Dominators are massive and flow a ton of air, but otherwise they're just an oversized Holley. Even many of the parts interchange, so they are easy to work on.
`Let's start this story with the disclaimer: A 1,050- or 1,150-cfm Dominator on the street is usually not a good idea. Unless you're packin' at least 400 inches and 550 hp, a Dominator is not the carb of choice for a streeter. These are cavernous carburetors that will sacrifice throttle response and off-idle driveability in favor of max airflow. So now that we've just convinced you that you must have a Dominator, we'll let you in on a few tuning secrets that can turn a fat, lazy 4500-series carb into a respectable fuel mixer.
To help us navigate around the big, bad Dominator, we hoofed it over to Sean Murphy Induction (SMI) where Sean gave us a guided tour through this big carb maze.
We'll break this carburetor down into individual sections to make it easier to understand the modifications that need to be made. The bottom line is that large carburetors can be made to work on the street. The choice is to either invest in a custom-built carb modified by a professional carb builder like SMI or spend the time, patience, and money in search of the knowledge and tricks to modify your own carburetor to perform up to current expectations. None of this will come easy and there's much more to the Dominators than we could cover here. If you do your homework, you can make a Dominator work on the street. Just consider yourself warned.
What's a Dominator?
Holley originally produced the Dominator carburetor in 1969 exclusively for Ford NASCAR and Trans-Am engines. Later, Holley made them available for other competition uses and they instantly appeared on high-winding small-blocks in NHRA Pro Stock racing. All Dominators use 2-inch throttle plates except for the new 1,250-cfm Dominators that employ bulbous 214-inch throttle blades bringing the total sizes to four: 750, 1,050, 1,150, and 1,250 cfm. Besides the skirted booster used in the 750, the only difference between the 750, 1,050, and 1,150 is the 1,150's larger venturi (11316 versus 11116).
Holley refers to this carb as the 4500 series, differentiating them from the smaller, square-flange 4150/4160 carbs. Dominators use a much larger carb flange, which demands its own intake-manifold mounting flange. Of course, you can use an adapter/spacer to run a 4,500 on a 4150-style manifold, but this often results in poor mixture distribution unless the adapter is custom fitted to the intake.
The idea behind the Dominator is obviously to flow large quantities of air. But velocity also plays a part in the carburetion game, which means a larger flow path also slows the air down through the carburetor. This is often a benefit for high-rpm drag-race applications. Slowing the air down through the carburetor allows the heavier fuel particles to make the difficult 90-degree transition into the individual inlet ports. For a street-driven engine, it is this same large airflow path that is the reason behind less-than-crisp throttle response and rich mixture tendencies that are typical of the 4500-series carburetor.