Ice core molded engine manifold

Abstract

A method of injecting molding an intake manifold for an internal combustion engine includes forming a thin-walled hollow shell to match the interior configuration of the manifold, inserting tapered mandrels in the openings of the shell, the mandrels being configured to define grip surfaces thereon, filling the shell with water, freezing the water to form a core assembly with the mandrels secured by the action of the ice gripping the grip surfaces, supporting the core assembly by the mandrels in a mold cavity that defines the outer configuration of the manifold, and injecting flowable, hardenable material in the space between the cavity wall and the core assembly. The manifold and the core assembly are removed and the ice is melted out. The manifold is formed with flanges that have outwardly tapered interiors for ready removal of the complementarily tapered mandrels. The shell has lips that engage and are partially surrounded by the material of the flanges but set back from the mounting surfaces of the flanges. Surface protrusions are formed on the outer surface of the shell to help secure the shell to the wall of the molded manifold.

Dependencies are inferred from the claim text.