Double pumper with mechanical secondaries

[gary j zingle]

"Why dont you like the double pumper with mechanical secondaries?"

With mechanical secondaries when you stomp the go pedal the
secondaries open wide. The result is that the air flow speed through
the carb drops dramatically. Without speed the air does not pick up fuel.=


In a light weight car with a large motor the resulting bog can be overcom=
e
with an extra shot of fuel (double accelarator pump) that helps the motor=

until it can catch up and pull some air.

With a 12000 lb motorhome the duration of the extra shot of fuel would ne=
ed
to be very long.

Vacumn operated secondaries only open when the motor can handle the
extra air. If you stomp the go pedal they will slowly open as the RPM
increases.

HTH

Regards

Gary Zingle
1973 GMC 26 foot

 

[ronald b. kazi]

Thanks for the explanation Gary. I am sure it will work okay for now till I get
my Howell unit, which is after my lottery check arrives.

Ron and Julie

>
> "Why dont you like the double pumper with mechanical secondaries?"
>
> With mechanical secondaries when you stomp the go pedal the
> secondaries open wide. The result is that the air flow speed through
> the carb drops dramatically. Without speed the air does not pick up fuel.
>
> In a light weight car with a large motor the resulting bog can be overcome
> with an extra shot of fuel (double accelarator pump) that helps the motor
> until it can catch up and pull some air.
>
> With a 12000 lb motorhome the duration of the extra shot of fuel would need
> to be very long.
>
> Vacumn operated secondaries only open when the motor can handle the
> extra air. If you stomp the go pedal they will slowly open as the RPM
> increases.
>
> HTH
>
> Regards
>
> Gary Zingle
> 1973 GMC 26 foot