There is a flame arrestor in the block where the breather pipe is. There is also (or should be) a flame arrestor in the rocker cover-to-air cleaner hose.

The rocker cover hose should blow air out when the engine is running. Don't know about the breather tube.

your right . what i was trying 2 say was that the engine pipe 2 manifold has a severe vaccum and the flame arrester blows as it should b the other way around.does it mean that engine is stuffed or what.i tried 2 send pm earliar but im not computer wise. i dont know were it went or if u got it awaiting response

I don't quite follow your terminology.
But the A series breather hoses go as follows,
The hose from the left side of the block goes to the PCV valve in the inlet manifold. This draws in any vapors/fumes that are in the crankcase. And the hose which comes out the top of the rocker cover goes to the air cleaner. This ensures that any air drawn into the crankcase by the suction of the pcv is clean air and free from any contaminates.

This is why it's known as positive crankcase ventilation, as opposed to passive crakcase ventilation. (such as having a catchcan)

need someone who knows the a12 back 2 front. with the engine vent that goes 2 the pcv valve it sucks and the pipe that goes 2 the flame arrester blows.im 2 believe this should b the other way around according 2 my manual.would anybody know why this would b happening?any advice would b great.