EGR To Non-EGR Conversion - Good Idea?

[Strykr73]

Admittedly, the voodoo magic that is EGR is not something I understand. My car has it from factory, and supposedly it helps with fuel economy, but it seems like a hassle to maintain and needless added complexity to choke out the performance.

I've been considering moving to a 4-Barrel carb, which means also replacing the intake manifold. The factory setup on the 318, with the Carter BBD 2-barrel and the stock intake, works fine for a low-speed cruise around the block, but... you know...

So I've been looking at the offerings from Edelbrock for 4-Barrels and intake manifolds. They have options with and without EGR, and with and without electronic choke. I've pretty much settled on an electronic choke, but I'm not sure if I should also kick the EGR to the curb. To me it seems like a great plan, but since I know so little about it, I want to solicit some opinions first. Is removing the EGR by changing out the intake manifold a good idea?

I don't want to mess around with Holley carbs. I know significantly less about how they work, and would rather stick to what I know. For reference, these are the two options I'm weighing right now:
Option 1: Intake Edelbrock 3776: Performer 318/360 Intake Manifold SB-Chrysler 318-360ci 1972-86 - JEGS High Performance | Carb Edelbrock 1400: Performer Series 600 CFM EGR Carburetor with Electric Choke - JEGS High Performance
Option 2: Intake Edelbrock 7576: RPM Air-Gap Intake Manifold SB-Chrysler 318/340/360 - JEGS High Performance | Carb Edelbrock 1406: 600CFM Carburetor with Electric Choke - JEGS High Performance

I like the idea of having the raised intake runners for thermal's sake. With the tendency of modern fuels to evaporate, I'm much more inclined to keep the heat away from the carb, and especially the bowls, as much as possible.

Any other tips and tricks on the 2 to 4 barrel conversion process is welcome, since I've never done this before.

 

[R413]

Stock 1973 318? You don’t want the air gap intake On that car.

use the performer. I’d dump the egr.

 

[Photon440]

EGR doesn't help with economy, it's there to reduce emissions. By putting burned exhaust gases back into the mix, the combustion doesn't burn as well, meaning that it is cooler and produces less NOx.

 

[RJRENTON]

Admittedly, the voodoo magic that is EGR is not something I understand. My car has it from factory, and supposedly it helps with fuel economy, but it seems like a hassle to maintain and needless added complexity to choke out the performance.

I've been considering moving to a 4-Barrel carb, which means also replacing the intake manifold. The factory setup on the 318, with the Carter BBD 2-barrel and the stock intake, works fine for a low-speed cruise around the block, but... you know...

So I've been looking at the offerings from Edelbrock for 4-Barrels and intake manifolds. They have options with and without EGR, and with and without electronic choke. I've pretty much settled on an electronic choke, but I'm not sure if I should also kick the EGR to the curb. To me it seems like a great plan, but since I know so little about it, I want to solicit some opinions first. Is removing the EGR by changing out the intake manifold a good idea?

I don't want to mess around with Holley carbs. I know significantly less about how they work, and would rather stick to what I know. For reference, these are the two options I'm weighing right now:
Option 1: Intake Edelbrock 3776: Performer 318/360 Intake Manifold SB-Chrysler 318-360ci 1972-86 - JEGS High Performance | Carb Edelbrock 1400: Performer Series 600 CFM EGR Carburetor with Electric Choke - JEGS High Performance
Option 2: Intake Edelbrock 7576: RPM Air-Gap Intake Manifold SB-Chrysler 318/340/360 - JEGS High Performance | Carb Edelbrock 1406: 600CFM Carburetor with Electric Choke - JEGS High Performance

I like the idea of having the raised intake runners for thermal's sake. With the tendency of modern fuels to evaporate, I'm much more inclined to keep the heat away from the carb, and especially the bowls, as much as possible.

Any other tips and tricks on the 2 to 4 barrel conversion process is welcome, since I've never done this before.

EGR (Exhaust Gas Recirculation) was introduced as a emission control device. EGR is introduced below the the carb in the intake manifold in an effort to reduce combustion chamber temperature by adding exhaust gas, which is basically inert. NOx emissions are produced above ~1500° F, due to combusting gasoline and air...with the nitrogen component in the air (~ 80% , balance is oxygen). NOx emissions are said to cause photochemical SMOG. EGR DOESN'T INCREASE FUEL MILEAGE but actually degrades it by not allowing the engine to full power. The combustion process slows down. EGR is typically metered by a valve, controlled by a ported vacuum source on the carb, on the manifolds cross over passage and cored passsges to the plenum under the carb. EGR usually requires more ignition advance characteristics to allow for a slower burn and hotter spark plugs to prevent fouling. If you're building an engine, you ABSOLUTELY do not want EGR unless your ride must pass emission inspections., where you live......just my opinion of course ......
BOB RENTON

 

[71Beeper]

The Air Gap is still a dual plane intake, you should have no issues running it on a 318.
There may be a slight port mismatch, but that can be taken care of by gasket matching.
The one issue you may have is hood clearance.

Also, the 2 carbs you mentioned - don't bother with them.
The new Edelbrock AVS2 is the carb you want.

 

[R413]

The Air Gap is still a dual plane intake, you should have no issues running it on a 318.
There may be a slight port mismatch, but that can be taken care of by gasket matching.
The one issue you may have is hood clearance.

Also, the 2 carbs you mentioned - don't bother with them.
The new Edelbrock AVS2 is the carb you want.

here is why the air gap is bad for a stock 318.

1)there is no heat crossover in the plenum. This is needed for proper fuel atomization. Critical on a low compression stock engine. No so much on a racing engine. The poster lives in PA, it’s cold there many months.

Have you ever has a small block mopar with a pluged up heat crossover? They run terrible this way. Remove intake and clean it out car runs good again.

2) generally air gap is for hi performance and has larger plenum volume and intake ports, also bad on a stock engine.

3) gasket matching? This means hog out the heads on a stock 318 Because the intake ports on the manifold are oversized. This mismatch tells you the intake is wrong for this engine. Now this is no longer an afternoon intake swap.

 

[71Beeper]

R413 - The op mentions this in his posting...."I like the idea of having the raised intake runners for thermal's sake. With the tendency of modern fuels to evaporate, I'm much more inclined to keep the heat away from the carb, and especially the bowls, as much as possible."

Perfect reason for an air gap intake.

Also, I would assume that PA has its hot summer months too. And that's when you don't need any type of crossover, especially with today's ethanol combined fuel.
I'll gladly put up with a little rough idle when the engine is cold and waiting to put a bit of heat into it.

You ask if I've ever had a small block with a plugged up cross over. The answer is yes, I have.
I plug off the cross over put inserting wads of tinfoil into the cross over. My previous LD340 intake that was on my 360 was done that way.
Here is my current set-up.

I would assume that the op wants to improve the performance of his 318, not just make due with the way it is now.
Don't forget that the air gap is a dual plane intake, and yes the plenum will be larger than a stock 318 cast iron intake.
As far as port mismatch goes - the engine will still run even if the ports are not matched.

Hopefully the op will do some other mods that will help that 318 engine.