<VV> Single Carburetor - Better formatted

[Jim Davis]

Or use a new Safeguard with the built in MAP sensor and program the 
vacuum advance you want.
Jim Davis

On 4/22/2013 11:12 PM, Sethracer at aol.com wrote:
> Mike wrote:
>
> Do  NOT  use ported vacuum, but draw directly from manifold  vacuum.
>   
>   
> So Seth writes:
>
>
> Mike  and I will have to disagree on this one, I guess. I believe you
> should
> give the distributor what it expects. The Corvair distributors (Turbo
> models  excluded) were designed to have a stable timing at idle based  on
> the
> initial  setting only, with no vacuum or mechanical advance.  Vacuum was
> only
> applied when  the throttle was opened, mechanical  advance at some higher
> RPM.
> You could do the  mod that Matt  suggested, eliminating the Vacuum advance
> completely. If the  initial  timing is set with this mod done, you won't
> have
> the stumble you   describe - if that idle drop is the culprit, and I think
> it
> is. Running  with out  vacuum advance, however, will impact gas mileage at
> part  throttle cruise.  Engine vacuum is a reflection of engine load. An
> engine
> with a light load can  tolerate extra advance and, as GM originally
> intended, more advance is better.  (Okay there is some question on an
> engine that
> is designed to NEVER ping, More  advance past a certain  point gives no HP
> advantage. I assure you the  Corvair engine is not  that engine.) Just
> short of
> pinging is where the Corvair  engine  lives a happy life. If you cannot
> find
> a "ported" vacuum source on  the  2GC, you should either look for another
> carb, or eliminate the  connection  entirely. GM built several dozen
> different
> 2GC models  over 25+ years of  production. Models that fed vacuum at idle
> to
> the  distributor were designed to  work with that style distributor. (not
> ours). If you feed manifold vacuum  to our distributors, opening the
> throttle -
> which drops the vacuum signal, will  instantly retard the  timing - You
> already know the result of that. PS - Which  distributor  number are you
> using on
> the 110 motor? -Seth  Emerson