In my quest for perfect all around driveability I'm down to 2 last niggling issues with my newley rebuilt Holley 600 Vac secondary carb.
I would think both issues are related, but one is showing improvement while the other is not.
1st Issue:
This is the one that I've almost worked out...
A hesitation when going from cruise speed to WOT. It started as a major flat spot...not a bog... just a delay followed by a sharp burst of smooth power.
The first adjustment I made was to the Pump arm Lever...I found it was too loose and set it for .010 clearance at wot as per holley instructions.
That helped shorten the delay, but completely eliminate it.
I then tried to richen the idle mixture a bit... but that made no major change...
I then readjusted both floats so the gas tricked out vs. just being level with the lower threads of the sight hole.
That's almost cured the problem, it's down to just a split second delay now. Although if I'm just cruising at 40 mph, in 3rd gear at about 2500 rpm, if I mash the pedal, the minor delay sends a quick shockload through the drivetrain which I don't care for. I'm sure my universal joints weren't happy with it.
I'd like to try a different pump cam and see if that helps...I have an orange cam on setting 1 right now.
Some folks are saying that the Blue cam helped cure a similar issue.
If that dont work, maybe I need to step up to a larger squirter? I'm getting instant fuel when I move the throttle lever barely by hand.
See next post for problem 2..