Radium Engineering Universal Coolant Tank, 1240mL – 20-2270

Radium Engineering Universal Coolant Tank, 1240mL

Part Number: 20-2270

Coolant expansion tanks are necessary for proper air bleeding in applications that utilise a rear mounted radiator or a low mounted radiator such as a V-Mount. However, expansion tanks are also valuable when integrated into a common radiator setup. To allow heat expansion, traditional coolant systems require air to be present in the top portion of the radiator during low temperatures. A coolant expansion tank permits the radiator to be 100% filled with coolant in all conditions.

This Radium Engineering Coolant Expansion Tank holds 1240mL and is a multi-piece design constructed of CNC billet 6061 aluminium. A pressure cap is not included — the CNC billet receiver is compatible with Type-A "radiator" caps. The tank features two internal chambers that are not isolated from each other, with cross-over passages at the top and bottom.

NOTE: This product is not a coolant overflow tank. It is designed to be a part of the pressurised coolant system.

Pressure Caps (Sold Separately)

The optional Radium Engineering pressure caps allow the user to select a range of pressure. A high pressure cap increases the boiling point in the cooling system, providing improved cooling efficiency — particularly valuable when tracking the vehicle in extreme conditions.

• Radium Pressure Cap – 1.1 Bar (110 kPa, 15.6 psi)
• Radium Pressure Cap – 1.3 Bar (130 kPa, 18.9 psi)
• Radium Pressure Cap – 1.5 Bar (150 kPa, 21.8 psi)

Specs & Features

The coolant tank includes the following ports:

• 6AN ORB (9/16"-18) top port – Inlet for incoming hot water; natural bleed for the system.
• 10AN ORB (7/8"-14) bottom port (opposite the inlet) – Drain back outlet; typically plumbed to the water pump inlet fitting on the suction side.
• 10AN ORB (7/8"-14) bottom port (under the inlet port) – Not commonly used. If applicable, connect to the highest point of the engine to allow air bubbles trapped in the radiator or engine to travel up to the coolant tank.
• Barbed cap fitting – Overflow/purge port.

Included

• Billet Aluminium Coolant Tank
• Anodised Aluminium Mounting Bracket
• Water Level Window, Height: 4.6" (118mm)
• Type-A Pressure Cap Receiver
• Aluminium Pressure Bleed 1/4" Barb
• Stainless Steel Hardware

Why Radium Engineering?

• ✅ Manufactured in the USA to motorsport-grade tolerances
• ✅ CNC-machined billet aluminium components for maximum strength and precision
• ✅ Trusted by tuners and race teams running real-world high-power builds
• ✅ Bolt-on fitment — no cutting, drilling, or fabrication required
• ✅ Compatible with a wide range of AN fittings and pressurised coolant system configurations