


Radium Engineering AOS-R - Universal VTA (Vent to Atmosphere)
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Description
Radium Engineering AOS-R - Universal VTA (Vent to Atmosphere)
Application: Universal (not recommended for MAF engines)
Part Type: Air oil separator-return (AOS-R), vent to atmosphere
Part Number: 20-0819
Like a catch can, the Radium AOS-R (Air Oil Separator-Return) keeps blow-by oil and pollutants out of the intake, intercooler and manifold. Unlike a catch can, it returns the separated oil to the sump above the oil level, so it needs no emptying, and it is heated by engine coolant to stop water condensation reaching the oil.
The VTA version vents through a slotted, baffled top and has two side inlets, suiting dual-bank engines with two crankcase vents. A large outlet chamber slows the air so contaminants drop out, and a diffuser returns oil sludge to the can. An integrated water trap around the bottom edge keeps condensation out of the sump, and the billet unit splits into three large pieces for service.
Key Features
- Oil Return: Separated oil drains back to the sump – no emptying required
- Coolant Heated: Heating chamber keeps the unit warm and prevents internal condensation
- Water Trap: Integrated trap keeps condensation out of the sump
- Dual-Stage VTA: Large outlet chamber and diffuser, designed not to restrict flow
- Dual Inlets: Two 7/8"-14 (10AN ORB) side inlets for dual-bank engines
- Serviceable: Splits into three large pieces; dipstick for inspection
- 360° Mount: Aluminium mount allows full rotation
What's Included
- Machined aluminium AOS-R (VTA)
- Aluminium mount allowing 360° rotation
- 2 x 5/16" barbed coolant fittings
- Stainless steel hardware
Optional Parts
- Radium 14-0351 10AN ORB Plug, Round Internal Hex (14-0351) – plugs one inlet for single-vent setups
- Radium Air Oil Separator - Universal Kit (20-0219) – VTE (vent to engine) version, recommended for MAF engines
- Radium O-Ring Service Kit (20-0685) – AOS-R O-ring service kit
Important Notes
- Not recommended for MAF (mass air flow) engines – the vent creates an air leak; use the 20-0219 VTE version instead
- For a single-vent setup, plug one inlet with Radium 14-0351
- The engine needs a breather/return port high enough to keep oil from being drawn into the unit but low enough for a downhill hose back to the engine; the unit's bottom port must sit higher than the engine return port
- Coolant must be routed to the unit for heating; in freezing climates insulate exposed hoses (sleeving not included)
- When operating properly the unit is empty after sitting – remove the dipstick to inspect if a return obstruction is suspected
- 10AN ORB fittings and hoses are not included
- Installation instructions are available in the Instructions tab
Vehicle Fitment
- Universal – see Application
Not sure if this suits your vehicle? Email sales@coore.com.au and our team will confirm fitment.

