Thanks Chris for the Info....
I can and will Tune this Carb.... I just needed to fix the Problem up front
and had the choice of a Bigger Barry Grant 1015 ( 850 that has been worked
over some )
I also have some Timing issues to deal with... I have a Snap-on timing Light
that is Digital and I don't think it's Worth much.... Interesting Waste of
money... and it's nice to be able to see the RPM while your Timing without
checking the tach but I think the MSD messes with it.
Wow I am excited about this weekend ... Been To Long and I am getting the
fever to go RACING.....
Keith
----- Original Message -----
From: Chris R Harris <yesford@clear.net.nz>
To: land-speed <land-speed@autox.team.net>
Sent: Tuesday, March 28, 2000 5:25 PM
Subject: Carb adjustments
> List,
> Keith has solved his problem by changing carbs, but could have
> corrected the original with a little work.
> The problem was due to being lean in the 'off idle' or 'transition
> circuit'. This overlooked and misunderstood circuit is responsible for
> almost all off idle flat spots.
>
> Hold your Holley above your head right side up and notice the idle fuel
> port clearly below the primary butterflies. Also note the transition slot
> partly covered by the butterfly (throttle closed). If at your best curb
> idle speed adjustment more than 40 thou of this slot is exposed below the
> butterflies you will very likely get an off idle flat spot (lean) until
the
> main circuit kicks in. As George suggested the best way to get this
> butterfly to transition slot phasing corrected if you need lots of
throttle
> opening to feed a low vacuum engine at idle, simply drill a hole in each
> primary butterfly close to the transition slot to allow more air through
> and close the butterflies to correct position.
>
> Keith was obviously running on this lean circuit which can give a bunch of
> revs with little throttle opening on an unloaded engine. To richen this
> circuit you can decrease the idle/transition air bleeds in the top of the
> main body. They are the outer larger holes which altering is only becoming
> an option on new racing style Holleys and BG's. Alternately open up the
> idle fuel restrictors in the primary metering block face, facing into the
> fuel bowl as in most double pumper carbs. If these restrictors aren't
> fitted there, they are under the 2 outer core plugs on the top edge of the
> metering block. Just make sure you have replacement plugs before you tear
> them out. Some tap these core holes and tap for threaded plugs.
>
> If your not the patient type, you can often cover an off idle flat spot by
> increasing the accelerator pump shooter nozzle size and/or volume, but
this
> is only a band aid deal.
>
> Can't comment on your black plug 3 x 2's Doug. I ran progressive 3x2s on
my
> first rod. They were 3 1956 Ford 2V's on an old 57 Ford 'Y' block. Half
> of the central carb gave me 70 mph and superb (for its day) acceleration
> when I hit it and the outside jugs came on line. Really great deal, never
> lost tune once set up.
>
> Chris Harris. New Zealand.
>
>
>
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