12006AD110 Subaru PISTON SET,OS,0.25, Price: 38.80$, Weight: 0.501kg

Oversize 0.25 Piston Set for Subaru Engines

Built for a clean rebuild after a light rebore, this 0.25 mm oversize piston set restores tight cylinder fit, stable compression, and quiet operation. It’s the right choice when your bores are worn, scuffed, or out of round, preventing oil burning and power loss. Ideal for daily driving and spirited use .

Why you need it

Worn stock pistons and cylinders cause blow‑by, blue smoke, and knocking. Matching the rebored cylinder with 0.25 pistons brings back sealing, fuel efficiency, and smooth idle. Expect easier starts, stronger mid‑range, and reduced oil use.

How it works

The piston travels up and down, compressing the air‑fuel mix and turning combustion force into crankshaft motion. Precision skirt profile, tight weight matching, and optimized ring lands keep friction low and sealing high. Use only 0.25 oversize rings and confirm correct clearances.

What happens if it’s damaged ⚠️

Symptoms include rattling on cold start, heavy oil consumption, carboned plugs, loss of compression, and metallic debris in oil. Severe failure can score bores, crack ring lands, and even damage the block or turbo.

Tech notes

Hone to spec with proper cross‑hatch, measure with micrometer and bore gauge, set ring end gaps, orient arrows to the front, and torque fasteners by the service manual. Always clean oil galleries and pre‑lube on assembly.

Compatibility

• Legacy
• Impreza
• Forester