12033AC300 Subaru RING SET-PISTON, Price: 99.77$, Weight: 1kg

Piston Ring Kit for Subaru Boxer 2.0 — Restore Compression 🔧

This high-precision set seals the combustion chamber, keeps oil out of the burn zone, and carries heat from the piston to the cylinder wall. It is essential during an engine rebuild or when you notice low compression, oil use, or smoke. Fresh rings bring back power, fuel economy, and smooth idle, while protecting the catalyst and reducing emissions. 🛠️

How it worked

The pack combines two compression rings and a tri-piece oil control ring. Gas pressure loads the top ring against the bore for a tight seal; the second ring supports compression and scrapes residue; the oil assembly meters and returns excess oil through drain ports. Moly or phosphate-faced rings bed in fast, resist scuffing, and keep seal under heat at high RPM. Heat transfer from piston to cylinder prevents hot spots and knock. 🧩

What happens if it’s broken or worn

Expect blow‑by, power loss, hard starts, blue exhaust, rising oil consumption, and fouled plugs. Crankcase pressure climbs, PCV struggles, and fuel wash thins engine oil, risking bearing wear. A snapped ring can score the cylinder and break piston lands, forcing a full rebuild. ⚠️

Install tips

Hone to a proper plateau finish, check end‑gaps, verify ring side clearance, stagger ring gaps ~120°, lube with clean engine oil, and face all markings upward. Measure bore size and roundness before fitting. 🔍

Compatibility

• Brz