HE COSMOSTAR 1-1/4" Radiator Hose Barb Coupler with 1/8" NPT Steam Port — Black Anodized Aluminum for LS Swap Cooling

The HE COSMOSTAR 1-1/4" Radiator Hose Barb Coupler with 1/8" NPT steam port is an aluminum coolant crossover adapter that joins 1-1/4" radiator hoses and provides a dedicated steam/bleed port for LS swap engines.

This compact anodized billet adapter is designed for LS family swaps and custom cooling setups where a reliable, top-of-system steam vent and a secure hose splice are needed. It fits standard 1-1/4" radiator hoses, incorporates a 1/8" NPT tapped port for steam vents or temperature sensors, and is finished in black to resist corrosion and wear. The unit is built for simple installation and long-term durability in high-heat engine bays.

How does this adapter integrate with an LS swap coolant system?

The adapter creates a crossover or splice point in the upper radiator hose run and provides a 1/8" NPT port at the highest convenient location for venting air. It lets you mount a steam valve, bleeder, or small sensor without cutting additional fittings into the radiator or thermostat housing. The barb ends accept 1-1/4" hose and clamp down for a sealed connection.

• 1-1/4" hose barb on both sides for direct splice of factory-style hoses.
• 1/8" NPT threaded port for steam vent, petcock, or temperature sensor.
• Black anodized CNC billet aluminum resists heat and corrosion.
• Compact profile fits tight engine bays common with LS swaps.

Will it hold up to high under-hood temperatures and vibration?

This adapter is machined from billet aluminum and anodized for surface protection, offering strong thermal and mechanical stability compared with plastic fittings. The metal body tolerates repeated heating cycles and the anodized finish helps prevent surface corrosion and wear from clamp edges. Properly tightened hose clamps and correct hose fitment are essential to prevent leaks under vibration.

• Billet aluminum core for thermal resilience and strength.
• Black anodize protects against corrosion and scratches.
• Barbed design reduces hose slippage under vibration.
• Use quality clamps and check torque after initial heat cycles.

How easy is installation for a DIY LS swap or coolant refresh?

• No specialty tools—cut hose, slide on, clamp, and thread in vent hardware.
• Prepares a neat, high-point steam vent location for effective bleeding.
• Works with common LS swaps (LS1, LS3, LQ4, etc.) using 1-1/4" hoses.
• Minimal clearance footprint for tight radiator hose routing.

What accessories or parts should I pair with this coupler?

To complete a reliable steam venting solution, pair the adapter with a 1/8" NPT steam petcock, auto-bleeder, or inline temperature sensor depending on your needs. Use high-quality stainless clamps and OEM-style radiator hose rated for coolant service. If your hoses are worn or undersized, replace them to ensure a leak-free installation.

• 1/8" NPT steam petcock or automatic bleeder valve.
• Stainless hex or worm-drive hose clamps sized for 1-1/4" hoses.
• Heat- and coolant-rated radiator hoses (1-1/4" ID).
• Thread sealant suitable for NPT fittings (non-perm if you may service later).

Who is this for: This HE COSMOSTAR adapter is aimed at car builders, performance mechanics, and DIY enthusiasts performing LS-series engine swaps or custom cooling system work who need a durable, compact way to splice 1-1/4" radiator hoses and add a proper steam/bleed point. If you require a metal, long-lasting hose splice with a dedicated 1/8" NPT port for venting or sensors, this part gives a clean, serviceable solution for street, track, or custom installations.