Check Valve Only for Crankcase Evac Kit

The Check Valve Only for Crankcase Evac Kit by Allstar Performance is a critical component for any engine equipped with a crankcase evacuation system. Designed specifically to manage crankcase pressure and prevent backflow, this one-way valve protects your engine by allowing controlled venting while blocking reverse flow that could introduce contaminants or cause pressure buildup. Engine builders, racing teams, and serious performance enthusiasts rely on this valve to maintain proper crankcase ventilation, extending engine life and improving reliability under demanding conditions.

This check valve features a 1/2 inch NPT female inlet connection paired with a 5/8 inch hose barb outlet, allowing seamless integration into existing crankcase evacuation systems. Constructed from durable steel with cadmium plating, the valve resists corrosion and withstands the thermal cycling and pressure fluctuations typical of high-performance engines. The internal check mechanism operates with minimal resistance, ensuring efficient gas flow while maintaining reliable one-way operation—critical for preventing oil vapors from being forced back into the crankcase during high-RPM or high-boost applications.

This replacement check valve is ideal for installation in Allstar crankcase evacuation kits or as a standalone upgrade for existing systems requiring valve replacement. It works with both naturally aspirated and forced-induction engines, making it a versatile choice for street cars, track vehicles, and engine stands. Compact at 2.4 x 2 x 4.2 inches and weighing just 0.2 pounds, the valve installs easily and requires no special tools. Verify your system's connection sizes before ordering to ensure proper fit with your inlet and outlet hose configurations.