The Carb Shop Blow Through Holley - Tech Information

Above are images show some of the proprietary modifications that are given meticulous attention and designed to maximize the boosters signal response and fuel flow capability. The basis for the custom booster is a stock Holley part that is machined and massaged to accept The Carb Shop's custom billet annular insert.

One thing that isn't custom is the booster's installation. It fits snuggly in the stock location.
One thing that isn't custom is the booster's installation. It fits snuggly in the stock l
Here we see how the booster tube is filleted into the body.
This trick tool flares the end leaving a smooth transition for the fuel to flow from the blow-through the metering block and finally into the venturi.
This trick tool flares the end leaving a smooth transition for the fuel to flow from the b

With the boosters in place, each body takes its turn in the mill where the surfaces are machined flat and square, providing both a better seal and smooth and precise fuel metering. Usually the surface is cleaned up with one pass. But sometimes another cut is needed to smooth out the high and low spots.
With the boosters in place, each body takes its turn in the mill where the surfaces are ma
The bottom of the main body also receives the squaring-up treatment. Once off the mill the sharp edges get deburred by hand.
The bottom of the main body also receives the squaring-up treatment. Once off the mill th
Note how clean the machine surfacing is.

Another of The Carb Shops tricks; custom downfeed needle and seats are designed for more fuel delivery and reduced aerated fuel conditions.
Another of The Carb Shops tricks; custom downfeed needle and seats are designed for more f
The hidden secrets to The Carb Shop's success are contained in what starts out as a stock Holley metering block. Extensive custom modifications are made to the idle circuits, main wells and air bleed passages in an effort to maximize the fuel's path into the engine.
The hidden secrets to The Carb Shop's success are contained in what starts out as a stock
The metering block's main circuit receives these threaded brass inserts that have a specific emulsion hole drilled that corresponds to the needs of the customer's particular application. Note how large the main well transfer opening is.
The metering block's main circuit receives these threaded brass inserts that have a specif

Trick high-flow jet extensions insure the maximum amount of fuel transfer from the main jets. Note the modified oversize hole compared with the stock one.
Trick high-flow jet extensions insure the maximum amount of fuel transfer from the main je
Accelerator pump squirters can also find themselves getting modified to feed the particular needs of a specific engine combination. Check out the secondary billet annular venturi boosters.
Accelerator pump squirters can also find themselves getting modified to feed the particula
ustom air bleed jets are also employed in The Carb Shop's custom blow-through fuel meters.

This maximizes the emulsion and idle circuits for better overall efficiency, drivability and most importantly, performance.
This maximizes the emulsion and idle circuits for better overall efficiency, drivability a
Last, but by no means least, is this custom crossover balance tube, which equalizes the float bowl chambers. In a boost-induced environment, too much pressure above the butterflies can create havoc with the fuel in the bowls. This can lead to irregular fuel flow through the boosters, or even no flow at all. This trick-of-the-trade is one reason that the blow-through fuel meters from The Carb Shop are making the power and performance they do.
Last, but by no means least, is this custom crossover balance tube, which equalizes the fl