Our hypereutectic aluminum alloy pistons have a high silicon content. These pistons are much stronger than a regular cast piston. You can run tighter skirt clearances with a hypereutectic piston than with a forged piston and avoid that cold start piston slap. In addition to strength, the hypereutectic improves resistance to scuffs and seizure, and generally runs cooler.

Hypereutectic aluminum has 15% less thermal expansion than conventional piston alloys. The silicon keeps the heat in the combustion chamber and prevents heat transfer, allowing the piston to run cooler. The silicon gives the hypereutectic its thermal and wear characteristics.