Guys ffs its a one way valve. On most if not all early 90's cars.

Read here

http://en.wikipedia.org/wiki/PCV_valve

View this image - it is the vacuum route for the PCV system on all recent honda engines



If you follow the route from the intake arm , you will see that the "charge" travels into the head , circulates down past the pistons and thru the back of the block past the oil seperator ( OEM catch can). This then blows back up past the PCV ( positive crankcase valve) and then into the inlet manifold.