Well, the way the factory did it is described in my previous post to this thread. Other makers have done it differently.
Theoretically, yes, but generally extracting a real benefit from this requires modern precisely (computer) controlled EGR and ignition timing in conjunction with high compression and a knock sensor. The EGR we're working with on the slant-6 is pretty stone-age, and only very gross/rough control of it is possible. Running more advance is just a method of trying to get back some of what the EGR takes away. A directly comparable situation is that of operating a naturally-aspirated engine at elevations above sea level. The air is less dense (less oxygen per unit volume), so power output and tendency to ping are both reduced. Advancing the ignition timing beyond the (sea level) factory spec can get back some of what the less dense atmosphere takes away, but not even close to all of it. EGR is just a method of making the intake air charge less dense; there's no net benefit here. Especially with the reduced energy content per unit volume of current ethanol-blended gasoline (if you don't have it in your area yet, you almost certainly soon will), you're better off eliminating the EGR and tailoring your advance curve to your driving conditions, fuel, and vehicle configuration.

Still waiting to learn if you're going to be running a catalytic converter in your vehicle...
Yes, completely different and not interchangeable.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan for the through explanation you have sold me on the block off plate. I have no requirement for a cat or egr where I am now in eastern Idaho. In the course of doing research here (mostly your responses) on the cat I came to realize that without EFI running the engine closer to stoich that sounds impossible to be successful.

Thanks!

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74 Dodge Charger 225 factory A/C auto 1920 carb stock exhaust.

Mods;
HEI, MSD B3, Magnecor 8 mm, ZFR5N, .060 rotor, CH410X cap, new 3874814 dist, fuel mod, valves hot .010 & .020, all new hoses, JP chain, brake hoses and fluid.

Well that's kind of an old post, now.

I've since been whole-heartedly sold on HEI v.s. EI.

The goal is maximum reliability, fuel ecomomy and safety.

I'm keeping the cat and smog system for two reasons: 1) I just replaced both tubes/check valves, pump and cat last summer, and getting rid of them now is more work than leaving them. 2) I have to pass NJ inspection one more time before I can get historic plates.

Admittedly I have yet to follow all of HardCharger's links, and maybe this has been addressed already:

Could I bypass the EGR solenoid, cap off the manifold vacuum port to the EGR amplifier, and attach the amplifier's manifold vacuum line to T in the vacuum switch for the purge canister?

My thinking is that evap vacuum switch would only have manifold vacuum applied when the engine is warmed up, and as such, the EGR amplifier could only be able to generate enough vacuum to open the EGR valve after it has warmed up.

(my guess is I'm missing something, and if it was that easy everybody with a late truck/van who did a lean burn elimination would have done it.)

I'm not looking to have the EGR working optimally, but rather if I can keep some of the fuel economy benefit of the EGR without having to keep the as-designed system in working order, or buying a different vacuum switch (I guess it would require one with two separate circuits to replace the original 2-port evap. can. one, and it would have to function as the solenoid valve does now--I can't put a T in the head and install 2 different vacuum switches, can I?)

Purge tie-in probably will not work correctly. There is no fuel economy benefit to EGR.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

really? I figured if it's burning stuff from the exhaust, then that stuff burning produces some energy, and that much less fuel is required.

No. The whole purpose of EGR is to dilute the intake fuel/air charge with noncombustible exhaust gas, to lower peak combustion chamber temperatures, thereby reducing the formation of NOx. It is not a fuel economy device. If the exhaust is substantially combustible, the engine's running way too rich.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

oh, then come historic plates, EGR is toast.

Thanks.

Theoretically EGR can improve mileage a little bit....

When there is EGR, there's less pumping loss at part throttle.

With less pumping loss, the engine doesn't have to work as hard to pull in the mixture.

But you need a computer to deal with the EGR, timing and fuel to gain anything.............

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Mmmm...I doubt it. What's your thinking here?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

BSFC..........

An engine get's it's best BSFC at WOT, usually somewhere around peak torque.

At part throttle BSFC goes up (i.e. pumping loss) because the engine expends more energy sucking the mixture past the throttle valve(s).

Also effective CR will go down as there's less air to be compressed, also decreasing efficiency and raising BSFC.

EGR can help with the first, maybe the second.

The inert gas will keep the compression up (more gas in cylinder). This one may be a wash as the A/F mixture is more diluted through out the whole cylinder..........

But pumping loss will be less with the EGR as the engine doesn't have to suck as hard to get the combinded mixture/EGR gas into the cylinder. Exhaust backpressure may even give some push.....

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Disagree. Same volume of gas in cylinder, just less oxygen. EGR is not forced induction, not even a little bit.
Disagree. Remember, the EGR jet's orifice is a small fraction of an inch in diameter. There is no forced induction at work here — not even a little bit.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

for 15 dollars you can block it off and not have to worry about any of this

as shown here




before the $15.00 EGR block off plate is installed

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isaiah6:8
www.kenithomas.com

Yep, that block off plate is on my list.

Nice ride!

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74 Dodge Charger 225 factory A/C auto 1920 carb stock exhaust.

Mods;
HEI, MSD B3, Magnecor 8 mm, ZFR5N, .060 rotor, CH410X cap, new 3874814 dist, fuel mod, valves hot .010 & .020, all new hoses, JP chain, brake hoses and fluid.

http://www.autospeed.com/A_110577/hDg34 ... ticle.html


http://www.autospeed.com/cms/A_110555/article.html


http://www.autospeed.com/cms/A_110581/article.html

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

What does the acronym BSFC mean?

_________________
74 Dodge Charger 225 factory A/C auto 1920 carb stock exhaust.

Mods;
HEI, MSD B3, Magnecor 8 mm, ZFR5N, .060 rotor, CH410X cap, new 3874814 dist, fuel mod, valves hot .010 & .020, all new hoses, JP chain, brake hoses and fluid.