Dual Carbs cold on one side

[Mark A. Segraves]

I've got dual Brosol carbs with Empi intake manifolds on my 75'
Super Beetle with a bored 1835cc Mofoco engine. After driving it for a
while (highspeeds seem to do the trick), I start to lose power, and
eventually the car won't even idle without cutting out. Someone told me
I was having that icing problem on the carbs so I checked them after
driving for a while and sure enough; they were cold. The problem is that
one is colder than the other. This I don't understand.
I was wondering how I could get some heat to them. Would I have
an air hose? Where would it come from? Where and how would I attach it?
Please help me.

[x]

sounds like the tin on the back of the engine is leaking cold air on that
carb. make sure it is sealed correctly. when going at speed that air
would be quite cold and could easily drop that carbs temp down to a point
that the gas is not getting vaporized correctly. this could lead to the
plugs on that side getting wet and not firing correctly. if this is a
single barrel carb both cylinders on that head are probobly involved. if
it is a dual barrel carb with a true split dual intake manifold the
fouling is possibly just in number three (the one that would be getting
hit by the cold draft.

the...@gte.net

In article <34A15F...@nwu.edu>, "Mark A. Segraves"

[Jason Black]

LaRose Racing wrote:
>
> Mark,
>
> Normally speaking, the heat that rises off the head will
> "heat-up" the dual carburetors, especially since the carb bodies
> and manifold flanges are now even closer to the heat of the
> engine, and some kind of pre-heat to the manifolds should be
> unecessary. The only thing that could cause icing in the carbs,
> might be from the air intake--through the air filter, since when
> you live in extremely cold climates, the preheat "stove" on most
> OEM air filter cases, takes care of that. Since you suggest only
> one side is seemingly very cold (upon touch), I wonder if you
> don't have two *different* base gaskets on the head, where the
> manifolds bolts up---some gaskets are made of stamped and
> perforated metal (conduct heat more readily), and some are made
> of a composite paper and fabric fibers, and the paper ones
> "insulate" the heat from the head better.
>
> Of course, during the warmer months, you want the intake charge
> to be cooler (for more power), and the winter, you want it to be
> warmer, as you are trying to achieve an ideal intake temperature
> year around, so don't get carried away with modifications to the
> temperature of the fuel/intake charge, that you can't reverse,
> when it gets warmer again.
> Michelle
> LAROSE RACING
Please consider also that with a typical (in my case..Kadrons) dual carb
set, only one of the carbs' air cleaners has the breather tube attached
to it. Thus, one carb will be sucking in cold outside air PLUS air
heated from being inside the engine. So, of course one side will be
colder. What I plan to do about it is to attach a breather tube to the
underside of my other carb's air cleaner and split the breather tube
with a tee fitting. This way, both carbs will run warmer and not ice up
like the one without a breather has been known to do.
Jason Black
vw...@earthlink.net

[LaRose Racing]