Abstract: A system for preventing microwelding of a piston ring installed in a circumferential groove of a piston, wherein the ring has at least one piston groove engaging surface which is coated with thermal set resin, polytetrafluoroethylene and molydisulfide. This composition provides critical lubrication during the piston and piston ring break-in period and prevents localized high pressure, and high temperature areas which promote microwelding.

Abstract: A multiple sealing system for an engine gasket utilizes a retaining ring and a spring energized seal disposed within an annular U-shaped flange adjacent a gasket body. The spring energized seal acts as a primary seal against combustion gases under all engine operating conditions. The retaining ring acts as a positive mechanical stop for the spring energized combustion seal, protects the spring energized combustion seal from thermally induced crushing, and acts as a secondary seal against combustion gases. The U-shaped flange positions and supports the seals relative to the gasket body.

Abstract: An annular combustion seal ring for an engine gasket includes a central section having a generally circular cross-section and at least one tab section extending radially away from the central section. The ring is formed from a homogeneous composite powdered metal with material zones of varying densities. The composite powdered metal combustion seal ring has numerous advantages. Not only is it possible to design and manufacture a ring having a desired yield strength in both the vertical and hoop directions, but the stiffness along a particular axis may be selectively varied as a function of seal loading. Also, the varying density zones may provided by layers of material. In other aspects of the invention, the powdered metal may be primarily titanium with trace elements of the composite powdered metal providing lubrication to reduce the coefficient of friction at the ring's outer surface.

Abstract: A retaining ring for an engine gasket has an annular section with convex upper and lower surfaces. The ring is formed from a homogeneous composite powdered metal with multiple density material zones. The composite powdered metal retaining ring has numerous advantages. It is possible to design and manufacture a ring having a desired yield strength in both the vertical and hoop directions, wherein the stiffness along a particular axis may be selectively variable as a function of seal loading. The multiple density zones may be provided by layers of material. In other aspects of the invention, the powdered metal may be primarily titanium with trace elements of the composite powdered metal providing lubrication to reduce the coefficient of friction of the composite metal at the ring's outer surface.