Originally Posted by Tod74
You don't need a power valve when running wide open all the time.
When you remove it you must increase jet size 8-10 numbers. The power valve allows for less jet to make the thing more drive-able at part throttle...When vacuum drops below the spec on the PV it opens and allows the extra fuel to make up for the 8-10 jet sizes that are not there, but need to be to prevent a lean condition at WOT.
That's my understanding of it Carb guys feel free to corrcet me if needed.
Hmmmm....that makes since. The jets are 81....does that sound close to being right?
Anyway....with the PV out of the equation...maybe I'm not chasing a rich condition for the poor idle....we really only suspected this because it seemed to get better as we moved the butterflies open (more air). But now I'm not so sure....maybe we were opening the butterflies up enough on the primary idle adjustment to get into the "transfer slots" which pulls in more fuel and bypasses the idle system.
I did however check the intake vacuum at idle while in drive....barely making 5 inches. That is really low....I dont know the cam profile, but this makes me think its fairly aggresive. Maybe I can improve that with idle screw adjustments.
Any thoughts on that would be appreciated too!
If nothing else....I'm sure learning a bunch.
Thanks Tod.