S&S CYCLE 3-7/16" Bore Cylinder and Stroker Piston Kit for Big Twin Engines – Part 91-9017

Upgrade your Big Twin motorcycle with the S&S CYCLE 3-7/16" Bore Cylinder and Stroker Piston Kit, designed for versatile engine builds and replacements. This comprehensive kit allows you to construct 84", 86", or 88" stroker engines, or to replace cylinders and pistons in an existing S&S® stock bore stroker setup. The kit is compatible with engines utilizing 4-1/2", 4-5/8", or 4-3/4" stroke flywheels, making it suitable for a wide range of custom configurations. Crafted in the USA, these components ensure durability and high performance for demanding riders and builders alike. The kit includes high tensile cast iron cylinders with a 3.4375" bore, forged pistons with rings and wristpins, head gaskets, stainless steel head bolts with washers, base nuts, and base gaskets. These parts are engineered to withstand high compression ratios and deliver reliable power output. Whether you're building a new engine or restoring an existing one, this kit provides the essential components for a high-performance upgrade that is built to last. The various compression ratios—ranging from 8.4:1 to 10.8:1—offer flexibility for different riding styles and performance preferences, ensuring you get the desired balance of power and efficiency. The precision manufacturing and quality materials used in this kit make it a trusted choice for professional builders and enthusiasts seeking premium components for their Harley-Davidson Big Twin engines.

Features:

• Suitable for building 84", 86", or 88" stroker engines for Big Twins

• Compatible with 4-1/2", 4-5/8", or 4-3/4" stroke flywheels

• Includes high tensile cast iron cylinders with 3.4375" bore

• Forged pistons with rings and wristpins for durability

• High-quality head gaskets and stainless steel head bolts with washers

• Made in the USA with precision manufacturing