Macdon221
Well-Known Member
Good Day All,
Trying to set up a Carter 4429S on a newly redone 68 440 with just a mild street cam.
Moderately familiar with the AVS.
Background....
1. The ignition system is all good. New fresh distributor in, timing set at 15 degrees...idles smooth.
2. Fresh carb rebuild from woodruff. Carb never used before Excellent work!. I have also checked all the settings/measurements myself as per the FSM. All are good.
3. Stock 101 tall main jets. Stock 95 secondary jets. Stock metering rods.
4. Using a thick gasket.
5. Stock manifold intake
6. Vacuum advance port capped to eliminate a leak there.
7.Choke diaphragm capped at carb to rule out leak there.
8. Brake booster and headlight vacuum port capped to eliminate any vacuum leak there.
Here is my problem and symptoms....
1. Low Vacuum...around 11 inches. This is carb problem "I think"....previous carb was ok and on the dyno 14 inches.
2. Constant low whistling sound from the carb. And a little screech when the accelerator is pushed. I originally thought it was a belt....but no it is the carb. I tried to pinpoint it with a stethoscope and could not. Sprayed around gaskets outside...no change. If I put my hand right over top of the carb it muffles the sound. So I know its the carb.
3. I can't get the idle to go below 1000rpm. Throttle fully closed and pressure holding the throttle closed still wont idle down.
4. Mixture screws....they really make no difference....but when I screw them fully in while idling...the manifold vacuum begins to rise to around 12...So I am approaching a better mixture setting.....but I can't get it even lean enough to shut off or run too lean and become rough. Assuming because fuel is also entering from a different circuit because the idle still around 1050rpm. The mixture screw's are correct. I tried 2 different sets as well. When set at 2 turns out you can see them protruding in the bore. Should they?
The manifold is freshly painted....could this be the issue...not a true flat surface?
I have tried 2 or 3 different carb base gaskets as well...no real change. The sound changes in intensity with a gasket change...but does not get rid of the constant whistle and little screech on acceleration.
Any more ideas to help me out?
Thanks
Macdon221
Trying to set up a Carter 4429S on a newly redone 68 440 with just a mild street cam.
Moderately familiar with the AVS.
Background....
1. The ignition system is all good. New fresh distributor in, timing set at 15 degrees...idles smooth.
2. Fresh carb rebuild from woodruff. Carb never used before Excellent work!. I have also checked all the settings/measurements myself as per the FSM. All are good.
3. Stock 101 tall main jets. Stock 95 secondary jets. Stock metering rods.
4. Using a thick gasket.
5. Stock manifold intake
6. Vacuum advance port capped to eliminate a leak there.
7.Choke diaphragm capped at carb to rule out leak there.
8. Brake booster and headlight vacuum port capped to eliminate any vacuum leak there.
Here is my problem and symptoms....
1. Low Vacuum...around 11 inches. This is carb problem "I think"....previous carb was ok and on the dyno 14 inches.
2. Constant low whistling sound from the carb. And a little screech when the accelerator is pushed. I originally thought it was a belt....but no it is the carb. I tried to pinpoint it with a stethoscope and could not. Sprayed around gaskets outside...no change. If I put my hand right over top of the carb it muffles the sound. So I know its the carb.
3. I can't get the idle to go below 1000rpm. Throttle fully closed and pressure holding the throttle closed still wont idle down.
4. Mixture screws....they really make no difference....but when I screw them fully in while idling...the manifold vacuum begins to rise to around 12...So I am approaching a better mixture setting.....but I can't get it even lean enough to shut off or run too lean and become rough. Assuming because fuel is also entering from a different circuit because the idle still around 1050rpm. The mixture screw's are correct. I tried 2 different sets as well. When set at 2 turns out you can see them protruding in the bore. Should they?
The manifold is freshly painted....could this be the issue...not a true flat surface?
I have tried 2 or 3 different carb base gaskets as well...no real change. The sound changes in intensity with a gasket change...but does not get rid of the constant whistle and little screech on acceleration.
Any more ideas to help me out?
Thanks
Macdon221
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