Hey Guys,

I am planning to remove the emission add-on parts of my 1980 corvette as part of a larger project starting now through the winter. So expect more threads soon. I know this is no longer needed, its getting rusty and looks ugly, plus it takes up more room in an already small engine bay.

Can you offer any suggestions on removing this system? It has been disconnected from the pulley system for a number of years and was as such when I bought it, so I am not sure what else was done to remove it from "the equation" of main operation.

What tools will I need?
Parts to plug any holes that are created from removing parts?
Any "be careful you could also damage...." advice
Etc.

Thank you.

 

You'll need a digital camera to take lots of pics, make sure that you take several pics from every angle, before removing anything, . . . . . just in case it has to be put back together. Make sure that you document just where everything goes, hoses, wires, brackets, etc.
Bag and tag everything.

 

What part are you speaking of?

 

It sounds like the AIR pump judging from his description. Removing it entails plugging the vacuum hoses and plugging the holes in the exhaust manifold. I can't remember the thread off the top of my head, but a pipe cap can be used to block the exhaust system where the check valves were.

 

Yes, I believe its the air pump. It sits on the left side of the engine looking from the front of the car. It has a pulley spindle on the front.

 

Generally, when referring to left or right placement you should use the perspective of the driver of the vehicle.

Using that as a guide point, you'll have a power steering pump on the lower left, alternator upper left, AIR pump just right of center (to the right of the air cleaner to radiator ducting) and AC compressor at the upper right. This assumes the car is as originally configured.

 

The only thing I used for my '81 was a bag...trash that is.

 

Back in 1980 to my new 80 I removed the air pump, replaced the catalytic converter with a test pipe, and recurved the distributor. All of that cost less than $25 at the time and really brought the engine to life.

 

Step #1 reach in and grab eissions ****.
Step #2. Pull real hard and toss as far as possible.

 

The air pump removal is pretty straight forward, you will not need any special tools.
You may run into an issue with the bracket on the back that is bolted to a stud on the exhaust man on the pass side. You will need some brass plugs for the ports on the exhaust manifolds. Are you going to delete the EGR also? You need a blockoff plate for that.
With the pump deleted you can lose one of the Temp Vac Switches, maybe 2 from the intake and thermostat housing.
Post up a few pics I can probably point to more.

 

What would I need to plug them? Rubber plugs, pipe end caps, etc.
Are they threaded or just holes?

 

What is the EGR?

Can I pick up brass plugs and a blockoff plate at the hardware stores or is that a rock auto\willcox type of buy?

 

According to Rock Auto, the check valve thread is 1/2" - 14 Dry-Seal NPSF.

You could alternately plug the hoses going into each check valve with a rubber plug (if you can find one) or use short sections of rubber hose with a plug in it.

 

That sounds interesting.

Anyone in the area of Indianapolis wants to spend a few hours and take this apart together? I don't drink beer, but I can provide some.

 

I removed the AIR tubes from my manifolds and plugged the holes with 1/4" NPT plugs.

 

I'm FAR from an eco-freak but the emission controls are not "useless"!

The EVAP (fuel vapor recovery system) has zero impact on performance, requires only rare maintenance (typically hoses) and actually recovers the fuel that used to evaporate into the atmosphere to be used to run the engine. There is truly no reason not to keep the EVAP system working properly!

EGR (exhaust gas recirculation) is an effective system that greatly decreases unburned or partially burned fuel in the exhaust. Debate rages regarding how much (if any) negative effect it has on performance but for a street car it is negligible. EGR valves do fail and the system requires cleaning every decade or so but new valves are readily available.

A.I.R. (Air Injection Reaction) is nothing but a pump that forces atmospheric air into the exhaust manifold where the temperature is still hot enough that the added oxygen helps burn away any remaining fuel in the exhaust. Yes, the air pump takes some power to operate but not enough to matter for a street car yet it really does reduce fuel emissions from the exhaust.

The catalytic converter in 1980 was quite restrictive and definitely reduced power at WOT. In theory it nearly eliminates some forms of pollutants even if much/most of the worst pollutants were already removed by the above systems. Without a functioning A.I.R. system on these non-electronic cars the catalytic converter will rapidly destroy itself. Less restrictive cats are available that have little or no performance hit with a stock motor.

Even if you remove the catalytic converter, reset timing/distributor curve for higher performance, use a more aggressive cam shaft, etc. there is very little to gain by not keeping the EGR and A.I.R. systems working while still making a significant reduction in pollutants.

 

SwampeastMike, one point of clarity.

EGR valves do not exist to re-burn unburned fuel. They exist to recirculate inert gas into the cylinders to lower combustion chambers and in doing so, decrease oxide of nitrogen emissions. This also allows engines to run a bit leaner which decreases fuel consumption and unburnt fuel. Of course, if you go too lean you can also have an issue with unburnt fuel as the too-lean mixture won't combust.

Your description of AIR and EVAP are excellent, and while I think the benefits of EGR and AIR are a bit more debatable, I think EVAP is an EXCELLENT system and should remain on any car.

At WOT, EGR is not operable on these cars as it's vacuum-actuated and there shouldn't be any vacuum hitting the EGR at maximum load.

 

Thanks for the clarification. I was working from memory (bad obviously) regarding which emission components the EGR system mainly reduced. I did how verify before writing this that the effects of EGR on performance were highly debatable and irrelevant to a street driven car.

 

There is a counterpoint that I just thought of regarding performance: pretty much every EGR intake is a low-rise dual plane. So to support EGR, you are not allowed to use some much better, more modern intake designs. Additionally, EGR requires (at least in the carbed small-block Chevy designs) hot exhaust gas running through the intake manifold, which will add heat to the intake charge, carb, etc.

But, as said before, assuming you're running a stock intake with the exhaust crossover active, there's no performance change.

 

That's what they said on the early shark cars. I helped throw a few units away. Now those smog units that were thrown in the trash bring $1500+.

Never toss original stuff. You don't have to photo document it if you don't want to, but put it in a box. You will sell the car someday.