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Old 05-10-2013, 06:17 PM
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You had best pressure (shop air) check what you did there.
That vac port on the metering block is for ported vacuum advance.. Goes down to the throttle bores in the base plate.

(drilling the base plate is not needed. The spot to drill is thru the main body of the side of the carb just into the power valve cavity,,long small diamter drill , then plug the hole in the bottom of the PV cavity in the body.
then redrill that new small hole with a slightly bigger drill about 1/4" deep just deep enough for a pressed in tube ...Then press a tube into the hole you just made in the side of the main body of the carb.

You can do it, the way you did it, but you must also block the ported vac passage in the main body down to the throttle base of the carb .
or it will leak too.
I am not convinced from your post that you plugged that hole too.
Just make sure you plugged that hole too.

While you got the carbs apart: what is the orrifice size of the PVCR's and the idle feed restrictions and the idle and high speed air bleeds on each of carbs..??? are they matching carbs? Do not assume they are both the same inside.....look....

Now is the time to look and write down all the internal fuel metering orrifice sizes on each carb..


Now is the time to verify and properly pre-set the throttle blade Tslot exposure on all 8 barrels evenly
before install. Get this correct as a base line.

remove the tiny secondary throttle stop set screw from the throttle base and reinstall it from the top side of the throttle shaft boss so you can adjust the secondary throttle idle position (T slot exposure at idle) with the carbs installed on the motor.
You need to get this right on all 8 barrels before reinstalling the carbs.
Verify ignition timing using a timing light. Do not depend on the computer ECU doing X to the timing.. Verify actual timing setup with a timing light.
You do not want an advance curve at all.... Fixed locked timing that does not move with rpm, load or throttle position.

Last edited by F-BIRD'88; 05-10-2013 at 06:40 PM.
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