Wiseco 4995PS Forged Piston Kit Twin Cam 88 Standard Bore 3.750in 10.5:1 Compression

The Wiseco 4995PS is a high-performance forged piston kit engineered for the Harley-Davidson Twin Cam 88 engine. Featuring a standard bore size of 3.750 inches (3.7475 in. actual), a domed top design, and a 10.5:1 compression ratio, this kit is purpose-built to deliver increased power and long-term durability over stock cast pistons.

Key Features:

• USA forged construction — engineered, forged, and machined in Mentor, OH for superior tensile strength and service life
• High-silicon, low-expansion aluminum alloy — delivers reduced weight, improved heat transfer, and exceptional durability under high-stress conditions
• Domed top piston design — optimized for 10.5:1 high-compression performance builds
• Diamond-turned CNC finish — precision machining ensures consistent sizing and compatibility with cast iron, chrome, Nikasil, and boron composite cylinder bore compositions
• VM ring package — includes rings specifically engineered for this application
• Wrist pin and circlips included for a complete installation-ready kit
• Designed specifically for the Twin Cam 88 engine platform to optimize performance and durability

Wiseco's forged pistons offer a clear advantage over cast alternatives. Forgings feature a condensed, aligned grain structure that produces higher mechanical properties and superior resistance to impact and fatigue — critical qualities for high-performance and racing applications. The 4995PS kit is an ideal choice for engine rebuilds targeting increased compression and reliable power output.