Kb Pistons Hypereutectic Cast Piston - Pistons EVO 80ci 9.6:1 .005 — Harley-Davidson (1984-1999)

KB Pistons Hypereutectic cast piston for EVO 80ci engines, featuring 16% silicon content for superior thermal barrier properties and low expansion. Designed for tight piston-to-cylinder clearances in air-cooled big twins, delivering optimal ring seal and quieter operation.

Features

• Hypereutectic alloy with 16% silicon content
• Low thermal expansion rate
• Tight piston-to-cylinder wall clearances
• 9.6:1 compression ratio
• Suitable for stock and mild compression ratios up to 10.5:1

Specifications

• Brand: KB Pistons
• Manufacturer Part #: KB305.005
• UPC: 800745130068
• Compression Ratio: 9.6:1
• Engine: EVO 80ci
• Length: 9.5 in
• Width: 4.8 in
• Height: 4.6 in
• Weight: 2.75 lbs
• Country of Origin: Mexico

Fitment

Fits air-cooled Harley EVO 80ci engines. Optimized for stock and mild compression ratios up to 10.5:1 running on pump fuel.

Frequently Asked Questions

What compression ratio do these pistons deliver?

These pistons are cast for 9.6:1 compression ratio. Suitable for stock or mild builds up to 10.5:1 running on pump fuel.

Will these pistons fit my big twin engine?

These are designed for EVO 80ci air-cooled engines. Verify your engine displacement and year before ordering to ensure compatibility.

Why use hypereutectic pistons?

Hypereutectic alloy with 16% silicon provides superior thermal barrier properties and low expansion, allowing tighter clearances for better ring seal and quieter running in air-cooled engines.

Can I run these on regular fuel?

Yes — these pistons are engineered for pump fuel in stock and mild compression builds. High-boost or nitrous applications require different piston designs.