<VV> 4-carb question

[Bryan Blackwell]

Answer inline:

On Jul 7, 2011, at 5:07 PM, Chris & Bill Strickland wrote:

> Bryan Blackwell wrote:
> 
>> The secondaries all have stiffer return springs on them, I've never heard of them opening on just the engine vacuum.
>> 
> 
> It would be my understanding that the 66 and later linkages (I've never had a set of these) actually have a lockout device to prevent the secondaries from opening until the primaries are full open -- if the manifold vac doesn't open the secondaries, why would this lockout be needed?

Those lockouts keep you from using the secondaries until the chokes open.

>  Likewise, why would GM have spent the money to change the linkage?  The 65 linkage is apparently much simpler, and it will open the secondaries.

Correct, chokes or no.  I'm not sure the exact thing they were fixing, but I'd guess either they were after a drivability issue, or they wanted to limit power and potential damage when cold.
> 
> The only oem return spring I'm aware of on 65 secondaries is the one in the accelerator pump hole.
> 
Correct.

--Bryan