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Smog - What can I tear off?

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climbingmadman2000

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Hi,

I have a 73 K5 that's now smog exempt. What can I safely remove? For example, can the EGR valve come off? Pros/cons? What about the AIR system?

Also, any recommendations for a replacement carb for the stock QJet? I'm considering an Edelbrock Performer...

Thanks,

Eric /forums/images/graemlins/k5.gif
 
I would say rip off everything but the PCV valve. Engines must have some sort of Positive Crankcase Ventilation. The ultimate crankcase ventilation is to run a hose from each valve cover into the headers. The pull of the exhaust going out the headers will pull the crankcase vapors with it, but this type of setup is used mostly for drag racing.
 
egr can come off, smog pump, canister too i believe /forums/images/graemlins/dunno.gif.
but if your goin to be wheeling and its goin to see some hills i would leave the quadrajet on there. performers will kill the engine easier, when climbing or goin down hills,you'll have to be on the gas more often.unless you got the $ to afford a avenger series carb or some other one dedicated to offroad.
 
You could go as far as replacing the intake manifold with a Performer type but I agree about keeping the Qjet, it works good at steep angles. Anything else smog related can go. I plugged the exhaust manifolds vs replacing them w/headers because I didn't want to lose any torque and I also didn't want any of the typical header related problems like A/C brackets etc. Works for me.
 
The rig's actually got headers on it - with smog ports, believe it or not. They leak and they're loud and I'm considering putting manifolds back on. And it's already got a Performer manifold on it. The reason I'm thinking of replacing the QJet is that the truck gets BAD mileage (like 8mpg...please!), surges and misses at low speed, and lacks power at high speed. I'm going to check all the obvious stuff - it just had a tuneup and I wonder if something is loose or not adjusted right. But a rebuilt QJet is a bad idea, from what I hear, so I thought a new carb might be a good idea. Edelbrock does make an off-road carb with spring-loaded seats...anyone heard about it?

Thanks,

Eric
 
[ QUOTE ]
The reason I'm thinking of replacing the QJet is that the truck gets BAD mileage (like 8mpg...please!)

[/ QUOTE ]

Removing EGR isn't going to help you get better mileage.

I can see disabling EGR if it doesn't work and you don't feel like fixing it, but EGR is figured into the way the Q-jet works at cruise, and if you remove it, you can cause some issues. (carbs jetted to run lean at cruise because EGR takes up volume in the cylinder, but without actual EGR, you then end up with an overly lean cruise mixture, which is not good. All this of course assumes it's the original carb.

Nothing wrong with a rebuilt Q-jet if it's not physically damaged. You can get into it and clean it up for about $20 (cost of a gasket set) but float, bushing the throttle shaft, etc., can add cost, but probably should be done to get it "right" and make sure they aren't a problem.
 
Thanks guys...so what do you think of the driveability problems I note below...do I have a carburetion problem, or something simpler, dya think?

Edelbrock sells NEW QJets for about $800 list (yike!).

"The reason I'm thinking of replacing the QJet is that the truck gets BAD mileage (like 8mpg...please!), surges and misses at low speed, and lacks power at high speed. I'm going to check all the obvious stuff - it just had a tuneup and I wonder if something is loose or not adjusted right."
 
Might be a good idea to keep all the stuff you take(not chop)off--in case the "emission police"make you put it back on someday.I removed the A/C pump and the air pump off the 305 going in my 79 C10,debating whether to leave the EGR,if it interferes with my carb its history,and the cat converter is another maybe--I dont have to emission test it (anything under 1984 exempt here,so far)but I wouldnt doubt if they try to get more old vehicles off the road by making us restore all the smog crap,hoping we chucked it all,and cant find it in the boneyards.I can see it now--All emission stuff for a chevy for 300 bucks on E-bay someday--dont laugh,it might just come to be someday not so far off---. /forums/images/graemlins/rolleyes.gif /forums/images/graemlins/screwy.gif
 
Pull one plug wire at a time while the truck is idling, see if any cylinders are dead. Will at *least* give you a clue where to focus if you've got a dead or misfiring cylinder.

