George, you are completely right. Apparently we are not quite finished with a frustrating month of extremely cold temperatures in the shop and several outside projects talking time when it is possible to work. It is ten degrees this morning. My p port stuff is on hold for a couple more weeks but the project is only stalled physically. Mentally it is moving forward nicely. The only question before me is wether or not the remotely installed injectors will work. If not I will IMMEDIATELY relocate them. There are no other unknowns facing the p port. It will develop a lot of power, it will have good throttle response, it will idle. It will be light weight and have a small foot print. It is not an experiment waiting to be proven. I am just copying known and proven technology that has been around for a long time. Design of the intake manifold is a problem for me because I am still enamored with injectors on the cool side and am trying to make it work. Jerry

P.S to Rusty. You said a good street port would develop about the same power as a good p port at our rpms. Sorry but this is simply not true.



On Monday, March 14, 2005, at 01:50 AM, George Lendich wrote:

 
Bill supporting your statement - Mazda supplied P-Ported housings. I can't remember why they did whether it was for competition racing or such - they idled OK.
 
The secret is to identify that which works best for our needs (AVIATION) and set it up for that.
 
Overlap causes inlet fuel contamination/ dilution, SURE, but so to do most engines, which have up to 30 degrees overlap ( if I remember correctly).
In radical cam reciprocating engines, the cam keeps the valves open longer - hence overlap. Two strokes have overlap.
 
The mixing of gases can be minimized with timing and shape of the ports and velocity of the incoming gases - this is what Jerry's doing.
 
It would be prudent to wait for his development outcomes.
 
I calculated velocity and timing as did Jerry and he had expert advice, mine was a bit rudimentary but the outcomes agreed. This is supported by the Powersport specifications, so I don't see Jerry being too far off the mark.
 
George ( down under) 
 
 
 Group,

 I really would like to know where the idea that the PP rotary won't idle came from? 
This is total baloney. Lynn Hanover has commented several times that his PP 12A idles just fine. Some carburated engines with unusual manifolds sometimes have problems. This is true for both PP and side port engines. Many of the earlier rotary engines used P ports.
 If and engine is radically ported in either port type, (just like a radically cammed piston engine), it can be difficult to make idle. If you keep the port timing reasonable the engine ?WILL IDLE FINE, especially a EFI engine. The throttle plates being close to the housings makes things work better. The MB C111 used various rotary configurations. Most of the engines were peripheral ported. There was no problem with idle, but the sealing problems of that era prevented a production version. If your engine is set up carefully without radical timing idle won't  be a problem. The real problems encountered by many people are caused by large ports and extended port timings.
Bill Jepson