Jaguar Duplex System: Operation
Duplex Manifolding System employs the metering system of carburetors to feed fuel mixture to combustion chambers through two manifolds. Two throttles are employed. The first, being in its normal position in the carburetor and the second located in the secondary throttle housing. Linkage between the two throttles are arranged so that on part throttle opening (used during most city driving and cruising), the secondary throttle remains closed, routing mixture through primary mixture pipe to an exhaust heated conditioning chamber and returning it to the inlet manifold past the secondary throttles. This makes sure of an air/fuel ratio being distributed to cylinders so an overall leaner mixture can be employed. Deposition of wet fuel in the inlet manifold is avoided. At 20° of primary throttle opening, the secondary throttle comes into operation until, at full throttle, both butterflies are fully opened.