How did it run before tuneup? What did the tuneup include? If it didn't include pulling the cap, I would, and double check that the rotor/cap are still in good shape, especially where the terminals are. If they are corroded (but not heavily worn) clean them up and re-install.

It could pretty much be anything, or a combination of anything though. Just going to have to narrow down the options.
 
I plan to keep all the smog stuff and original equip that I remove...for later, "legal" purposes and in case a future buyer is interested in "all original" parts...

The tuneup included new plugs, points, condenser, cap, rotor, and wires. The truck ran OK (not great) before the tuneup...but I didn't have it long before I had it tuned up, so can't really say. I plan to check all the fundamentals before doing anything to the carb, to rule out anything obvious.

There's a guy in Santa Clara who will rebuild my QJet for $245 including parts, guarantees his work for a year, flow tests and adjusts the carb before he returns it. That's a lot cheaper than a new carb and sounds fair to me...any comments? Can anyone recommend a carb rebuilder?

Also, where can I get exhaust manifolds for this beast, to replace the headers that are on it now?
 
had a member in cal get pulled over and they checked under the hood...$350.00 right off the bat...then he had to find a reinstall all the org smog stuff /forums/images/graemlins/deal.gif
 
Well, if *you* can rebuild the carb, $245 is expensive.

Obviously you can't flow test the carb, nor adjust it before install more than factory specs on float, but even if you bush the primary throttle shaft, buy a rebuild kit and a float, you will still come in around $100. None of it but bushing the throttle shaft is very technical.

I say try your hand at rebuilding it, ESPECIALLY if the primary throttle shaft has very little vertical play in it, which means you can get away without bushing it.
 
[ QUOTE ]
had a member in cal get pulled over and they checked under the hood...$350.00 right off the bat...then he had to find a reinstall all the org smog stuff

[/ QUOTE ]

This is just one of the many reasons I moved away from the Soviet Republic of California. I now live in Nevada (i.e. The United States of America), and could not be happier.
 
[ QUOTE ]
had a member in cal get pulled over and they checked under the hood

[/ QUOTE ]

that was me /forums/images/graemlins/frown.gif it turn out to be around 150 on parts. i wrote a letter to the EPA/CARB (think it's in the first gen section still, somewhere if you want to read it)


[ QUOTE ]
This is just one of the many reasons I moved away from the Soviet Republic of California. I now live in Nevada (i.e. The United States of America), and could not be happier.

[/ QUOTE ]
under FEDERAL LAW it is illegal to remove any smog equipment and it must be in working order. there was 400+ counties around the (SR)USA that were raided...

ARQ.
 
Thanks guys. So, here's what I'm getting from all this:

1. Stay with the QJet and rebuild it, or have it rebuilt.
2. "Technically" I should leave all the smog stuff alone, especially EGR since it affects the way the QJet works at cruise.

I doubt the AIR system costs me much horsepower anyway.

Really all I want is a reliable, fun toy...it doesn't have to breathe fire or go 100mph.

Incidentally, some muffler shops around here say that it'll be about a day's labor to replace headers with manifolds and run my existing exhaust up to the manifolds. Think I'll just live with the headers for now /forums/images/graemlins/tongue.gif.

When I get ambitious I'll get a crate motor or rebuild this one with all the bells and whistles /forums/images/graemlins/hack.gif.

Thanks again. I think you all have saved me enough money and hassle that I can justify paying for membership on this board /forums/images/graemlins/smile.gif

Eric
 
almost forgot to mention, the epa/carb guys seem to work during regular work hours 7-5pm down here in socal /forums/images/graemlins/thumb.gif that is what i got from the calls and appointments i tried to make for em to see my completed project.

ARQ.
 
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