Holley Carburetors. Mike Mavrigian

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СКАЧАТЬ indicating that it’s a 1,050-cfm HP unit for a single 4-barrel installation. Depending on design, Dominators are available designed for 1 × 4 (one 4-barrel carb) or 2 × 4 (two 4-barrel carbs for a dual setup) mounted to the intake manifold.

       Although 4150- and 4160-series carbs do not display the model number, the Dominator identification does include the series number, which in this case is 4500. The build date indicates the 203rd day of a year ending in 4. Since this carb was recently purchased, I assume that it was built in 2004 or 2014.

      The list number may be preceded by either the word “LIST” or by the letter “L.” The factory used the word “LIST” or the letter “L” randomly. Don’t worry about it. Some carbs have it and some don’t.

      For example, a LIST 3310 is a 4150 series with either a 750- or 780-cfm rating, depending on when it was made. Another example is a Street Avenger carb’s choke housing/air horn stamped with the part number (e.g. 80670), without “LIST” or “L.”

      A dash followed by a single- or double-digit number may be found immediately following the part number. This dash number simply indicates that a running change for that particular part number of carb had occurred (perhaps a die was changed, or other evolutionary production change). A –1 indicates the first running change. A –4 indicates the fourth running change, etc. From a selection/purchasing standpoint, you don’t need to be concerned with this number.

      Located underneath the part number is a four-digit number, which indicates the build date. For instance, a build date might be 1954. This indicates that this particular carb was built on the 195th day of a year ending in “4” (which could mean 1974, 1984, 1994, or 2004).

      Although this may seem confusing, dating a Holley carburetor is generally not too difficult. A date code should appear below the list number. Older carburetors have a three-digit code, while carbs made after 1972 used a four-digit code. You can always call Holley’s tech hotline and ask a Holley technician to help decipher the date code, but remember, this number doesn’t have any particular use for you, so you really don’t need to worry about it.

       Series 4150 and 4160

      Holley 4150s and 4160s are built on similar platforms with a few distinct differences. They both have square bores; the primary and secondary throttle bores are the same size, in a “square” configuration, in contrast to a spread-bore that has smaller primary and larger secondary bores.

      The 4150 is a square-bore carb with center-hung floats and dual fuel feed inlets, and replaceable jets in both primary and secondary metering blocks. The 4150 carbs with vacuum-operated secondaries have an accelerator pump and a power valve on the primary bowl, but no accelerator pump or power valve on the secondary bowl.

      The 4150 carbs with mechanical secondaries are known as Double Pumper carbs; they have the addition of a secondary accelerator pump, and depending on the specific part number, may also have a power valve on the secondary side.

      The Series 4160 carbs also have a square-bore pattern but with more basic features. The primary side has a metering block with jets, but the secondary side has a thin metering plate with pre-sized orifices.

      Although a metering block has replaceable jets for tuning purposes, a metering plate (used in the secondary side of 4160 carbs) requires changing the metering plate for secondary “jet” size tuning. Metering plates are available in a range of main-hole and idle-hole configurations. Secondary metering plates are secured to the main body with six 8-32 clutch-head screws, so you should obtain a 5/32-inch clutch-head driver for proper servicing during removal and installation.

      A 4160 can be converted to a 4150 by adding a secondary metering block in place of the metering plate and swapping to center–hung-float fuel bowls. A 4150 can be converted to a 4160, although it is not a popular modification.

       This side-by-side comparison of fuel-bowl styles makes them easy to identify. At the left is a 4160 (PN 1850) carb equipped with a side-hung float. At the right is a 4150 carb with a center-hung float. The 4150 carb has a metering block at the secondary side; the 4160 has a secondary metering plate. A 4160 is easily converted to the 4150 configuration.

      4160 Details

       This 4160 (PN 1850) carb has the metering block on the primary side (left) and no metering block at the secondary side (right). The secondary side includes a metering plate with no replaceable jets.

       The 4160 carb has a single fuel inlet that accepts a slip-on fuel hose. This banjo-style fitting can easily be changed to a banjo fitting with a –6 AN threaded hose-end connection.

       Because the 4160 carb has only a front/primary side fuel inlet, fuel is transferred to the rear bowl via this external fuel transfer tube.

       Fuel bowls have either side-hung or center-hung floats. This is easy to identify by looking at the shape of the fuel bowl. If it is rectangular without a “V” protrusion on the casting, the bowl has a side-hung float, such as this example (PN 1850).

       With the front bowl removed from this 4160-series carb, you can clearly see the jets near the bottom and the power valve at the lower center of the metering block.

       When the primary fuel bowl is removed, you can see that the metering block is held to the body by the gasket. Small alignment dowels serve to center the block in place.

       This fuel bowl, removed from a 4160-series carb (PN 1850) reveals a side-hung float, meaning that the float is hinged at one side. A side-hung float may be more susceptible to fuel-level changes during hard turns in contrast to a center-hung float that maintains fuel level better during turns.

       With the front fuel bowl removed from this 4160 carb, the primary metering block is exposed; it is sandwiched between the body and bowl, and is gasketed on each side. The fuel bowl’s four screws secure both the metering block and bowl to the carb body.

       Removing the secondary fuel bowl from this 4160 carb reveals a metering plate, which is secured to the body with six small flat-top СКАЧАТЬ