Another Boggie One
Bought a '70 Duster 340 back in late November and just starting to work on tuning. The engine is a '72 360, and heads/block looks stock. I doubt there is a special cam. Has 340 intake and 340 exhaust manifolds. Original type distributor has a Pertronix I. I replaced the original AVS with a Holley Avenger 670 because the AVS had a bog. Same bog in the new carb as well. I've made no changes to jets. Vacuum advance set to use ported spark. No vacuum seen at that port at idle, so I know the primary butterflies are not too far open. Auto transmission (probably stock converter) with 3.23 posi & G60/14 tires in back.
Car has a huge bog when starting out from a dead stop, or when pressing the gas after it coasts down a long hill. If I very gently open the throttle, the engine will not bog. Mid range and above seems fine. I can see good flow from acc pump squirters when I barely move the throttle. Here is what I've done:
Tried initial timing from 14-22*. Idles at 650 at 14* initial in gear. Idles at 850 in neutral.
With initial at 14*, the total timing is 40* around 1800 RPM
Set idle screw down low and adjusted mixture on all 4 corners for best RPM
Made sure no clearance between accelerator pump arm and screw
Made sure fuel level is right at the bottom of the sight glass on both bowls
Bought a '70 Duster 340 back in late November and just starting to work on tuning. The engine is a '72 360, and heads/block looks stock. I doubt there is a special cam. Has 340 intake and 340 exhaust manifolds. Original type distributor has a Pertronix I. I replaced the original AVS with a Holley Avenger 670 because the AVS had a bog. Same bog in the new carb as well. I've made no changes to jets. Vacuum advance set to use ported spark. No vacuum seen at that port at idle, so I know the primary butterflies are not too far open. Auto transmission (probably stock converter) with 3.23 posi & G60/14 tires in back.
Car has a huge bog when starting out from a dead stop, or when pressing the gas after it coasts down a long hill. If I very gently open the throttle, the engine will not bog. Mid range and above seems fine. I can see good flow from acc pump squirters when I barely move the throttle. Here is what I've done:
Tried initial timing from 14-22*. Idles at 650 at 14* initial in gear. Idles at 850 in neutral.
With initial at 14*, the total timing is 40* around 1800 RPM
Set idle screw down low and adjusted mixture on all 4 corners for best RPM
Made sure no clearance between accelerator pump arm and screw
Made sure fuel level is right at the bottom of the sight glass on both bowls