JE Pistons ZV9900 Piston Ring Set 3.898 in. Bore 0.0374 in. Top / 0.079 in. Oil 1 Cyl.JE Pistons ZV9900 Piston Ring Set 3. 898 in. Bore 0. 0374 in. Top 0. 079 in. Oil 1 Cyl. JE Piston Rings are designed to maximize horsepower through precision sealing of combustion pressure. They are offered in a huge selection of sizes, various materials, and in multiple thicknesses to suit a wide variety of engines. JE Pistons also offers an array of custom piston ring services including back cutting, dyke cutting, lapping, grinding, and PVD coating.