Supertech Subaru STi 99.5mm Bore Piston Rings - 1.2x3.4mm / 1.2x4mm / 2.5x2.8mm - Set of 4

If you're rebuilding the engine in your Subaru STi and need to replace the piston rings, this set from Supertech is a solid option. These rings are designed for a 99.5mm bore, which is a common size for performance Subaru engines. Getting the right rings is critical for proper engine function; they seal the combustion chamber, control oil consumption, and transfer heat from the piston to the cylinder wall.

This set features a specific ring groove sizing: 1.2mm for the top ring, 1.2mm for the second ring, and 2.5mm for the oil ring. This combination is often found in performance applications where precise sealing and oil control are important. Supertech is known for making well-built internal engine components, and these rings are made to meet the demands of a performance engine rebuild.

When you're putting your engine back together, make sure you have all the necessary components. These rings are sold as a set of four, enough for one engine. Always refer to your vehicle's service manual for the correct installation procedures and specifications.