Big Bore Replacement Piston Kit | 85" | 92" | 100" | 109" EVO

Revolution Performance Big Bore Replacement Piston Kits are custom forged piston sets for Evo bolt-on big bore cylinders in 85", 92", 100" and 109".

Pistons are a wear item on a big bore motor, and matching a replacement set to the cylinder it lives in matters more than matching it to a displacement number. These are the sets Revolution builds for its own Bolt-On Big Bore cylinders, which means bore clearance and ring end gap are already worked out rather than something you calculate and hope for.

How the Piston Kits Are Built

Each piston is custom forged from high strength aluminum alloy, with a skirt coating to cut friction during break in and at cold start. High tech manufacturing keeps operating strength up and thermal expansion down, which is what allows tighter clearances in a motor that runs hot. High tension compression rings use 3mm oil scraper rails, and the pin is offset to smooth out the piston's transition across top dead center. Chrome piston pins and retainer clips are included. Made in the USA.

Piston Kit Specifications

• For Evolution motors, sizes 85", 92", 100" and 109"
• Custom forged high strength aluminum alloy
• Skirt coating for reduced friction
• High tension compression rings with 3mm oil scraper rails
• Offset pin design
• Includes pistons, rings, chrome pins and retainer clips
• Replacement rings sold separately, as a set for one piston
• Made in the USA

Compatibility Notes for the Piston Kits

These kits are intended for use with Revolution Big Bore cylinders only. They are not recommended for use with cast iron or ductile sleeved cylinders. ⚠️ VERIFY which cylinders are in your motor before ordering, since running these pistons in the wrong bore risks the whole top end.