Injector Sizing: REALLY dumb question

[Gary Derian]

Think about the conditions at light throttle cruise.  The exhaust is at
atmospheric pressure plus a little backpressure.  The intake system is under
a vacuum.  At the end of the exhaust stroke the exhaust valve is still open
a little, then the intake valve begins to open.  Residual exhaust gas in the
chamber at slightly above atmosphere, vacuum in the port, where else will
the residual gasses go?.

Gary Derian <gderian at cybergate.net>

>>At light throttle, a hot blast of exhaust shoots up the intake port when
the
>>valve opens.
>
>If this was going on in my motor, I would be inclined to wrap the headers
>(still hot) around the guy who ground the cam, and vice versa. A bit of
>cool air going into the exhaust on overlap to cool the e valve, etc. is one
>thing, but the other ===unh unh.
>
>Regards, Greg
>