Unless you plan on doing some sustained full throttle
runs, the large lines and hi perf pump are
superfluous since a daily driver normally only needs
0.5*HP/6lbs, or ~27GPH. Well within an OEM system's
~40GPH capability. Production cars with carbs
typically lean out under hard acceleration from fuel
starvation, but since it's usually only for a second
or two at a time, it's no big deal.
I assume though there will be some serious WFO going
on occasionally, so.....
If the opening in the tank is too small, then the
high volume pump will be trying to pull against a
positive static pressure, causing it to bleed off the
excess pressure that you bought it for. The last
thing you want is a restriction.
I'm not familiar with the pump you're using, but the
line should be as large as it's inlet will allow, or
3/8" min for 250-375HP. The 1/2" pipe is a good
'catch all' size for street motors, just in case you
do a performance upgrade later.
Minimum fuel flow should be 0.23*HP (~75GPH for
325HP) for a dead head regulator, or 0.17*HP (~55GPH)
for a return style regulator. The return line needs
to be 3/8" min for 45-90GPH.
Frankly, I'm surprised you didn't convert to high
pressure electric. Less stress on the cam, much
reduced possibility of getting vapor lock, less
pressure drop from "G" forces, and it helps offset
line frictional losses.
GM
----- Original Message -----
> Well, I'm not sure whether it's a waste of time or
not, unless someone can
> come up with the max fuel flow possible thru the
OEM tank to pump line.
> However, the 3/8" line from the pump to the carb
may be unnecessary for most
> street tuning. The only advantage to the larger
line may be some resistance
> to heat. Or maybe it'll serve as a sorta fuel log
;o) I don't really know.
> BTW, The carb and the Edel fuel pump are set up for
6-7psi.
> stephan
>
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