Air pumps & EGR-from The Source

[Dana Loomis <dloomis@domain.elided>]

In light of the recent discussion of the use of air injection pumps and EGR
on US-model Alfas, I thought some excerpts from a piece by Don Black in the
February 1974 Alfa Owner (v. 14, no. 2, p. 3-5) might be of interest.  The
article, titled "A Discussion of Alfa Romeo Design Philosophy," offers an
interesting comparison of then-current Alfa Romeos to domestic and imported
alternatives from the perspective of specific output, fuel economy, weight
and mechanical design.  Don Black's words on the two emission-control
devices follow. 

"Air pumps need Bhp, they take it from the engine and it doesn't get on the
road where it belongs.  Most engines use secondary air systems to reduce
emissions.  These pumps cost about 0.5 mph, add to this pumps for power
steering (0.3-0.5 mpg), aircon compressor (1.5 mpg) and you are using a
great deal of your engine's output to power accessories!  Air pumps burn
excess fuel in the exhaust manifold caused by carburettors overfueling
during various driving modes.  The air pump is in effect a corrective
device for another device (carb) that can't keep up with its
responsibilities. Airpumps are expensive, need to be maintained and add
6-15 lbs plus plumbing.  Who needs them?  Certainly not Alfa Romeo.  The
precise matching of fuel metering to engine requirements (the job of the 3D
cam) eliminates the cause for needing an air pump....

"EGR is quickly becoming an owner's nightmare.  Most domestic and imports
use exhaust gas recirculation to control oxides of nitrogen emissions.  EGR
allows up to 20% recycle of exhaust gases back into the induction system
(much like breathing into a bag) in order to lower NOx.  It does work
effectively; it lowers NOx and Bhp, up to 15% of the power can be lost.
EGR systems are "gadgety" and expensive.  They require frequent maintenance
and cause "driveability blues" among most of their owners.  With MFI
[mechanical fuel injection] we control NOx formation within the combustion
chambers before it begins, therefore no after treatment is needed."  

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