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Ellison Throttle Body Injector

VW Installation

Unlike most other carburetors which are adapted for aircraft use, the EFS-2 throttle body injector was designed specifically for the converted VW aircraft engine. Other carburetors used with this engine may utilize "add on" mixture controls and require constant mixture control adjustment whenever the throttle setting is changed.   The EFS-2 incorporates a mixture control designed into the unit, not added on. Changes in throttle setting do not significantly affect fuel air ratio.

The EFS-2 also has a diaphragm controlled regulator in place of a float bowl, allowing side draft, up or down draft orientations. The unit is not subject to changes in fuel metering due to G loads and therefore will operate in all flight attitudes.

Many VW installations suffer from poor fuel distribution resulting from poor manifold design. With the EFS-2 a more efficient manifold can be installed, allowing the throttle body to mount on the top of the engine. A sketch of this type of manifold is presented below.

For VW engines with displacements greater than 3000 cc the EFS-3A should be used.

VW above-engine manifold sketches

Those who have installed this manifold have reported greatly improved performance. If you wish to mount the throttle body under or in back of the engine, the Great Plains Aircraft supply dual port manifold is one of the better designs.

Installation Requirements

See comments related to carburetor heat, vapor formationfuel filtration, and primer suggestions when planning a TBI installation on a VW engine.

Ordering Information


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