[Tom Vaught]

The next 4 pictures will help in identifying 4 "Control Orifices" found in all Good Holley Metering Blocks.

1) The Idle Feed Restriction
2) The Kill Bleed"
3) The Emulsion Holes
4) The Power Valve Channel Restrictions

A Pointer (attached to a hand) shows each restriction.

The Idle Feed Restrictions typically have a .030" to .040" restriction with most performance blocks being in the .036"
or .038" restriction size.

The Kill Bleed is typically a .026" restriction and its purpose is to stop syphoning of the fuel when the circuit is no longer active.

The Emulsion Holes are typically .026" to .028" with .028" being the most used size. The Good Metering Block for many years
only needed two Emulsion Hole restrictions to the Main Well. Then some hotrodders added a third hole neer the bottom of the
Emulsion Channel. And before you knew it we had 4 hole and 5 hole emulsion hole metering blocks (typically with only two or
3 holes actually used). I helped a FORD NASCAR team years ago with a carb set up for WOT racing and Caution Lap F.E. and
we had 10 Emulsion Holes in the custom metering blocks and dual Emulsion Channels. But it worked well for THAT APPLICATION.
Worthless expense on a typical carb.

The Last Picture is of the Power Valve Channel Restrictions. They can be in the .059" to .067" hole size with 850 CFM carbs using
the smaller PVCRs (.059") and larger jets. Lower CFM carbs = Larger PVCRs and smaller jets.

This concludes my info for the morning on Holley Carbs.

Tom V.