Donald H Locker wrote:
> Begging to differ, the greatest change is in the annular area (between
> the needle and the jet) available for fuel to pass through into the
> airstream (which is significantly below atmospheric pressure.)
Since I'd already mentioned this, you're not differening with me.
> The
> pressure change of 1/8 inch of fuel is approximately equivalent to
> 0.075 inch of water, about 0.14 mm of mercury. Totally
> inconsequential.
Not at all. While the numbers are slight, so is the volume of liquid fuel
flow, especially
when compared against the vast quantity of air it is mixing with. Put it on a
volume level,
which is how it's being blended, and very minute changes in liquid flow have
great impact on
the total blended fuel mixture entering the cylinders. That's why the needle
is gradually
tapered, and why american type carburetor jets are so closely sized in
replacement
increments. You're dealing with very small changes.
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