Dual PCV Valve Setup

Dual PCV valve setup:

-Run one short (1-3inches) section hose from the lower intake manifold to a PCV valve (AC #CV893C/ GM part # 25095468 or equivalent ) flowing as directed in the diagram. -Run the other side of the PCV valve to the middle “input” of a 1/4” plastic T with the same sized tubing. -Zip-tie all the ends. -Run the other two hoses to the front and rear valve covers. Use a larger size hose: 1/2” ID. If you cant get a T that has the appropriate sized barbs get the larger size and stretch the smaller hose to fit. A heat gun helps with this sometimes. -The front valve cover should have a drilled out PCV valve (Fram part #FV331 or equiv: $3.75)

You now have 3 options:

Option 1: -Buy 2 vented filters (K&N Part # 62-2470 or equiv) and attach to the front and rear valve covers via tube. Inside diameter of the 62-2470 is 5/16”, use a barbed coupler or a flared tube and zip ties to ensure a secure seal.

Option 2: -Buy 2 PCV valves and attach them to the other ports of the front and rear via appropriate sized tubing according to the flow diagram. Dump the exits of the PCV valves into a sealed container with a filtered outlet or filter them using a simple home-depot-style filter setup.

Option 3:

-Buy a single PCV valve and use a similar T setup as the lower intake manifold. Either dump the exit of the PCV valve into a sealed container with a filtered outlet or filter it using a simple home-depot-style filter setup.

Make sure your system works. Vacuum applied to the first valve from the lower-intake- manifold side should create a vacuum originating from the second PCV valve(s). Pressure applied to the first PCV from the intake manifold side should not pass through it. Positive pressure applied to the second PCV valve(s) from the valve cover should flow through and blow that pressure through the filter(s). Vacuum applied to the second PCV valve from the valve cover-side should not result in any flow. Follow the diagram and it should work perfectly. This will substantially out perform the stock PCV setup and will cost less than a questionable crank-vent system, which has been scrutinized for results. Remember to check your filters or catch can frequently, and especially after a hard run in boost. If you are getting excess oil through the system you may need to inspect the compression of your engine, specifically the ring seal.