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Mid 80's big block smog junk. Keep or remove?

shady

shady

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Generally the masses say RIP THAT CHIT OFF! But is it that big of a difference in power or economy either way?
I'm about to do a full tune up on my recently purchased 85 CCdrw with the carburated 454.
I noticed that there seems to be A LOT of smog related components under the hood. More than I'm used to seeing anyway. And I realized that a lot of it is in the way of the tune up..

So it seems like a good time to ditch that stuff to me. :dunno:

Should I remove only what's in the way, and put it back on? (No emissions checks or inspections here)
Or pull it all off, cap/plug remaining holes, and leave it that way?

Is there a noticeable benefit either way?

Other option is just leave it the hell heone since it seems to run decent now lol. I just have no idea how old the plugs, wires, dizzy cap/rotor, etc All is.

I'd alost go as far as it's all original since it looks that way and only has 79,000 original miles on it.
 
frankin5 said:
Don't let the Feds see you remove it.
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He's in Iowa dude. No friggen way the Feds are going to do a damn thing about it. Hell, they didn't even discover the VW diesel emissions cheat if it wasn't for some little community college back east that figured it out and told the feds. So one dude pulling off some emissions garbage that was crappy from the get go isn't going to be a blip on the radar for them.
 
Never heard of it being illegal. Just that it caused problems in inspection states...

I didn't think of people needing it.. that's a good idea.
Hell, I still have a full tbi system for a 350 laying around. Maybe someone would want that too :thinking:. Might have to do a CL post or something.

It doesn't make a difference as far as economy or anything then? Not that I'm gonna get much with this truck lol. But every .5 mpg would help.

The only part of the system that I'm sure I can't save to sell would be the tubes connecting to the exhaust... I haven't seen one of those screw out yet.
 
Economy goes down but doubt you'll notice it

Spray wd-40 rust release penetrating oil on it everyday for a week and maybe you'll get em out heat helps too just don't burn it down
 
Since the setups got more complicated as the years went on 85 and 86 are about the biggest rats nets of vacuum hoses the General ever released (TBI was a sort of fresh start). That said, do careful research before ripping stuff off. Evaluate each thing separately instead of lumping "emissions crap". There are things you definitely want, like the 2 choke pull-off canisters and the stuff that control them, for cold weather starting. You want the vacuum advance to work on the dizzy and there are lots of gizmos hooked to that. AIR is annoying and can be deleted, but things like EGR require re-tuning of the carb when they are gone. It seems like simplifying is the key to making it clean and running well, but in general the quickest way to make it run right is to have all the stock stuff working well. If you are going EFI, that's a different story.

Performance-wise, none of that is holding you back at all, other than the factory exhaust. Do make sure the exhaust heat riser and the intake THERMAC devices open properly as those can kill tons of power when not working.

Also, if there is any running issue, look at mechanical advance, plugs, carb and the other basics first before becoming suspicious of the evil emissions devices.
 
Not suspicious of them, and no running issues really. I just figured it could benefit from a full tune up, and that stuffs all over under the hood... Sort of making a PITA to get to everything without pulling it off... And I thought,,,,, while it's off...? Why put it back? Lol..

So I threw the question out just to see what others thought.
 
One thing I experienced with a SBC ('83 305) was that by disabling the EGR it cruised lean, which caused it to surge.

The emissions stuff isn't costing HP. Realistically if there is ANY thought that it may be required later (move, sell to someone out of state, etc) then it's best not to pull it. Some of that stuff is stupid expensive to replace, and some of it (AIR pump for one) doesn't seem to work well after sitting. Not to mention trying to remember how to route the rats nest. Be careful of broken fittings and cracked hoses though...they are common on the various plastic switches and vacuum lines.
 
As dyeager535 said, the "emissions crap" is not costing you a single bit of power or MPGs, assuming it's all working properly. Ditching it most likely WILL cause a drop in MPGs. If part of it isn't working properly, removing it isn't likely to gain you any power or MPGs either.

This is another one of those myths, rooted in a small bit of truth when the emissions stuff first started appearing in the 70s, that needed to die a LONG time ago. Much like the ever popular "to test an alternator, you remove the battery cables while the vehicle is running", which worked great on generator equipped vehicles, but is a very good way to fry parts on alternator equipped vehicles.

The reality is that people just didn't understand how all this stuff worked when it first came out, and falsely equated "emissions crap" with much lower power in the motors of the time, when the root cause was that the motors themselves were detuned a LOT in order to comply with emissions regulations. The first few years, yes, emissions equipment were choking off motors, but motor design quickly caught up. But even in the early years, due to low compression ratios, low flow heads, low power cams, etc, merely removing the emissions related stuff wasn't going to magically add gobs of power to the motors. The power outputs remained low for quite a few years partially due to insurance issues of the time, partially due to the 70's and 80's gas crisis, and partially due to demand for monster power, gas guzzling vehicles just wasn't there any more.

By the mid 80's, merely taking the stuff off without retuning the motor was going to cause far more harm than any good, especially with things like EGR, that can cause the lean condition, and higher cylinder temps which in turn leads to detonation issues.The way around this is to adjust to a richer mixture in the carb, and backing off timing...both of which will cause a drop in power AND MPGs. At WOT the EGR is disabled anyways, so it has zero effect on max power.

