Ward 143" Big Bore Kit for m8

Description:

If you’re chasing massive power, the Ward Performance 143" Big Bore Kit is the answer. Whether you’re building a monster street bike or a drag-strip machine, this kit delivers incredible performance. With OEM cylinders resleeved to 4.5", forged CP pistons, and optional +2mm Ward CNC ported heads, it’s engineered to dominate. We tested this setup in our own shop, and the results speak for themselves—200 HP and 173 ft-lbs of torque on pump gas, all motor (achieved with +2mm Ward CNC ported heads featuring a 70mm square intake port mod, Burns flush-mount 2" exhaust mod, and our WP143 cam).

The resleeved 4.5" cylinders are bored and honed with torque plates for perfect fitment and long-term durability. These precision-installed ductile iron liners offer massive displacement while maintaining strength, but the engine cases will need to be bored to accommodate the larger liners.

This kit pairs perfectly with our high-performance +2mm Ward CNC ported heads and works seamlessly with optional WP143 and WP143S camshafts, designed specifically for this build. The WP143 cam delivers a more aggressive profile for maximum power, while the WP143S cam offers smoother delivery for street-focused builds. Both options unlock the full potential of the 143" kit, allowing you to tailor your powerband to your riding style.

    • Resleeved 4.5" OEM Cylinders: Precision bored and honed with ductile iron liners for long-term durability.

    • Forged CP Pistons and Rings: Pre-set ring gaps using precision diamond ring filer for easy installation.

    • Cometic Head and Base Gaskets: Reliable sealing for high-performance builds.

    • Optional Heads: Available with +2mm Ward CNC ported heads for maximum airflow.

    • Optional Camshafts: Choose from the WP143 or WP143S camshafts, both designed specifically for this kit.

  • Selecting the perfect camshaft, compression ratio, and head configuration can be complex—but we’ve got you covered. With decades of engine development experience, Ward Performance will help you find the perfect combination for your riding style and performance goals. Contact us for more information.

    • Still have questions or need help deciding?

    • No worries! We know performance upgrades can be a big decision, and we're here to help.

    • If you're unsure about anything, don't hesitate to reach out to us or visit our FAQ page for more information. We're just a message away and ready to assist!

  • Custom Forged CP Pistons and rings

    Pre-set ring gaps using precision diamond ring filer for easy installation.

  • Cometic MLS Head and Base Gaskets

    High performance multi-layer-steel composition. Reliable sealing for high-performance builds.

  • Optional CNC Ported Heads

    Available with Ward CNC ported heads for maximum airflow and power.

  • Optional High Performance Camshafts

    The WP143 and WP143S camshafts are designed specifically for this kit.