One of the very first facts learned in "carburetion 101" is there are three major ways to improve fuel atomization:
(1) Increase carburetor air velocity
(2) Provide heat
(3) Throw additional fuel at the problem
This is even more true on an inline engine where the carb(s) are offset from the heat of the engine than for a V-8 where one has the heat from the engine right under the carb.
Running with no heat on a street engine may be possible in Honolulu, San Diego, Miami or the high desert; but anywhere else asking for icing issues.
On a race engine where RPM continually exceeds 5000 RPM or so, there will be sufficient air velocity to not need the heat.
Jon.