About the only thing that could be removed without a negative response are the air pumps, as they're only designed to get the catalytic converters up to running temp faster on a cold motor. However, if you frequently make short trips, you may never get the cat up to temp, and it will quickly clog, which will have a negative effect on power across the board. Cutting the cat out and straight piping it will also likely cause the motor to run lean, causing drivability issues. Contrary to popular belief, more exhaust flow isn't necessarily a good thing on power output in general (where the backpressure myth comes into play, where people believe that backpressure is REQUIRED for an engine to run properly, and yes, that is very much a myth perpetuated by people who don't understand how exhaust systems work).

All told, there really is no benefit beyond cleaning up the look under the hood to removing this stuff, on a stock motor, and plenty of negatives. The big reason why it LOOKS like a nightmare under there is because virtually everything was vacuum driven in those days, as opposed to modern vehicles having it all being electrical. Vacuum hoses take up a lot more space than wires....
 
My old '86 C20 454 Burb came with two smog pumps. All the stuff associated with those caused simple jobs to become needlessly tedious. Like changing the thermostat or even checking the oil.

Removing all the smog pump stuff has zero negative effects on economy or driveability. It's only there to give 'improved' readings from the tailpipe sniffer. It doesn't even really have anything to do with heating up the catalytic converters, as my Burb also still had the original catless dual exhaust. '86 was the last year for that btw.
 
USSkoval said:
My old '86 C20 454 Burb came with two smog pumps. All the stuff associated with those caused simple jobs to become needlessly tedious. Like changing the thermostat or even checking the oil.

Removing all the smog pump stuff has zero negative effects on economy or driveability. It's only there to give 'improved' readings from the tailpipe sniffer. It doesn't even really have anything to do with heating up the catalytic converters, as my Burb also still had the original catless dual exhaust. '86 was the last year for that btw.
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Yeah that's the only thing I would remove with no ill effects. Did that on my 75 wagoneer because the pump was seized.
 
imiceman44 said:
Yeah that's the only thing I would remove with no ill effects. Did that on my 75 wagoneer because the pump was seized.
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Agreed. All the other vacuum switches and stuff all help the truck run better in various climates.
 
Strip the engine down to the block and heads... throw in a small off road cam and lifters for good low end torque to work with those smog heads...throw on a cheap aluminum dual plane intake and 650 cfm off road holley or quadrajet...slap in a rebuilt HEI, new plugs and wires..cut out the cats..tune carb and ignition timing and then shut the damn hood...
 
wasted wages said:
Strip the engine down to the block and heads... throw in a small off road cam and lifters for good low end torque to work with those smog heads...throw on a cheap aluminum dual plane intake and 650 cfm off road holley or quadrajet...slap in a rebuilt HEI, new plugs and wires..cut out the cats..tune carb and ignition timing and then shut the damn hood...
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Well he could do that too, but our advise was for cleaning under hood not transforming using lots of $$$
 
wasted wages said:
Strip the engine down to the block and heads... throw in a small off road cam and lifters for good low end torque to work with those smog heads...throw on a cheap aluminum dual plane intake and 650 cfm off road holley or quadrajet...slap in a rebuilt HEI, new plugs and wires..cut out the cats..tune carb and ignition timing and then shut the damn hood...
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Lol, except the carb part your not far off from the eventual plan... But that's later on.
 
USSkoval said:
Removing all the smog pump stuff has zero negative effects on economy or driveability. It's only there to give 'improved' readings from the tailpipe sniffer. It doesn't even really have anything to do with heating up the catalytic converters, as my Burb also still had the original catless dual exhaust. '86 was the last year for that btw.
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Again, people don't understand how these systems work, or their functions. Even on vehicles without cats, air pumps DO serve a purpose, and it's not just about tricking the tail pipe sniffers. Emissions related air pumps first started showing up on cars about a decade before catalytic converters did.

When the engine is running rich for whatever reason, typically for several minutes after startup on a cold engine, there will be unburnt fuel sent down the exhaust. The air injected by these pumps helps to burn off that fuel in the exhaust system rather that sending it raw down the tail pipe. This is a benefit for those of us that like to run topless, as it will help to minimize the raw fuel smell that rolls back into the cab. Installing a converter works even better. My Samurai went from being miserable to drive topless to being like a brand new car, smell wise, simply just from installing a catalytic converter. GF wouldn't get anywhere near that thing before because of the exhaust smell, lol.

Later, when catalytics started appearing on cars, the air pumps had a secondary benefit of bringing the catalyst up to temp faster.
 
urbex said:
Again, people don't understand how these systems work, or their functions. Even on vehicles without cats, air pumps DO serve a purpose, and it's not just about tricking the tail pipe sniffers. Emissions related air pumps first started showing up on cars about a decade before catalytic converters did.

When the engine is running rich for whatever reason, typically for several minutes after startup on a cold engine, there will be unburnt fuel sent down the exhaust. The air injected by these pumps helps to burn off that fuel in the exhaust system rather that sending it raw down the tail pipe. This is a benefit for those of us that like to run topless, as it will help to minimize the raw fuel smell that rolls back into the cab. Installing a converter works even better. My Samurai went from being miserable to drive topless to being like a brand new car, smell wise, simply just from installing a catalytic converter. GF wouldn't get anywhere near that thing before because of the exhaust smell, lol.

Later, when catalytics started appearing on cars, the air pumps had a secondary benefit of bringing the catalyst up to temp faster.
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That's all fine and dandy, but burning off the excess gasses in the exhaust doesn't improve mpg, or how the engine runs. The pumps can be removed without any negative impacts to fuel economy. As for the fumes, a carbed and catless big block is going to make plenty of unwanted fumes, with or without smog pumps.
 
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