get her to pass.

No cat right now, but I know thats gonna be a must. What about timing? Is it better to have it retarted or advanced to reduce emissions? Carb is a holley 600DP, almost leaned out completely. Would putting a lower thermostat in, like say 165* or so, help keep the combustion temps down? I dont have EGR on this thing. Ill more than likely just tweek it a little right now and take it up to my shop and she how she runs, but I just gotta know where to start. Any help is greatly appreciated!!

 

retarded timing is better for emissions... (huh, wait, is that right?) It's like that stock, and i'm fairly sure it's due to emissions...


no, a higher temp t-stat is better for emissions, helps the engine get warm enough for complete combustion...

maybe try a can of "guaranteed to pass emissions" witches brew...

 

Try all of the stuff listed above but tape a 50 dollar bill where the sticker needs to be and you should be fine.

 

you could add a cat and swap the top end for a junkyard TPI on smog day so it looks stock... the guy wont be able to tell a 383 from a 350 from the outside.

depends on how extensive they get though

i know out here in cali, they visually check everything, AND check the timing, make sure the EGR is functioning, gas and radiator cap pressure test, inspect all vacuum lines to make sure they're hooked up, etc...

they tried to fail me because i had a vac line to my heater valve capped off

i simply asked him for some hose and did it right there... but still

i couldn't believe how stringent they were.

 

If the "inspection" is just the sniffer test and not a visual, then most likely they only test for hydrocarbons & CO. You'd best ask to be sure, because if they check for NOx, then you'll want timing retarded, and an EGR valve would be helfful. If not, you'll want it advanced to keep the hydrocarbons clean.

A cat makes a huge difference in either case.

 

well apparently we test for HC, CO and NOx round here. SO retard the timing (like what, 5* base? right now its at 13* base, 34* total, mechanical only, no vaccum), keep the thermo thats in it now (195 I believe), lean the hell out of the carb and put on a cat. Thats sounds like a good recipe to me!

 

Here in cali.

My car passed as a 305, no EFE valve, disconnected Thermac, 8* timing, etc., 160* Thermo, fans at 210

I used crap Arco gas. And they do enhanced smog (Loaded/Resistance on wheels)

Just make sure it all works together.