Purchased a 74 and started fiddling with the tuning. Discovered the vacuum advance was not working and the tach drive gear was stripped. While replacing the tach shaft I also installed an Accell Point eliminator kit (made a noticeable improvement). I replaced the vacuum advance pot and am still not getting a quick crisp response that I would like.

It has a Carter Quad-jet, I have gone thru the timing instructions in the posted sticky. I notice I get 36 deg. At 2850ish but the advance continues to rise as I increase the rpm's. I just received a weight and spring kit yesterday and will fiddle around with it today.

After installing the new VA and following the sticky directions, I did not notice an increase in idle rpms after installing the vacuum hose. It is connected to an upper port on the carb. I also tried the lower port and both seem like they are metered. I bought a T fitting and added it to the head light port on the manifold. I ran out of time last night and did not check the vacuum pressure with a gage but still did not notice an increase in rpm's.

I have checked the vacuum in the past while fixing the lights and was reading about 15hg.

Any advice on how to get a good crisp/quick response when throttling? I can see that the accelerator pump is working fine.

Bill

 

if the timing is still increasing as you continue to increase engine rpms that at your listed 2850rpm point the timing is not "all in" yet.
Depending on the springs that are in there, such as the factory spec springs the timing may not come all in untill 400orpm or possibly even higher. you first want to see at what point the timing is all in by. it's it in by 3000 or so than great. If it's significantly above 3000rpm than try a lighter spring on the weights so that the timing comes all somewhere between 2500-3000rpm. Once you get that set than you can set your timing for 36º at the point that it's all in by.

On your vacuum advance, typically a full manifold vacuum port is lower down on the carb body such as by the base plate as full manifold vacuum ports pull vacuum from below the throttle plate.

Not sure what carb you have. Carter carb are one type and quada-Jet carbs are by Rodchester therefore a different carb. Port locations will vary.
An easy way to find a full manifold vacuum source even without a vacuum gauge id simply use your finger. With the car at idle put your finger over a port and if you feel vacuum at idle it's a full manifold vacuum source. If you don't feel vacuum on your finger at idle it's a ported vacuum connection.

Once you get your distributor set up and also connected to full manifold vacuum, i'd recomment using a vacuum gauge on the carb, also connected to a full manifold vacuum port, you adjust your idle mixture. With the vacuum gauge connected adjust idle mixture until you get the highest vacuum reading you can.

 

Carter made bunches of Quadra-Jets under license for Rochester. Technically, the Rochester and Carter Quadra-Jets ought to be the same for the same application (vehicle).

 

It sounds like you're trying to set the initial advance with the vacuum still hooked up. With the vacuum advance disconnected, set initial advance at 12 to 16 degrees. Then, using the two softest springs in the kit, increase engine speed until the timing stops advancing. This may happen rather quickly (2200 RPM). Now, replace one of the springs with a medium spring. Do the test again. you're looking to have the timing all in at about 2800 RPM.

When you're done with all this hook up the vacuum advance and check the timing. If it has not changed the unit may be defective or installed improperly.

BigBlockk

Later.....

 

that I didn't realize. thanks for the correction

 

What if you get no fluctuation? I hooked the vacuum gage to the manifold port where the headlights get their vacuum source and I turned both (one at a time) needle valves all the way closed and backed them out 1.5 turns and then turned them a ¼ turn increments both ways and did not see any difference in vacuum. How much do I need to turn the needle valves? Am I connecting my gage to the wrong place? I have a Carter Quad-jet (74) and it only has two ports and neither of them are full vacuum.

Thanks for the help
Bill