An inlet manifold system particularly adapted for a "V-8" to "V-16" Type internal combustion engine. Such an engine has a first and a second bank of cylinders, each bank having a plurality of combustion cylinders, the banks being parallel to each other. The manifold includes: a] a first elongated secondary manifold disposed substantially parallel to and above the first bank of cylinders; b] a second elongated secondary manifold disposed substantially parallel to and above the second bank of cylinders; c] a first set of a plurality of substantially parallel, spaced apart, demand runners joined to the first secondary manifold along its length, each demand runner extending from the first secondary manifold to a cylinder in the second bank of cylinders and in fluid connection with the first secondary manifold and the cylinder; d] a second set of a plurality of substantially parallel, spaced apart, demand runners joined to the second secondary manifold along its length, each demand runner extending from the second secondary manifold to a cylinder in the first bank of cylinders and in fluid connection with the second secondary manifold and the cylinder; e] a first set of a plurality of substantially parallel, spaced apart, supply runners joined to the first secondary manifold along its length and in fluid connection therewith; and f] a second set of a plurality of substantially parallel, spaced apart, supply runners joined to the second secondary manifold along its length and in fluid connection therewith. The demand runners and the supply runners are connected to the first and second secondary manifolds such that each pair of adjacent spaced apart demand runners has an supply runner therebetween.