12013AB631 Subaru PISTON SET-RH OS0.25, Price: 43.66$, Weight: 1kg

0.25 mm Oversize RH Piston Kit for Subaru Boxer ⚙️

Restore compression and smooth power with this right‑hand bank oversize piston kit. Designed for cylinders that have been rebored or show wear, the 0.25 mm oversize brings piston‑to‑wall clearance back to spec, cutting oil use and blow‑by. High‑silicon aluminum, precision machined, with low‑friction skirt coating for quiet cold starts and long life. Balanced weight helps keep vibration low in the flat‑four layout. 🚗

Why you need it 🧰

Use when the RH cylinder shows scoring, taper, or out‑of‑round, or after detonation damage. After a 0.25 over hone, a matched piston is required to regain sealing, power, and fuel economy.

How it works 🔧

The piston rides the bore on its coated skirt while rings seal compression and control oil. The wrist pin ties it to the rod, turning combustion pressure into crank rotation. RH orientation ensures correct offset and crown alignment in the right bank.

If worn or broken ❗

Expect low compression, blue smoke, oil consumption, rattling on cold start, misfires, and metal debris. Continued use can score the cylinder, trigger knock, overheat, or even seize the engine.

Install notes ✅

Bore/hone with torque plates to final size, verify clearance, set ring gaps, lube during assembly, arrow to front, and balance with the opposite bank. Always torque to spec.

Compatibility

• Brz