Vaccum secondaries? Do they open?

["Ernie Stepney" <stepney@xxxxxxxxx>]

On Rochester Q'jets they are referred to as the secondary air valve and
are held closed by spring tension, which is adjustable, which prevents
them from opening untill the rpm are high enough to create sufficient
intake manifold depression 
to pull them open.

Regards: Ernie


-----Original Message-----
From: mailing-list-owner@xxxxxxxxxxxxxxxx
[mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of Brian
Collinsworth
Sent: May 4, 2003 5:09 PM
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: Vaccum secondaries? Do they open?


I am pretty sure it is simply called an air door.
Brian


> 
> Correct, the actual butterfly is mechanically controlled by the 
> throttle position and the top flap (is there a real name for that 
> part?) is controlled by a few factors.