Method of using syntactic foam to reduce noise and machine using same

Abstract

A method of decreasing engine noise in machines, such as internal combustion engines, by replacing metallic engine components that serve as noise transmission pathways such as oil pans, valve covers, gear covers with similar components made of syntactic foam with a density of at least 0.5 g/cm3 and a hardness at least about equal to that of an equivalent metallic engine part which it is replacing. The syntactic foam is comprised of fluid-filled microballoons in a foam matrix. The microballoons have an outer shell harder than that of the surrounding foam matrix, and a majority of the microballoons are out of contact with one another.

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