Quote: Michael, the charge passing through the chamber on the overlap cycle has always been a problem at high rpm, simply due to the location of the valves opposing each other. They have seemed to alleviated that somewhat. The new rocker gear and related geometry has certainly helped, but it was not the complete answer.
The cams have changed a lot since then. It seemed the old cams were 292-296 duration and 106 LSA and the newer cams are in the high 270-low 280 duration and wider LSAs like 110-112 (as far as I know). This gives a lot less overlap for the intake charge to blow out the exhaust. This might be several years old by now.
