Holley stumble trouble
Another shot at trying to explain the issue...
If the top of the main well is sealed, no kill bleed, no hole at in dogleg;
Then the first place air bleeds through into the main well is the upper e-hole.
This air helps lift some fuel into the angle channel leading to the booster.
Our theory is a hole in the dogleg creates an easier path for the air to flow. So instead of the booster pulling on fuel, it pulls on air.
To be complete here, when a siphon break (aka kill bleed) is drilled into the angle passage, it sometimes actually helps start the booster flow. That's because its blowing in the correct direction. So it may cause a little delay, but then makes for a more consistant initiation. Size also matters.
Another shot at trying to explain the issue...
If the top of the main well is sealed, no kill bleed, no hole at in dogleg;
Then the first place air bleeds through into the main well is the upper e-hole.
This air helps lift some fuel into the angle channel leading to the booster.
Our theory is a hole in the dogleg creates an easier path for the air to flow. So instead of the booster pulling on fuel, it pulls on air.
To be complete here, when a siphon break (aka kill bleed) is drilled into the angle passage, it sometimes actually helps start the booster flow. That's because its blowing in the correct direction. So it may cause a little delay, but then makes for a more consistant initiation. Size also matters.