April 16, 2013
Contributers: MustangMan

New Mighty Demon 850 annular carburetor for big-blocks and big small-blocks

Demon Carburetion has introduced a new 850cfm carburetor with annular boosters for high performing big-block engines and large displacement or high-revving small blocks. Check out all the details on this new carb in the blog below.

Prepared with 1.560in venturii and intended to operate with 425 to 540cu in engines with camshaft duration of 240-plus @ 0.050in valve opening, this new carburetor demonstrates its talents in street car use, bracket racing, and heads-up class racing.

With mechanically operated secondary throttles and equipped with removable air bleeds and idle-feed restrictors, it possesses all the features of the former Race Demon with the exception of removable emulsion bleeds and boosters.

The removable idle-feed restrictors are particularly helpful for perfecting the idle mixture on individual engine combinations—excelling with differing camshafts, cylinder heads, and intakes. For example, if the throttle plates are adjusted to the correct position yet the idle mixture is too lean or too rich and cannot be remedied by ignition timing, simply replace the idle-feed restrictors.

Years ago Demon envisioned the possibility of increasing idle speed without disturbing the throttle plates from their correct position. The ingenious concept involved inserting a screwdriver in the air cleaner stud hole and making an adjustment. Happily, this innovation known as the Idle-eze™ is provided on the new 850 annular model as is four-corner idle adjustment, power valve backfire protection and a kick-down mechanism that accepts Ford’s transmission linkage.

As expected this Mighty Demon features billet metering blocks and base plates as well as throttle plates mounted on Teflon-coated throttle shafts that prevent galling in the bores of the aluminum base plates. An appealing prospect, these are much improved from earlier models and demonstrate a precision-fit that is slick and smooth in operation.

A carburetor for docile engines this is not. Instead it is a race-style carburetor with annular boost venturii, each with eight discharge orifices for increased signal strength and a reputation for impressive fuel distribution. The new Mighty Demon 850 annular is finished in a clear die chromate.

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