fuel mileage and performance

hotrodguy":2vsasc5l said:
Thanks Guys, I have a local guy with a distributor machine , he set the dizzy up initially using David's book. This car is my daily driver so I need to get this work done here. My gut on all this is I still do not have enough mechanical advance. I could be wrong. The 1 time I plugged the vacuum advance and gave it 20 degrees initial it ran so much better, it was running rich before rejetting and this is when mileage really fell off. If I go to a 1101 carb does Will have the manifold adapters, I understand his parts inventory is limited. I do not expect a high performance engine just make this run as efficiently as possible.

wait, you are running mechanical advance only? that could be part of your problem with fuel economy. that and teh richer jetting. the vacuum advance is there to improve fuel economy at part throttle.
 
I tried running mechanical advance only and mileage went down, I did this for just a short time. I run both mechanical and vacuum now, but performance and fuel economy are not great.
 
You could also try timing the engine at higher speed than idle. Disconnect the vacuum advance, run the engine up to 3000 rpm, and set the timing to 34 degrees. See where the timing is when you return to idle. That will be the base timing. Then connect the vacuum.

As David said, the SCV carbs wont provide the correct vacuum signal for a later distributor. The SCV feeds that port with a venturi vacuum that is only good for the Load-o-matic style of distributor. I would reconnect the vacuum advance to a manifold source after timing the distributor as above and see how that works out.
 
Jack-David. I went back to full manifold vacuum, checked dynamic timing- with vacuum hooked up 55 degrees, plugged vacuum , new timing 40 degrees backed off dizzy to 34 degrees, ran badly kicked it up 4 degrees. Running very well, best possibly ever, looking for mileage to increase also. I" going to run it like this for a while. Much thanks for your help. Randy
 
hotrodguy":3qr5t7e5 said:
Jack-David. I went back to full manifold vacuum, checked dynamic timing- with vacuum hooked up 55 degrees, plugged vacuum , new timing 40 degrees backed off dizzy to 34 degrees, ran badly kicked it up 4 degrees. Running very well, best possibly ever, looking for mileage to increase also. I" going to run it like this for a while. Much thanks for your help. Randy

Sounds good -
(y)
check in a bit later, if you would please, let us know then...
;)
 
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