Holley 4150 Fuel sequencing

rumblefish360 said
Crude but effective for starting the conversion.
The top arrow depicting the power valve is not accurate. The power valve activates when the vacuum is low. A PV rated at 6.5 will open up when the vacuum drops to that level, 6.5.

The idle arrows belong with the primary arrrow. The circuit is feed from the primary jets. Once you step on the gas pedal, the blades open up exposing the primary run slots in the primary barrels.

What is the running/tuning issue?
Click to expand...
Thanks Rumble.
I was getting a nasty Bog/hesitation like a stall on hard acceleration. This occurred from a standing start or from a roll. Basically, If I give it a goose it would whined up and go silent (waaaaah...zilch) falling on it's face. BUT, If I lift off the throttle power would come back and I could get into it again. I felt like it was starving for fuel but didn't know exactly where this was happening. This started me on the path of understanding the fuel integration sequence.

At first I though it was an issue transitioning off idle bringing in the primaries but after some experimentation I've come to the realization the issue was occurring on the transition after the primary as I was bringing in the secondaries.

I was able to get it pretty dang good by making the following adjustments:
  1. slightly increasing the float level in the Primary bowl just above the bottom of the sight hole to have a little more fuel in the pot.
  2. turned the fuel mixture screws on the metering block out two turns from bottom to richen it a bit.
  3. moved the accelerator pump cam to the first position which shortened the squirt duration but brought more fuel in the Primaries sooner.
All of this has given me the incentive to better understand how fuel supply is managed in the carb.

My particulars:
Thanks
AlV