SpeedFactory Upper Coolant Fill Neck for Honda/Acura LS/B20

SpeedFactory Upper Coolant Fill Neck - Honda/Acura LS/B20 B Series Engines

Running a custom radiator setup or SpeedFactory tucked radiator on your LS or B20 engine? You need a proper way to fill your cooling system from the highest point, or you'll never get all the air out. This SpeedFactory upper coolant fill neck relocates the high point of your cooling system so you can fill and bleed it properly. It bolts to your cylinder head where the factory upper coolant passage is, and it gives you a proper filler neck with a radiator cap at the highest point in the system. No more trying to burp air out of a radiator that's mounted low in the chassis.

This is for LS and B20 Non-VTEC engines. If you are looking for the B Series VTEC coolant neck, you'll want to look for SFR-06-061 or 06-062.

Why You Need a High Point Fill Neck

Air rises. If your radiator cap is lower than the top of your engine, you'll never get all the air out of your cooling system. Air pockets get trapped in the head and block, which causes hot spots and overheating. A proper fill neck at the highest point of the system lets air escape when you fill the coolant, and it makes bleeding the system way easier. This is critical on tucked radiator setups where the radiator is mounted low and there's no good way to fill from the high point without a fill neck like this.

Laser Cut Head Flange for Perfect Fit

SpeedFactory manufactures these fill necks in-house using high quality aluminum. The head flange is laser cut to match the coolant passage on LS (B18A/B) and B20 cylinder heads, so it fits perfectly every time. You're not dealing with gasket leaks or misaligned flanges. Just bolt it to your head with a new gasket and you're done.

Two Outlet Configurations

SpeedFactory makes this fill neck in two different outlet configurations to work with different radiator setups:

-16AN Outlet

Use this version if you're running -16AN braided hose or hard lines to your radiator. The -16AN fitting gives you a clean, leak-free connection to your cooling system plumbing.

32mm Standard Hose End Outlet

Use this version if you're running standard 32mm radiator hose. This is the most common setup for tucked radiators and custom cooling systems using rubber hose.

Requires Type A Radiator Cap

This fill neck uses a Type A radiator cap interface. You need either a SpeedFactory Type A radiator cap or a Hybrid Racing Type F radiator cap.

What You Get

• SpeedFactory upper coolant fill neck for LS/B20 engines
• Manufactured in-house from high quality aluminum
• Laser cut head flange for perfect fit
• Relocates high point of cooling system for easy filling and bleeding
• Available in -16AN or 32mm standard hose end outlet
• Type A radiator cap interface

Compatible Engines

• B18A/B (Integra LS, RS, GS - non-VTEC)
• B20B (CR-V - non-VTEC)
• B20Z (CR-V - non-VTEC)

Available Configurations

• -16AN outlet (for braided hose or hard lines)
• 32mm standard hose end outlet (for rubber radiator hose)

Required Radiator Cap

• SpeedFactory Type A radiator cap
• Hybrid Racing Type F radiator cap

Important: This fill neck is for LS (B18A/B) and B20 (B20B, B20Z) non-VTEC engines only. It does not fit VTEC B series engines (B16, B18C). Requires Type A radiator cap (SpeedFactory Type A or Hybrid Racing Type F). Use a new head gasket or coolant passage gasket when installing.