There are many reasons why the cars have fuel smell problems, but the fact
they have carburetors isn't the reason per se, though for a variety of
reasons they may be a contributing factor.
A properly applied mechanical FI system will give the gains you want, but so
will a more efficient, performance oriented carb / cam / ignition system,
and I assume it will be cheaper, easier to install, and dial in.
I gained a couple of mpg's and much improved driveabilty just by switching
to a Holley 500CFM 2bbl. More should be available using a Holley 4360 450CFM
spreadbore 4bbl / dual plane manifold. With it's small primaries, throttle
response should be 'right now' crisp, with fuel economy improved through
high flow velocity; and with it's mechanical secondaries, you can to a
certain extent dial in how much they affect part throttle operation, while
still providing top end power. Don't be fooled by it's low CFM rating either
WRT top end power. Measured using 2bbl criteria for comparison purposes
yields 630CFM, far more than needed, so leaner secondary jets can be used.
I assume a different cam will be required for maximum efficiency. This
combined with the carb swap allows for more timing since the higher flow
rate combined with complementary cam profiles will mimic a higher
compression ratio. A perk is that these changes also increases torque,
allowing a higher final drive ratio, if one is available, for further
increases in economy.
A higher compression ratio can be used if you want to add water / alcohol
injection.
Hotter ignition systems allow wider plug gaps, increasing efficiency.
Whatever's used though will require tuned length, small diameter exhaust
manifolds for scavenging purposes, and a motor in top notch shape for best
performance / economy.
An electronic FI system gives the greatest gains, combined with ultra hot
ignitions, complementary cams, tuned exhausts, etc., but will require much
more effort / parts sub / $$. I haven't kept current with the aftermarket,
so I don't know what all is available for this motor. In the long run, it's
probably easier and cheaper to buy a complete motor / transmission /
electronics system from the appropriate wrecked Ford.
In the end though, $5K-10K and one heck of a lot of work / frustration /
time lost driving it, to improve it's average mileage ~6mpg over my low buck
carb swap doesn't compute IMO. That's a lot of gas at present, projected
rates.
The middle road seems the best solution IMO. The spreadbore, or whatever the
latest version is, combined with a complementary intake, tubular headers
will get you the most bang / buck. I'm a bit out of date, but I'm guessing
<$800 max / weekend of serious labor will net you a ~3mpg average gain with
more performance, and much better driveability.
If gas prices should rise enough to justify it, then ignition, head work /
cam, etc., can be done later.
WRT carbs and security systems, convert to an electric pump with a separate
hidden cutout switch. Combined with door interlock / ignition cutouts,
they'll either give up or at least run out of gas before they can get very
far.
WRT vacuum systems, all I can say is to bullet proof each connection,
replace hoses periodically, and pray the big components don't leak / fail.
GM
----- Original Message -----
>
> * I want to increase fuel economy. Yes, I know--that's hard to do
> considering it's a two-ton car with a V8, but I plan on driving this
> thing. A lot. And gas isn't cheap where I live. From what I understand,
> my friend's SV-1 averages around 14-18 mpg in mixed driving, and I want
> to better that by around 3-4 mpg on both ends.
>
> * I am the caretaker of a 1970 Stingray and know what problems a carb
> can bring. For instance, the smell of unburned gasoline is not the
> world's sweetest perfume to me. Try as I might, however, I cannot chase
> that smell from my dad's Vette and my friend's Bricklin suffers the same
> malady. In addition, I don't like relying on vacuum pressure for much of
> anything. I also own a 1989 Chrysler Conquest TSI whose vacuum system
> was obviously designed by Satan. Dad's Vette isn't much better.
>
> * FI systems, in theory, are always more efficient and put the power
> down quicker. They are also less susceptible to bouts with cold weather,
> and as an added bonus, you can integrate an electronic FI system into a
> vehicle alarm.
>
> Jess
>
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