I was thinking recently about engines and came up with an idea. I highly doubt this would be possible but tell me if any of you technical geniuss think this could possibly be pulled off. Ok so my idea is that you could have all of the valves within a cylinder concentrating solely on whatever cycle the engine is on. So if it's in the intake cycle then all four valves in that cylinder (let's just say this is a four valve per cylinder engine) are opened up letting in the air/fuel mixture, and then once we get into the exhuast cycle some type of other little valve mechanism located very closely to above the cylinder moves and switches the path of flow and instead of connecting it to the intake manifold it instead is now connected to the exhaust. And all four valves could open up to let the exhaust gasses out. Then once it went back to the intake stage that other valve mechanism could reconnect it to the intake manifold. Since airflow is such an important factor in an engine's performance i figured this idea would be very beneficial. The one drawback i thought of though is that there would be no valve timing overlap. But possibly you could have just one valve opened for the exhaust slightly into the intake cycle and then quickly closed to provide a little bit of valve overlap. Or maybe you wouldn't even need that because the benefits of 4 interchangeable intake and exhaust valves would be such a gain that valve overlap wouldnt be a concern anymore. So what do you guys think? Plausible idea or just not possible?