oletrucks
[Top] [All Lists]

Re: [oletrucks] Dual carbs/vacuum advance q

To: "Old Trucks List" <oletrucks@autox.team.net>
Subject: Re: [oletrucks] Dual carbs/vacuum advance q
From: Bob Fischer <bfischer@utm.net>
Date: Mon, 11 Dec 2000 12:36:20 -0800
Best I can recall the progressive linkage setups both stock (Olds, Pontiac, 
Chev) and after market, all were used with triple intakes for the reason 
you mention, the unequal distribution of fuel causing cylinder starvation.
I can also see that multiple carbs mounted and controlled in this manner on 
the inlet of the roots type blowers would work just fine, since it's a 
common relatively small plenum chamber.
During high school my friend had a triple setup on his 47 Chevy coupe made 
from the stock manifold. We brazed some aftermarket cast iron carb mounts 
to the stock manifold, directly over holes we had  cut in it and files 
relatively smooth. He got the carb mounts and progressive linkage from a 
catalog available in those days from Almquist, similar to Honest Charlie.

>It's interesting you mention the progressive setup.  I tried that on my
>setup and it worked horribly.  First, there is no plenum in the manifold and
>I'm not sure how one would add one (it's a pretty small opening).  Second,
>the inlines are prone to fuel condensation in the manifold, therefore heat
>must! be added to the base of the manifold (this may or may not have an
>effect).  I also think the carbs are spaced too far apart and the cylinders
>that are spaced far from the primary carb get starved for fuel.  If someone
>figures out how to get a progressive setup to work on an inline, please
>email the group as I'm very interested (especially with Rochesters).
>
>
> > Not quite the same as a stovebolt withdual jugs...but on my
> > blown 454 in my 55 Belair, two Holley 650cfm 4bbl carbs, I run a
> > progressive linkage, with the rear carb opening about halfway
> > before the front one starts to open.  I have the vacuum advance
> > connected to the rear carb, ported vacuum.


"Nothin lasts forever except old Fords and a natural stone" - Willie Nelson

http://home.utm.net/bfischer
e-mail - bfischer@utm.net  or  robert.f.fischer.jr@syntegra.com
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

<Prev in Thread] Current Thread [Next in Thread>