Designed for mountain motors and other big-cube applications, Holley’s new Gen 3 Ultra Dominator will flow up to 1475 cfm.
“As the motors got bigger and the cylinder heads got bigger, racers need more cfm,” says Holley’s Bill Tichenor.
Originally released in 1969 for NASCAR racing, the Dominator or 4500 series carburetor is now used mostly in drag racing. Holley implemented a host of changes and upgrades for the Gen 3, completely redesigning the main body and developing an all-new, high-capacity fuel bowl.
“We used extensive CFD analysis to design the main body,” says Tichenor, noting the main body is 5/16-inch taller than the previous generation Dominator. The higher platform allows for a larger, more contoured radius on the air entries. Other improvements to the main body include:
- Integrated idle-bypass valve that allows idle adjustment without disrupting the relationship between the throttle plate and transfer slot
- 12-hole billet booster inserts for improved atomization
- Extended air-cleaner flange to accommodate new air-scoop adapters
- Contoured hex-head squirter screws to streamline air flow
- Adjustable stainless-steel linkage and knurled idle screws
Billet aluminum metering blocks are used for improved gasket sealing, corrosion protection and cleaner appearance.
“We have all new calibrations,” adds Tichenor, “that are optimized for new fuels and bigger engines.”
The new fuel bowls offer 20 percent more capacity to help eliminate starvation, but there are also numerous other features to provide consistent fuel delivery:
- Fuel shelf is located below needle and seat to minimize aeration
- Internal baffles control fuel slosh and minimize float-level fluctuations
- Fuel trough is designed into the floor of the bowl to route fuel flow directly to the jets
- Clear sight windows for fuel-level adjustments
- Drain plug in the front center of the bowl for easy jet changes
Overall, the new Dominator is 3.8 pounds or 28 pecent lighter than the original model. The Ultra Dominator comes in three finishes: shiny aluminum with either black or red billet metering blocks or Hard Core Gray with a black metering block. Additional options include a throttle-position sensor kit for data acquisition systems, air-scoop adapters in different finishes and large-bore carb spacers will soon be available.
The Gen 3 dominator is available in six different sizes: 950, 1050, 1150, 1250, 1350 or 1475 cfm.