TV Bellcrank Distance

[A. G. Olphart]

Do all 2004R TV valves require the same overall travel?
Same as 700?

The reference diagrams I've located on the net are for the 700, and show a center to center distance of 1.094 to 1.125 throttle shaft to TV pull pin. (Pull pin 23 degrees to the rear of throttle shaft with throttle closed).

However, an electronic Quadrajet (#17086003), pulled from a Monte SS for the throttle shaft measures 1.175 (.050 too long). The angle looks about right.

So what is right?

 

[jakeshoe]

The 1.125" is correct, I like it to be on the shorter side rather than longer.

There may have been some variations and there is definitely some room for machining error.

There were different length/rate TV plunger springs. You can have a longer radius of arc if you use a longer TV plunger spring....

 

[A. G. Olphart]

Thanks Jake...

Why do you like them on the shorter end of tolerances?

Without a lot of deep thinking (not my forte), it would seem that longer would make for quicker and maybe more TV pressure.

 

[jakeshoe]

The longer the radius of arc is, the longer it attempts to pull the TV cable.

The issue with this is that if you adjust the TV cable for full pull at WOT it will allow the TV plunger to be less depressed at idle (min TV).

This means that you don't get the critical initial pressure rise off idle, even though you have good pressure at Max TV.

Shorter radius means that the min TV is higher for a given max TV setting. You may have to back off the MAX TV setting but you'll still have the same max pressure.

 

[A. G. Olphart]

Cool, makes sense with the expert explanation.
Thanks again.

 

[chris718]

There are 13 known different tv plunger springs and 8 different throttle configuration I have seen so far.