Ancient History

[Arnaldo Echevarria]

>>> So, how does one take a 400+ CID engine and get that kind of mileage
>>> unless he's running a 1.7:1 rear end (i.e. L-O-W r's) -- even if he had
>>> 100% VE ?

3.08:1 gears, actually

>
>So, you're telling me these mpg figures don't bother you?
>
>Tom

Do these numbers really bother anyone?  12mpg highway for a 455? I mean,
I've read about 46-48mpg from a turbo v-6; 28-30mpg from 5.7L z/28's,
and 31mpg from 5.0L mustangs.  While I don't believe any of them; i'd say
12mpg from a 455 is much more believable because I've been driving the car
eight months since I built the engine and keep very accurate track of the 
gas mileage.  I calibrate my tach every month - if I spin that engine over
5300rpm it's over - I use a friend's digital speedometer to do so.  I know
what the correction factor on the speedometer is, It's so precise I can tell
tire wear (because the speedometer constant changes just a bit).  Just saying
so doesn't make it so, I realize that; but believe me, I'm not one of those
"oh yeah - 30mpg at least from my v-8".  I have driven in far too many 30mpg
5.0L mustangs (only to get 18-20) and 27mpg 5.7L '95 Z/28s (only to get 22.5)
Maybe those cars get that kind of mileage at 60mph going down a hill with a 
tailwind, a real skinny driver and at a high altitude (higher altitudes get
better gas mileage, especially with efi).
When I say highway, I mean just that: jump on the freeway and drive.  That also
means slowing down a little, speeding up, passing the old people, showing a
Porshe
a thing or two :), and finding a place on I75 or I95 to get gas (you know how 
you get off a freeway only to find out the gas station you're stopping for
is out
of business and then you realize why the billboard had such a cheap price)

AND NOW, A QUESTION, a question:
how much better is using some sort of mechanical injection that creates an
excellent a/f mixture (dilutes it greatly) over using a conventinal efi
injector on the manifold pointing at a valve?  Is it really that important
that the fuel is injected as close to the valve as possible? At high RPMs it
doesn't matter anyway 'cause the fuel will just sit on the valve anyway.  

What I'm getting at is which plays a greater role at low RPMs: a/f mixture,
temp of mixture, or timing of injection?

What I'm trying to decide whether I should conceive some sort of mechanical fuel
injection system (timed or untimed) or should I just drill 8 injector holes in
my intake manifold, buy 8 injectors (not cheap), and go from there?

Arnaldo Echevarria
aec at ao.net