There's nothing new under the sun, and that's especially true with carburetors. Carbs have been designed, developed, and refined for the last hundred years, so pretty much everything you can do with them has been done, right?
Well, yes and no.
Up until now, most carbs, including the performance models, have been OE-based, or revisions of OE designs. From the 97 to the Double Pumper, from the AFB to the Q-Jet to the ThermoQuad, they've all built on one another, and the lineage goes directly back to Original Equipment.
The new Street Demon series of carbs is exciting to us because it almost looks like they took a "clean slate" approach with designing a carb, pulling several features from existing carb technology, but put them together in a way that hasn't been done before.
There are a number of things we like about it, most of which center around the simplicity of its design. There's a certain elegance in simplicity, and these carbs have it.
There have been other carbs in the past that have been "top load" styles, with a top of the body coming off to access the internal components, but the Street Demon has three main pieces: the top, the bowl/body, and the throttle plate. Among other things, this design only has one place for them to leak fuel—the one-piece horizontal gasket on top of the bowls, where the fuel will have to travel up before it can weep past the gasket.
The other thing we really like about it is the optional phenolic main body. We'll admit to being fans of the old Chrysler Thermoquad for this reason, and the fuel-insulating properties of its plastic body. Insulating the engine heat from the fuel is always a good thing, and the fuel bowls being made of plastic material is going to do a great job of keeping the fuel cooler. It's an obvious advantage if you're hot lapping at the dragstrip, but we're more enthused by the idea of eliminating a source of vapor locking in heavy summer traffic.
Besides the three-piece design allowing easy access to internal parts, and the phenolic main body, the biggest difference over other carbs is the three-barrel design. We don't have flow numbers on it, but dyno testing on a couple of 409s (one a stroked street engine, the other a big 509-inch full race motor) at Lamar Walden Automotive shows them to flow like monsters, making more power than modern AFB-style carbs with similarly advertised cfm numbers. Because of the huge rear secondary, the primaries are smaller than a similarly rated four-barrel carb, much like a Quadrajet or Thermoquad. This should help in dialing in the carbs for around-town driving on the smaller primaries, while giving a lot more flow when the pedal is mashed.
Clean design, easy to tune, leak resistant, a bright finish, and a host of other features make this carb a great solution for street rods, hot rods, daily drivers, and race cars.