Charlie B. wrote:
>
> Martin,
>
> Maybe I can help.
> > 1) Only the vapor hose from the tank connected to the carbon canister. (The
>anti-run-on
> > switch in the base of the canister was gone before I ever got the car
>...but the SU's
> > tune down to an idle low enough not to matter.)
>
> No problem there.
> >
> > 2) There are no "float chamber vent tubes" on the SU's to connect in an
>anti-run-on configuration.
>
> If you want to be environmentally correct, you can take the float bowl
> covers off, drill out the existing vent holes to a size that would
> correspond to the O/D of some small brass tubing. "T" the two float
> bowls together and run that line down to the charcoal cannister.
> >
> > 3) The manifold is vented in a "T" configuration back to the large intakes
>on both
> > carburetors.
>
> That's your negative crankcase ventilation--necessary on a Spitfire.
> >
> > My question is this -- do I need do anything more with the carbon canister?
> Shouldn't
> > its float chamber vent port be plugged, and the center purge port be
>vacuumed off and
> > back into the system? Has anyone else figured this one out?
> > Hook that port up to bowl vents (above) or just cap it off. Both of my
> cannisters are vented into the back plate of the rear air filter.
> Theoretically, the charcoal collects all the fuel vapors while the car
> is not running. When you start the car, the air filter chamber should
> create just enough vacuum to draw off the fumes, without providing so
> much vacuum that you start sucking gasoline from the fuel tank.
>
> Works for me,
> Charlie B.
Charles ... interesting idea on the float bowl adaptation. I suspect my
problem here,
however, is that the HS4's create too much vacuum for this canister system(?)
I
connected one of the lesser CC vent tubes to the back of an air filter and got
gas
coming up. Ditto when the twin crankcase ventilation tubes included a "T" for
the CC's
center purge port. What I may try now, is to put in a "restrictor" (sp?) tube
in a line
from the air filter that limits the amount of vacuum the left carb can apply to
the CC.
If I get so motivated, that is ...
Thanks, as always ...
--
Martin Secrest
74 Spitfire
73 GT6
Arlington, VA
PS: I'm also thinking of adapting a pair of Weber DCOE's to my Briggs &
Stratton 3.5 hp
lawnmower. That (plus a free flow muffler) just might give me the extra kick I
need
when I let the lawn grow a little too long next spring.
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