Street/Strip Crankcase Vacuum using a PCV Valve

Here's the evac system I had been using. These valve covers are a circle track design that originally used a crossover tube with a couple small breathers, I eliminated the crossover setup and made some adapters to plumb them into a separator can that I had also installed a pcv valve into. The hose out the bottom is connected to a standpipe inside the separator, other end of that hose connected to the inlet of the electric pump. Outlet of the electric pump had a large header evac style check valve to eliminate the vacuum leak when the pump was not turned on. Using the pcv valve as a crankcase vacuum source worked so well that I rarely turned on the electric pump, got to the point that I considered the electric pump system as dead weight.

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I ended up eliminating the hoses, separator, electric pump, and check valve. I replaced them with a modified version of the original crossover tube. Basically I made some Delrin check ball seats that fit inside the aluminum crossover tube's breather standpipes...


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For the check balls, I bought some 1" dia nylon bearing balls, cost me around $5. I also installed my homemade adjustable pcv valve that had formerly been installed in the separator...

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The plastic elbow on the pcv valve rotates, I pointed it off to the side and attached it to it's hose.

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These check balls are pretty light-weight, launching the car does not cause them to become un-seated and leak crankcase vacuum.

Grant

Interesting. So at high vacuum the balls cover the breather holes and at low vacuum the balls get out of the way and let crankcase pressure out of the breathers. Am I getting that right???

So no vacuum pump either? I’d like to test all that on a dyno and see what happens.