<VV> Single Carburetor

[Sethracer at aol.com]

_johnvi at cloud9.net_ (mailto:johnvi at cloud9.net)   writes:

I have a  65 110 that I have rigged with a single Rochester 2 barrel   
Carb.  Runs fine, idles fine, the problem is the engine doesn't  have  
much low end torque, once I'm moving along it is okay but off  the  
line I need to keep the revs up.  I think the drop in  vacuum from a  
carb that may be too big is throwing off the timing,  the distributer  
vacuum retards the timing when I press on the gas to  start out.  Does  
anyone have experience with these single carb  applications?  any ideas?
 
John - Do a test. Install a timing light and check the advance setting at  
idle. With the car idling, remove (and plug) the hose that connects to  the 
vacuum advance unit on the distributor. Disconnect it at the distributor  
end. Does the idle speed and/or the idle timing setting change? The Corvair  
distributor is design to have no vacuum advance applied at idle. Depending on 
 where you are pulling the vacuum from the Carburetor, you may be supplying 
a  high vacuum signal. As soon as you step on the throttle, that vacuum 
would drop  - and the distributor will go to retard - and the engine will 
stumble. There  should be a port on the Carburetor that enters the throttle bore 
above the  throttle plate and therefore provides vacuum advance only when 
you come up off  idle. That, and resetting the initial advance, will cure the 
stumble, I  think.  - Seth Emerson