Radium Engineering catch cans feature large 10AN ORB ports, a 4AN ORB drain port, 2-step oil separation baffling, and an O-ring sealed dipstick.

20-0387-FL Dual Catch Can Kit, MK4 Supra, Fluid Lock 

These catch cans vent-to-engine permitting a true PCV system. The 2 catch cans function completely independent of each other and do NOT vent-to-atmosphere (VTA), thus are emissions and track legal. Closed loop systems remove the oil and sludge from the PCV gasses before it is routed to the engine to be burned. A closed loop system also promotes negative crankcase pressure for optimal performance. Furthermore, closed systems prevent unwanted oil vapors from entering the cabin.

As shown above, one catch can plumbs inline with the PCV (positive crankcase ventilation) valve and retains it's factory function. When the intake manifold pressure is close to or greater than atmospheric pressure, the PCV "check" valve closes and, thus, this hose experiences no flow. Conversely, the PCV hose will experience "metered" vacuum when the engine is idling, steady state cruising, and decelerating. This would normally draw unwanted crankcase vapor, unspent fuel, and oil sludge into the intake manifold immediately after a high load run. Note: Because the Radium catch cans are pressure sealed, they are great for this boosted application so intake manifold connection is permitted. The hose and fittings for the PCV catch can are -6AN.

The other catch can plumbs inline with the CCV (crankcase vent) port experiences atmospheric pressure at low loads. But when the engine is at high load (WOT), this hose will experience blow-by flow from the crankcase. This would normally lead to oil and sludge accumulation in the air filter intake pipe. Oil accumulation will occur in the intercooler which lowers the thermal efficiency properties of the heat exchanger and leads to decreased performance. The hose and fittings for the CCV catch can are -8AN.

Because of the many OEM component variations for this chassis, 3 different brackets are included for optimal mounting. These multiple locations provide a solution for all RHD and LHD vehicles including those using a large single turbo, the stock twin turbos, the updated brake master cylinder, and even early models that have rear brake TRAC. All brackets use factory holes and integrate perfectly with the surrounding components. No cutting, drilling or permanent modification to the vehicle is required.

NOTE: This catch can kit is NOT compatible with Radium Engineering 2JZ press-in valve cover fittings. The press-in fittings are 10AN and it deletes the PCV valve so it can no longer be plumbed to the intake manifold. These catch can kits are designed for the stock 8AN and 6AN hose sizes.