Intake Manifold: Description and Operation

INTAKE/EXHAUST MANIFOLD
The intake manifold is a tuned two-piece semi-permanent mold aluminum casting with individual primary runners leading from a plenum to the cylinders. The manifold is designed to boost torque in the 3600 rpm range and contributes to the engine's broad, flat torque curve, which was desired for excellent engine tractability, response and usable power output. The intake manifold is also cored with upper level EGR passages for balanced cylinder to cylinder EGR distribution.
The exhaust manifolds are log type with a crossover and are attached directly to the cylinder heads. They are made from nodular cast iron.