Mini Breather 4AN

The Mini Breather 4AN by ALLSTAR PERFORMANCE is a compact crankcase ventilation breather designed for engine builders and performance enthusiasts who need reliable blow-by gas management in tight engine compartments. This breather exists to prevent crankcase pressure buildup that can damage seals, gaskets, and oil levels—a critical concern in modified engines running higher boost, compression, or cylinder pressures.

Whether you're building a street rod, turbocharged daily driver, or competition engine, proper crankcase evacuation is non-negotiable for longevity. This unit features a 4AN inlet and outlet connection, allowing seamless integration with -4 braided hose lines commonly used in high-flow cooling and fuel systems. The compact form factor fits into confined spaces where traditional catch cans or filter assemblies would interfere with headers, turbos, or custom intake manifolds.

Allstar's engineering emphasizes efficient separation of oil mist and vapors while minimizing restriction, critical for engines producing elevated crankcase pressure. The lightweight construction at 0.15 lbs adds negligible mass to your engine bay while delivering solid corrosion resistance. Street rodders, turbo kit installers, and LS engine swappers benefit most from this breather's space-saving design and proven reliability.