In a message dated 1/4/2005 11:31:46 PM Central Standard Time, 13brv3@bellsouth.net writes:

<< I know PP is one of Lynn's favorite subjects, so maybe he'll chime in here.
I want to believe, really.   Cheers,
Rusty     >>


Richard Sohn has both on his single rotor. I believe he said the side port had no advantage. From a standstill the Pport is far more tractable than the bridge ported engine. I have both style engines.  If you make your own, you will be controlling the overlap and the closing point. So the Pport will be as tractable as you make it. Others have built the butterfly close to the rotor housing to improve idle and off idle performance. My car has runners tuned for about 8,800 RPM. Very short. In the aircraft the runners would be much longer, and there might be an argument for moving the butterfly to get a good idle. The long runner at well below ambient pressure provides a large volume that fills with exhaust gas at idle, acting like a vacuum cleaner. The short runner just has less volume, so it screws up the idle a bit less. When I get some time I will build a Pport 13B with well over 200 HP. Starting with little overlap and a  small port and going up to way too big. And dyno at each step. We need to get pointed in the right direction on this stuff and quit spinning our wheels. If you turbo at very low levels I see a very late closing intake Pport and a very late opening for very little overlap at all. Off idle would stink a bit, but once the boost starts to over come some of the reversion caused by compression, things would pick up nicely.  With maybe high pressure mechanical injection between the spark plugs. just before TDC. Just some ideas


Lynn E. Hanover