SpeedFactory Upper Coolant Fill Neck for Honda H Series

SpeedFactory Upper Coolant Fill Neck - Honda H-Series

Built a custom cooling system on your H-series and now you're fighting air pockets and a car that won't quit running warm? Yeah, that's the classic headache when your factory fill point is gone or buried. This SpeedFactory upper coolant fill neck fixes it. It relocates the high point of your cooling system to a proper fill neck, so you finally have a clean, easy way to fill the system and, just as importantly, bleed the air out of it. Fill it, burp it, done.

Why The High Point Matters So Much

Here's the deal, and if you've ever bled a custom cooling system you already feel this in your bones. Air rises, so your cooling system needs its fill and bleed point at the highest spot, or air gets trapped somewhere in there and just sits. And trapped air is bad news, it creates hot spots, makes your temps climb, and turns burping the system into an all-afternoon fight. On a tucked bay, a swap, or any custom radiator setup, the factory fill neck is usually relocated or gone entirely, which is exactly how you end up chasing air. This neck puts a real fill point back at the top of your system, so coolant goes in easy and air comes out easy. No more guessing, no more overheating because you couldn't get the last bubble out.

Built In-House, Fits Right

This is SpeedFactory's own fabrication, made in-house from high-quality aluminum, with laser-cut head flanges so it seats clean and fits right every time. It's the kind of piece you want on a cooling system you built with care, precise and solid, not some generic weld-on that never quite lines up. And it works whether you're running a custom radiator or one of SpeedFactory's Race or Tucked radiators.

Pick Your Configuration

Grab the version that matches how you're plumbing your system:

• -16AN for an AN-plumbed setup, so it ties right into your AN lines and fittings.
• 32mm standard hose end for a conventional rubber hose connection.

Just match it to the rest of your cooling plumbing and you're set.

Cap Compatibility

This neck is designed to work with SpeedFactory Type A radiator caps and Hybrid Racing Type F radiator caps, so make sure you've got one of those on hand to seal it up and hold system pressure. If you don't already have a compatible cap, grab one to go with your neck.

What You Get

• SpeedFactory upper coolant fill neck for the Honda H-series
• Relocates the high point of your cooling system for easy filling and air bleeding
• Made in-house from high-quality aluminum with laser-cut head flanges
• Choice of -16AN or 32mm standard hose end configuration
• Works with custom radiators and SpeedFactory Race/Tucked radiators
• Compatible with SpeedFactory Type A and Hybrid Racing Type F radiator caps

Fits These Setups

• Honda H-series (H22/H23) custom cooling systems

Note: SpeedFactory upper coolant fill neck for the Honda H-series, designed to ease filling and bleeding of a custom cooling system by relocating the system's high point to a proper fill neck. Compatible with most aftermarket radiator setups, including custom radiators and SpeedFactory Race and Tucked radiators. Manufactured in-house from high-quality aluminum with laser-cut head flanges for an accurate fit. Available in -16AN or 32mm standard hose end configurations; select the version that matches your cooling system plumbing. Designed to work with SpeedFactory Type A radiator caps and Hybrid Racing Type F radiator caps; a compatible cap is required to seal the system. One fill neck per order.