I just completed the installation of the Hex ("Cross")bar (21 1/8" long) from CB Performance, using the same placement of the throttle cable and carburetor throttle arms as was on the old hex bar. I used new ball studs and springs, and liberally greased them. I left 1/8" end play at each end of the installed bar.
The car had been running roughly (no backfiring) prior to the installation, but I attributed this to the large amount of horizontal play in the worn old hex bar. Following George Browns' instructions from the SOC Library articles, I checked to see that the throttle plates ("butterflies") were parallel to the carburetor bore lines at full throttle. Interestingly, the plates were properly vertical on the 44 IDF on the driver's side, but the one on the passenger side was about 1/3 open.
George said that the throttle actuating rods (the ones that extend from the throttle arms to the carburetor should be perpendicular to the hex-bar. Mine were oriented originally at about 30 degrees in relation to the hex-bar. Questions" (1) Do the actuating rods have to be perpendicular to the hex-bar; if so, there will be some rather major adjusting on my part to do this. (2) To get the butterflies all oriented the same way at full throttle, I assume that the actuating rods are the ones that need adjusting, rather than sliding the throttle rods back/forth on the hex bar. Is this correct?
(3) Is there an easier way to keep the throttle open while making these adjustments, other than having a helper keep his or her foot on the accellerator pedal? Remember, I have never done this before.
George explained that once the butterflies are all parallel to each other, idle sync can be fine-tuned with the actuating bar adjustment.
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